'49 8BA Valve stem seals Stock 8BA - Pretty sure I have problems here. Blowing a lot of blue smoke until warmed up. Rings appear ok. Compression check: All but #7 are @118. #7 is 110.
Any ideas for poor man's fix? I live in a mobile home park with no garage and pulling the engine is not an option. Thanks for any input advice. |
Re: '49 8BA Valve stem seals 1. Make sure all tin, the little clips that shield bottom of valley and the vertical tube ventilation stack, are in place.
2. Make sure draft tube is open all the way...there is a screen thing in there that can clog it. It is the exit for stock ventilation system. 3. Consider a PCV kit, simple and cheap on this. |
Re: '49 8BA Valve stem seals Bruce - Will do. I've considered PCV kits before. How do they work and how will that reduce oil burning? Thanks for input. George M.
|
Re: '49 8BA Valve stem seals sounds like valve guide seals or the valve guides them selfs, both can be fixes with out pulling the engine, just pull intake manifold and heads, only the intake guides get the rubber seal, or as others have done use silicone to seal the guides, if you have or can borrow the valve guide tool it can be done in a day.
|
Re: '49 8BA Valve stem seals I'm not sure whether the PCV will lower oil burning, change it to more efficient oil burning, or possibly end it!
Stock system: Car movement and/or backwash from fan over the draft tube hypothetically pull crud out, clean air in via the filler cap. Not very consistent or powerful. PCV replaces draft tube, provides more pull and consistency. It might...dump oil into system in a new place upstream and leave you chugging along in a blue cloud, it might allow the oil burning to be more thorough and clean, but I hope it will motivate oil not to climb through your guides as much! Dunno, but it is an experiment I would try if motivated not to do a real teardown and valve job! Best place for it, if your manifold is so drilled, is the plug around behind where windshield wiper fitting lives that is meant for truck vac brakes...this contains 2 small drillings into both chambers of manifold and the 3/8 or whateve pipe threads are easily adapted to a hose. Stock seals cover only outside diameter of guides...on an old engine I doubt they are the problem, as that area should now be completely sealed by fried crud! |
Re: '49 8BA Valve stem seals I think your wasting your time if you think guide seal are bad. I want anyone on the barn that reads this if thay have ever removed the intake valve guides from an old engine (whitch come out hard enough even with correct tool) and found the that guide seal broken or gone or anything. Those guides don't move once there in there and usually stuck to block pretty hard. If anything is worn it's the valve stem and the guide ID. They would have to be replaced. My money is just worn out rings or the breather pipe system is plugged up. You probably have decent compression because the oil is sealing the rings for a compression test. THis not like an overheads valve engine where if the valve seals or worn out the oil be sucked into the cyl. Walt
|
Re: '49 8BA Valve stem seals Walt - Ouch! But, Tnx. My son has been wanting the car for sometime. He's younger (and richer) than me. Good time to let him join the "fun".
|
Re: '49 8BA Valve stem seals Walt, you may be right, but, bad valve guides or seals will smoke when first started and then quit after a little bit, worn rings smoke all the time,
|
Re: '49 8BA Valve stem seals NOTHING has ever gotten past the outside of a flathead guide, but plenty has sure gone past the inside!
By the way...I believe Ron once did some experiments with turning down the lower part of the 8BA guide and adding the same sorts of seals used on modified SBC's. How did that turn out? |
Re: '49 8BA Valve stem seals Quote:
|
Re: '49 8BA Valve stem seals There is a distinct difference between valve guide seals and valve stem seals. You won't have valve stem seals.You will have guide seals and very little gets past the guide fit to the block after a few years of running.The worn stems and guide are usually the culprit along with a worn set of rings,there is no magic fix for this scenario.Worn guides respond well to good vacuum.Trouble shoot it with a serviceable vacuum gauge.
R |
Re: '49 8BA Valve stem seals Flatjack & Ronnie are right.
Flatheads don't have valve stem seals, and the oil would have to defy gravity to get up there anyway. Smoky flathead = piston rings worn or stuck. |
Re: '49 8BA Valve stem seals Bruce
The stem seals worked just fine, however installing the valve guide assembly was a bi**h. I found that knurling the guide for a tight fit (.0005/.001') worked just as well and did that to all my engines. some new guides are very loose. As for the guide its self, Walt is right. Once installed they fit very tight and the leakage would be very small if any. besides the early two piece guide didn't have a seal. I just put a thin film of RTV on the guide before I install it. |
All times are GMT -5. The time now is 08:14 PM. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.