Supercharge stock 454 mag? - Page 2

blue thunder · 10-08-2009, 08:03 PM

You already have a more static compression. I think it is 8.7:1 if a mag engine. Thats a nice bump over the 525sc which I believe was 7:1. You need a v-6 tbolt module with only 14* total advance. The v-8 have about 24 degrees which in order to make it idle right would put the all in timing too high.

I run the mechanical block mounted fuel pump but you can do what ever works for you.

Eclipse232 · 10-09-2009, 01:17 AM

Which mechanical block mounted fuel pump do you use? The one that sits on top of the sea pump? Or am i thinking of something else?

blue thunder · 10-09-2009, 12:34 PM

I used holley pumps and they bolt to the block like a traditional bbc. The sea pump is on its own.

Griff · 10-09-2009, 02:50 PM

525SC has 7.5:1 CR and runs a 22* advance module with a total advance of 35*
454Mag has 8.75:1 CR and run a 24* advance module with total advance at 32*

The module curves are not very different. You could run the stock module as long as you can get the engine to idle with only 8* of initial timing. I would not run more than 32* total with the 8.75 CR. You will also need to run 93 octane fuel.

Eclipse232 · 10-09-2009, 04:50 PM

I know this is gonna sound stupid again but is there any option to either supercharge or procharge without running 93 octane? Also without changing that much timing?

Sunshadow · 10-09-2009, 08:00 PM

Quote:

Originally Posted by Eclipse232

I know this is gonna sound stupid again but is there any option to either supercharge or procharge without running 93 octane? Also without changing that much timing?

maybe you don't really want to mess with it?

Griff · 10-10-2009, 12:18 AM

Quote:

Originally Posted by Eclipse232

I know this is gonna sound stupid again but is there any option to either supercharge or procharge without running 93 octane? Also without changing that much timing?

High performance needs high octane to make HP safely and live, especially when supercharging. You may be able to get by with 91 octane with about 4lbs of boost max.

Pay close attention to the effective compression ratio chart with regard to running 92 octane. Holley says 12:1 max for 92 octane. I would say more like 11.5:1 for a marine engine.
http://www.holley.com/data/TechServi...ech%20Info.pdf

blue thunder · 10-10-2009, 10:36 AM

One point worth mentioning on my setup is I get away with more because I have aluminum heads. More effective compression for sure. I have been at 12.7:1 for 2 yrs of hard running and now at 13.4:1. If you have iron heads follow the chart as the chart is based on iron heads.

baja_brian · 10-10-2009, 11:21 AM

Nice thread. Since we are talking about prochargers, is there many objections to a Vortec supercharger vs a procharger. They appear to have the same dynamics and concepts.

On a marine application it is almost a must to go intercooled, correct?

blue thunder · 10-10-2009, 07:02 PM

Mine are not intercooled.