[78MayanW87]

Getting started on my 400 rebuild finally. After pulling the timing cover off, it appears that there is a fairly significant? amount of corrosion on the engine side around the water ports. My question is, is it bad enough that I need to go ahead and replace the cover? How common is this issue? Also, I noticed a groove being worn on the inside of the cover by what I am guessing is the cam bolt and eccentric. Thoughts on this as well would be appreciated. Thanks for the help!

[steve25]

Was there a gasket at all there when you pulled it a part?

You can use Devon Aluminum epoxy to fill in and level off those pits where the gasket seats.

The other pitting in the water passage s does not look to enough to have a concern over.

Pitting like that takes place from way over due antifreeze changes.
What does the cam retaining plate look like?
Is it flat on the cam side or has a groove been worn in it.

I have seen such when a motor was rebuilt and the cam plug in the rear of the motor was driven in with too small a socket and bowed it out which then left no front and rear play to the cam.

Does the rear of the cam look like it was rubbing on the cam plug?

When you pulled the pump off the timing cover was there a plate like this behind it?

[78MayanW87]

Hey Steve25 - Thanks for responding back so quickly!

Yes, there was a combination of paper gasket and RTV.

The cam retaining plate, does in fact have a groove in it. Not deep, but its there. I cannot make out any kind of wear pattern on the back of the cam and the cam plug in the back of the block appears to have been set at the proper depth with no noticeable bulge like it was driven in with too small a socket as you suggested.

There was a plate between the timing cover and the water pump.

See attached pics and let me know if there is anything else you would like to see in greater detail. Thanks again!

[Tim Corcoran]

The corrosion on the timing cover can be cleaned up real good and fill the groove/pits with JB Weld and file smooth after hard. Depending on how bad the divider plate is corroded you may want to replace it. Also there are bushings in the timing cover that need to be removed and replaced. Also there are small inserts that go between the timing cover and the engine block that locate the cover in the correct position for the crank seal. If these inserts are missing they are available and need to be in place upon re-assembly.

[Shiny]

After you clean it, if you see any corrosion pits that connect oil and coolant, I encourage you to replace the cover.

Yours doesn't look as bad as mine, but JB Weld did not hold and the resulting experience with coolant in the oil was both memorable and humiliating. Others may have had better luck but in hindsight, trying to salvage my cover was not worth it.

[sdbob]

I had experience with one that I didnt notice was corroded.Water pump on it, used ,bI put it in a daily driver 350 ,back in college. I noticed anti freeze and water in oil. I took it home to Latrobe to fix it. Changed oil once on way home to try s save bearings. Time I got it home then found problem bearings were pitted. My 2cts.

[Tim Corcoran]

If needed

https://butlerperformance.com/i-2445...timing%2Bcover

[Tim Corcoran]

Don't forget to change these

https://butlerperformance.com/i-2445...timing%2Bcover

[78MayanW87]

Originally Posted by Shiny

After you clean it, if you see any corrosion pits that connect oil and coolant, I encourage you to replace the cover.

Yours doesn't look as bad as mine, but JB Weld did not hold and the resulting experience with coolant in the oil was both memorable and humiliating. Others may have had better luck but in hindsight, trying to salvage my cover was not worth it.

Yeah...I don't think that mine is in horrible shape, but I am wondering what the drawback would be of just skipping the Devcon/JB Weld steps and replacing it with a repop from Ames. I am assuming that their replacement is a good one.

[78MayanW87]

Originally Posted by Tim Corcoran

If needed

https://butlerperformance.com/i-2445...timing%2Bcover

Any difference between the Ames product and Butler's? Any votes for one over the other?

[78MayanW87]

Originally Posted by Tim Corcoran

Don't forget to change these

https://butlerperformance.com/i-2445...timing%2Bcover

Got it! Thanks Tim!

[PunchT37]

Maybe a new one with the timing numbers on it?

[indymanjoe]

i got mine from ames years ago and was real happy with it. cant go wrong between Ames and Butler.

[PunchT37]

Don’t forget these if yours are damaged or missing.

https://butlerperformance.com/i-2445...tegory:1408043

[78MayanW87]

Originally Posted by PunchT37

Don’t forget these if yours are damaged or missing.

https://butlerperformance.com/i-2445...tegory:1408043

Yes sir! Not missing but pretty beat up and out of round.

[b-man]

I would replace that cover with a new one along with all the associated parts.

That’s the one design flaw in a Pontiac engine. The fact that water can enter the crankcase if the timing cover gasket fails or the cover itself corrodes.