Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Hotrodding Basics (
-   -   Want to build an SBC on alcohol (

nskyline34 10-20-2012 09:39 PM

Want to build an SBC on alcohol
Hey guys, I'm new to the forum and hopefully I can get some help here. I'm wanting to build an 355ci or 383ci (not sure which would be better for my goals) on alcohol for a mud truck. I'm looking for something that can handle 8000 rpm and is in the neighborhood of 750hp on methanol and NA. Please help guys. I'm going off of VERY little knowledge of sprint car motors that these numbers are possible. Let me know. But I'm drawing the line at $15,000 on this thing. Lets here the ideas, everything from rotating assy, to heads, cam and grind profiles, and fuel delivery (carb vs hilborn)

vinniekq2 10-20-2012 11:14 PM

What are you wanting to use for induction?to make 750 horse power on ethanol you need to use very high compression,or forced induction.Not sure 15k is enough money,,,figure on 4k just for the injection

nskyline34 10-21-2012 08:11 AM

I was thinking naturally aspirated with hilborn injection and 15:1 compression, but kinda starting to think that's a pipe dream...

nskyline34 10-21-2012 08:15 AM

I know for 12k I can hit 1,000hp with a 468 and an 8-71 on pump gas but I thought alcohol was much more volitle...

monster76 10-21-2012 08:16 AM

Find a couple reputable engine builders in your area that only build high performance engines and ask them this same question most of them would be more than happy to help you in hopes of recieving your business. And good luck sounds like a cool project

monster76 10-21-2012 08:22 AM

Btw my buddy just had a 434 built for spray done ot cost him 25k and it out down 740the on race fuel

vinniekq2 10-21-2012 10:25 AM

the cheapest way to make 1,000 reliable horse power would be a boosted 540/555.A normally aspirate 598 would cost 17k on pump gas

nskyline34 10-21-2012 01:53 PM


Originally Posted by F-BIRD'88 (Post 1601468)
Methanol will work very well as a fuel for the same engine combo.
Whats the problem?

Oh ok, I just thought I could do it NA. What compression should I run? This motor is at 8.5:1 right now... If I were to do a carbon copy on alcohol should it be more like 10:1 or should I just turn more boost more more power? Right now it's breathing though dual 750 double pumped, what should that be for alcohol? Also what do I need to do to turn more RPM with it? Is 7500 rpm possible with a 468 and an 8-71 on alcohol? The internals are all forged, but should I use aluminum rods? What cylinder heads can handle this?

nskyline34 10-21-2012 01:56 PM

I've built plenty of engines myself, I'm not about to start taking them to people to build for me. This is why I'm asking, I don't know what heads and ect to run to handle the power and 7500 rpm with an 8-71 and a BBC. Let's forget the money and just talk parts... If it cost more so be it, just want a 7500 rpm 468 BBC with a blower and alcohol and NO LESS THAN 1,000hp

vinniekq2 10-21-2012 02:20 PM

468 would need heads flowing 375 cfm with 80% exhaust flow ratio. The solid roller needs 640 lift and duration about 255@50 with a lobe separation at 114 ish.8 or 9 plus pounds boost,2x 1050 cfm holley HPs,2 1/8 headers,etc,standard parts

nskyline34 10-21-2012 03:14 PM

What about injection? Is that better than carb with alcohol? What kit/company is good with alky injection on blown applications? Also why comp ratio will this need?

vinniekq2 10-21-2012 03:26 PM

original post was to make 800 hp with a small mouse?

nskyline34 10-21-2012 03:56 PM

The original intent was 700-750 with an SBC with hilborn injection on alky. I want it to spin 7500-8000 rpm. It's basically a sprint car motor. I just have no clue about heads or valves or anything. Can u help with that? Basically if the 700's aren't possible then I want as much as I can squeeze out of it. What do you think are realistic numbers and parts?

vinniekq2 10-21-2012 04:12 PM

when you figure out what you need,why not start a new thread and say Im using X fuel and need an N.A. or boosted engine? looking for x power? need X rpm,etc and go from there.Explain rpm requirements and if the engine is strictly race,,,just picking a horse power number means nothing to people trying to help.explain (briefly) h.p. torque,rpm requirements etc and get everyone to chip in experience.

S10 Racer 10-21-2012 10:37 PM

I have a friend that has an Ostrich 360 Sprint car motor for sale for 15K. Can probably be had for a touch less. Dynoed at 650 I believe, ready to run. You can search or and find plenty of what you are looking for. Keep in mind that all the high reving motors have to use good quality parts to keep them together and even then, they get freshened up after about 20 shows. Word of caution, unless you have lots of money for parts, stay away from the SBC 410 sprint motors. Those things will scream and capable of 900+hp but they are very costly to maintain and need freshened after about 10 shows. Most sprint car motors are built with restrictions for their sanctioning body so with a little work, you can get even more power out of them.
We run a SBC 383 Hilborn Injected on alcohol in our wingless sprint. We run the W.A.R. series here in Missouri so restrictions in that class do not apply. It's more like "run what you brung". Alcohol wants high compression, the more the better. Keep in mind that an alcohol motor is a maintenance nighmare but if you have time to keep it in good working condition, it's worth it because of the x-tra HP. You need to drain the fuel lines, remove the injectors and blow dry all the alcohol out of the system. Alcohol is very corrosive on aluminum and magnesium parts.
I know probably none of this answered your questions but it's an insight to start with.

All times are GMT -6. The time now is 02:56 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.