engine question

i have a 85 bronco with a 351 ho in it. more people see these threads and a lot of yall deal with 351's is why im asking in here. I noticed that i had gas in my oil, it was real thin and smelled like gas. So i changed my fuel pump (mechanical) and after i ran it a little while (all this time its blowing white smoke out the tailpipe also) i had gas in my oil again, and im wondering how else this can happen. is it possible my heads are cracked? thx!!!

p.s. its also leaking oil from somewhere, i havent hunted too much yet because im trying to fix the whole gas thing. would it be easier to just swap in a 302.

If you have gas in your oil then it could be numerous things. Cracked head or heads, blown head gaskets, hung valves, leaking intake gasket, ect ect ect. More than likely the heads are bad. You could swap in a 302 but then there is alot of computer stuff to swap as well. I dont know id a 5.8 computer will properly run a 5.0 or not. Being a '85 model I'm gonna assume its a speed density system. I know where a '89 5.8 is depending on how close you are and if you are interested. Its out of a 1989 F-150 with a C-6 behind it. But its got about 183k miles on it. Its my friend's dad's motor and tranny that he is selling. Let me know if you are interested.

pistons rings. i'd bet my title. i've taken motors apart (a dodge included :biggrin: ) that had some piston rings literally fall out of the ringlands when i removed the pistons... they were literally broken in half. sounds like your'e in for an expensive rebuild. or you could find an approx. 80,000 mile motor for pretty cheap and just drop that in there. lots of guys do that when they get a stang with a worn out motor.

the last motor i took apart was the 351w i'm building or my stang (jsut got my rods and a nice belt drive :iceslolan ). the motor wouldn't turn more than about 40* in either direction when i first got it. when i pulled the passenger side head, it all became clear. the whole #1 cylinder was rusted up to where the piston sat for all those years (bout 5 i think). i actually managed to break it free by coating the cyl walls in brake parts cleaner overnight and twisting the flywheel sharply a few times. good thing i did, or that piston would never have come out of the bore. i still have taht piston, and the rings were rusted into the lands and i had to break them free... i'm just keeping them for memorabilia of course.

so yeah, pointless stories from me. good luck with your motor.

[QUOTE=351wStang]a 5.8 computer will properly run a 5.0 or not. Being a '85 model I'm gonna assume its a speed density system. [QUOTE]


it should be carb'd...

sorry, it has a 4 barrel holly. 351wstang, thx, but my uncle has a 302 he said i could have if i just do the swap, plus i dont wanna have to fool with running a computer. So basically i would be better off swapping the 302 in then try and rebuild or find the prob with the 351? it has 97k miles on it.

I'd say drop in the 302 but remember, the intake manifolds are different so use the 302 piece. Your exhaust manifolds (or headers if so equipped) will sit lower in the frame due to the decreased engine deck height, but that shouldn't be an issue in a truck.

Sounds like a good excuse to build a very well warmed over 351!

Oh, yeah, the 302 will also have a different firing order from your 351 unless the 302 is an HO from a fuel injected car...

so will i have to change brain boxes and/or distributors? yeah for real, i have never rebuilt an engine, so this is a good excuse. i screw up, what the hell, its messed up already anyways.

You won't have to change distributors, and I doubt brain boxes. Just make sure the plug wires are in the right order.

Gotta learn sometime, right? and this way you'll be able to drive it while you learn on the 351.

oh ok, thx.

Good luck, and don't worry about screwing up. Just have the machine work done at a good shop, and double, even triple check absolutely everything. I would personally also enlist the help of someone who's done a few engine rebuilds, also. Usually they show up at the cost of a six pack or two. An experienced guy will show you a few pointers that will save lots of time, and you'll probably want his help when it comest to installing the cam and timing it, stuff like that.

sweet, yea i have an uncle that fits that description :) thx for your help!