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**Thumpin455** · February 1, 2011, 06:28 PM

Re: 79 Trans Am (the inebriated mule)

Today the crank kit was ordered for the 455 block that has been sitting here for two years waiting. I decided against dome pistons, both as a cost consideration and for flame travel. Plus flat top slugs lets me try different heads easier, so I can adjust compression, quench, port flow, or whatever else. The nice thing about a Pontiac is I can go from 7.7:1 to nearly 14:1 with a head swap and flat top pistons. Another nice thing about a 455 is grunt, this one is getting a 4.25" stroke and a 4.181" bore so it will make a ton of bottom end torque. The reciprocating assembly is relatively light but without aluminum rods, hopefully to cut down on weight and make it rev easier. The 400 based engine with the same parts winds incredibly quick, so this should be a fun one to drive.

Currently there is a set of ported 670 heads from a 1967 428 Pontiac sitting here. They make for about 11.3:1, but they have the center exhaust crossovers filled, have a less efficient chamber shape, and they flow [email protected] so they lose a bit of velocity compared stock ports. The compression with them is a bit less than I want, and I need the heat under the carb that they cant provide, along with no capability for EGR, so they are temporary and more of a way to show the differences in chamber shape, and heat management. The heads I plan to use for more testing are 1969 #48 heads, they are RAIII or 350 HO heads, have small open chambers with big valves, and flow pretty well. Milling them can get me very near the 13:1, but they are currently bare sitting under my workbench.

The first cam it will get is a Summit Racing 2802 grind that people like for the street. Its a 224/234 with 114 LSA and .465/.488 lift, making it a nice cam for low compression engines that need to build some cylinder pressure. With this cam, and either of the heads above, there is no way this engine will run on pump gasoline, it just wont do it without knocking the bearings out or cracking ring lands. Pump gasoline is out of the question completely, but E85 and HE100 should work quite well in it. I plan to swap cams a few times to see what differences valve timing has on mileage and power with the alky.

**Thumpin455** · February 1, 2011, 06:36 PM

Re: 79 Trans Am (the inebriated mule)

One of the first things I am doing is rebuilding a Qjet for it. Eventually I want to run EFI but it isnt in the budget just yet. If the EZ EFI from FAST can work with ethanol then I might try that one first. It depends on just how much the injectors can flow, and if the ECU can handle it. I would prefer to have the ability to tune it myself, but its the cheap and easy way to get into EFI.

The carb kit from Cliff Ruggles is waiting with the carb, probably going to get started on it tomorrow. A numbered drill bit set is about all I need to convert a Qjet to ethanol, but this one is getting new throttle shaft bushings and the main jet plugs replaced as well. This one probably wont go on this engine, but I will show you what it takes to get a Qjet to work with ethanol. I have one done and its on my GTO, but it still needs some attention and tuning, so you will see both of them. The new one will have a choke on it, and it will be tested extensively as soon as the snow is gone enough for me to work on it. I am building it for a friend to use on his GTO.

**fahrenschnell** · February 1, 2011, 06:57 PM

Re: 79 Trans Am (the inebriated mule)

I love TA's.......first car I ever went fast in.....Very Cool.

Seth

**Huskinhano** · February 1, 2011, 08:05 PM

Re: 79 Trans Am (the inebriated mule)

I'd look to see what kind of piston choices there are for low tension metric rings. A number of years ago I GM engine engineer IIRC said about 50% of engine friction comes from just the pistons and rings. Bearing account for about 25% and a flat tappet cam about 25%

**milner351** · February 1, 2011, 08:06 PM

Re: 79 Trans Am (the inebriated mule)

Sweet - rolling resistance and aero are a big deal.

On a car like this you'll need about only 15HP to push it down the road at 50mph, so throttling losses (lotsa vacuum) will be a factor that will hurt the engine efficiency.

Taking advantage of the low numerical rear gear that's already there is a great idea.

Running a 350 instead of a 455 might be a worthwhile Idea too - but using what ya got is never a bad thing!

Compression ratio is a huge efficiency improver - so - using homebrew ethanol is pure genius.

Cool project!

**Thumpin455** · February 1, 2011, 09:37 PM

Re: 79 Trans Am (the inebriated mule)

With these gears it is just above idle at cruise, so the vacuum works for me rather than against me. Good signal to the carb, better fuel mix, and plenty of torque right where I need it. That is also why I am not using a 350, not enough grunt to pull the gear and relatively heavy car. The 403 would work, but the compression issues keep it from being the choice. I've gotten 20mpg from both a 403 in one of my other Trans Ams and the 455 in the 70 GTO on pump gas. Both those had low compression, headers, highway gears, and Qjets. If I cant get at least that then I will be upset.

I like the power the 455s make, they dont care what gear is behind them, they dont care how much weight they are pulling as long as its under 4500lbs. The 350 Pontiac has too small a bore for my liking, even smaller than the LS1, and the heads have 2.11 intake valves, so there are shrouding issues. Not to mention to get the compression where I want it would require a LARGE dome, and that would mess with the flame front. Even with the 3.75" stroke, they just dont have the bottom end I am looking for. I have a 400 sitting here, but there again I can only get it to 11.5:1 give or take with a head swap and flat top pistons. The 400 will work very well, and make good power, pull the gear, but the 455 is the cheapest way to get the squeeze up.

Its getting the same ROSS slugs that are in my 467 race engine, so it has the low tension thin rings, not the stock type thick suckers. I would like to go with a hydraulic roller, but the funds just arent there and it would require me to set up all the heads for that type of camshaft. So the lowly flat tappet gets the nod. Rollers would make cam swaps easy and cheap, but I can do 5 or 6 flat swaps for the price of a roller retrofit.

The other car that is going to get some E85 changes is the 98 Gran Prix I use as a winter beater. That way I can show how to do an old car or a newer one and make it fuel efficient on ethanol. :P

The 65 GTO and 71 Mustang will also get some work, one of them needs to be out of the shop soon so I can get the rear frame rail fixed on the TA, dont need the car folding in half with all the torque this engine will make.

**DanStokes** · February 2, 2011, 08:01 AM

Re: 79 Trans Am (the inebriated mule)

Great project, Todd! And it's good to see you up and at 'em!

Cylinder head question - with alcohol on the street, do you stay away from aluminum heads? I'm thinking that alcohol tends to make them run cooler and so do aluminum heads. Coupled together, the adiabatic efficiency may drop thru the floor. For fuel economy you need enough heat in the combustion chamber to burn the fuel well. Just wondered what your take was.

BTW - I know almost nothing about alcohol other that the difference between methanol and ethanol. I DID do some work trying to get a Diesel to run on neat (pure, 100%) methanol but the metallurgy was a fixed deal - there were no aluminum heads for a IH DT466B. So we didn't look into this. No, you can't run a Diesel on neat methanol as there isn't enough heat energy for it to auto-ignite. I suspect M85 would have worked fine but the boss wouldn't let us explore that.

Have fun!
Dan

**Darren N.** · February 2, 2011, 10:49 AM

Re: 79 Trans Am (the inebriated mule)

Very cool, Todd.

I have a buddy who's into Olds' as well. He has yet to get his hands on a 455 but the 350 and 403 he has built are plenty healthy.

Like John mentioned, increasing the compression ratio is the most effective way to increase thermal efficiency.

I'm guessing that if you want to make a rough fuel efficiency comparison to the 20mpg you got out of your previous gasoline (?) Olds engines, you'll have to scale your ethanol mpg to account for its lower energy density than gasoline.

Like many of the other BS'ers, I'm totally digging the fact that you're home brewing your own fuel.

Originally posted by DanStokes

Cylinder head question - with alcohol on the street, do you stay away from aluminum heads? I'm thinking that alcohol tends to make them run cooler and so do aluminum heads. Coupled together, the adiabatic efficiency may drop thru the floor. For fuel economy you need enough heat in the combustion chamber to burn the fuel well. Just wondered what your take was.

Ooooh, that's a good question! I'm also interested.

Originally posted by DanStokes

No, you can't run a Diesel on neat methanol as there isn't enough heat energy for it to auto-ignite. I suspect M85 would have worked fine but the boss wouldn't let us explore that.

Maybe methanol didn't auto-ignite given the compression ratio of your setup, but (in theory) if the compression ratio was increased it would auto-ignite at some point. When you say M85, do you mean 85% methanol and 15% Diesel fuel? That sounds like a fun experiment to me! It's too bad you didn't get to play with hydrogen because that seems to auto-ignite quite well :D .

I love the fact that you were able to play with this kind of stuff when you were working. ;D

If you're bored (or curious as I am), Google pulled up this old paper on the subject. Skip to the conclusion section: apparently they found methanol to be [somewhat] similar to MTBE in its auto-ignition characterics. In other words, as likely to auto-ignite as a commonly used anti-knock agent... maybe with a little Diesel added to mix things would get interesting?

HTTP Status 429 – Too Many Requests

http://dspace.mit.edu/bitstream/handle/1721.1/12023/31307780.pdf?sequence=1

[pardon the topic derailment]

**DanStokes** · February 2, 2011, 01:43 PM

Re: 79 Trans Am (the inebriated mule)

One of the engineers (NOT the boss) did the calculation for how much compression pressure (calculated into CR) it would take to auto-ignite methanol. I forget the number but it was beyond practical limits.

Dan

**Thumpin455** · February 2, 2011, 02:21 PM

Re: 79 Trans Am (the inebriated mule)

BTW my 455 is Pontiac, though I do have a couple Olds 455s in Nebraska, one has the small chamber E heads on it, and they are future projects along these lines.

One thing that makes ethanol so useful as a fuel is its resistance to compression ignition, so you can use high compression such as in a diesel for more efficiency. A bud of mine in Nebraska used to run 350 Olds diesels in his figure 8 car, he has been running a 455 Olds lately. Its a FWD Riviera/Toronado so the Olds works good for it, stock parts etc. Anyway, the Olds diesel is based on a gas 350, so you can install a distributor for spark ignition system. We are working out how to machine the heads to put spark plugs where the glow plugs go. Its more of an idea than a project at this point, but the Olds would make a very effective ethanol engine, its built to take the compression and has plenty of it just as it is. You just need an ignition source because it is very hard to get ethanol/methanol to diesel.

You can mix ethanol or methanol with diesel, it burns cleaner, and uses less fuel to make the same power since alcohol has its own O2 in it. I like the idea of converting one to ignition though.

The main reason I am using iron heads is I have them, and this is a low buck deal. If I go and use exotic stuff then people will attribute any success to the parts, and assume you need those parts to do this. You can use any head that is on the engine as long as you can get the compression up where you need it to take advantage of ethanol.
If it dissipates heat faster then raise compression and limit the transfer to the water jacket/radiator/air. I plan to do the 3800 V6 in the Gran Prix, but without the compression, and eventually I will build an LSx engine with 13:1 or so to take advantage of all the benefits of the engine design they have. I am using a dinosaur to show anything will work, and hell I love these old 455 Pontiacs. They make me drool with the grunt they produce and to me they are cheap to build.

**DanStokes** · February 2, 2011, 02:47 PM

Re: 79 Trans Am (the inebriated mule)

Darren - yes, "M85" is 85% methanol and 15% Diesel. I don't know why but the convention is to list the type of alcohol first (M for methanol, E for ethanol) followed by the percentage of alcohol. So E10 would be 10% ethanol and 90% fuel - usually gasoline in this case. I'm not sure how they differentiate between the hydrocarbon fuel stock - gasoline or Diesel. Maybe we're just supposed to KNOW that?

Dan

**Thumpin455** · February 2, 2011, 02:49 PM

Re: 79 Trans Am (the inebriated mule)

When I say 20mpg that isnt converting anything, that is 20 gallons of E85/HE100. No equivalents, no extrapolation, 20mpg is 20 miles to each gallon. The energy content is only part of the deal, and BTUs/Joules are not a fair measure of how much work a liquid fuel can produce. The properties of that fuel play a huge part of how efficient an engine can be while using it.

Sure gasoline has more BTUs, but what is a BTU? Its the energy needed to heat a gallon of water one degree. Are we heating water with an engine? Gasoline heats lots of water, it heats everything in the engine to the point we have lots of energy wasted heating the engine, water, and eventually air. Much more than the heater core needs to keep you toasty warm in -20F. Why doesnt a gas engine have high efficiency? It wastes heat. Plain and simple.

High compression is only part of the deal. There is an energy release when a liquid goes to vapor, like when you boil water. Also a vapor will burn more readily, more completely, with less waste heat than a much larger spray will. Imagine if the fuel went from liquid to vapor rather than a spray directly from the injector. The vastly finer droplets in a fog have a faster burn rate than the larger atomized droplets, so they will expand readily in the time it takes the piston to travel down the bore on the power stroke without heating things as much as the larger spray will. In other words, you get more work and less waste heat. So if you can get more work from the fuel and it doesnt overheat everything around it, that is a plus to efficiency, is it not?

Ethanol boils at a relatively low 173F, we can utilize that to achieve a dense fog rather than a very dense spray. While it boils it also pulls heat out of the parts around it. Latent heat of vaporization is very high with alcohol fuels, and quite low with gasoline. Gasoline could be vaporized but the components in it have very different boiling points, thus before it all boils, one part has long since boiled off and filled the fuel lines with gas. You know this as vapor lock. Smokey Yunick achieved it, and he was running the intake air and fuel very hot to get gasoline to do this. That required exotic parts, unique cam timing, and with that comes expense. He needed very high EGT and the incoming air was well over 450F to do it.

Since we only need 173F to get ethanol to vaporize, we can exploit that easily with common and simple parts. Nothing exotic about this engine, and it will utilize as much of this as I can conjure up on a budget. A carb makes it harder because at 173F the fuel will start boiling out of the float bowl. Raise the fuel presure and it boils at a higher temperature, lower the pressure at it boils lower, we can use that too. EFI would allow me to raise the line pressure to the point where I could get 200F fuel temps and that would make for instantaneous vaporization when it hits the vacuum of the intake tract. I see that as a double whammy, vacuum and heat make it happen much faster and more completely. Then shove it into a tight space and light it. Plenty of power with very little waste heat.

That is something you simply cannot do with gasoline with current inexpensive engine parts, but ethanol does it quite well. A gasoline engine will still need low compression ratios to ward off detonation with the hot air/fuel, where an ethanol engine can enjoy the benefits of really making that fuel work without breaking ring lands, holing pistons, or knocking the upper rod bearings flat.

**Thumpin455** · February 2, 2011, 02:51 PM

Re: 79 Trans Am (the inebriated mule)

Alcohol also carries some oxygen into the chamber on its own. So we dont need to ingest as much from the atmosphere to make the same power. That means I can use smaller cross section high velocity ports with more runner length to increase torque output. That is a strong point to the Pontiac design that they were blessed with since the 50s. I could probably get away with running 326 or 350 heads on this 455 with the small valves and still make decent power and torque. These engines dont need lots of RPM to make power. They are a very good engine to exploit the properties of ethanol and its ability to increase low and mid range torque.

Make a thick flat torque curve, put a highway gear behind it, make it slippery so it doesnt take much power to move it through the air and you will use less fuel. The engine just isnt working hard and it isnt turning as many revolutions per mile as a smaller engine that needs more gearing to push the mass. So you travel more distance on fewer revolutions.

Stack up all these properties and you can make for a very efficient engine. If I could reduce friction inside it, roller cams with 50mm roller bearings, smaller rod journals, less windage, thin ring packs, and all the other things the LS1 is blessed with in addition to high velocity ports, then this 455 could make some serious power and use minimal fuel doing it.

Now grow that fuel in a small pond that makes me 500-1000 gallons a year and it makes gasoline and the mid east look pretty damn bad. I havent even touched on longevity because of no carbon buildup on valves, pistons, and contaminating the oil. On a 100% ethanol engine there isnt any of that. So this engine could last a million miles if I dont throw a rod apart or break something by dropping something down the carb. Oil changes would be every 20,000 miles or so, and mostly due to the breakdown from heat, it still looks clear when it comes out.

Now gas looks really crappy. I like to build engines once and run them forever. Its nice when they are clean if i take them apart for a cam swap or to port the heads.

**Thumpin455** · February 2, 2011, 02:59 PM

Re: 79 Trans Am (the inebriated mule)

Originally posted by DanStokes

Darren - yes, "M85" is 85% methanol and 15% Diesel. I don't know why but the convention is to list the type of alcohol first (M for methanol, E for ethanol) followed by the percentage of alcohol. So E10 would be 10% ethanol and 90% fuel - usually gasoline in this case. I'm not sure how they differentiate between the hydrocarbon fuel stock - gasoline or Diesel. Maybe we're just supposed to KNOW that?

Dan

A couple issues with methanol. Its much more corrosive than ethanol, gasoline, or diesel. You need quality stuff to keep it from eating your fuel system. Also they tried methanol with gasoline before MTBE, they found it produced more problems emissions wise than it solved. I cant recall right now what increased with methanol and gas being mixed, but the EPA and CARB said 'Oh hell no..'

It takes nearly twice as much methanol to make the same power as ethanol. Its also very toxic so it requires special handling. I like the stuff for certain applications, like Top Fuel, but not so much for general transportation.

Part of the reason they used methanol first was the fuel companies could control the source easily, unlike ethanol where anyone can make it. Methanol can be made from natural gas very easily, and who controls the natural gas? It makes good business sense to use the things you have control of first, and they did that. Ethanol is the last thing they wanted to try, because its easy to produce, readily available, relatively non toxic, dilutes easy with water, and cheap to make. They would have to buy it and mix it rather than have their own supply of it, so of course the oil and gas companies are resistant to it.

They arent idiots. They want to sell their product, and they dont want anyone to realize that ethanol is better for the engines than gasoline.

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79 Trans Am (the inebriated mule)

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