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MG MGB GT V8 Factory Originals Technical - Timing cover & Oil pump?

Hey Guys/Gals I need your expertise...
I was just cleaning the timing cover from my '85 3.5 RR and noticed on the inside (and outside) of the cover anround the oil seal area, that I have a bunch of cracks. They aren't through-n-through (as far as I can tell) but there are many. It looks as though these are maybe stress cracks, maybe from the heat? Is this normal? When I bolt on my harmonic balancer, pulleys and such, is there a lot of stress pressure created in this area? Oh and by the way; I'm putting this on a 4.0 block and crank so I'll be using the "spacer" I got from D&D.
Now of the oil pump question... I read that later RR oil pumps were "high volume" pumps from the factory. What year(s) did this start, and is this an item that should be rebuilt/replaced while I'm building this engine? The original engine had 114K miles, it was just wrecked when I got it from the salvage yard. I don't now if it was running but thought it didn't matter since I was rebuilding it anyway.

Thanks, in advance, for all of your help.

I would switch to a buick front cover no matter what. The water pumps are different, and rover water pumps are god awful expensive!

I bought a buick 300 H2O pump to use on this cover. Dan (D&D) said it would fit and that I needed it if I plan on using AC. I'm pretty sure a buick 300 front cover will fit (right?). I think I remember a thread in which you gave a link to new front covers,am I right, were can I get one? What oil pump do I use? I've seen where MGV8'rs are/have used Milodon high volume oil pumps but when I've searched many sites and cannot find that Milodon makes these for buick 215, or 300's? I assume the remote oil filter kit they sell for these conversions will work on this cover?

Thanks for your help,

Any of the 215 Buick, Olds, 300 Buick, & some V6 Buick front covers as well as the early Rover covers will bolt on. There are also aftermarket Buick style front covers available. Any of these covers will take a Rover, 215, or 300 water pump, with the 215 or 300 being the preferred one to use because of shorter length.

The 300 water pump has a bit more flow & the outlet is at a better angle than the 215, so that would be my choice, regardless of whether I planned on A/C or not.

The biggest drawback to the Buick/Olds covers is the rope crank seal, which almost always leaks. There is hardly a mechanic left alive who knows how to install the rope seal properly, & few hobbiests who can do the job. D & D & others offer a modern neoprene seal which you really must use. Some of the V6 front covers came with the neoprene seal, but the timing marks are wrong, however this can be accomodated by cutting new timing marks in the balancer.

In the area of oil pumps, the Buick 300 cover has a deeper pump cavity & uses longer gears for more oil flow. Melling offers a repair kit & also a high volume kit for the 215 covers that essentially duplicates the 300 pump. Installation requires drilling 2 holes in precise locations & uses roll pins to hold a spacer plate in place. If you doubt your own abilities, have a machine shop do the work. If you are buying a cover from one of our V8 suppliers, most will provide the kit & install at a reasonable price.

An advantage to using the Buick/Olds oil pump is that you can use the Delco distributer in place of the Rover unit. Price caps & points & you will find that 2 or 3 tuneups will save you enough money for a decent dinner for your other half. As well, you can use many aftermarket dizzys if you wish.

For any Rover or 215 Buick/Olds, my choice of covers would be 215 GM with neoprene seal, Buick or Olds 215 harmonic balancer, uprated oil pump if the engine capacity was 3.9 or larger, Buick 300 water pump, Delco dizzy with Pertronics conversion. If using a Rover, check with Towrey or D & D about the balancer.

Anything I left out?

Jim Stuart
Jim Stuart

Just remember if using a buick 300 cover, the locating dowels are 1/4", not 5/16", so you will have to drill them out in the cover, lest you crack it trying to tighten it down

Thanks for great info, sounds like a 300 cover with melling oil high volume pump is what I want.
Last thing, I plan on using the Hot Wire inj unit that came with my 3.5 so I figured I was bound to the dizzy it came with. Any experiance with an aftermarket dizzy that will work with the setup I purpose?

BTW, any body interested in a clean used rover front cover, I hear they make nice planters?



The 300 cover includes the high volume pump as stock, you do not need the Melling kit.
Jim Stuart

I used an '86 front cover from a 3.5 on my 3.9 and it had just the crack pattern you describe. I also cleaned it up (took hrs) and put in a new seal and I have not had a problem with any seepage/leaking. It's still as clean as it was 9 months ago. In case it makes a difference I should add I used silicon (ulta grey,everything proof)when assembleing the seal and cover onto the motor.
I wanted to use the '86 RR front cover because it is the same as the RV8 and the offset water pump (up and to the right)allows more room to have a fan behind the radiator. This is much more efficient than in front.

The SDI in either '79 or '80 had a larger pump than the P5/6 and the RR certainly had this larger pump and improved Oil seals by 1985.

Been following this thread with interest, since I have a 3.9 sitting in the garage to replace my 215.

I have been trying to figure out how to proceed with the distributor/timing cover/oil pump. I already run the 300 water pump on my 215. As for the balancer, I was thinking that Dan told me that I could use my Buick 215 balancer on the Rover 3.9.


I am using a Buick balancer on my Rover 4.2, so I amsure you can use either the Buick or Olds balancer on a 3.9.
Jim Stuart

Carl . . . I've got an Olds 215 balancer on my Rover 4.0. Works great. I had to use a spacer, but they're simple to make, or Dan L. has them in stock.
Gordon Elkins

This thread was discussed between 20/10/2003 and 26/10/2003

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