Modifying a stock 454/502 mpi intake
#11
Platinum Member
Platinum Member
Thread Starter
Re: Modifying a stock 454/502 mpi intake
I also bought some msd part # 2105 rail clips for the injectors so i didn't have to rob the old clips off old injectors and risk having them not fit tight( cost about 5$).I hooked fuel pump up and presurized the rails/fittings to check for leaks,everything holds and seems o/k.The motor this is going on is a 540,i'm running a procharger m-3 with 12 rib 3.85 pulley(it made 8-10 psi boost on my boat last 2 years). My cam is a hyd roller custom grind i got from RM builder/A.K.A marine kinetics w/600 lift and 233/240 degrees duration at .050,i'm now going to be using AFR 315 cmc heads,i had new pistons thermal barrier coated,skirts coated,combustion chambers,valves and exhaust runners thermal barrier coated by Swain Tech. The short block is a merlin block,HRC ultimate duty crank and their billet rods,14 qt hardin marine oil pan,it should (hopefully)stay together!What kind of power do you guys think it might make? I'm having Tyler Crockett dyno it,he is doing the efi programing on the dyno and he likes to program everything fuel safe w/11.4-11.5 air fuel ratios that can be held WFO for sustained periods,not these B.S. 12.5-13.0 ratios that make real big numbers but actually won't work in any thing other than a short burst drag application.I hope if anyone out there is working on a stock manifold i was of help,Smitty
Last edited by articfriends; 05-23-2005 at 07:27 PM.
#13
Registered
Join Date: Aug 2004
Location: Fairhaven, MD.
Posts: 261
Likes: 0
Received 0 Likes
on
0 Posts
Re: Modifying a stock 454/502 mpi intake
I just finished opening up the passage to the #7 injector on mine. It turned out to be much easier than I thought it would be. I bought a $5 lateral cutting bit at the local hardware store for my dremell tool. It worked great. Just make sure to have the bit fully inserted into the passage BEFORE you turn the switch on so you don't risk damaging the o ring sealing surface. I now have an oval passage instead of a round passage but it will flow a lot more fuel. I also had AS&M do the MPI intake manifold modifications. They look great...lets just hope I see the 20HP gain that they claim.
#14
VIP Member
Re: Modifying a stock 454/502 mpi intake
Artic--
Dustin Whipple makes a 2000 cfm throttle body assy. I have them on my Whipple setup. I just got my shortblocks back and now I am reassembling them. I was going to use the stock fuel rail but now you've got me thinking about a change.
Dustin Whipple makes a 2000 cfm throttle body assy. I have them on my Whipple setup. I just got my shortblocks back and now I am reassembling them. I was going to use the stock fuel rail but now you've got me thinking about a change.
__________________
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
#15
Platinum Member
Platinum Member
Thread Starter
Re: Modifying a stock 454/502 mpi intake
Originally Posted by Bigwavz
Artic--
Dustin Whipple makes a 2000 cfm throttle body assy. I have them on my Whipple setup. I just got my shortblocks back and now I am reassembling them. I was going to use the stock fuel rail but now you've got me thinking about a change.
Dustin Whipple makes a 2000 cfm throttle body assy. I have them on my Whipple setup. I just got my shortblocks back and now I am reassembling them. I was going to use the stock fuel rail but now you've got me thinking about a change.
#16
Registered
Re: Modifying a stock 454/502 mpi intake
I don't think anybody needs a 2000 CFM throttle body on blowthrough. The stock throttle body flows enough when the air density is higher. A 1000 CFM throttle body would flow 1600 CFM at a density ratio of 1.6. That's 120 lb/min of air, enough for ~1200 HP.
#17
VIP Member
Re: Modifying a stock 454/502 mpi intake
Yes the Whipple bolts in place of the stocker. I bought the boat with them on it and with one broken engine. I will have it running by the 12 of june if all goes well.I am going to have a buddy machine the rail center hole larger and we will ditch the stock fuel line and bore the hole in the side bigger to accept a -8 fitting and hope for the best.
__________________
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
#18
Platinum Member
Platinum Member
Thread Starter
Re: Modifying a stock 454/502 mpi intake
Originally Posted by tomcat
I predict over 900 HP! Do you have any photos of the diffuser that was in front of the throttle body? Nice job.
#20
Platinum Member
Platinum Member
Thread Starter
Re: Modifying a stock 454/502 mpi intake
Its sunday afternoon,we are STILL hacking and whittling .The newest snag is there is NO clearence for air horn on supercharger w/stainless marine hi tq 3 manifolds,not even enough room for a rubber 90 to supercharger either. Its going to be chicken wire w/hose clamps on inlet . We might still see the water today,i detuned motor from 3.850 pulley to 4.00 pulley until I have enough fuel pressure. Bought a Kenne Bell voltage booster for fuel pump but if we want to see the water this wknd its going on this next week,Smitty