408ci advice?
408ci advice? So i have in mind of building a 408ci shortblock with a 12:1 compression and using pump gas so i could drive it on the weekends. A couple friends of mine told me the dome piston is a bad idea an so is a 12:1 with pump gas. I wanted to know what you guys thought of this set up and what advice you have to build a 12:1 with pump gas. If im not able to use 12:1 with pump gas i was thinking of just goin with a 13:1 n high octane weekend warrior
Wiseco +5cc dome pistons
.040" gasket
72cc heads
Wiseco +5cc dome pistons
.040" gasket
72cc heads
TECH Fanatic
Joined: Jun 2006
Posts: 1,326
Likes: 0
From: Hayward CA
So i have in mind of building a 408ci shortblock with a 12:1 compression and using pump gas so i could drive it on the weekends. A couple friends of mine told me the dome piston is a bad idea an so is a 12:1 with pump gas. I wanted to know what you guys thought of this set up and what advice you have to build a 12:1 with pump gas. If im not able to use 12:1 with pump gas i was thinking of just goin with a 13:1 n high octane weekend warrior
Wiseco +5cc dome pistons
.040" gasket
72cc heads
Wiseco +5cc dome pistons
.040" gasket
72cc heads
12:1 is not a good idea for pump gas ( typicaly 91-93 octane), 13:1 is a PIA to run race gas in a street car and do you know race fuel cost? I would re-think it. What are you trying to accomplish?
The idea of 13:1 was only if I was to build a stright race car and not be able to drive to the mall or cruise it on the weekend
Last edited by Outlaw E36; Dec 4, 2009 at 03:37 AM.
You can get by with 12:1 on 93, Just depends on what kind of cam you run. Based on what you are saying I would say set your sights a little lower. You can make good power with lower compression... It all depends on the combination.
TECH Fanatic
Joined: Jun 2006
Posts: 1,326
Likes: 0
From: Hayward CA
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Yea well you dont make more power by hanging the intake valve open to relieve compression and if your backing timing down your not making more power either.
Last edited by 99blancoSS; Dec 4, 2009 at 12:46 PM.
Thats what i was told that it wasnt a good idea but i read a couple threads were people were using pump gas on a 12:1. My goal was to build a streetable race car (not a DD) with good power so I figure the best thing was a 12:1 compression.
The idea of 13:1 was only if I was to build a stright race car and not be able to drive to the mall or cruise it on the weekend
The idea of 13:1 was only if I was to build a stright race car and not be able to drive to the mall or cruise it on the weekend
Listen to the guys who said it's not a good idea. Hi compression is not a bragging right. 11:1 on 91 octane is what we recommned and HKE has some of the fastest N/A cars you will find. 9.4 seconds on 91 octane with a 3300 lb car.
Last edited by 99blancoSS; Dec 4, 2009 at 01:25 PM.
My old 408 was 12:1. I raced it on 104 (really 105 my track doesn't have 104 so I had to mix 110 and 100) (1/2 and 1/2) but anyway, I did drive it on the street with pump gas all the time BUT BUT BUT, you cannot go WOT on the pump gas if it's tuned on the race.
If you go 13:1, you'll have to drive it on the race, maybe a race/pump mix but still can't go WOT unless you have full race gas in it. That's how I did it anyways. Now I have 13:1and drive it on the full 110 octane or a 110/93 mix. I can't go WOT on the street anyway, unless I want to kill myself.
If you go 13:1, you'll have to drive it on the race, maybe a race/pump mix but still can't go WOT unless you have full race gas in it. That's how I did it anyways. Now I have 13:1and drive it on the full 110 octane or a 110/93 mix. I can't go WOT on the street anyway, unless I want to kill myself.
power. But how much power difference would it be from 11:1 to 12:1.?
and nitrous
My old 408 was 12:1. I raced it on 104 (really 105 my track doesn't have 104 so I had to mix 110 and 100) (1/2 and 1/2) but anyway, I did drive it on the street with pump gas all the time BUT BUT BUT, you cannot go WOT on the pump gas if it's tuned on the race.
If you go 13:1, you'll have to drive it on the race, maybe a race/pump mix but still can't go WOT unless you have full race gas in it. That's how I did it anyways. Now I have 13:1and drive it on the full 110 octane or a 110/93 mix. I can't go WOT on the street anyway, unless I want to kill myself.
If you go 13:1, you'll have to drive it on the race, maybe a race/pump mix but still can't go WOT unless you have full race gas in it. That's how I did it anyways. Now I have 13:1and drive it on the full 110 octane or a 110/93 mix. I can't go WOT on the street anyway, unless I want to kill myself.
Listen to 99blancoss. He will keep you pointed in the right direction. Keep it at 11.0 to 11.5. Spend the money on some good heads and a good cam.
Bumping the compression from 11.0 to 12.0 is not going to net you much power worth the cost of having to buy/find racefuel. You can run 11-11.5 and make the power you need.
Bumping the compression from 11.0 to 12.0 is not going to net you much power worth the cost of having to buy/find racefuel. You can run 11-11.5 and make the power you need.
I run 11.38:1 CR on my 408 with 93 octane. I have TFS 235cc heads milled to 64cc and a custom cam(246/254). I put down 515rwhp with only a little bit of tuning and a shitty intake setup. Im hoping for 550 rwhp when its all said and done. Listen to 99blancoss he knows his ****
IMO there is no point in running that high of compression in a street car. Too expensive and too much of a pain to switch back and forth from pump to race gas.
IMO there is no point in running that high of compression in a street car. Too expensive and too much of a pain to switch back and forth from pump to race gas.
TECH Fanatic
Joined: Mar 2003
Posts: 1,112
Likes: 0
From: Dallas