Bronco Forum - Full Size Ford Bronco Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
274 Posts
Discussion Starter · #1 ·
Ok, background story on 1988 5.0L:

Odometer shows 90K...interior has very little wear...but lots of parts replaced to be that low of mileage like starter, alt, water pump, suspension stuff, etc. Had a burnt #8 exhaust valve so I took heads in to be checked out and found out one was cracked and the other was warped. Bought a replacement head and now have a rebuilt set ready to go back on. But...I was talking to the engine guy and it was his opinion that my truck has been overheated pretty bad at one point based on the damage to the heads. He strongly recommended new main/rod bearings. Sounded good to me because I was already planning on resealing the oil pan, putting in a new oil pump, and the timing cover is off as well. Pulled the engine out last night.

Crank is hopefully ok so the plan is new main, rod, and cam bearings. I have a cam bearing install tool so that part will be pretty easy.

Tried to pull the lifters out of their bores...they are all mushroomed enough that they won't come out the top. I'm planning on pulling the cam, pushing the lifters into the block/oil pan, and replacing them. If they are mushroomed that far I might as well I guess. I already have a bottle of the special cam lube you need now.

Here's my main question: How common is it to rering a block and not have the rings seat? I've been told several times to rering with cast rings because they seat better...and I already have a ball hone that is the recommended grit for cast rings. I just don't want to hone the cylinders, put in the new rings, and end up with less seal and compression than I had with the original rings. The combustion chambers weren't really carboned up so I don't think this truck was an oil burner before I tore into it. So...should I leave the old pistons and rings in place with new bearings/cam/lifters/etc. or would it be stupid to not hone and install rings?

Please let me know if you have any other thoughts about my plan. I've never tried to rering an engine before...they were all worn badly enough that it wasn't possible or we just stuck in rebuilt engines. I can't afford a rebuild right now...I'm currently eBaying stuff to pay for the remaining stuff as it is.... :cry

Thanks,

Derek
 

·
Satyr of the Midwest
Joined
·
17,738 Posts
You should probably get another camshaft to go with new lifters. At least that's what I always advise people sticking with hydraulic flat lifters to do. You have another timing set too, right?


I mentioned this in another thread somewhere recently, but Plastigage the rod and main bearings. Use the standard size bearings, and see what your clearances are.

Use a bore micrometer and dimension the bores, then go from there. The Haynes manual should show how to do it. There is an upper service limit to using standard size pistons & rings (4.005 inch, IIRC), and you also have to beware of cylinder taper. If you're already there, or it'd take that much honing to get the cylinders to the final finish, you're going to have to have the bores cut, i.e. the motor's gonna have to come out. That'd mean new pistons, too.

I can identify with you wanting to rering, but I also have a good friend from my Mustang racing days that tried to do the same thing with his 5.0L. Each and every time we'd go to the track after his rebuild, he'd get to about the 1000-foot mark, and his car would start blowing blue smoke like crazy. I'm not fully convinced he broke it in correctly, but I'm also not convinced he checked the ring end gap right, either. My point is, don't just hope for the best. Check EVERYTHING, and dimension properly. If you just slap it together, we'll be having this conversation within a month from now again.
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #3 ·
You should probably get another camshaft to go with new lifters. At least that's what I always advise people sticking with hydraulic flat lifters to do. You have another timing set too, right?.
I meant to say cam & lifters...planning on doing both as a set. The PO put a new double roller timing set on it not long ago and it is still in good shape.

I mentioned this in another thread somewhere recently, but Plastigage the rod and main bearings. Use the standard size bearings, and see what your clearances are.
Already planning on that too. Although, if they weren't loose enough to be heard before I tore it apart they should be good after new bearings are in. Might be a little looser than recommended but...

Use a bore micrometer and dimension the bores, then go from there. The Haynes manual should show how to do it. There is an upper service limit to using standard size pistons & rings (4.005 inch, IIRC), and you also have to beware of cylinder taper. If you're already there, or it'd take that much honing to get the cylinders to the final finish, you're going to have to have the bores cut, i.e. the motor's gonna have to come out. That'd mean new pistons, too.
Just a little background on me...I've had machining classes, bored engines, etc. Just wasn't sure what the wear limit is...(the 5 thou you mention). Always worked in shops where money wasn't much of an issue and stuff just automatically got full rebuilds. Sad to say but boring and pistons are out of my price range right now. If it is worn beyond that & new rings might not seal I'll probably just leave the old pistons and rings in place and put in new bearings. Hate doing that though.

I can identify with you wanting to rering, but I also have a good friend from my Mustang racing days that tried to do the same thing with his 5.0L. Each and every time we'd go to the track after his rebuild, he'd get to about the 1000-foot mark, and his car would start blowing blue smoke like crazy. I'm not fully convinced he broke it in correctly, but I'm also not convinced he checked the ring end gap right, either. My point is, don't just hope for the best. Check EVERYTHING, and dimension properly. If you just slap it together, we'll be having this conversation within a month from now again.
Blowing smoke like that is EXACTLY what I'm worried about. I really need to find a few hundred $$$ laying around somewhere....

Thanks!
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top