Engine Builder

Projects #003 & #004

2008-10-30T20:48:00.000-07:00

I ran the truck (P-002) on the wide band O2 sensor. In a nutshell the only immediate adjustment made was the fuel pressure. I'll write more on it later.

Now I want to talk about the new projects. These are daily drivers.

P-003 - 1995 Acura Integra RS Hatchback
P-004 - 1994 Honda Civic DX 2 Door Coupe

I'll start with P-004 first.

P-004 is my wife's car. It is a zippy little runner. While more zip is always welcome my primary focus with this vehicle will be economy. There are a number of modifications that could improve either zip or economy but right now I'm going to write about a mod that will do both. The clutch is dying so while I'm in there I'm replacing the stock flywheel with a light aluminum flywheel from Fidanza. The flywheel looks like a good unit. This will reduce the overall weight of the car by about 7-10 lbs. That is not a lot but every bit helps. The real benefit comes from it lightening rotational weight. The less rotational weight the easier it is for the engine to rev-up. The easier it is to rev up the engine the less energy required to accelerate. One of the reasons vehicles get better mileage on the freeway is that they aren't spending energy (burning fuel) to accellerate the car. It requires far less fuel to maitain speed than to build it.

P-003 is my daily driver. It has 200k+ miles on it and presently gets about 30 mpg and accelerates well. I would love to build this car up into a fire breathing road warrior but the fact is that I will only be able to get so much from it. If the Integra were a rear or all wheel drive car I would be more inclined to build a serious mill for it but since it is front wheel drive I can only get so much. A car has four tires doing three things - accelerating, braking, and turning. Both front a rear wheels experience side loads durring a turn but the front tires much more of the load than the rear. When you add the force of acceleration you quickly approach the limits of the friction the tires can supply.

A simple way of increasing friction is to make the tires wider (don't give my any of that crap physics teachers pull about the weight being spread over a wider area so the friction is the same with a narrow tire as with a wide tire. The coeffiecent of friction of a tire is not linear. As long as the traction is not compromised (rain, gravel, etc.) the wider tire of the same compound has more grip). I plan on getting wider tires but there is still a relatively low practical limit on the power you can use from a front wheel drive car. There are people who drag race front wheel drive cars. Some people find drag racing to be stupid. I don't. However, I also don't find drag racing compelling. I love seeing the cars run a greatly appreciate the work a research that goes in to the cars but I don't want to do it. I like curves and most of the things you do to a car to make it a good drag car make it hadle curves poorly.

My original plan had been to modify the cylinder head and the cam to get some significant flow improvement. I quickly found in my research that this was not a viable option because everything was pretty well optimized already. So then I was thinking about a super charger. but the output on superchargers tend to drop off with RPMs. Turbos, however, do not. However, turbos (good ones) are not cheap nor are the bits that go with it. Additionally, how much power will I be able to use from a turbo? This will also hurt the gas mileage some. Today I came to the realization that nitrous oxide injection just might be the ticket. I was going to install it on the turbo version to eliminate turbo lag but now I think it might just do it on its own. N2O can be set up in stages to give pretty specific levels of output. Right now that is where I think I will focus on the big power. However, there are other areas.

Get the propper alignment angles. The car was lowered by the previous owner so the caster is out of spec.
Cold air intake.
Free flowing exhaust. I'll start with the muffler.
New suspension bushings.
Water injection. I'm thinking about setting this up for daily driving to I can run more spark advance. I need to read up on the car's ignition system.
MSD type ignition? With all the complimentary upgrades. I'm not sure if it would help much. The car is definitely of the open chamber design but the combustion chamber may be small enough that it doesn't really matter. If/when I install N2O I will have to upgrade to something to make ignition absolutely certain.
N2O
Wide low profile tires. How wide? I don't know. I need to talk to some tire shops about what will fit. I also need to find some rims that I think are worth spending money on. I am one of the biggest rim snobs and there are very few truly good looking rims out there. I'm looking for a clean, simple, open, 5-spoke wheel.

Something like that. Unfortunately that is a Porsche wheel and I haven't seen anything like it for an Integra.
New clutch.
Aluminum flywheel.

I'm sure more ideas will come but that is what I have for now.

The owner of P-001 is back in town so I may be doing some work on that too.
Builder

Project #002 Phases 1, 2, & 3

2008-10-25T17:17:00.000-07:00

Phase 1 - Exhaust Leaks
Exhaust leaks are eliminated. Replaced both donuts on the manifolds and installed one of the Remflex gaskets on the passenger side manifold. This was a piece of cake until I got to the top rear bolt on the manifold. I am very grateful this is not a modern vehicle, otherwise the bolt would almost certainly have broken off. In the end it came out and it all went back together just fine.

The other gasket will need to be replaced but it is fine for now.

Phase 2 - Reliable Ignition System
The ignition system is not quite as reliable as I would like but I think it is good enough for the initial tuning I will be doing. I have a nice set of Accel spiral core wires for the truck. If these wires are treated right they should last for nearly the life of the rig so I want to do a nice job routing them. When I bought the wires I also bought a plug wire stripper and crimper tool. This turned out to be a total wast of money. First, the plug wires came with a set of vice mounted crimpers. Second, the wire strippers suck. It is important that I get nice clean stripped ends to get a clean wire install. So I ordered another tool that I think will be just the thing. Unfortunately it is a special order item and hasn't arrived yet. This puts the whole ignition system upgrade on hold. I can't install the new ignition box and coil until I install the new plug wires and I can't install them until I get the wire stripper. I'm using this time to get the wire routing sorted. I will be ordering some wire routing accessories this week. They'll probably get here before the wire stripper. The present ignition system will be good enough for our purposes we just won't know how lean we can go in a few driving circumstances.

Phase 3 - Carburetor Tuning
This is the one I really wanted to write about. The carburetor is a Carter AFB competition series. This will be the routine we follow:

Tune primary barrels at low manifold vacuum (high load) and WOT (Wide Open Throttle). Lock out the secondaries so we are just measuring the primaries. This will establish the jet size. There is no point in adjusting the metering rods if the primary jets won't flow enough fuel. I will be using the metering rods with the narrowest enrichment diameter (They will flow the most fuel).
Test A/F ratio with primaries at WOT over varying load conditions. I will want to see when the metering rods are moving and how the air/fuel ratio looks.
Tune/observe primary part throttle A/F ratio over various manifold vacuum readings. I am not sure how well I will be able to tune this because of the metering rods I have. This is where the metering rod tuning will commence. There are three tuning areas. The metering rod's enrichment diameter, the metering rod's economy diameter, and the spring that determines when the metering rods move (i.e. when the two metering rod diameters are inserted into the jet). This is where I will be making adjustments in these three areas.
Tune idle and off idle circuits. This carb does not permit easy adjustment of the mixture of these circuits. The idle adjustment screws only adjust idle mixture VOLUME. It looks like the fuel restriction for the idle circuits is hard to get to but I may be able to do the adjusting I need by varying the size of the idle air bleed. I will have to check in to this before I start drilling. These are serious modifications.
Now with these circuits in order I will unlock the secondaries and test the overall fuel mixture at WOT. Since the other circuits should be in order any variance from the ideal (or at least the best achieved at the other load conditions) will be corrected by changes to the secondary jets.

That sounds pretty straight forward. We'll see what the results are.

Builder

Project #002

2008-10-08T10:44:00.000-07:00

Vehicle: 1975 Ford F-250 Camper special
Engine: 390

Objective: Improve/maximize efficiency

It has been over a year since I last posted. Many things did not go to plan. But now I have a new project.

The truck tows a fair sized boat and is presently getting 4 MPG. I think that can be improved to at least 8 or 12 while it is towing and perhaps even twenty when it is empty. The issue is efficiency. This means that a properly metered mixture is well atomized and evenly distributed to the cylinders in a way that keeps the fuel in suspension and is then introduced into a well designed combustion chamber with enough swirl to completely burn the air fuel mixture when it is ignited by a very reliable ignition system with a well chosen advance curve and the exhaust leaves through a nearly zero back pressure exhaust system.

I see this job having many phases. There are a few that may overlap.

Phase 1
Eliminate all exhaust leaks.

The Ford 390 is notorious for its manifold gaskets failing. I've throw down the gauntlet and bought some Remflex exhaust manifold gaskets. I have not installed them yet but I have heard a bunch of good things from various people in various fields. I personally had a very good experience with the company. They are located in Washington state where they make the gaskets. I called them up and spoke to a human being who actually cared whether I got what I needed. I really hope their gaskets are as good as their service.

When I do this I will need to replace the manifold bolts. The gaskets are a lot thicker and the bolts are 33 years old.

The reason this is important (besides the exhaust leak) is that I don't want to get a reading on my wide band O2 sensor that is falsely lean. This will lead me to make the mixture richer than it should be and that will hurt the MPG.

Phase 2
Make the ignition system reliable.

There are two parts to this.

First I will replace the spark plugs, plug wires, and cap and rotor. This will make that side of the ignition system solid. I will be using spiral core wires instead of the usual carbon filament type. They cost about two or three times as much but almost last forever.

Second, I am in the middle of researching ignition enhancements. Specifically the multiple spark discharge type of ignition. David Vizard says in his book "Performance With Economy" that they virtually eliminate misfires and greatly reduce the time the choke needs to spend on. This is an obvious potential economy improvement. The question is how much will it cost. This may be a later addition.

Phase 3
Tune carburetor.

I have purchased a Zeitronix wide band O2 sensor. This was not cheap but considering the features you get it's a great value (It plug into your computer and gives you simultaneous data-logging of RPM, A/F ratio, manifold pressure (vacuum in this case), exhaust gas temperature, throttle position, and a user determined input of 0 to 5 volts. I bought the additional MAP (Manifold Absolute Pressure) sensor so I can look at the screen and get a pretty good idea of what is going on. I have attempted multiple times to dive into this carb using a single wire lambda sensor but it only got me close. This setup gives me an actual air/fuel ratio. With a real A/F ratio there is no guessing. . .as long as there isn't any air getting into the exhaust system up stream and there aren't misfires sending cylinder fulls of air and unburned fuel into the exhaust (hence phases 1 and 2). I did a quick check and I found the A/F ratio was around 11:1 full throttle/full load (It shouldn't be any lower than 12:1 and in this case I'm shooting for 13:1 or 13.5:1) and it got as lean as 15:1 only for brief moments. So it looks like there are some sizable improvements to be made.

That covers the immediate future. At some later date I will delve into the following

Phase 4
Design and install new exhaust system.

Phase 5
Major work
- Port heads (for efficiency - see here)
- Enlarge exhaust valve (perhaps)
- Address any valve shrouding
- CC Heads
- Intake with good flow and mixture distribution (Stock, modified stock, or aftermarket. Whichever looks to be the best)
- Wide LCA (Lobe Center line Angle) cam.

Phase 6
- IR intake system.

Builder

4" Is Out!

2007-08-03T10:36:00.000-07:00

My research has been slowed down considerably but has not been stopped. I believe that I have established that the 4" stroke is not feasible for phase 1 of project #001. I still have not read anything about the reliability of the engine but I have seen plenty on the difficulty of assembling such an engine in a stock block. Some very knowledgeable and experienced builders said, I think verbatim, you are fool if you try to build a 4" stroke engine in a stock block.

First, there is A LOT of grinding of numerous places on the block so that the crank and rods won't hit anything. This entails assembling the bottom end, finding where there is interference, disassembling the engine, grinding (but not too much!), cleaning the block, reassembling, finding that you didn't grind enough, and repeating the process only to start all over again with the next place of interference.

Second, the block holds the cam too close to the crank with a 4" stroke and requires the use of a smaller diameter camshaft. This is referred to as a "reduced base circle" camshaft. This also means that the lobes can't be too high or they will hit the connecting rods. I'm not sure if I will be running a camshaft with high enough lift for that to be an issue. It is looking like I will be using a high lift short duration camshaft for low end torque so interference may be an issue. Since I don't know just how far I want to open the valves, I don't know how much total lift I will need but some of the guys were having to run higher ration rocker arms to get the lift they needed. With the higher ratio the valve springs can push harder on the camshaft (more leverage) and in some cases cause the reduced base circle camshafts to flex. I don't know exactly how this ended up being bad for the engines. The two bad things I can think of right off the bat are breaking the camshaft from flexing it and the flexing giving inconsistent opening and closing of the valves.

Third, as mentioned before, special "clearanced" connecting rods had to be used. There was even discussion of using crankshafts with smaller rod journals to bring the outer circumference of the crankshaft down. Clearanced rods don't seem like a big deal to me but reducing bearing surface is not in line with the kind of reliability I am after.

I don't think any one of those things alone or in concert are way beyond my capability but they sound like A LOT of work and definitely not the engine to start out with.

There was a simple (and expensive, for me) solution. Buy an after market block with a raised camshaft location and a taller deck height that was designed to accommodate a 4" stroke. This makes sense to me! There are some other headaches that come along with this solution but none that get in the way like the PRICE. I looks like these block sell for $1,000-$2,000.

So there's an end to that. There was a discussion of using a 3.82" (I think that dimension is correct, I know it is close) stroke but, at the moment, I'm inclined to go with the 3.75" stroke. I'm guessing that there is greater parts availability for it and I know I can get decent rod/stroke ratios. I guess that is the next thing to check on.

Builder

Out of the frying pan

2007-07-26T08:42:00.000-07:00

I am out of China and in Spain. I was thinking that I would now be free to research to my hearts content. two issues have arisen.

First, I do not have regular Internet access and have to pay by time. Not a good way to go about hours of research per day. that said I will be researching as time (and money) allow and am focusing right now on the reliability of the 4 inch stoke engine.

Second, being in Spain seems like a good time to focus on improving my Spanish. I am in a good situation to do this and I don´t often spend a month at a time in Spain. This will curtail my research and posts but it will not end them.

I´ll write when I do.

Builder

Man! Still busy!

2007-07-18T18:01:00.000-07:00

I thought I was going to be free for this week to write and research to my heart's content. No such luck. I am now moving out of my apartment to go to yet another country and it is taking a lot more work than I thought.

I did correspond with my engine partner and he said that he thought my multiple engine idea was great. So that change in the plan is official, project #001 now has three phases:

Phase 1

Build an engine as cheaply as possible without sacrificing reliability in any way and taking every affordable step to improve fuel mileage and low-end torque.

Phase 2

Build an engine to whatever specs my partner wants.

Phase 3

Build an engine using everything that I have learned to build the engine for reliability, durability, efficiency, and low-end torque like a racer builds an engine for power.

I have compiled a pretty thorough list of questions and am in the process exploring each of the questions. Just more circling around really but it helps me organize my thoughts and find structure. That's always a good thing.

More to come when this current storm of busyness blows over.

Builder

Ahhhhhh

2007-07-12T23:06:00.000-07:00

It is done. That load of work is completed leaving me free. . .yes free. I am still decompressing, de-adrenalizing, and just plain relaxing. So naturally I'm looking at engines.

Lets see if I can't sketch out a battle plan here.

My resources are uneven. I don't have access to any of my books (although I did find a copy of Vizard's How to Modify Ford S.O.H.C Engines) I can't call around and get prices, and I can't buy anyone lunch, sit down, and pick their brain. On the other hand I do have places like Speedtalk and I have managed to amass a fair number of online articles from knowledgable people (like Vizard).

Questions.

The first question I have is about intake manifold heat.

What are ALL the reasons that manifolds come stock with coolant and exhuast passages?

What effect does heating the intake manifold have on the range of temperatures that an engine is serviceable in?

Then

What, if any, reliability issues are there with a 4" stroke?
What is the minimum durable compression height (or distance)?
What is the lightest durable piston?

Of course I have many more questions than these but these are some critical ones. I need to know what camshaft to use. In order to select the camshaft I need to know how much air the engine needs. To know how much air the engine needs I need to know what RPM it is running at and its displacement. I must know the stroke in order to know the displacement. I think I will start with that.

I am also reading Vizard's SOHC book. I couldn't figure out who the market was for a while. I guess this was the engine in the Ford Pinto. A great deal of the information is specific to this engine but Mr. Vizard also goes into the theory behind the specifics and that applies to everything and is what I need!

That isn't much of a battle plan but it is a few good first steps. I shouldn't expect too much from myself when my brain is still fried (all the work).

And I'm off!!

Builder

Finished the Lump

2007-07-12T09:02:00.000-07:00

I had a BUNCH of stupid crap paperwork type stuff to do that I have now finally knocked out. I will now be free to throw myself fully into researching all my questions. I will lay out the plan tomorrow but I am planning on posting once a day for the foreseeable future provided that I have something to say. I'm not going to post crap for the sake of posting.

Whooooooooooooooohh. . . . . . .

Breath deep and release a deep sigh of relief.

See you tomorrow!

Builder

It's All in the Cylinder Heads

2007-07-06T08:39:00.000-07:00

It is all in the cylinder heads. Port shape, port volume, valve size, valve shrouding. . . They all have an impact on the way the air/fuel mixture enters the cylinder. How does the port flow as the valve is opened? What is the maximum volume the port can flow? You’d think that the larger the port the more it will flow and the more power the cylinder will make. No, and here is where there is a bunch of disinformation and arcane references to “witchcraft” and flatly incorrect statements like “the bigger the better” or just as incorrect “some restriction is good” come from.

First thing to do is to get the air moving. Since this an intake port for an engine the air will begin moving when the valve opens and the piston goes down (For this port we will pretend that the valve is always open). Apparently the maximum pressure drop created by the cylinder descending is 28” of water¹. This isn’t very much. This translates to 2.06” Hg. This means that the port shape is critical to having good flow. I should also say that I don’t see how this is accurate seeing that the manifold vacuum of an engine can easily reach 25” Hg! Of course this is with the throttle plates closed at idle or on deceleration. As you open the throttle plates and put the engine under load the manifold vacuum will easily drop to 10” Hg and at WOT (wide open throttle) I know I have seen manifold vacuum drop to 4” Hg. It has been almost a year since I did any of this testing but I think I have seen vacuum numbers as low as 2” Hg at WOT and heavy load. WOT with high load is when you want maximum power so I guess it makes sense to measure port flow at this pressure drop. But I am getting ahead of myself.

First, let’s consider a port. Let’s think about an imaginary port that is simply a section of pipe. To make things easier we will not even consider how the air enters or leaves the pipe. We also don’t care how long the pipe is. All we care about is its diameter, or more specifically, its cross-sectional area. Let’s look at two pipes. One pipe has an inside diameter (ID) of 1” and the other pipe has an ID of 4”. Now, let’s pick a flow number. I am choosing arbitrary numbers. I don’t know the real numbers for any of this (YET!). Let’s say that we’ve determined that our cylinder needs to be fed 100 cubic feet per minute (CFM). This 100 CFM needs to pass through our straight pipe port.

The formula for determining the velocity for an ideal gas (one without friction, turbulence, etc.) is as follows:

CFM
------------------- = Velocity of flow
Area of opening

So let’s look at the 1” ID pipe.

Area = πr²

Area = π1² = π

Well isn’t that handy.

For this we will just say that π (pi, pronounced “pie”) is 3.14. π is actually an irrational non-repeating decimal that goes on forever. Some folks have calculated it out to millions of places but that’s about as useful to us as the number of angels that can dance on the head of a pin. So the cross sectional area of the 1” ID pipe is 3.14 in². When we convert that to feet we get 0.02180555555ft². We plug that into the formula and we get:

100 CFM
---------------------- = 4585.99 ft/min
0.02180555555ft²

The 1in ID pipe flows 100 CFM at the rate of 4585.99 ft/min.

Let’s look at the 4in ID pipe now.

Area = π4² = 16π = 50.24 in²

Convert 50.24 in² into 0.3488888889ft², plug it in and you get:

100 CFM
-------------------- = 286.62 ft/min
0.3488888889ft²

The 4in ID pipe flows 100 CFM at the rate of 286.62 ft/min.

4585.99 ft/min vs. 286.62 ft/min. That is a pretty big difference in velocity! Of course that is also a big difference in diameter. I chose such different diameters to make the difference clear.

“Big deal. There are two different velocities.”

Yes, it is a big deal when you consider that air has mass and therefore the faster it goes the more momentum it has. It is a pretty simple formula:

P = mv

Or momentum equals mass times velocity. This means that when the air flows into the cylinder from the 1in ID port it will have about 16 times the inertia as the 4in ID port. This ramming effect is helpful in getting air to continue to enter the cylinder even after the piston has started coming up. This improves volumetric efficiency (VE). Improving VE improves torque. Getting good cylinder filling at low RPMs is essential for good low end torque. This is where the misguided statement about “Some restriction is good” comes from.

This means we want the smallest ports possible right? Let’s really get that air moving!
Not exactly. This is where that 28” H₂0 comes into play.

After a fair amount of searching on the internet I was unable to find a formula that approximates the pressure differential required to produce a given volume of flow through a pipe. No doubt such a thing exists but I have been unable to find it. Fortunately it is not critical for us to understand the basics of what is going on.

As we just saw, smaller ports are good. However, we do not want ports too small or else they won’t flow enough (it was here that I was hoping to show the difference in the pressures required for the 1in ID and 4in ID pipes to flow 100 CFM).

“So what do we want?”

We want the smallest ports possible that will still flow the volume we need at 28” H₂0.

“So is that it? Is that all we need to know?”

Of course not! And the truth is that I don’t know what all the things are to pay attention to, but here is one more thing.

Port shape.

We want to port to be shaped to accomplish three things (that I’m aware of). First, we want the shape to match the way the air wants to flow. We don’t want there to be sharp bends where the air piles up or where the inside of the bend is so sharp that the air wants to shoot past and make flow disturbing eddies. Second, we want a shape that sets the air to flow smoothly over the valve and into the cylinder. Third, we want the head to promote swirl into the flow so that the air is swirling around in the cylinder. This is supposed to do lots of good things (increase torque, help the mix burn faster thus reducing the spark advance, improve fuel mileage, I think there are more things but I don’t know).

So that is what I know. Now let’s see what questions I need to answer.

- How much flow do I need for my application?
- How big do the ports need to be in order to do that?
- What influence does stroke have on this?
- Ramming and airspeed are important but how important is the swirl? How much difference will it make on power, torque, fuel efficiency, etc.?
- What other questions should I be asking?

"What about exhaust ports?"

Obviously similar things apply but the flow is mainly in the opposite direction.

"Mainly?"

Yes both intake and exhaust ports can have flow on both directions but this, like exhaust ports, is something that I will need to learn more about.

"Hey! What about valve shrouding?"

I'll talk about that later. It isn't really a part of what takes place in the port.

Well that took a while but it was worth it. I really feel like I have a much more solid grasp of what I know and a better understanding of what I don’t.

Builder

¹The way inches of water is computed can be described easiest by telling you how to make a gauge. Take a board attach a clear tube to it (without puncturing the tube!) so that the tube forms a ‘U’. Then fill the tube until water is halfway up the ‘U’. Then attach one end of the ‘U’ tube to a port connecting to an area with a pressure drop and keep the other end open to the air. Keep the ‘U’ vertical. If there is a pressure drop then one side of the ‘U’ will be higher than the other. Measure the distance from the top of the two water columns. This is how many inches of water the port is pulling. The name of this device is a manometer.

Happy Birthday to the Best Damn Country in the World

2007-07-04T07:11:00.000-07:00

O say, can you see, by the dawn’s early light,
What so proudly we hailed at the twilight's last gleaming,
Whose broad stripes and bright stars, through the perilous fight
O’er the ramparts we watched, were so gallantly streaming?
And the rockets’ red glare, the bombs bursting in air
Gave proof through the night that our flag was still there;

O say, does that star-spangled banner yet wave
O’er the land of the free and the home of the brave?

On the shore, dimly seen thro’ the mist of the deep,
Where the foe’s haughty host in dread silence reposes,
What is that which the breeze, o’er the towering steep,
As it fitfully blows, half conceals, half discloses?
Now it catches the gleam of the morning’s first beam,
In full glory reflected, now shines on the stream

’Tis the star-spangled banner. Oh! long may it wave
O’er the land of the free and the home of the brave!

And where is that band who so vauntingly swore
That the havoc of war and the battle’s confusion
A home and a country should leave us no more?
Their blood has washed out their foul footsteps' pollution.
No refuge could save the hireling and slave
From the terror of flight, or the gloom of the grave,

And the star-spangled banner in triumph doth wave
O’er the land of the free and the home of the brave.

Oh! thus be it ever, when freemen shall stand
Between their loved homes and the war’s desolation,
Blest with vict’ry and peace, may the Heav’n-rescued land
Praise the Power that hath made and preserved us a nation!
Then conquer we must, when our cause it is just,
And this be our motto: "In God is our Trust"

And the star-spangled banner in triumph shall wave
O’er the land of the free and the home of the brave.

- Francis Scott Key

I have an Idea!

2007-07-03T21:36:00.000-07:00

I’ve been making plans to build my ultimate engine first crack out of the box. While I have been around and nothing that I am planning on doing is outside of my abilities, the fact is that I have never opened up this particular engine and I’ve never built an engine from scratch. So what I am thinking is that I should build an engine or two before I dive in with a big project.

What I plan to propose to my project partner is that I just build an engine without too much focus of the goals (outside of reliability) and do it on the cheap. Having been a repair business I know people and have accounts with parts suppliers that offer me smokin’ deals on some stuff. So I would build a solid 50k mile engine. Then I would take the engine that is already in the Jeep and build it how my friend wants it. And then I would build the engine and take it to the limit.

Even with this plan though I need to know what I am trying to learn so I can build an engine that will work for the application.

I’ll have to run that by him and see what he thinks.

Builder

Disclaimer

2007-07-03T08:52:00.000-07:00

It needs to be clear that I have little to nothing original to add to this or most any other subject. While some of the thoughts and ideas to originate with me (i.e. I thought them up on my own), if they are even remotely helpful in making things work better you can be damn sure that I am not the first to think of it. There is nothing new under the sun and the lucidity that can be found (if any) in my writing is the result of David Vizard, many excellent techs I have worked with, and my physics professors.

Additionally, this blog is about my thoughts and what I am doing. What I come up with may or may not work for me. If you try it then it is up to you to make it work, not me. If something I say here doesn't work then I will refund you what you paid me to read it. . .nothing.

Builder

WOW

2007-07-02T02:16:00.000-07:00

I’ve been reading up some at the Speed Talk forum. While there are some idiots there for the most part it is a bunch of guys who REALLY know their stuff. The amount you have to know in order to truly know something is staggering. I’m hoping to acquire a level of expertise with the small block Chevy and I feel intimidated by it. These guys are as familiar as I would like to be with the SBC on many engines.

WoW!!

Builder

Not a Clue

2007-07-02T01:44:00.000-07:00

After spending a few hours on the Summit website I gathered a rough price list for most of the parts involved in assembling an engine. I should qualify this list by saying I did not search for the best deal and simply looked for things that seemed like a good idea. I estimated the price for a core block and core heads. I’m not sure but I suspect that after doing the numbers I may find that it is nearly as expensive (maybe even cheaper!) to buy pre-assembled after market heads.

So what was the damage?

$5,473

Here is the list.

Part	Notes	Price
Engine Block	Used core (Price estimated)	150
Cylinder heads (2)	Used cores (Price estimated)	150
Crankshaft	Scat cast steel crank. Price for crank is pretty much the same regardless of stroke	190
Connecting rods (8)		200
Pistons (8)		275
Piston rings		100
ARP Studs		150
Headers		400
Carburetor	Thinking about a Speed Demon. Tunability and reliability are essential	500
K&N Air filter and housing	4” High 14” diameter. I’ve had good experience with K&N. KNN-60-1290	85
K&N substack	Won’t work on the Speed Demon but will use it if I select a different Carb	25
Camshaft	Flat tappet	125
Lifters	Hydraulic	100
Pushrods	Custom length (preassembled)	160 (90)
Rocker arms (16)	ST-2740	200
Valve covers (2)		50
Timing Chain	Double roller	90
Timing cover		20
Valves (16)		340
Valve springs and retainers		160
Valve seats	No idea what the price is but at this point pre-assembled after market heads are starting to sound like a good idea
Gasket set	Supposedly all the gaskets I’ll need	125
Intake manifold		200
Harmonic balancer	St-3995	270
Machine Work
- Bore and Hone		250
- Align hone	If needed. No price.
- Balance		200
Cylinder head Machine work. Guides, seats, deck.	No ideas on pricing but again, after market is looking better all the time
Bearings
- Cam		18
- Main		27
- Rod		32
Fuel pump	High volume low pressure	75
Fuel filter		10
Oil filter		10
Oil pan	MOR-20190 I'll need a different pan for a 4” stroke	136
- Windage tray		25
- Oil pickup		40
Oil pump	Standard volume ST-4398	30
Oil pump driveshaft		18
Water pump	High volume	175
T-stat		10
Ignition system
- Distributor	HEI	300
- Plug wires	Good stuff	110
- Spark Plugs		12
Total	And not all expenses are accounted for	5473

I should also point out that this does not include the price for specialized tools like micrometers and burettes.

This has been an enlightening exercise. I hear people discuss buying parts and refer to their costs that don’t make sense until you start really adding up the costs. If you are spending $6,000 to $8,000 on an engine then $1,300 for a block doesn’t seem like so much. This is especially true if you are building a high output motor. Well, I’m not. I’m looking for a modest power output hovering around 1 HP and 1lb ft per cubic inch.

However, I have an idea!

Builder

More Thoughts Re Budget

2007-06-22T23:38:00.000-07:00

Wow. I thought I had a good idea of what I would be spending.

Not a clue.

I repeat, “I did not have a clue”

I was planning on forking out about $1,000. Well. . .I am about two thirds of the way through pricing out the parts list and I think I’m already over $2,000. The truth is that most of this is just idle circling around until I can get my hands on the necessary information for determining what the engine needs to give me the performance I want. Carburetors, crankshafts, connecting rods, pistons, oil pumps. . .they are all fun but the source of the engines power, or lack thereof, is the cylinder heads, more on that later.

Builder

Connecting Rod to Stroke Ratios

2007-06-20T18:35:00.000-07:00

I spent some time, in the last post, discussing rod-to-stroke ratios but never actually looked at them. So here is a quickie.

First, rod-to-stroke ratios are determined by dividing the rod length by the stroke length.

For example, the stock 350 connecting rod is 5.7” from center to center. Rod lengths are determined by measuring the distance between the center of the big end hole and the small end hole. The stroke for a stock 350 is 3.480”.

We then compute the ratio as follows:

5.7”
-------- = 1.64
3.480”

1.64 is the rod-to-stroke ratio.

I have yet to see a reason for not putting the longest rods you can in an engine. The longest length you “can” fit depends on the purpose of the engine. If you stretch the rod lengths too far then you get troubles with the piston. As you increase rod length you have to decrease compression height (compression height [or distance] is the distance from the center of the wrist pin to the top pf the piston*). As you decrease compression height you begin crowding the rings and that can lead to reliability issues. There are various tricks to reducing compression height, like using a smaller diameter wrist pin, but these tricks are both expensive and relatively short lived. So for me the longest rods I “can” fit are with pistons with compression heights that permit reliability and a long service life. For the purposes of this evaluation I’m choosing (somewhat arbitrarily) 1.2” for the minimum compression height. Further research will determine what my true minimum is.

Back to rod-stroke ratios. All of the previous to say that I am presently trying to put the longest rods possible in the motor and want to see how these ratios look compared to each other.

Stroke

3.480”

3.750”

4.000”

Max Rod Length

6.08”

5.95”

5.82”

Rod-Stoke Ratio

1.747

1.587

1.455

It is ironic that as the stroke increases, and you need a longer rod to maintain rod-stroke ratio, the maximum rod length decreases.

Well, I don’t know what to do with these numbers but I know I don’t like the ratio for the 4.000” stroke.

More study is needed

Builder

* This isn’t strictly true with domed pistons but if you cut the dome off so the piston was flat, then you would have the compression height.

Looking at strokes

2007-06-20T10:43:00.000-07:00

This has turned into a composite of several smaller posts.

With regard to Project #001, I’ve been thinking about fuel efficiency. I will have to check this out more thoroughly but it seems to be that the longer the stroke, the better. As best as I can understand it seems that this would mean that the pressure energy developed would have more leverage on the crankshaft. More leverage means less pressure is required for the same torque (force of twist). Less pressure is less air/fuel mixture. Less air/fuel mixture means less fuel. And less fuel means better mileage.

As a result I am seriously beginning to consider using a 4.000” stroke. For those of you reading this that are not familiar with SB Chevs this is a LONG stroke. In fact I believe that you can’t use a bigger stroke in a stock block or else the crank and rods hit the cam.

Here is a displacement table. Numbers are CID (Stock displacements in bold)

Block stock bore (over bore)

3.480” stroke

Stock 350 crank

3.750” stroke

Stock 400 crank

4.000” stroke **

Stroker!!

350 4.000” (4.030)

349.8 (355.1)

376.9 (382.6*)

402.1 (408.1)

400 4.125” (4.155)

372 (377.4)

400.9 (406.7)

427.6 (433.8)

* This is usually referred to as a 383 stroker motor.

** Anything in this column is a stroker motor!

4.000” stroke is long and it would require some block modification to fit. It also gives a rod length to stroke ratio that is lower than the 3.480” and 3.750” strokes and I don’t like that but I think it is still serviceable. Hell, lots of people are running these strokers so I KNOW that it is serviceable. The question is how does this lower ratio effect efficiency and service life?

Let’s also look at percentage of increase for the strokes

Crank Stroke

3.480”

3.750”

4.000”

Percentage increase over stock 350 crank

7.76%

14.94%

Now that is interesting. When I look at the percentages it looks very different from just looking at absolute number increases. On the one hand a 3.750” crank is over a ¼” longer than the 3.480” crank. This seems like a large increase. On the other hand it is only 7.76% larger. Hardly insignificant but it doesn’t sound as impressive as ¼”. I find the 4.000” crank to be a different story. It is over ½” longer and almost 15% longer. Both these numbers are significant.

Of course this is all just number crunching without experience. For Project #001 the two issues are the influences of these strokes on durability and fuel efficiency. Adequate torque can be accomplished with a stock dimensioned 350. This means that I am looking for a way to increase efficiency.

I have found an excellent forum

http://speedtalk.com/

I have about 500-600 papers to grade but when I am done I will be devoting myself to this forum and see what I find out about the reliability of the 4.000" stroke.

Builder

More to come (maybe)

It looks like I am back. . .for now

2007-06-20T10:30:00.000-07:00

Well, it looks like I have access to blogger.com again. I don't know how long it will last but it is here for now.

I have been writing in the mean time and will start posting from what I have written. It is kind of strange, or rather it feels kind of strange writing to nobody but it does feel good to write down what I have been thinking.

So enjoy the following.

Builder

Interuption

2007-06-09T07:52:00.000-07:00

I have not been able to load this page from where I live so I will soon be posting a lot at once.

Builder

The Point

2007-05-25T02:26:00.000-07:00

The point is not simply to build powerful engines or even cool engines. The point is to learn about what factors influence the various aspects of an engine's performance and to understand both how they influence each other and how to use these factors to make an engine do what I want.

There is no end to how much I could learn about this. Sometimes this makes it hard to dig in, because the deeper I dig the more things I discover that I don't really understand.

I started looking for an engine project wanting to experiment with really long connecting rods. Not only do longer connecting rods reduce how hard the piston is forced into the side of the cylinder, thus reducing friction and thereby increasing power output, but they keep the piston still longer at the top and bottom of the stroke. This means that the combustion chamber is more stable at the top of the power stroke. It also means that you can get better cylinder filling at the bottom of the intake stroke. This is not an exhaustive list but what little research I have done indicates that longer rods can help flatten out the power curve. My thinking was to take a 350 or 400 block, find the longest rods available for a SB and put in a crank with a short enough stroke to accommodate it. I think that an engine like this would be well suited to high RPMs.

However, the project that I have decided on is not one where I need to build a high revving engine. My goal is to build and engine with good low end torque, reliability, efficiency and flat torque curve.

So back to the point. I have been spending part of today learning about the Lotus Engineering Engine Simulation Program. I have heard that it is a good simulation program but you need to really know your stuff before you can get meaningful results from it. They have a free version that is, I believe, fully functional in all respects but limits you to one cylinder. You can get it get it here:

http://www.lesoft.co.uk/

Since I am mainly interested in the dynamics of engine performance right now it doesn't matter to me that it is only one cylinder.

I should mention that I heard about this program at Eng Tips a site for engineers. The automotive section is very interesting. The automotive section starts here:

http://www.eng-tips.com/threadcategory.cfm?lev2=6

I'm looking forward to getting this simulation program figured out. You won't get very far without the tutorial. This is a separate download and essential if you want to learn how to use it.

I am really curious about the effect of connecting rod length and on how heat absorption into the cylinder head and pistons affects engine performance and efficiency.

Shoot. This thread was supposed to be about David Vizard. I guess it will have to wait.

Builder

Project #001 - Getting Started

2007-05-24T01:34:00.000-07:00

I'm wanting to construct a purpose built engine right? So I need a purpose. For cost and parts selection reasons I've decided that my first engine will be a Chevrolet small block V8. I'm not stateside yet and when I am I will be broke. I don't really feel like building a hot rod. The engine is only about a quarter of a well built hot rod and everything I want to do is going to be "well built." I don't really want to buy a vehicle just to build an engine for it. The idea feels contrived. I need to find a vehicle that could use a small block.

After thinking about it for a bit I thought of my buddy with a Willys Jeep. It currently has an unremarkable 350 in it. It is a rig that is for going down trails and off road. It seemed like a good candidate. Its focus was narrow so that should help minimize compromises. I emailed my friend and asked him if he'd be interested in running my engine. The deal is that it is my engine and I take care of everything on the engine except for the exhaust after the headers. He helps me pull his old motor out and put the new motor in. He has to keep records of the mileage and do all the maintenance. I figure that by the time that he is done doing all the other stuff he wants to do (Widening and lengthening the body, new frame, new suspension, etc.) that I should be ready with the engine. He said yes. So I asked about the requirements. He wants:

Good low end torque (What is good?)
Absolute Reliability
Good gas mileage

He has a dream of an engine like that getting 25 MPG cruising at 70 MPH. I'll see if I can make it happen. His Jeep is hardly aerodynamic and at 70 MPH he'll be pushing a lot of air. Using the right gears are going to be vital to achieve the mileage goal.

I threw in a few more requirements, somewhat arbitrarily, just for fun.

400 HP
6,000 RPM Redline
Flat power band throughout the RPM range

These are absolutely negotiable if they interfere with the first three.

Not having done this before I'm not sure what the next step is. I'm pretty sure that thought and research are a big part of it. To bad I left my Vizard books in the States.

Builder

Beginning

2007-05-24T00:19:00.000-07:00

I am currently living in China. It is not my first time living here and like before it has provided me with the time to evaluate my life and priorities. During my time here I have come to see, quite clearly at times, that life is short and that death is certain.

"So what does this have to do with building engines?"

Good question. I have wanted to build an engine for years. I have loved engines since I was a kid. This led me to go to school to become a mechanic (Automotive technician sounds so pretentious) and have worked as one for several years. In this time I have assembled engines but I never built one. I had always felt like it was too expensive and too impractical but I have come to realize that I will die and it would suck to die and never have built an engine. So now I am doing it.

"What is the difference between assembling and building and engine?"

Assembling an engine taking the supplied parts and putting them together. This is no small feat and there is plenty to know about assembly. Building an engine is the process of assessing the requirements of the engine's intended application and then selecting the parts that are best suited. That is what I want to do. I want to create purpose built engines.

I created this blog as a place for me to record my thoughts and as a form of structure and accountability. I doubt very much many or even any people will want to read this. . .but the might! And if someone does I don't want to have a bunch of crap down here that makes me look like an idiot.

If I really get into this I may begin learning things that other people might find useful. Jack's Machine Shop does great work or Fuzz Flow air filters are crap. Perhaps this kind of information is already out on the net but there is nothing wrong with multiple sources of good info. After reading some articles from some of the automotive magazines on this subject, I am struck with how they read like advertisements. We have got to make full use of the Internet to spread the straight info.

You may call me Builder.