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Double roller installation

R

Regalgse00

New member
So I'm going to be putting my xp cam in and I have a double roller as well. Someone told me that when installing the double roller you have to correct the angle of how it sits or whatever. Or can I just use my machines pump cover and slap it in as a stock replacement ?
 


Or whatever?

There are many, many threads on the subject... It would benefit you to know what your 'friend' is referring to prior to jumping in the pool? No? Best to search, read, learn... THEN ask, if you still have questions. You'll ask yourself why you need a 2xroller with an XP in the first place...

Why DO you need a 2xroller?
 
This is what he said

I've done a lot of installs with XP and S1X cams. Typically and for years people used replacement stockers or singles, as long as they used a 105lb spring. If you go to a much higher rate etc then you would want a double.

Keep in mind if you go double roller, you need to have the crank gear machined to the same bevel as our US crank. The double roller is made for an Aussie motor which has a different nose on the end of the crank. This corrects the geometry of the chain. Add a milled pump cover and you should never have a problem.

If you can get on CGP, look in the drivetrain areas. There are posts by Janice where zoomer and a few others are talking back and forth after double roller chain failures.

Janice found that the crank gear on the DR set has a different chamber to sit against the crank than the crank has. This causes the chain to get pulled in a direction it was never intended to handle. Zoomer did some research with the vendors and it was determined that the DR set was built for the Holden aka Aussie 3.8L motor. That crank has a different chamfer/nose. To get the chain to run properly on our US cranked motors, you need to correct the chamfer angle.

The part of this whole thing that bothers me is ZZP sells the chain set and does not machine them or note that it's not for the US motor. Yet...Zoomer was in the discussions.
 


if you go to club GP at the top of the l67 forum is a thread that i still have active pictures in that tell the whole damn story, including a drawing of the crank gear, chambfer and pocket details. and the average of the amount to grind off the cam gear for the cam motion or comp cam noses.

all the shop has to do is clean the ID of the recess with a sharp 90* cutter, to the RM depth, your just going out to remove the radius that RM leaves that dosnet fit our crank, iirc the drawing is at 1.810" ID, and i size mine directly to the cranks for a press fit at the snout shoulder as well as the snout thrust face (stronger/stiffer for OD blower) if you go to 1.811 or 12 youll have plenty of clearance unless you dont mind carefull sanding with crocus cloth...

the chambfer is 45* and should extend 1/32 past the tits of the keyway slots.

now you can test fit your crank gear and cam gear and use your magnetic dial indicator to check the offset relative to each other (make sure you move the crank and cam through endplay and average each, grind this off the cam gear backside.

congradulations you chain is running within a couple thou of perfectly straight and will outlast your motor (plus when you pull the chain off in the future it wont sit like a cone.)

if you keep the RM pocket depth (dont funcing touch the thrust face) then youll be close enough with .026-28 off intense cams (cam motion) and .024-26 on comp/zzp and youll still be within 4 thou

out of the box ive seen as little as .014 to as much as .022 gear misalignment

if only RM had not use a radiused nose tool on the ****ing snout pocket all youd have to do is the chambfer.

if your ballsy you could hand file a radius on the edge of the crank snout shoulder...but you still have to enlarge the chambfer for the larger US crank fillet
 
Friend has arrived. :th_king-evil:

I mentioned the post by Janice and "others" on CGP etc. James however 400sbc pointed you straight to the exact measurements though.

James.. you were one of the "others"..lol Please..stop throwing rolocs at me.
 
i know janice agree'd with me, dunno how far he took it though...i had a guy down under get me direct snout data from their engines once i noticed the gearsets werent installing flush against the crank thrust face but instead ~.014 off
 
Well I'll definitely be making sure to bring my block and double roller into a machine shop and just have them install it and tell them to match the gears
 


Bring the info James posted as well. I hadn't realized he was the main driver on that convo... and now he's gonna beat me with a roloc.
 
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