prochargers burning up pistons

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09-06-2006 | 12:44 AM

#11

articfriends

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Joined: Jun 2004

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From: frankenmuth michigan

Re: prochargers burning up pistons

Quote:

Originally Posted by smokin hot

It's a 502 mag efi 30 over with je flat top forged pistons, the intake runners have been cut down,heads have bowl blending with 2.250 intake valves and stock size iconel exhaust valves. I'm running full comp hyd. roller setup with aeromotive fuel pump and 100 micron filter at 40 psi, and 5 lbs. of boost. I also have a enlarged throttle body and am running keith eickert headders.Any input is appreciated and am wondering what size injectors I should be running.

Are you boost referencing your fuel pressure? Your set-up sunds very similar to my 502 set-up I had before going bigger. Assuming you have the newer 98-2000 style stock merc micro injectors that are rated at 43 lbs per hour they will only support 458 hp at 43.5 psi at a BSFC of .6. You will either need more fuel pressure under boost than the 40psi your running or bigger injectors,other wise you will have lots of pistons to give away as ashtrays every christmas. Here is a website that you can plug your injector size in and see what I mean,you need to change the bsfc to .6 or so when running your numbers thru to get a accurate idea for a blower motor though,Smitty
http://www.injector.com/injectorselection.php
http://www.csgnetwork.com/fiflowcalc.html

Last edited by articfriends; 09-06-2006 at 12:53 AM.

09-06-2006 | 12:51 AM

#12

articfriends

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Joined: Jun 2004

Posts: 7,317

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From: frankenmuth michigan

Re: prochargers burning up pistons

Who enlarged your 502 mpi throttle body,I been trying to find a source for this for 6 years? When I say boost referencing I mean if your fuel pressure is at 40 while cruising it needs to go up to 55 to 70psi while under boost. You absolutely need to have a accurate fuel pressure gauge on your helm to moniter this other wise you will not be able to keep a motor running rich or lean enough. As mentioned also the only real way to be sure your Air fuel ratio is correct is to have motor dynoed using your complete set-up then have computer adjusted/re-mapped perfectly. You can possibly bandaid it and just run it in the boat but you have to err on the rich side with your fuel system and fuel map,Smitty

09-06-2006 | 06:30 AM

#13

twisted mentality

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From: metairie,louisiana

Re: prochargers burning up pistons

Thanks for the input, it is much appreciated. Smitty the original owner had it done so I'm not quite sure where he got it.I think it may have been Arizona speed and marine.

09-06-2006 | 10:47 AM

#14

RBeyer

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Joined: Nov 2003

Posts: 825

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From: Antioch, IL

Re: prochargers burning up pistons

I agree with Smitty. New injectors, watch fuel pressure my initial fuel pressure is set to 34 a Pro-Charger recomendation your Aeromotive should increase into the 70's at full boost.
If you don't have a dyno source I had good luck with Arizona Speed and Marine. Talk with a tech not a sales person they will require all of your motor information they have built enough motors to remap the ECM correctly. Mine works perfect and has not been dynoed approx 200 hours.
Good luck.