Are there any written directions for installing valve seals floating around out there somewhere.

My horror story - I have a 72 stringray (purchased new) with the base engine - professionally rebuilt early this year, at least that was their advertisement, I installed the engine the first time (followed break in procedures) and a cam lobe failed, pulled engine and gave it to the rebuilder - he checked all and decided to put in roller cam, rockers and bored to 30. Installed engine second time - smoked at idle both sides - pulled engine gave to rebuilder, he then said that it was overfueling - cleaned clyinders, put back together and I installed once again. Strange that it was overfueling with a new carb and electric pump.
I have come to the conclusion that the engine shop and their claim to be professionals is far from the truth.

Still smoking - not like vavle seals as it down not smoke on initial startup - only after running a few miles it will smoke on both sides at idle and more if you give it some RPMs.

I checked the plugs and #s 3, 5, 2 and 8 are oil fouled. I suspect the valve seals or intake gasket is the culprit. I have checked the compression and all are running in the low 170s. Have not completed a leak down but probably should to confirm the problem. I pulled the intake and it appears that oil is going through the ports so that makes me believe it is the intake gasket.

I will replace the intake gasket with a FelPro .060 thick gasket vice the .030 that is currently on it and replace the positive stop plastic crack valve seals with viton umbrellas.

Any other suggestions would be greatly appreciated.
thanks
t2

 

Well it could be rings and your leakdown should help determine that. If the heads were machined too much it could be your intake to head gasket like you suspect. Do the ends of the intake clear the block?
You could try a very thin layer of clay between the heads and intake and see what kind of mismatch you are looking at.

As for changing out seals, you need an air compressor with an adapter to screw into the spark plug opening which will hold the valves in place and a valve spring compressor that works from the top like one that pivots on the rocker stud.

 

I agree on the intake fit. At this point it would be best to fix one thing at a time. You may find the intake is the whole problem so there is no need for changing the valve seals. But I'd think the engine would not run very well if the intake was letting oil in from under it. This is about the same as a vacuum leak.

Changing the seals on the car is not an easy job and runs the risk of a valve falling into a cylinder.

If you can, find out how the gaskets are fitting the intake and heads before you install it. Try putting cardboard inplace of gaskets and torque or snug the bolts down this will show the seal pattern.Then you can check the gasket fit on the cardboard. Of course you need cardboard as close to the gasket thickness as you can get it.

If you do find the valve seals need replaced it is much easier to do with the intake out of the way. Catch 22.

I hope you still have the same engine you started with. Did you check the serial numbers? This is a big deal on that model. Best of luck and sorry to hear another f story about engine rebuilder wantabee's .

 

Thanks - It is the original engine as I purchased the car new in 1972 - that is why I had a professional rebuild the engine vice doing it myself, I have done a few 289s/302s in the past and probably should have done this one - but thought I would have a professional do it rather than take a chance of screwing it up. So much for that thought.

Being a backyard mechanic we use to bring the piston to TDC and stuff rope in the spark plug hole to stop the valve from falling into the cylinder - I imagine that will still work but may get a compressor to hold it up. Good idea with the cardboard I will try that tomorrow and see what the fit looks like.
thanks again
t2

 

Scott, thanks for your reply
Yes - ends of the Eldenbrock Performer extend pass the block - I was thinking about putting the stock intake (cast) back on vice the Performer - I will try the clay to see what the fit looks like with both intakes and use the one that looks like the best fit.

The heads were not machined - but of course I am depending upon the rebuilder to tell me that and at this point I'm not sure I can believe anything coming from that shop.

 

Just to clarify, what I meant to ask was is there a gap between the ends of your intake and the block or does the intake rest on the block.
Also, some of those Fel Pro intake gaskets are pretty hard and do not crush nicely. The OEM composite ones are low crush and seal very well.

 

Scott
I will pull the intake off Friday - must eat Turkey tomorrow -clean it up and set it down to see what kind of gap is present. Not sure as to the type of gasket currently on the car - I do remember using RTV vice the end pieces the last time I put the intake on.
thanks
t2

 

All above are good suggestions to check.

I'll add this:
Rings and leakdown check can FOOL you. If rings were installed UPSIDE down ... they'll pump oil past them & use/burn oil ... but they'll usually check good on a comp test. I'm not counsel nor do I know what you paid or agreed to ... but seems as though machine shop may risk potential litigation.

 

CT, I am sure its your valve seals. My stock 71 SB would start smoking at stoplights when warm out one side. My dads 69' BB was also smoking when hot and going down the freeway. I replaced seals in both cars and now nether car smokes at start up, idle or WOT.


Just get you an adapter for a compression tester, use the hose to pump air into the cylinder to hold the valve up. Only need about 40-50psi and it doesn't matter what stroke its on. You may have to tap on the top of the spring compressor with a hammer to help free the retainers/keepers from the valve stem, then take your magnet and pull out the keepers. Becareful to not damage the new seal when pressing it down over the valve. The tops of the valve stems may be slightly mushroomed and they will cut the seal ever so slightly if it gets **** eyed when pressing it over the stem. It will not take but 2-3 hrs tops.


Also don't use o-ring type or umbrella seals. Use the tight fit viton seals with the spring clamp, they will fit your factory guide and and seal well.

 

Pulled the intake today - the runners/ports are dark and look oily - took a flashlight and looked down at the valves and they had oil sitting on top of them. I'm thinking the only way for oil to get to the top of the valves is through the valve seal. Although I'm kind of perplexed as to why the car didn't smoke on start-up unless it was warm i.e., sitting all night it wouldn't smoke at all on startup. Only after I had run it a few miles.
I guess it could also get through if it was leaking past the intake gasket but believe that would only occur while the engine was running and not sit on top of the valve. I will change the valve seals this weekend and put my stock intake back on vice the aluminum eldenbrock 2101. I purchased the Eldenbrock 9758 Vitron Umbrella Seals from Summit. Certainly hope this corrects the problem.
\thanks for your suggestions - any thoughts on the oil sitting on top of the valves?
t2

 

Is your vette an automatic?
If so, a leaking modulator valve on the transmission can feed transmission oil into the intake.
Pull the vacuum line to the modulator to see if any oil is present.

Barry

 

Barry - 4 speed
thanks
t2

 

Have you any suggestions on what I can use to clean up the oil off the top of the valves without pulling the head?
thanks
t2

 

I've used a shop vac with some 1/2" or 5/8" clear plastic tubing duct tapped to the vac's hose before.

 

thanks scott - what do you think about the oil sitting on top of the valves - intake or valve seals - basicially new heads with hard plastic positive stop valve seals

 

The white hard plastic seals with the viton rubber insert that I'm thinking off are called "Umbrella Seals" for use on the exhaust side only combined with the stock rubber "O" ring at the top of the valve stem like the '80-82 Vettes used. I'm familiar with the Fel Pro P/N SS72877 set which is similar to the stock GM setup and for the intakes GM used a positive seal along with the "O" ring like Fel Pro SS72527. The hard plastic umbrellas do not provide a very good seal for the intakes. The intakes should have a Positive type seal installed or the stock "O" ring along with the stock splash guards.

What did your intake gasket look like? Were there signs of good compression around the entire port perimeter?

 

Scott - not sure what you mean about around the entire port perimeter of the gasket? What should it look like?

 

Did the removed intake gaskets show signs that they were squashed around the ports to make a good seal.

With that much oil, it could be guides, seals and gaskets.

 

Gaskets did not appear to be crushed to any degree. They are pretty thin with metal in the middle. Can see a very small outline but little else. I have a set of FelPro seals but they are all rubber umbrellas - no rubber O rings - should I use those or the Eldenbrock umbrellas (vitron). The Eldenbrock ones look similiar to the hard plastic that I am taking off but they have the rubber (vitron) insert with a spring around the top. They do not fit tight at the base and appear like they would ride up the stem. Should I also put the rubber O rings on as well?
thanks for your help
t2

 

I would use either a stock GM intake manifold gasket set or one of the new high peformance sealing sets from Victor Reinz sets through Napa. For seals, if you use the Edelbrock umbrellas, I would also use the stock O rings like the original GM configuration. I would also use positive intake seals like the Fel Pro seals I listed earlier for the intakes, the kit comes with O rings as well. Make sure you know what your guides sizes are because the come in different diameters. Any Schucks, Checker/Kragen, Autozone can order those numbers or have them in stock for about $15/set.