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

take the STOCK crank gear/oil pump gear off and turn it around. there is a chamfer (angle) on the rear side where it mates up with the crank. you need to mirror that same angle onto the JP crank gear.

DO NOT forget to put both pieces of the JP double on. i forgot the oil pump gear when i put mine back together the first time and i spun a bearing because of no oil. the stock is a single piece, as is the rollmaster. the JP is a TWO PIECE system.


i have not done any of this, but i milled my oil pump cover and i havent had any problems yet. i havent opened it up to look, but i figure if it breaks then i get to make it even faster than it is now.

i wouldnt try. even if the chain would hold, the tensioner would go by by and then eat the chain with it.

use the jp. if you need to get it machined, take it somewhere. i bet you someone would modify it for like $20. it is an easy fix if you know how to do it.

you ARE copying the stock timing chain crank gear. that is the only one that matters. the stock crank gear and oil pump gear are ONE piece. the JP double is TWO pieces, one for the crank gear, one for the oil pump gear.

once you pull the front cover, you can just slide the crank gear/oil pump gear off. compare the back side of that one to the JP crank gear. you will then see clearly what i am talking about.

has there been any reasons for timing gears yet? i mean, how many people have really broken a double roller that was clearanced properly?

Originally Posted by Bio248

has there been any reasons for timing gears yet? i mean, how many people have really broken a double roller that was clearanced properly?

I've seen at least 1 person who posted pics of a double rollmaster crank gear in 2-3 pieces. Clearance was good from the chain to cover, the gear was not machined though to match chamfers.

The JP timing sets have their own thread of failures i linked below:

Basically get a double rollmaster, not a JP timing set and also match the crank gear with your stock crank gear, especially focusing on the inside chamfer.

ClubGP Message Forum troubleshooting

Right, it's been found that there's were a lot of issues from not understanding the issue and installing incorrectly because many thought the sets were good for US motors as well as Aussie motors. Yet the issue ended up being that difference.

Originally Posted by FoSHO99

Basically get a double rollmaster, not a JP timing set and also match the crank gear with your stock crank gear, especially focusing on the inside chamfer.

ClubGP Message Forum troubleshooting

from my understanding, the JP and rollmaster sets are the same and they have been for a while, right? why would it make a difference so long as all the variables are checked before the motor is sealed up?

i personally ran a JP set straight out of the box (not chamfered correctly) with a shaved down oil pump cover for around 30k before i sold my car still running with it. luck of the draw?

Originally Posted by Bio248

from my understanding, the JP and rollmaster sets are the same and they have been for a while, right? why would it make a difference so long as all the variables are checked before the motor is sealed up?

i personally ran a JP set straight out of the box (not chamfered correctly) with a shaved down oil pump cover for around 30k before i sold my car still running with it. luck of the draw?

The rollmaster and Jp are different, the JP being a 2 piece crank gear and also has a different pitch on the chain, making them non-interchangeable. There was a thread on clubgp that focused more in depth on the exact differences, but the search function sucks and I can't find it. Someone -either Janice or Farnsworth had pics and specs of all 3 sets including stock and measurements. The JP set was more off than the rollmaster, possibly in more than one way. The Rollmaster was just easier to fix and is more reliable of the 2 so far.

Originally Posted by miker56

Is there anyone that has pictures of the correct setup?

THere was a thread on clubgp, although even though i call myself an expert searcher on that forum, I can't find it. That forum software/support hasn't updated anything since 2001.

all you have to do is take your stock crank gear and the double roller gear to a machine shop and tell them to match the new chamfer to the old gear.

Right...I've got pics of it I'll post later...that way you don't have to worry about clearance issues. You don't have to double gasket the front cover and you also don't have to machine down the oil pump cover if you match it to the stocker height wise.