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Apr 28, 2011 5:42 pm
Apr 28, 2011 5:42 pm
Subject: Re: Severe Oil leak
Hi Alistair,
No, never had any problems due to the wrapping,
I have seen many cast manifolds crack due to old age and lean mixtures and or retarded ignition though! It is easy to blame something like thermotec etc or antifreeze for causing manifold cracks or water leaks but we are talking about 70 year old parts now! that were not particularly well designed or developed when new! so it's about time that some of them show their age ;o)
But no, if the manifold is absolutely flat, fitted well and not over tightened or forced on to tight studs (the manifolds need to slide on loosely before tightening nuts) then you will not have any problems that can not be attributed to old age! If the mixture is correct then the manifolds should be very cool compared to any normal more modern type engine. We regularly check manifold temps while running on our rolling road and never see over 400 deg C even at full throttle with powerful engines on the rolling road!
Though you certainly will if the engine is not setup correctly. You can easily see the manifolds glow red hot if the timing is retarded or mixture to weak!
One of the bigger difficulties is to seal the manifold to the head "without" over tightening! We use black silicone sealer which is absolutely the best exhaust sealer you will ever find!
And on engines where we are expecting high outputs compared to std, we use no gaskets and use Only Silicone sealer! But again the importance of flat manifold flange faces can not be over stressed!
Best regards,
Julian
Hi Alistair,
No, never had any problems due to the wrapping,
I have seen many cast manifolds crack due to old age and lean mixtures and or retarded ignition though! It is easy to blame something like thermotec etc or antifreeze for causing manifold cracks or water leaks but we are talking about 70 year old parts now! that were not particularly well designed or developed when new! so it's about time that some of them show their age ;o)
But no, if the manifold is absolutely flat, fitted well and not over tightened or forced on to tight studs (the manifolds need to slide on loosely before tightening nuts) then you will not have any problems that can not be attributed to old age! If the mixture is correct then the manifolds should be very cool compared to any normal more modern type engine. We regularly check manifold temps while running on our rolling road and never see over 400 deg C even at full throttle with powerful engines on the rolling road!
Though you certainly will if the engine is not setup correctly. You can easily see the manifolds glow red hot if the timing is retarded or mixture to weak!
One of the bigger difficulties is to seal the manifold to the head "without" over tightening! We use black silicone sealer which is absolutely the best exhaust sealer you will ever find!
And on engines where we are expecting high outputs compared to std, we use no gaskets and use Only Silicone sealer! But again the importance of flat manifold flange faces can not be over stressed!
Best regards,
Julian