alcohol vs gas?

[Smitty19]

I've got a 19' daytona jet with a blown 555 8.6 compresion with a 14-71 made a 1040 with a 10 before the 14 runs 110 plus mph,600lb hul was told I could go to alcohol without changing comprestion knowing it takes twice the fuel how much more power could I expect? How much of a hassle is the whole clean the fuel lines mantainance ect?. it not a trailer queen I drive it
any feed back would be a help.

[Morg]

I was told to use Pro-Blend fuel treatment with the alky. I had alky in my fuel system from March to December. Never drained. All is good. No gell, No chalk.
I wise man once told me "Gasoline is for lawn mowers".
I don't know enough about the compression to know if that is enough. More would be better.
Are you running an injector??

[78Eliminator]

Infomaniac's deal in his cougar was I "think" a 509 and a 6/71 with around 8:1 compression. He ran the hell out of the motor on alcohol with no problems.
The first hour you run it, you might be blowing black smoke out your exhaust as the alcohol cleans your combustion chambers LOL :D

[Blown 472]

Infomaniac's deal in his cougar was I "think" a 509 and a 6/71 with around 8:1 compression. He ran the hell out of the motor on alcohol with no problems.
The first hour you run it, you might be blowing black smoke out your exhaust as the alcohol cleans your combustion chambers LOL :D
How much power you figure you are making with your dealio?

[78Eliminator]

How much power you figure you are making with your dealio?
Me? I have no idea. My deal is a 8:1 460 blown injected gas motor. I dunno, with the blower 5% over maybe 800?
You see, when I bought the hydro I have now, it came with that motor in it. I went through it with Fiat48 and that is what I am running in it to get used to the boat. The blown injected alcohol 522 is sitting in my garage for now.

[BOOGEYMAN]

Why go through twice the fuel and leave the static compression at 8.6?? You will not see the real advantage to alcohol by leaving the compression that low. Would be better to spend a little more cash and put some different slugs in it and get all the power from that alcohol that you are looking for. Step it up to 11 and have some real fun!!!

[Smitty19]

this thread was doubled by accdent but to answer your question,motors to fresh to change and was thinking of trying it first I could always change compresion latter I would have spun the blower harder with the big blower and alcohol looking,at options

[Blown 472]

Me? I have no idea. My deal is a 8:1 460 blown injected gas motor. I dunno, with the blower 5% over maybe 800?
You see, when I bought the hydro I have now, it came with that motor in it. I went through it with Fiat48 and that is what I am running in it to get used to the boat. The blown injected alcohol 522 is sitting in my garage for now.
Is the 460 a gas motta?

[Fiat48]

It's a gas motor with good heads but a tiny little camshaft(which was already in the motor when he got it). Strictly for driver's training. With a cam change, nozzle change and add alcohol the hydro can run easy 8.0's. Even without the 2 speed.

[Blown 472]

It's a gas motor with good heads but a tiny little camshaft(which was already in the motor when he got it). Strictly for driver's training. With a cam change, nozzle change and add alcohol the hydro can run easy 8.0's. Even without the 2 speed.
Drivers training? that involve a spare of undies?:sqeyes:

[78Eliminator]

Drivers training? that involve a spare of undies?:sqeyes:
The hydro feels pretty good with the small cam. Like all the pros have been telling me over and over, I have to take the boat out and "wear it out". Only way to graduate to a larger cam, then alcohol.......some day maybe the 522. I was on a finanacial roller coaster for a while and things are looking ok now, so I am going to start running it a lot more.

[GofastRacer]

The hydro feels pretty good with the small cam. Like all the pros have been telling me over and over, I have to take the boat out and "wear it out". Only way to graduate to a larger cam, then alcohol.......some day maybe the 522. I was on a finanacial roller coaster for a while and things are looking ok now, so I am going to start running it a lot more.
You are a smart man!..:cool:

[Blown 472]

The hydro feels pretty good with the small cam. Like all the pros have been telling me over and over, I have to take the boat out and "wear it out". Only way to graduate to a larger cam, then alcohol.......some day maybe the 522. I was on a finanacial roller coaster for a while and things are looking ok now, so I am going to start running it a lot more.
So you are going to run this small motta on gas then on alky with out changing comp ratio? how much more power will ya make on just alky?

[Fiat48]

So you are going to run this small motta on gas then on alky with out changing comp ratio? how much more power will ya make on just alky?
I can't give you any hp numbers because I don't know. I quit chasing and trying to believe Hp numbers long ago. But I can give you some actual changes and results regarding low and high compression with alcohol.
But it is drag car related:
23 T altered 125 inch chassis (picture of car is in spam section if you care to look) 2000 lbs wet with driver. Tuned to run 7.50 e.t at the time.
496 inch (4.310 x 4.250) BBC 8 to 1 compression, 6/71.
Blower overdrive to run 7.50 seconds = 6% overdrive. (7500 engine rpm)
Above engine changed to 475 inches (4.350 x 4.00) 12 to 1 compression, 6/71. Same cam, same heads, same most everything. Same track and conditions.
Blower drive to run 7.50 seconds is now 6% UNDER drive.
So....loss of 21 ci, gain of 4 points of compression = 12% less blower speed to do the job.
Maybe you can get something out of that.
Now on Justin's deal I can back the little 460 into the 10's then step to 9's and even 8's as he progresses. The 522 is too much motor to back to 9's much less 10's without it slobbering all over itself.
A 509 I built with a 6/71 gas blower but on alcohol...no 2 speed and high gear only and near identical boat as Justin has ran 8.0 at Firebird with 4% OD in the blower on a hot day. And the 522 Justin has is a whole lot more motor everywhere than was this 509.

[Blown 472]

So it doesn't take a ton of boost to make power with it.:sqeyes: :sqeyes: I am sure my motor will like that.

[Morg]

So it doesn't take a ton of boost to make power with it.:sqeyes: :sqeyes: I am sure my motor will like that.
No, everybody knows it takes huge boost to make power.:) :) :)
I have to talk to Bob about giving out to many of his secrets.:D :D

[Unchained]

So it doesn't take a ton of boost to make power with it.:sqeyes: :sqeyes: I am sure my motor will like that.
I don't think it's quite as cut and dried as that.
There's no question Bob can engineer and build a motor better than most so that's a big factor. Someone else may not get the same results. I sure wouldn't.
The difference between 8:1 compression and 12:1 compression is probably 8 to 10# of boost.
The downside to a high compression motor for anything but race use is that the motor is always hitting that hard on every compression stroke even when you only want to cruise with it. Building heat and wear and tear.

[Fiat48]

Important thing is....both motors could do the job. There was no optimized camshaft, super trick heads etc. And since alcohol has such a wide tuning window....even the tune ups were the same between motors.
There is no magic. If there is such a thing as magic then I would call it the tune up. It's my belief most engines never perform to the extent that they could due to poor tuning. Maybe another is building an engine for an rpm it will actually see.
Simple really. All you do is build the engine as effecient as you can for the rpm range that it will see. Air in, air out. Air compressor. Then install a supplement air supply device on that for adjustabilty.

[Unchained]

And since alcohol has such a wide tuning window....even the tune ups were the same between motors.
There is no magic. If there is such a thing as magic then I would call it the tune up. It's my belief most engines never perform to the extent that they could due to poor tuning. Maybe another is building an engine for an rpm it will actually see.
I agree about the poor tuning that is very common.
I am always fine tuning things to get it optimised.
I run a lot more timing than most. 42+ degrees at cruise speed and 34 at 20# boost. I just did an inspection teardown and things looked excellent, just like the last times. I'm going to get a knock sensor so I can run more yet.
Bob, I am really impressed with your motor building and tuning ability especially after seeing that video. But I have to respectfully say, the alcohol wide tuning window thing I keep hearing is like saying, "I can't make small precise mixture adjustments so I need a wide tuning range".

[Fiat48]

The wide window we refer to is not as if to say that it is a substitute for correct fuel mixture....but rather a "luxury" that alcohol is so forgiving that it hauls ass if it is even close. Many times I will put the motor on the fat side just to be safe in finding the fuel curve. And sometimes I am just lazy. :D
An example of that would be that video. 1st pass was 2%...2nd pass was 4% and a passenger. I didn't change the pill nor would I have up to about 10% overdrive in the blower for the air conditions we were running at.
But I admit that is laziness....as I never have even pulled heat on a plug well with this motor. It's enough for me but I could step on it and lean it if I wanted more.
Blown gas would be much much more picky.
The sensors you refer to and the tuning EFI has definately got be very satsifying and interesting. Definatley a lot to be had there.

[Jspeeddemon]

My understanding is that there is no real power gain in the straight switch from gas to alcohol. The power increase comes from the ability of alcohol to tolerate, a lot more dynamic compression in the motor, which is either more static compression or more boost. It's six of one, half a dozen of another. The motor running, is performing on dynamic compression, after the cam bleeds off cylinder pressure and other factors. An 8.5:1 motor will perform as well as an 11:1 give or take a few HP's, by just overdriving the blower more and adding more boost. They end up at the same dynamic compression ratio effectively.

[396_WAYS_TO_SPIT]

I wise man once told me "Gasoline is for lawn mowers".
and alcohol is for humans:D

[Fiat48]

My understanding is that there is no real power gain in the straight switch from gas to alcohol. The power increase comes from the ability of alcohol to tolerate, a lot more dynamic compression in the motor, which is either more static compression or more boost. It's six of one, half a dozen of another. The motor running, is performing on dynamic compression, after the cam bleeds off cylinder pressure and other factors. An 8.5:1 motor will perform as well as an 11:1 give or take a few HP's, by just overdriving the blower more and adding more boost. They end up at the same dynamic compression ratio effectively.
That's a fine theory. As far as theory goes. But in reality....there is a performance gain with alcohol and no other changes. Try it and you shall see.

[GofastRacer]

Yes indeed!..

[DEL51]

what about e85,anyone try it yet?

[River Rat 005]

So your saying if you take an engine on gas, put alcohol in the tank, rejet for the alcohol, it will make more power than on gas?

[HONDOG]

Yes, I have freind who did just that in his drag car and picked up about .2 ET.

[River Rat 005]

Thanx, most of the time I hear that they also raised the boost and increase the timing.