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hey

i have 2000 miles on my sbc 350 and i have had a oil leak on the rear side since new and today we just replace the 4 piece oil pan gasket to a one piece gasket and replaced the small leaking crank shaft seal filled it back up with oil left drove 20 miles to the house and its was half qt. low the leak it had before i never had to add oil... valve covers a good no leaks anf the distibutor seal is good so all new gaskets today and its leaking around the rear still so anyone have any suggestions please let me know...
 

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The rear cam plug may be pushed in too far...The camshaft may have rubbed a hole in it.

I had this happen once. About the same amount of miles. I had a gear drive that pushed back on the cam and it literally wore a hole in the cam plug in the back of the block. I thought it was the rear main seal. NOPE. Only way to fix right is too pull the engine and remove the cam, pop out the plug and install a new one and make sure the cam cannot hit it. Mine was hammered in a bit too deep to start with.

Otherwise, the one piece pan gasket isnt gods gift to small Chevy's...You still usually need a dab of silicone in the corners by the caps and a thin layer of rtv just smeared in between the rear cap and the block, (Just a tiny smear) Also make sure your rear main seal is not even with the cap & block, It needs to have the ends offset a little bit. You understand? cap & block mate at 3 & 9 o'clock postion in the circle. The seal should be at like 4 & 10 o'clock to prevent a leak.


O, I also threw away the gear drive (Pete-Jackson) and put in a good double roller chain. Worked much better and didnt try to push the cam out the back of the block.
 

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when you put the new seal in did you put some sealant on it??? I use super weatherstripping and gasket adhesive from 3M and I have never had a leak from any gasket. You need to put some around the seal before you put it in and make sure it is dry.
 

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I sell automotive chemicals and the use of 3M weatherstrip adhesive has become a old "Tacky" way of doing things.

The one piece Fel-Pro gasket doesnt require any adhesives to work right. The use of more additional silicone in the corners is only insurance against a block or oil pan that has defects.
That particular one piece gasket has crush washers to prevent overtightening of the gasket so there is no worry there. So hopefully its been tightened correctly.

The use of silicone or 3M weatherstrip adhesive on core plugs and oil galley plugs is not recomended at all.

Use a high viscosity green threadlocker on the core plugs and for press in Galley plugs. For screw in Galley plugs Hylomar sealant is perfect.

The use of silicone with a gasket is usually a big NO-NO you typically use one or the other but not both. Reason being, Is the gasket relies on friction and clamping power to make it work right. Once silicone is applied the clamping pressure is no longer even and the gasket no longer has the correct friction. So as the gasket is tightened up it will tend to want to squirt out of position and either rip or cover & uncover critical surfaces. Usually using silicone with a gasket will cause leaks more than prevent them.
Using silicone alone is a great way to make a gasket especially in areas like intake manifold end-rails with sometimes wide gaps that need filled.

Gaskets alone also seal very well. Most of the time a paper style gasket will seep & weep after years of service and thats where people thought that applying other stuff to the gasket will fix it. But really the gasketing technology is much better today and seeping & weeping after years of service is rare.

I spoke with a customer yesterday who had issues using silicone on screw in galley plugs. I let him know that is not a good product to use. Reason being is that the silicone requires humidity to cure in open air. when you smear it threads and screw it in a hole the humidity and the air isnt present. So it will take possibly years for the silicone to fully cure. The use of threadlockers or Hylomar are better because the hylomar never hardens and is totally impervious to fuel & oil and the threadlockers cure when they are sealed off from the air causing it to harden.

I know its common practice to use PTFE thread sealants like white pipe dope. But its not the right thing to use on a engine. Oils and fuel break it down over time and it sticks out like a sore thumb. PTFE sealants are fine for use around water & plumbing. But for oil & fuel I do not advise its use.
 
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