[v8hed]

What should I use (if anything) on the mating surfaces/gasket of a new front timing cover? The mating surface on the block where the old timing cover was had traces of clear silicone sealer on it. Should I use some RTV on the new cover? I know I should use some blobs of RTV in the ends of the rubber pan seal, but what about on the main timing cover gasket?

Thanks!

[sexypizzaman]

Yes, I would definately recommend applying a thin layer on both sides of the gasket. I would use ultra black RTV as it is meant for oil resistance (eventhough I used ultra blue on my timing cover with no problems ) I would start by applying the RTV to the block surface, place your gasket on the block all lined up then bolt on the cover after you have applied some RTV to the timing cover surface. Good luck!!

[v8hed]

Originally Posted by sexypizzaman

Yes, I would definately recommend applying a thin layer on both sides of the gasket. I would use ultra black RTV as it is meant for oil resistance (eventhough I used ultra blue on my timing cover with no problems ) I would start by applying the RTV to the block surface, place your gasket on the block all lined up then bolt on the cover after you have applied some RTV to the timing cover surface. Good luck!!

Great, thanks

[oldbogie]

Originally Posted by v8hed

What should I use (if anything) on the mating surfaces/gasket of a new front timing cover? The mating surface on the block where the old timing cover was had traces of clear silicone sealer on it. Should I use some RTV on the new cover? I know I should use some blobs of RTV in the ends of the rubber pan seal, but what about on the main timing cover gasket?

Thanks!

I never use the stuff where it has a chance of getting into the oily side of the engine. I use non-hardening Permatex at the seal joints and a layer of wheel bearing grease on flat gaskets.

The Permatex is oil and fuel proof, silicone rubber is not. If Permatex happens to get into the oil it chops up into nearly microscopic particles that will flow with the oil without plugging anything and will drain with the oil change if the filter doesn't get. Given that it's approved for use on aircraft engines tells you it's harmless in the oil. Silicone rubber that gets into the oil circulates as particles, till something like a pickup screen or the filter get them. But anybody that's had an engine apart can see, lots of stuff circulates and splashes, often resulting in some level of damage. Further, Permatex will seal to an already oily surface, silicone rubber needs a very clean oil free surface to form a bond.

I apply a grease to gaskets for several reasons:

- holds them in place

- allows them to slide around as torque is pulled on the fasteners

- prevents them from sticking making removal so much simpler and cleaner.

If your covers are sheet metal they will deform a the fasteners are tightened, which is why you usually can't stop a gasket leak by pull more force on the fastener because it just furthers the deformation of the sheetmetal forcing the gasket away from the fastener and buckling the sheetmetal of the cover. Making some stiffeners from 1/8 thick steel that fits under the fastener and within the confines of the depressed edge of the cover, extending about 1/2 the distance to the next fastener hole, gets around the problem of distorting the cover.

If your cover is sheetmetal, then the lower lip is made from a separate piece spot welded to the cover. This forms a place where oil can get to the backside of the rubber gasket that seals this area, a layer of Permatex pressed into this gap will aid in closing this to engine oil which goes a long way toward reducing/eliminating leakage in the corners of this area.

Dry assemble this for a mock up, there are several sizes of gaskets used in the lipped area where the pan mates to the timing cover. You want to be sure of the fit or you'll likely develop leaks that can't be stopped without removing the engine to reseal the timing cover and pan interface.

Bogie

[T-bucket23]

If you insist on sealer only use it on the removable part not the block. If you ever need to take it apart again you will be glad you did

Chet

[swcash]

I've put many timing covers on without any leaks. Always put in a new crankshaft seal with a little non-hardening permatex around the outer surface.
I use 3m spray adhesive on the timing cover and the timing cover side of the gasket only. Set the gasket on the cover and align all of the holes. Slide the bolts through if you need to hold the gasket in place until the adhesive sets. I use nothing between the block and the gasket.
Of course you want to make sure the cover is absolutely flat and straight. Make sure the alignment dowels are installed first to insure proper placement for the front seal. Torque to recommended value. An in/lb torque wrench comes in handy if you have one.
Squido