[Birdguy]

When I originally built my non-Sprint OHC, I used a stone hone to profile the cylinder walls, and when I checked the compression all cylinders ran in the 150-155 range. After I had put a few hundred miles on it I noticed a light film of oil on the firewall aft of the filler tube as I had previously discussed on an earlier post. Also, the compression was down to 120 pounds or so on all cylinders, so apparently I was getting a good amount of blow-by past the rings and into the crankcase.

I SWAG'ed that the cure would be to hone the cylinders with a ball hone and a fresh set of rings. Doing so made a noticeable improvement on the profile of the wall surface. All the rings were gapped and the gaps are properly staggered.

It is now back in the car and today I started it up. Thanks to a leaking exhaust manifold gasket it was very easy to see that it is producing a very noticeable amount of smoke from burning oil.

Could this be a normal symptom of the rings needing to seat into the cylinder walls, or do I need to look for another cause?

[TheSilverBuick]

My cylinder bores are crap, and ball honed them, stuck new rings on, and they are still crap and it sucked plenty of oil through the rings and smoked terribly out the exhaust at idle. I put some solid crankcase vacuum to it and it cured both the oil consumption and the blue smoke out the tailpipe.

You may want to check how your PCV valve is functioning, but the only way I found to really pull the rings against the junk bores is with 5+inHg of vacuum in the crankcase. Not an easy solution =/

[Birdguy]

The PCV valve is practically new, and I checked it as part of the motor re-installation. I'm beginning to think I should have left well enough alone, but I never have been too good at doing that!

Since the original rebuild had so few miles on it (maybe 1,000 at most) I did reuse the head gasket having read numerous posts where others have done so with no ill effects. I'll just have to see how it behaves after some smoky miles have been put on it.

I do wish someone would make a better intake/exhaust manifold gasket than the crappy OEM style. Sure doesn't take much for that thing to leak by.

[TheSilverBuick]

I found that I need to lift up on the head/exhaust a smidge when tightening the first two bolts or so to get the exhaust to seal. Starting at the front the rear sags just enough to keep #6 from sealing. At least in my experience. I also had good success loosening up the bolts, lifting it and tightening them back down and it sealing back up.

Run the engine loaded up hard a few times (2nd or 3rd gear WOT), as well as give it some good engine braking. That helps with the rings.

[Birdguy]

Now you've done it.....you got me thinking. Perhaps one reason it has been so difficult for me to get the manifolds to seal is that I have been doing it with the exhaust pipe connected. On my next attempt I will unbolt the exhaust and see if that helps. If not, I may seriously consider taking the manifolds to a machine shop with a Bridgeport mill and have the ports decked. Thanks for the suggestions!

[TheSilverBuick]

Yeah, I failed getting it to seal EVERY TIME I've left the y-pipe connected. Even with a jack on the exhaust pipe I just can't get it to straighten up properly and have to disconnect it to get the manifold to seal.

[Jeff Hamlin]

It was suggested to me sometime ago and I will say it does help/work.
The trick to getting the Intake & Exhaust manifolds to seat better/properly is loosening the 3 bolts on the underside that mate the two manifolds together.
I didn't disconnect the exhaust pipe but loosening the 3 bolts,
this helped getting the intake and exhaust to seat independent of each other and then re-tighten to spec the 3 bottom bolts.

It worked for me. I had a consistent leak that would sound like a clarinet reed at high RPM.
It was driving me nuts as no matter how I tried to re-set/tighten the manifolds was fruitless,
until I did as above.

Give it a shot you've nothing to loose.
Be sure to soak the bolts with some PB Buster or the like before hand.

Best of luck.

[TheSilverBuick]

I've disconnected the intake from the exhaust and still had an issue with #6 not sealing up.

[Jeff Hamlin]

Well that Sux
Mine drove me nuts for almost a full summer before I got it to stop/seal.

[scooter1966]

For the sealing issue, were you using the factory steel gasket?

i have seen a different gasket from Flatoutgasket, not sure if that would help.

[TheSilverBuick]

I definitely had better luck with the composite(?) gasket than the OE steel one. I currently have an OE steel one on the car because they are only ~$12 at NAPA and I've been doing quite a bit of manifold removing and installing in the last few months =P

[Carousel-Red]

Has anyone ever tried the service manual recommendation, and did it work as a seal? "Coat face of manifolds liberally with a solution of graphite in alcohol."

[Birdguy]

Thanks for all the tips, guys. What I would up doing was this:

1) Used a conical grinding drill attachment to enlarge the holes in the stock metal gasket to eliminate any mis-alignment (which it had)
2) Used four 3/8 x 16 bolts cut approx. 3" long with heads removed and screwed into the head to used as guides for the lower bolt holes in the manifold
3) Unbolted the exhaust pipe to allow more freedom of movement
4) Loosened the three bolts holding the two manifolds together as Jeff suggested
5) Got manifold faces snugged up to gasket, ran in and snugged up the two upper bolts and followed with the four lowers (after removing the guides, of course)
6) Finished with torqueing up everything, re-tightening the three connecting bolts and bolting back the exhaust pipe.

One thing that helped a lot was the four guide bolts, as they not only helped align everything but also gave support and kept everything from being dead weight during the process.

Thanks again for the help, guys. Looks like I'll be making a car show this weekend after all!

[TheSilverBuick]

Making the show FTW!

[scooter1966]

Originally Posted by TheSilverBuick

I definitely had better luck with the composite(?) gasket than the OE steel one. I currently have an OE steel one on the car because they are only ~$12 at NAPA and I've been doing quite a bit of manifold removing and installing in the last few months =P

more questions on the gasket.

I have noticed that alot of the shared wall on the intake ports do not come out as far as the head face. The steel gasket will have a siamesed ports where as the composites have each runner individual. With these small open sections where there is no gasket material between the ports, how would that effect the overall ability for power output?

[TheSilverBuick]

My assumption is "not much". On a 200HP engine I'd be surprised if that gap is costing a horsepower or two. If the engine was making say 700HP, it might be costing 10HP? Again these are just my assumptions since the gap is pretty small.