Does anyone have any input on what type of valve seals to use on stock 327 heads? (casting number 3782461) Currently it blows a little oil from the exhaust, and I do not want to do a valve job at this time. Will the "umbrella" type seals work any better then the stock "O ring" type? Or will the new "Positive Teflon" type seals work the best? Did anyone ever install these "Positive" seals on this head? And if so, did they work O.K., and did you have to do any modifications to the heads?How do they stay on the heads? (What size seals will I need, 11/32 x .562?)
-
-
Re: Valve Seals? Stock/Umbrella/Positive teflon ty
The valve stem tower must be machined to use the Teflon seals , the umbrella can help to direct the oil away much better then the O-ring seal.
The old rule of thumb is bad valve seals when you let off the gas pedal (smoking) or just while accelerating (smoking) piston rings. -
Re: Valve Seals? Stock/Umbrella/Positive teflon ty
I thought bad o rings would also let oil seep in to the cylinders when the car is parked over night. I have no smoke except in the morning, and if I drive it two days in a row, none. Only if it sits awhile.
ChasmanComment
-
Re: Valve Seals? Stock/Umbrella/Positive teflon ty
Roy, some guides are factory machined. I would check to see if, infact, they have been machined. You will get quite a bit better oil control from the teflon seals.
Smoking on deceleration can be a sign of oil getting past the valve stem seals or worn or defective piston rings. Both will show up under high vacuum conditions.Dick WhittingtonComment
-
Re: Valve Seals? Stock/Umbrella/Positive teflon ty
Oil don't seep in to the cylinders from the valve seal rings while siting over night. The valve guide towers are too high .Oil piston ring could be sticking ( carbon build up ) ring expands after getting hot. Try running water down the Carb to brake up the carbon . Read past postings about that first. But if the return hole at the rear area of the head is plugged the oil can build up and flood the rear number 7 or 8 guides . Your PVC valve also could be dirty sucking oil when cold??Comment
-
Re: Umbrella type
I,ve used the perfect circle teflon seals, both with the guide cutting tool and once without cutting them,where I , removed the band spring then will slipped them over the guides then install the springs with snap ring tool,I like the felpro blue spring rubber valve seals,about $53.00 and I install them without any cutting,some machine shops only put them on the exhaust valves and O rings on the intakes valves.So a set will do two sets of heads.
....... 2 cents .......Comment
Comment