basic alcohol engine questions

[DEL51]

I was considering running alcohol in my 572 and have a few questions. What is considered an Ideal compression ratio and can you have any compromise on this?I have a 1471 littlefield,no high helix.Does this blower need some hard anodizing or other mods to work with alcohol?I heard that aluminum fuel tanks are out of the question,true? How do you determine the size of the injector hat.I was told that mechanical injection is "all or Nothing",meaning that you cant cruise at a mid range speed.What are the driving characteristics? Is there alot of blowby and oil contamination.Can this be used for regular boating.With all the crap going on in the middle east, alcohol may be the only alternative.Thanks,DEL51

[Unchained]

I considered running alcohol in my 540 Arias and did considerable research on it.
1) You burn almost twice the fuel volume
2) Everything will corrode unless additives are put in the fuel.
3) You need to run at least 11:1 static compression.
4) The engine will want to run cold and foul plugs.
5) The fumes are nasty and burn your eyes.
I am going to open a can of worms on this one but I asked two different engine builders with dyno's how much more horsepower will I get on alcohol compared to gasoline. One said none. The other said 4%
The only way you get more HP with alcohol is that it will allow you to run a lot more blower boost without detonation. So the additional HP is with the blower, not the fuel. I haven't run alcohol (in the engine)
I just got this info from others.

[nitro557]

gas burns at 14 parts air to 1 part fuel alc
at 6 parts air to 1 part fuel , you will make 1/3 more power on it and 10 time the maintenance , you can make ajustments in the fuel system to cruise but i tell you the oil dillution is bad it wont be a good lake toy motor, unless you make a couple of burps and put it on the trialer

[ponponracing]

I did and I am still playing with some alky deal in my shop. I'll try to help.
You may run alky with any compression ratio you want, it will work, but you have to set the timing accordingly. I'm running 16/1 static compression ratio in my rig and it works like 13/1 except for the good hp and torque it gives. Yes it will destroy aluminum, including metering blocks, but also rubber line, al. fittings, etc.. But it's not a question of minutes...There are additives you mix with alky that kind of retard greatly corrosion. The exact double consumption make the motor run cooler, but you have to use a carb that flows double liquid. It can be bought from many carb shops. Mechanical injection (the real word is constant flow) work very good good as long as it is tuned right, but it's mainly designed for wot operation. Mine works like a carb, very good idling, off idle, mid range and wot. But you have to know how to tune them or the adress of a good engine tuner. In most cases, you will have a better luck with brand new units from the factory. I always dealed with Kinsler and when they took care of calibration, there was just a final tuning to be performed. With the increase in power, you will have to run more rings clearance, causing contamination when not running hard. Blowby also but nothing to get nut. Yes I would use alcohol for regular boating, but according to me the two major problems are first, you need double fuel capacity in your boat, and second where will you fill up? The very good thing is that by running higher comp. ratio you will be amazed by the fuel economy, and also you will be considered as a mean guy by running alky.
It won't really foul plugs unless you use the wrong heat range and you go idling for hours, in this case I recommend "kicker" outboard motor. Big powerfull high cam engines are not really designed for idling. If you run a low comp. ratio gas motor, you will gain torque and hp, but I can't tell by how much. Maybe if I stop spending hours answering this forum I will have time to make comparaison on dyno. You may run more boost with alky than with gas. You will gain performance from your blower by running it tighter with methanol. Fumes are nasty, but they are behind you, killing moskitoes (you have any in your area?) and discouraging cops trying to catch you.
I forgot, you don't see alcohol burning at day light, you'll get use to handling methanol. As a safety, I suggest wearing a triple layer Nomex suit, socks, gloves, head cap. The nice thing about that is that you will give that cutie a ride, you will have to help her get dressed. Nasty job but someone has to do it. You won't be stuck with overweighted one since they won't fit your spare suit.I do use methanol in my Chinese fondue burner, it works.
Where are you Blowndragboat, can you take over?

[superdave013]

I have seen people switch blown gas engines over to alky and not change the compression. So it was low in the 8.5 range. The ran the blower soft and the boat still picked up lots over gas. They kept after me to switch but i never did. It's kinda hard to race blow gas with an alky burrner. Yes, my comp. would have noticed. I think that for lake use and not turnning your blower at 70% the oil contamination will not be as bad as what nitro557 is talking about. Hey, his deal is turned up like what you would see in a funny car! Sounds like fun but also race only. Even with blown gas and my turbo engines I change my oil alot. Did you see that Couger Tunnel in hot boat with the v-drive and the blown alky engine? The guy uses his for lake use only and he posts at this link. http://groups.yahoo.com/group/v-drive_boats
He can help give you some real world advice also as he is doing just what your wanting to do. Lower compression, soft on the blowe and it freaking screams! You should talk to him for sure.
Hey ponponracing, get off the board and on the dyno man! I want to see what you find out with the different compression ratios. I would like to take a 8.0 -1 deal and make some dyno pulls on gas, switch to alky and the power difference. Keep the blower boost the same and only adjust the fuel system and timming if needed.

[BLOWNDRAGBOAT]

I am right here PONPON. Just watchin with a huge GRIN on my face. Hell, ya think I might learn something? LOL

[ponponracing]

He Blowndragboat, stop grinning and talk. It's your world we are talking about. I'm sure you're dying to post your comments. I'm ready. I wasn't expecting you to learn something, but since I'm playing in your field, I'm expecting a hammer reply. Did I goof with: a:some of my answer, b:a little of my answer, c:most of my answer, d:all my answer, e:no goof here.
Superdave, my dynoman did some testing on low comp. motors that he switched to methanol. I'll try to make him talk and give me some comparisons. But I'm sure he didn't do it with blown motors.

[superdave013]

Originally posted by ponponracing:
He Blowndragboat, stop grinning and talk. It's your world we are talking about. I'm sure you're dying to post your comments. I'm ready. I wasn't expecting you to learn something, but since I'm playing in your field, I'm expecting a hammer reply. Did I goof with: a:some of my answer, b:a little of my answer, c:most of my answer, d:all my answer, e:no goof here.
Superdave, my dynoman did some testing on low comp. motors that he switched to methanol. I'll try to make him talk and give me some comparisons. But I'm sure he didn't do it with blown motors.
Right on, But the blown stuff is what I'm intersted in mostly. I just saw what some of my bracket racer buddies did and it seemed to work pretty sweet for a low buck deal.
Man, my spelling sure sucks. Reading my post above is hard even for me! And I wrote it. I'm not as think as you dumb I am! haha

[BLOWNDRAGBOAT]

Ok..let me get my thoughts togather so i don't talk for ever....Be right back

[BLOWNDRAGBOAT]

Ok....Let me try to answer the original questions that DEL had. Then I will try to make a few recommendations based on MY experiance.
1st)Compression. As a rule of thumb, the perfect piston for blown gas engine's is 7-8:1 I like 7:1 simply because it gives me more flexability on on how much blower I feed it as well as timing. BOTH bosst and timing can be considerably effective on blower motors so compression ratio is criticle. On alcohol motors, you want your STATIC compression ratio at 10-12:1. Make sure it's a piston SPECIFIC for alky applications. You can go more but you better have a very VERY thick wallet. If you go past the recommended limits, your entering the PURE racing engine zone that have low operation cycles such as drag racing ONLY.
2nd) Your 14:71 is pretty damn big and when you operate it at a certain level of overdrive, it actually absorbs crankshaft horsepower just to drive it. Heres an example. On a topfuel engine that produces an estimated 6000 horsepower, it takes anywhere from 800-1000 crankshaft horsepower JUST TO TURN the blower at the speeds that are required to produce those kind of numbers. SO, it takes power to make power when you start dealing with upwards of 15-25 or more pounds of boost. Your 14:71 rotor's clearance's need to be setup tighter for alky use and while your at it, have it re-stripped. If you need it done, just send it to me and I can do it. Hard anodizing is recommended.
3)Aluminum tanks. Its a toss up but in my raceboat, I run aluminum tanks. Afterall, your fittings are aluminum, as is an injector hat and many other components. Aluminum heads ect..... I don't let alcohol sit in my tanks. I pump them out frequently to keep the corrosiveness to a minimum. There are several additives on the market that you can add to your fuel system to lubricate it and cut down on the corrosive nature of alcohol. Chances are you will blow your motor up or at the very least, have to pull it apart for some reason LONG before the alcohol can eat it up.
4)Injector hats are decided by the size of the motor,the amount of fuel the motor requires ect..... The four sizes are Bugcatcher,birdcatcher,buzzardcatcher and barndoor. For what your gonna do with the boat, a birdcatcher is more than enough. A bugcatcher will probably be plenty. It really depends on how it's setup and going to be used.
5) Mechanical injection is VERY responsive. Most alcohol motors are very crisp and instant in thottle response,partly due to the increased blower boost and the use of alcohol for fuel. When its set up properly, it can be a blast to drive. When its off your gonna hate it. It can be very tempermental and if your not experianced in basic tuning let alone blown alcohol motors, you might wanna re-think it. Mechanical injection can and does run extremely well, you just need to know how to tweek it when something isn't perfect. I have been working with an electronic fuel injection unit that is pretty sweet but its f**kin expensive!!! It is made by Enderle fuel injection and is based off of an injector hat with direct port nozzles. You can choose a 16 or 32 nozzle setup. It has an ecu that is pre-calibrated but can be tuned with a laptop pc.
6) Driving characteristics. When it's setup right, it will flatten your eyeballs in the back of your skull. If you don't think a boat can leave as hard if not harder than a racecar from a dead stop, just let me know and you can come ride in mine. I PROMISE you will leave the whole experiance with your nuts in your throat.
7) Not alot of blowby because you will need to run zero gapless rings as well as o-ringing the block and heads.
8) Oil WILL NEED to be changed alot since it can become contaminated. I run a straight weight racing oil from REDLINE. It's desiged JUST for alcohol motors.
9)IT can be used as regularly as any other boat BUT that depends on your level of knowledge and mechanical ability to weather or not its NORMAL which means there's nothing normal about alcohol engines. Even starting one CAN be a spectator sport in itself if your not familiar and have a self primer setup. Starting to get the picture?
I will start another post recommending what I would do if I was spending YOUR money. As far as the middle east is concerned, if things keep going the way there going, the last thing ANY of us are gonna need to worry about is a boat!!!!! PEACE!!!! Part 2 will start in a second. I need to go close up my shop.
[This message has been edited by BLOWNDRAGBOAT (edited October 11, 2001).]