Will I need to re-ring my pistons?

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4spdcuda66

4spdcuda66

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I have a poly 318 in a '67 Fury. The engine was rebuilt about 42,000 miles ago. When I had the heads done, I told the machine shop SPECIFICALLY that I did not want knurled valve guides, I want guide inserts. A while back, I had to pull the intake because of a vacuum leak. While it was apart, I got my light into the intake ports and noticed severe carbon build up on the valves. Sometimes there is white smoke out the tailpipe. That smoke made me suspicious about whether or not the heads were done as I asked. I won't know for sure until I pull them and look for myself. The valve seals look good. My question is, if I find this to be the case and have the heads done correctly, (at a different shop) will I have to re-ring the pistons along with the head work? Would I be be okay to just clean the carbon off and lap them after I get the guides done? Thanks, FABO support group.
 
You won't have to, but if the shop didn't do the heads right, how do you know what they did to the rest?
 
RustyRatRod said:
You won't have to, but if the shop didn't do the heads right, how do you know what they did to the rest?
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Not sure what you mean. I did the assembly myself. I cleaned everything thoroughly when I got it all home. This was about fifteen years ago. Engine runs well, just smokes and has the carbon build up.
 
4spdcuda66 said:
Not sure what you mean. I did the assembly myself. I cleaned everything thoroughly when I got it all home. This was about fifteen years ago. Engine runs well, just smokes and has the carbon build up.
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Well, you said the shop did the heads. Since you didn't include the fact you did the short block.....one can only assume.
 
Thanks for the reply. I'll update at a later time. Not sure when I'll get out there and pull them.
 
4spdcuda66 said:
Thanks for the reply. I'll update at a later time. Not sure when I'll get out there and pull them.
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"If it was mine" and I already had to pull the heads, you can bet I would go through the short block again too. What kind of rings did you use?
 
RustyRatRod said:
"If it was mine" and I already had to pull the heads, you can bet I would go through the short block again too. What kind of rings did you use?
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I really don't remember. I think they were chromolly. Don't recall brand. Bearings were Clevite. I think it was all ordered as a kit, but not absolutely sure.
 
4spdcuda66 said:
I really don't remember. I think they were chromolly. Don't recall brand. Bearings were Clevite. I think it was all ordered as a kit, but not absolutely sure.
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Just so we're clear, there's no such ring. Not trying to be an ***, just letting you know. Lots of people throw that around. There are either regular cast iron unfaced rings, moly rings or chrome rings. Each ring requires a different hone finish to seat and past properly. I've had the best luck with just a good old moly ring. If you haven't torn it down yet, you can do a leak down test to determine "what" the problem is. That might save some time and money.
 
White smoke is coolant out of the tail pipe. Black smoke is unburned fuel and blue is oil burning. Has it been using coolant? Might be using just a little.
 
RustyRatRod said:
Just so we're clear, there's no such ring. Not trying to be an ***, just letting you know. Lots of people throw that around. There are either regular cast iron unfaced rings, moly rings or chrome rings. Each ring requires a different hone finish to seat and past properly. I've had the best luck with just a good old moly ring. If you haven't torn it down yet, you can do a leak down test to determine "what" the problem is. That might save some time and money.
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Yes, moly rings. I misspoke. I don't take you for an ***. You seem to know what you're talking about, and from what I've seen, you give sound advice and pull no punches.
 
4spdcuda66 said:
Yes, moly rings. I misspoke. I don't take you for an ***. You seem to know what you're talking about, and from what I've seen, you give sound advice and pull no punches.
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lol, yeah I guess that's a good description of me. My wife, Kitty says the same thing often. I don't know man. 42K miles and burning oil. I'll be damned if I don't think I would just do a fresh overhaul. Since you "know how" you got the labor licked right there. Parts are comparatively cheap, so "there's THAT". It sounds like the heads are comin off either way, so you're halfway home. Course, you da man and nobody can make that decision but you. Is this the original engine? I fit is, must be a Canadian car. They used the Poly one more year. I like those motors, personally. Cool stuff.
 
RustyRatRod said:
lol, yeah I guess that's a good description of me. My wife, Kitty says the same thing often. I don't know man. 42K miles and burning oil. I'll be damned if I don't think I would just do a fresh overhaul. Since you "know how" you got the labor licked right there. Parts are comparatively cheap, so "there's THAT". It sounds like the heads are comin off either way, so you're halfway home. Course, you da man and nobody can make that decision but you. Is this the original engine? I fit is, must be a Canadian car. They used the Poly one more year. I like those motors, personally. Cool stuff.
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Yep, engine is original to the car. I agree, heads off, halfway home. It's getting pulled and torn down. No sense in doing all that work to find problems somewhere else. Not really what I wanted to hear, but it makes the most sense. Thanks for chiming in. How's that Valiant coming along?
 
4spdcuda66 said:
Yep, engine is original to the car. I agree, heads off, halfway home. It's getting pulled and torn down. No sense in doing all that work to find problems somewhere else. Not really what I wanted to hear, but it makes the most sense. Thanks for chiming in. How's that Valiant coming along?
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It's slow. We both got sick right on top of Christmas and are both just now gettin over it. Plus I have this new job I found. I'm kinda at a standstill until the weather warms back up and I can get the headliner in and then get the front and back glass in. THEN I can start driving it some more. I do have a few things at the machine shop coming along, too.
 
RustyRatRod said:
It's slow. We both got sick right on top of Christmas and are both just now gettin over it. Plus I have this new job I found. I'm kinda at a standstill until the weather warms back up and I can get the headliner in and then get the front and back glass in. THEN I can start driving it some more. I do have a few things at the machine shop coming along, too.
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Always somethin'!
 
Do you know what valve seals were installed......umbrella.?
 
The oil rings might be stuck? But seeing carbon on the backside of intake valves makes me think a valve job might fix the problem. I'm not familiar with the poly, but could an intake gasket leak be sucking oil into the cylinder? Bad pcv valve?

A poly in a 67 fury? Canadian car?
 
pt70 said:
The oil rings might be stuck? But seeing carbon on the backside of intake valves makes me think a valve job might fix the problem. I'm not familiar with the poly, but could an intake gasket leak be sucking oil into the cylinder? Bad pcv valve?

A poly in a 67 fury? Canadian car?
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Must be. 66 was the last year for US cars, 67 was the last year for Poly's in Canadian built cars. Good engine. This one just needs some freshening up.
 
The issue is carbon on the intake valves and some white smoke. Valve seals. As to re-ringing it, I would run a compression test. If the numbers change drastically after putting a little oil in the cylinders I would probably make sure the bores were straight and round and dingle ball hone/re-ring. If no real change I would just address the original issue.
 
furrystump said:
The issue is carbon on the intake valves and some white smoke. Valve seals. As to re-ringing it, I would run a compression test. If the numbers change drastically after putting a little oil in the cylinders I would probably make sure the bores were straight and round and dingle ball hone/re-ring. If no real change I would just address the original issue.
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This is most likely the case. OP under what conditions does the white smoke come out of the exhaust pipes? If when decelerating or sitting still idling (with the engine fully warmed up), then it is the valves seals or some where in the intake. If under hard acceleration and not when idling, then most likely it is rings/pistons/bores. The seals 'looking' good' does not mean they are sealing well. And being 15 years old, they can easily already be hardening up. I had the valve seals start leaking on a 1970 Ford 302 in 1974 and at 70k miles... only 4 years from the factory.

So how much oil do you add and after how many miles? And do you have a PCV valve and what type is it? Also, do you know the piston type installed? PN or is it forged or stock or ???

Similar to the above, if the heads are still on, I'd run both a compression test and a leakdown test to get the best possible read on the ring and bore situation. The reason to do the leakdown is that if the rings are worn but are also oiling, then they can give good compression test readings without with adding oil to the cylinders. Then I'd pull a few springs, wiggle test the valves stems for excess looseness (not scientific!). If OK, then change all seals, and button back up and try again. Doing all this is not highly invasive and seals are cheap.
 
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