I can't answer why Opel changed their design but I can tell you in times past I purchased a new oil pump cover with the relief valve built into it. Included with it was a stiff spring to make the original bypass inoperative. You can install the old style pump cover without the bypass onto a newer timing cover but you'll need to replace the stronger spring with a weaker one. A non-mechanically inclined buddy of mine broke his oil pump cover by 'trying' to install it backwards. Without consulting with me, he installed a 'flat' cover. :banghead: We had some hellacious oil pressure, probably 60 or 70 psi at idle.

Harold

 

You missed one of the styles

There's one built with nubs for a 12 bolt head (to be drilled later?) but the two bolt holes aren't drilled.

 

I figured there were more out there. That is why I put my questions out there so we can consolidate our data.

 

There are also the newer types of covers. 2.0, 2.2, 2.4. Most differences don't affect us (like the crank trigger holder for the 2.4 covers), but the one thing to consider if you pick a late model cover to fit an older engine is this: The later covers have a deeper housing for the oil pump gears. They use anaerobic sealer for the pump cover itself, no gasket! If you put a gasket on a later cover, the oil pump gear end clearance will increase by about .004"-.005" and the engine will have crappy oil pressure at idle.:yup:

 

OK, My goal is to use an early type timing cover on a high compression engine with a Delta Head. All of these parts are stock. If I use the flat oil pump cover or one with the relief valve(+ stronger spring in other by-pass valve), I will still need the paper gasket. Correct?

What type of sealant, if any, should I use on this mating surface? Could I use an anaerobic sealer instead of a gasket or will this cause interference with the oil pump due to clearance issues?

 

If I use the flat oil pump cover or one with the relief valve(+ stronger spring in other by-pass valve), I will still need the paper gasket. Correct?

Yes.

What type of sealant, if any, should I use on this mating surface? Could I use an anaerobic sealer instead of a gasket or will this cause interference with the oil pump due to clearance issues?

Typically installed dry, but I use copper spray sealer to be honest. Gotta use the gasket on a 1.9 cover or the pump will bind. I've seen people forget this and shear the distributor shaft!

This is one of those clearances that needs to be checked, per the FSM. I have a selection of pump gaskets since they vary in thickness, and you can compensate for tolerance stack issues...worn cover, gears of different sizes, etc. So I check the end play of the gears and choose a gasket accordingly.

If I need more gasket thickness I use the spray copper sealer built up in multiple coats, letting it fully dry between coats, then rechecking the gasket thickness. IIRC, most gaskets fall within the .004" - .007" range.

http://www.permatex.com/products/au...asket_sealants/auto_Permatex_Copper_Spray-A-Gasket_Hi-Temp_Adhesive_Sealant.htm

 

...and remember that the "12 bolt" style chain cases, at least the ones with the holes drilled and tapped, sit flush with the top of the block, so that if you get the block deck milled, you MUST also mill the top of the chain case or else it will sit taller.

Conversely, the older chain cases sit a bit below the block deck; you probably should also get them milled the same amount that is removed from the block. For this style of case, you MUST use the head gasket with the cork or thick paper at the front that seals the chain case to the bottom of the head.

HTH

 

..., sit flush with the top of the block, so that if you get the block deck milled, you MUST also mill the top of the chain case or else it will sit taller.

Nothing like finding this out and only having time to file it down for clearance. :banghead: No leaks! :veryhappy I will admit to being paranoid about it for awhile though.

Harold

P.S. I would not bet on being able to do it twice successfully though.

 

Thanks guys, this is all good information. I may need to go to Garage Mahal for some measurements on the pump cover. Maybe during OctOpel fest

 

Jeff,

I use this.

Yamalube


Duane

 

Here is a question

with these cars having been worked on and parts swapped for 40 years. how can you determine the heavy spring from a weak one. ie verify if using the relief valve in pump cap you have a heavy spring in the timing cover.

 

Here is a question

how can you determine the heavy spring from a weak one. ie verify if using the relief valve in pump cap you have a heavy spring in the timing cover.

Look for a white stripe on the spring or compare it to the many others I'm sure you have.

Harold

 

I would take the HD spring out of a damaged timing case which had the relief valve on the oil pump and put it in the old style timing cover if I was going to replace the oil pump cover with the relief valve style. I would also compare the springs to each other or just order a new one from OGTS.

 

OK, slightly off topic, but I scraped and brushed 40 yrs of sludge off the exterior and interior of the timing cover. It is currently at my mechanics shop for a final rinse in his parts washer A lot of the original black paint has come off of the aluminum.

Should I repaint it with engine paint or leave the aluminum exposed. I like the look of the aluminum, but I don't want it to oxidize and look pitted in a few years.

Suggestions?

 

Should I repaint it with engine paint or leave the aluminum exposed. I like the look of the aluminum, but I don't want it to oxidize and look pitted in a few years.

Suggestions?

Jeff;
You know all Opels leak a little, so it won't oxidize:veryhappy

 

That is why I still have the original floorboards. Back in the day it had a small hole in the timing cover at the distributer so the undercarriage got a nice coating of oil.

My luck will be it will leak on one side so it will remain nice and the other side won't and oxidize.

I guess I'm lucky, my Opel doesn't leave spots in the garage.

The question is still open!! Maybe I should make a poll