I just got hold of a '87 f250 with a 460 in it. c6 trans, 4wd(dana 60 front, 70 rear), 3.73's, 35" bfgs, dual tanks.

Heres the specs that I know of on the motor. I'm hoping the cam has some #'s etched into it so I can take a look and see what I'm working with.

20,000 +/- mi.
edelbrock performer rpm heads
big lunati cam(not sure on duration/lift, but it sounds huge)
harland sharp rockers
solid lifters
weiand intake(pretty tall, not sure which model)
Edelbrock 750 carb
msd blaster coil
heddman headers into true duals(no cats, flowmaster 40's)



Here is the issue...

At cold start, I get about 50 or so psi oil pressure, it gradually comes down to around 20 once it warms up, increases with throttle but only to a certain amount, if i give it more than about a 1/4 throttle it wont increase,

Hot idle after riding down the street and back I get about 10+/- psi oil pressure. Seems like it fluctuates a tad real quick maybe a few psi back and forth.


Sitting still under no load it revs up somewhat decent with ok response, sounds pretty gnarly, it has some ticking/valve noise i think but no knock or anything. Coming back down from some revs it bogs down a little bit. Nothing crazy.

Now, accelerating down the road it just falls flat on its face. My stock '98 ram 1500 (tired 318) would leave it in the dust. Sounds like a underpowered moped trying to do a burnout, just awful. It does have 3.73's and 35 inch tires but it seems as if it should still have at least a little power. It stalls when I come to a slow or stop, I have to keep revving it a bit to get it to make it in my driveway(tight turn).

I checked compression, all 8 cylinders are right around 140 psi after engine was warmed up. All the spark plugs are a light brown, tan color.

The truck was sitting for about 2 years before I got it, other than that I don't really know much else. I'm just looking for some advice/ideas of what to check out/replace from some people familiar with these motors, I have no experience with 460's, I've done some work on 400m's and late model ls series motors but thats it.


Any ideas guys? I'd really like to get this thing running right so I can get it on the road and see what this motor really has lol. I was thinking maybe it jumped timing, or the valvetrain is out of whack with a small side of fueling issues but I really don't wanna say I'm certain on any one thing.

 

On the cam you describe you should have more than 140psi on compression. On big cams you need at least 10 to 1 compression and thats usually around 165 psi comp or better. Definetly look at timing for sure but I think you have a over cammed engine, or under compression engine. I run solids in my 460 but my compression is way up like 10 to 1 for pumpgas engine. Drop a Pm if anymore compression. Need to make sure firing on all cylinders also? Also your oil psi is getting scary!! Need to check gage and verify its actually 10 psi? IF its acutally 10 psi you need to drop pan and look for other problem. Make sure nothing is restricting oil pickup. Sometimes with big block you need to run engine oil restrictor kits to cam for a solid cam. Its a orfice at main bearing up to cam and helps keep oil on main bearings. Also you just may need to install new main bearings or worn cam bearings? Need to inspect and verify. good luck and hope the best. Sounds like you got a good engine but need to be completed properly and work oil pressure situation.

 

Alright thanks for the info, I found an issue that might be contributing to the oil pressure issues and/or valve train noise.


Drained the oil and antifreeze came out first, a good bit. I'm picking up some headgaskets and intake gaskets tomorrow hopefully the headgasket(s) are the source. I find it odd that my compression is consistently within 140 on all cylinders though if a headgasket is failing...

The vacuum advance was unhooked as well.

 

Just a thought, since it sat for a long time is the advance mechanism free in the dizzy ?

 

Also, as the Odometer on those trucks didn't reach any higher than 99,999 miles, the truck could have 20,000 or 120,000 or 220,000 (i would place my money on the last option).

 

Well I found the source of the coolant leak, the intake manifold gasket was leaking from the water jacket area. Put in a new valley pan and gasket, haven't fired it back up yet but hopefully clean oil and proper manifold pressure/vacuum will help a good bit.


The truck has 160000 on the body, 20000 on the motor, just to clarify.