Hi. I tried posting this in the trucks and vans forum, perhaps I can get an answer here.
I need to rebuild/replace my 351W engine in my 91 F-150 4X4. I thought about rebuilding it, and putting in a new cam, porting the heads, etc., but I am not sure I can do all that and still get it through emissions testing with the stock computer. Anyone have any experience with just what can and can't be done with these engines without changing computers?
If I want to change computers, who has the best one? Can I modify the engine for more power, get a new computer, and still pass emissions ( stroker? )?
If I can't do too much with the engine, I will try to find a good quality re-manufactured long block and drop it in.
I am not an expert in EFI so don't take this as the gospel.
You can perform a certain degree of modifications to your engine with the stock computer. A cam with slightly more duration and lift may be tolerated as well as polishing (not porting) of intake/exhaust runners. Your truck has the speed density system which pretty much has a predetermined fuel/air mixture, tho it can compensate for small changes. By changing cams or porting heads you increase the airflow thru the engine and if the computer does not increase the fuel injected accordingly you have gained nothing. The best course of action if pursuing performance would be to install a mass air flow kit so the computer can compensate for increased airflow.
DannyP
89 F-150 4x4 former EFI I-6 now carbed 351W, Edelbrock heads,cam,intake,carb.
MSD 6A, ZF, Sterling 10.25 with 3.55L's.
The best course of action if pursuing performance would be to install a mass air flow kit so the computer can compensate for increased airflow.
I haven't been able to find a mass airflow kit that will work on my truck. Do you know where to get one? The one that Ford sells works with the AOD and I have the E4OD.
Sorry, don't have a source for you. There are guys on this forum that have done this conversion, you just have to get their attention. Maybe start a thread titled "Speed density to mass Air conversion"? There should be info in the archives on this subject too.
DannyP
89 F-150 4x4 former EFI I-6 now carbed 351W, Edelbrock heads,cam,intake,carb.
MSD 6A, ZF, Sterling 10.25 with 3.55L's.
I haven't been able to find a mass airflow kit that will work on my truck. Do you know where to get one? The one that Ford sells works with the AOD and I have the E4OD.
i know that ford has one for 5.8 with the E4OD tranny, but its intended for the lightning. call summit, or email them, and ask them if it would work.
