Thread: Those of you with double roller timing chains....

Well, I have my front cover now, and all looks good inside. I didn't see any part of my chain rubbing on the front cover, well, any more rubbing than what was already there, but I remember there not being that much before the oil pump cover was machined.



Need to borrow a puller from my brother as the cam gear is pretty stubborn with not wanting to come off. I figure with all the miles on this, and I'm taking it off in time before worse can happen, this double roller chain set could be reused again, after the crank gear is machined of course. I would run it again it looks so good if that says anything. But bought a brand new one not knowing how this one would look once the cover came off.

~F~

The entire front cover, or are you just wanting to know the thickness of the oil pump cover before and after?

That I know and can help you with.

Stock oil pump cover thickness is .153"

MAX to remove from cover = .020"

Final measurement of cover after machining should read around .133"




Side note, I got my new double roller set that was machined installed tonight, went on very nicely, and all the way with the greatest of ease. I even got to install my balancer that I got from the Branson Meet Last year...

Pretty nice for a ZZP modified Australian one. This one is replacing my H-Body balancer that decided to give up before its time was up. Hopefully this one will treat me good.

I plan to have my double roller that I just removed machined, and plan to sell it for what I have in it in case anybody is interested. I can even add in a machined oil pump cover to sweeten the deal as well. The one I removed has less than 4K miles on it. It still have plenty of life left in it.


~F~

How does this issue affect the single roller?

ZZ Performance

I'm not planning on anything too extreme. Just pushrods, ER rockers, and 105# springs on the intake valves. I want something more reliable than the stock chain/damper setup but don't need a double roller nor do I wish to remove my balance shaft.

Originally Posted by whitcomb

non.. single roller isnt as big as the double roller, unless your talkin bout the crank gear bevel im not sure i that one.. from what ive read is dont waste your money on the single roller just run a new OEM chain and tensioner.. why are u runnin 105 on just the intake valves if i may ask?

ER rockers only require them on the intake. The exhaust ratio is different so it isn't necessary.

The stock chain/damper works for me then. I figured as long as I had it off (replacing the damper for good measure) I'd upgrade, but if it's no upgrade then the money isn't worth it.

Well after reading this thread, i informed a friend who planned to install a double roller. He e-mailed zzp and asked if they knew about the chamfer and if they planned to sell the rollers chamfered. They say the fix is running a double gasket. My buddy wasn't comfortable running a double gasket so i hooked him up with my uncle(machinist), he chamfered the timing gear for free.



He had it all assembled before i could take a pic of the gear all alone.



He's currently fixing his steering shaft. He forgot to disconnect it when he lower the passenger side of the cradle. At least he didn't break it. Soon we'll have two xp's in MT(that i know of).

Question for those of you opening up the front cover...

Do you have to remove the lower motor mount bracket? The GM service manual says that you have to remove it to gain access to some of the front cover bolts. I was just wondering.

Also says something about priming the oil pump and petroleum jelly?

Unless your motor mount setup is different than a grand prix you don't have to remove the motor mount. Not sure about priming the oil pump? What is the petroleum jelly for?

Don't worry about priming the pump. All you can do on our motors is crank it with the ignition and fuel pump disabled. We don't have a distributor shaft that we can stick a rod down like other vehicles.

As for petroleum jelly, it's not needed unless you're installing a dry oil pump assembly. It basically lubes and protects the gears until oil flow takes over. The heat will melt it and make it merge with the oil after the engine gets to temp.

I was wondering how I was going to prime the oil pump after I got things back together.

Yup like said above about priming the oil pump.

its not relaly needed unless its dry from the start. Even then you can get away with using some motor oil in the pump its self as a prelube, but it will build pressure on its own regardless as soon as the motor is started.

I have used white lith. grease, works well, and does break down and blends with the oil...which is good and bad at the same time. It will make your oil milky in color, making you think you have coolant leaking into the oil supply. That always sucks, when you find you you don't. I am against using this myself for this reason only...the color change of the oil after its circulated.

From now on, I use Vaseline as my oil pump prime. It will break down into the oil when it warms up. But after a start up and everything is cool, say you do an oil chance, and decide to cut apart your filter, you will find big chunks of the stuff that have not broken down yet. Thats not bad, cause they may have hit and stuck to the filter before they had a chance to get warm enough to break down completely. Normal, and will not cause any problems with anything what so ever. Just posting my findings what I have seen personally.

~F~

Thanks for that info farns. I got to get a notebook going on all this fantastic information.

Not sure, could be.

Sometimes, like when we will do a cam install, we will not prime the stock pump unless we open it up to replace the pump cover with a machined one. A trace of oil left in there is fine until its started. But a completely dry one is pretty brutal on the front cover. The front covers are already weak and cheap as they are, and made of very soft, pop tin aluminum. I have seen oil pumps like ours worn, that get starved of oil, actually start wearing INTO the aluminum front cover. Mostly on high mileage motors.


We do not have an after market pump for our cars, and don't really ever see one being made without having a custom front cover produced or a stock one being machined. Volume is always good, but our stock pumps are fine as they are.

~F~

So, you're saying if I open up the front cover to replace my timing chain and damper, I shouldn't have to worry about priming the oil pump?

Not unless you would flush the oil pump out with something like carb cleaner or some sort of solvent.