Anyone else have problems using a motor plate and having the water pump gaskets leaking. It's a A body with a 440. I have to replace the gaskets at least once a year due to them leaking. I have flat sanded the plate, tried lock tight and lock washers on the bolts and ultra grey rtv on the gaskets. Any idea's would be great.

Use Superformance gaskets and you'll have no leaks.

Member Roadhazard is the owner of the company.

Is it a plate or two piece ears? I've had the ears leak due to flex. Made tabs at the bottom of the plate to tie it into the timing cover to reduce flex. The empty hole in the 1st pic next to the crank trigger bracket is where the tab bolts. Decided to bolt a tab rather than weld it in case the timing cover needed to come off in the car. In the 2nd pic you can see the tabs at the bottom. 3 years no leaks.
Doug

Yes it is the 2 piece ears. I never thought about it flexing.

I will check those gaskets out.

The ears will let the engine pivot on the mount
bolts.. you have to lock it solid to the engine
(and the bolts wont do it.. a solid plate is
the best bet)

Although I had a one piece front plate, I found that after awhile (months) gaskets could leak. Then I just used only RTV (no gaskets) and it never leaked again.

I only use RTV on my SB junk.. it has never leaked

That's 1 thing I never tried, I think I might try it this time. If it leaks again I think I might find a different k frame and use solid mounts or make my own mounts on the k frame that in it now.

I found that the bolts would loosen during the season due to flexing. I check them regularly. Also, be sure to have an engine limiter to prevent fore/aft movement.

Never had a leak (1 piece plate) when sealed with Hylomar. And there is no cure time.

My bolts were still tight this time but I don't have anything on it for the fore and aft movement, I thought the trans mount would be enough but maybe not.

Is that like the stuff gm use's on the front diff case half and t case half ? There's is red though.

[/quote]My bolts were still tight this time but I don't have anything on it for the fore and aft movement, I thought the trans mount would be enough but maybe not. [/quote]

When we got the car it didn't have a limiter and the trans mount was toast. After a new quality rubber mount and a S&W limiter the mount looks like new after 5 years.

i don't know about the GM stuff, but what i use is a light blue. Also use it around the water holes with SCE copper head gaskets (o-ringed block). So far, there have been no leaks there either.

When we got the car it didn't have a limiter and the trans mount was toast. After a new quality rubber mount and a S&W limiter the mount looks like new after 5 years. [/quote]

I will check the mount and look into a limiter.

2 piece ears are difficult because of the flexing as said.
With that being said I would never, never, never use a silicone sealant on any joint that was flexible and difficult to seal with a gasket. What happens when you flex the joint and break the elastic bond/adhesion between components, under pressure?

My advise to the OP is modify the ears to be one or buy a one piece plate coupled with some quality gaskets. Make life easy.

Ditch the gaskets. Use rvt, then you can really tighten the bolts (no crushed gaskets), and it won't leak again.

RTV works for me. If you have a 2 piece mount and you install them with the outside ends hanging down then when the engine is installed in the chassis it will tend to rotate the outside ends up. Depending on the clearance between the bolts and the holes it could be quite a bit. Preloading the ears in the direction the engine weight will force them later will reduce the movement.

I prefer to use studs that are threaded on both ends with a smooth shank section in the area that the engine bears on. It makes installation and alignment easier plus the smooth shank has more bearing area.

1 piece plate, used gaskets for years ,always problems with leaks and bolts loosing up,use rtv, have not had an issue in 5 years.took the advice from a moparts poster,pat