I have an '89 F250 that I just installed a crate 351W in. The timing is advanced to like 12-13btdc. I removed the EGR valve (blocked off w/ the EGR Eliminator) and the Resonator and Cat converter during install and went 3" pipe all the way back. I am just really disappointed in the power it has. I just did the 500 mile break-in oil change and I was hoping it would loosen up a little. I have no check engine light and it runs smooth, but it gets pathetic mileage so far. Now I really wish I would of put in a comp cam and some good ceramic headers during install. Is there anything else I can try? I might change out the O2 sensor, but it runs fine cold and hot other than being a dog. Also, will the computer throw codes w/o giving a light? Maybe I need a code-checker to see if it is trying to tell me something? I am kind of at a loss. It just seems like something is really holding it back? Thanks guys!

Aaron

 

huh... sounds like a lemon mill. Our stock 351w in our 91 absolutely screams... it is terrible on mileage tho. But at the same time it has 230k on it.

 

So this crate engine.. is it a stock '89 spec crate engine?

If so then yeah it's not going to be much to write home about, the cam is REALLY holding it back. The motor will continue to loosen more and more for several thousand miles so it will improve but not a hugh amount.

Codes are easy to pull, put a jumper across STI and Sig-Rtn in the EEC test harness and turn the key to run, codes will flash on the check engine light. See fordfuelinjection.com for details and pics.

 

removing your cat will hurt your milage

 

Sorry, but how's that exactly??

 

A gas , street driven truck built w a cat is designed to run w a certain amount of backpressure(restriction). Without it , fuel milage will drop along w bottom end. It has been proved time and time again.

As for an all out race engine, that is a totaly different story

 

my 89 crate engine that I installed in my f150 was a dog as well. I ended up changing gears from 3.08 to 3.73 and adding a crane 444232 cam and it's now rather quick.

 

A certain amount of back pressure yes. Like LT headers and dual 3"+ open pipes. But if he still has the stock exhaust pipes/muffs/cats/manifold then losing the Cats would gain mileage and low-end. Still barely at all though because the worst restriction is the manifolds, this has been proved over and over again. If your talking his set-up alone with 3"ers then I'll agree if they're duals.

Now, back to your regularly schedule programing.

Is it 3" duals on your set-up?? What manifolds/headers? What is the engine specs; cam/heads/intake?

Are you running a SD computer? I wonder if maybe your crate has a MAF cam <114LSA. Or even the heads/intake, the whole combination may not mix well with your stock EEC if the combo isn't close to stock.

Specs!!!???

 

Paul, it is an '89 spec crate engine. I am sure they really tame them down to cover there warranty. What is a good computer-friendly cam to throw in this thing? Don't do much pulling, just want some more pep. Wish I would of done it on the stand.............Going to take a lot of work now! I am just running stock manifolds. Probably my other mistake. Thanks!

Aaron

 

Look no further than the Crane 444232 and add a pair of shorty headers since you dropped the rest of the stock exhaust. Gas milage will be bad as the motor breaks in but just out of curiosity what does it get? I'm assuming you have a 3" single exhaust attached to the stock Y pipe sans cats, if so that's fine. You could also pull the codes and check fuel pressure just to eliminate possible contributors to heavy fuel consumption.

 

I have not checked the mileage, but I fill the tank, it costs $40 and it is gone fast! It is a C6 though. Thanks for the recommendation on the cam. What kind of shorty headers are quality?

Aaron

 

Anything made from stainless steel. The C6 won't make much difference around town but it will make it thirsty on the highway. That truck probably has 3.55 gears?