1987 F250 460 performance rebuild, dumping the computer?
I'm pretty new to Fords, so please don't laugh at my question!
I recently purchased a 1987 Ford F250 2WD w/ a 460 in it as a tow vehicle for my (overlarge) boat. It is/ has the last year of the carburated 460 in it.
There is so much smog crap in there, it's not funny at all (dual air pump AIR system & EGR) from what I have seen so far poking around under the hood.
It has no CC, I believe it was exempt from that due to its GVWR.
The torque & HP rating for this sized motor is ridiculous, considering the gas mileage. I need some pulling power.
So I am going to do a mild performance rebuild on the motor to boost torque & HP.
I'm sure the computer/ smog system will not work w/ the de-smogged (legal in my state w/ farm plates) performance engine I'm going to build.
What all does the computer in this 1987 model year carburated F250 w/ 460 4bbl. control; & what will I need to do to go back to a conventional electronic ignition system sans the B.S. 1987 computer?
In other words, does it do anything other than flash the idiot lights on the dash when it's not happy?
If you want some power out of it, throw in an "RV" cam, better intake, and some headers (preferably long tubes), and maybe a different carb. That's all fairly simple stuff without major work.
Slapping on headers, an intake, and throwing a cam in it will give you considerable gain without even pulling the engine from the truck.
You can get rid of all of the AIR and computer stuff. Go with a Duraspark 2 distributor and ICM.
I'm getting my 1973 460 rebuilt right now, but it's been running happily in my 1988 F-350 for 15 years on a Duraspark 2 setup.
As I said, long tubes would probably be the best option for exhaust and just run true duals from there. If you don't want to go that route, shorty headers and a better y-pipe would flow better than your stock manifolds and y-pipe.
Many people are happy with aftermarket Edelbrock Performer, Performer RPM, and Weiand intakes. I've been using a Weiand Stealth intake on mine for a while, and I've liked it a lot. It's a high-rise intake, and I've also used a 1" spacer on top of it. It seemed that the Stealth intake helped me on torque and fuel mileage
Just about anything labeled as a "Towing" or "RV" cam will help you out with torque. I can tell you from experience that one of these can really wake an engine up.
I believe your stock carb is 650 CFM. You can keep it if you want. Some people would say that you NEED a 750 CFM carb. A 750 cfm carb would work fine, but you don't absolutely need it. I've chosen to run an Edelbrock 1406 600 CFM carb on my 460 and have been VERY happy with it. With the 600 CFM I've got plenty of low end torque, plenty of power to roar past people on the highway, and can get 12 MPG unloaded @60 MPH with a C6 trans (no overdrive), 4.56 gears, and 37s.
That is the beauty of the 87 460--no computer on it! All the smog pumps do is blow air into the exhaust ports to promote burning of the excess hydrocarbons in the exhaust. When you change the cam, make sure you get a good aftermarket timing chain set that will bring the cam centerline up to spec. The factory timing chain sprocket on the crank retarded the cam by approximately 7 degrees. Getting that back to zero with a performance cam will get you alot more power--along with the intake, carb, and headers already suggested.
Yes, I'm familiar w/ the retard timing set...I'm going to replace it w/ the Cloyes 3 position double roller model.
Edelbrock sells a performer package for the 460 w/ a 750 cfm carb, intake manifold, cam & lifters. The cam profile looks to be pretty mild increase on duration & lift over stock (this is a tow vehicle); but I have seen posts here stating that the ports on their 460 performer manifolds are not really up to par as far as configuration goes w/ matching the ports on the heads.
Anybody know about this being true, or is this just internet gossip?
Competition cams has what looks to be a pretty appropriate grind for my app., I was thinking about going w/ one of their cams, performer carb. & finding a nice low end torque intake manifold that will match them up...
Perhaps an Edelbrock 650 CFM carb would be more appropriate than a 750 CFM...
I was going to run the stock exhaust manifolds w/ dual exhaust as I was told that for my app. I would get decent enough flow w/ them. I was also told that there is an issue w/ restriction at the exhaust ports on the stock heads, & that just cleaning those up would really improve flow.
Wow. The Duraspark II stuff is cheap. Rock Auto has a new distributor for around $55 & the ICM for around $40. I notice that there were 2 versions of the Duraspark II, the 2nd one being one that adjusts spark timing for altitude compensation...Do you know how this model (altitude comp.) is designated? & does that model actually work like it's supposed to? Or should I stick w/ the standard one?
The reason I ask is that I live at 4200' in MT, & often travel between sea level & 6000' towing my boat....
Remember, this is my first Ford, so if any of my questions sound kind of uninformed, this is why...
Before you do anything, assume that the engine is good and try for high performance on a 26 Yo engine? I strongly recommend a compression check, first of all. Next, get a free flowing good high quality exhaust system, then headers, good headers, replace the retarded timing set, and I would look hard at a cam in the 256-262 advertised range. Edelbrock might work well. Remember that the 460 exhaust port is limiting, however it will support 325+ hp without much trouble, so the gains from a mild cam and bolt on upgrades probably will not see benefit from head porting or pocket porting. Now, I am not sure how much lift the stock heads will allow with standard springs, so keep in mind this when selecting a cam.
Another thing to consider, is with cam out, lifters, pushrods, intake, rockers off, exhaust unhooked, coolant drained, it is minimal to remove the bolts and take the heads off and have them freshened up. If this is considered, those should be D3 heads, and a cut of 0.020" should yield about 9:1 compression, and fresh springs and guides for the new cam.
My final recommendation is for the intake, go edelbrock performer RPM, as the performer is nothing more than a stock cast from aluminum, the RPM actually flows more, or go weiand stealth. and carburetor, I prefer holley, but for towing, edelbrock should work very well too, and your truck should be an animal on 85 octane up to 4000 rpm and a ton of torque.