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I saw somewhere a while back and i've serached an have not found it. Of someone who took EFI heads and got a valve job and put much larger valves in them. I was wondering if any of yall knew where that was. And any tips or sugguestions.
I have a 96 EFI 460 that i'm using and i got an extra 87 EFI 460 to get some parts off of so the truck won't be down for as long.
I'm using EFI heads with 2.25 x 1.76 valves, nicely ported by Scott Johnston (he frequents this site as "the mad porter"). He's very knowledgeable and could give you some good tips I am sure.
It's true that you may need to tweak the computer if you do too many mods. But if you have the money to do it, don't be afraid to experiment with your EFI motor.
Scott
'87 F250 HD, 521 EFI, ZF 5-speed, 6" lift, Dana 60 front axle
I just want some more power like 250-300 range. Instead of the 190 they come with. I don't want to go completely radical. I figured Longtube headers, work the heads and see how that goes. Then put a RV cam in it.
Is an RV cam worth while? OR should i just keep stock?
I'd be careful with any mods to that year engine. The speed density EFI won't take a lot of engine tweaks before the computer gets confused.
That's what "tweecer" is for. You buy the software and the fancy cable, attach it to your ECM using a "Craig Moates" adaptor giving you more memory, then load the lightening BIN into your existing ECM, and have at it, "tweecing" every parameter you want to.
Speed density can be "convinced" to run well with lumpy cams as well as forced induction applications.
The key factor with speed density, if not changing the computer at all, is to avoid overlap with the camshaft. The thumpa-thumpa-thumpa gives the MAP sensor "odd readings" at idle and lower RPMs and you'll find that it will pitch fits, hence the need to tweak.
But other than that, you can scale other things. Increase your airflow into the engine by 20% through porting, valvework, better exhaust flow, you can increase the injector size 20% to compensate and the EEC-IV won't know the difference, so you don't need to tweak the computer in this specific case. Already done this