Thread: Ported heads / springs / custom cam

Looking for a st3 or better heads
also might be looking at 130s / possible double roller already machined to fit properly
custom cam
etc

I'd spec one yourself and order it from Comp.

But that's just me

Me too but hey if someone wants to sell me one, then it keeps my budget happy

The local shops here want me to buy the barrel they will bend me over when they charge me for the head work.
It's stupid expensive here

I'll be point blank about it. I never installed a double roller because out of the box it didn't fit. I didn't have the resources to make it fit at the time.

Ill look into a custom spec cam with XFI lobes. Thanks for the tip

Pretty sure you need all of those things, because the chamfer of the gears is a different angle, and most people run thicker/2 gaskets AND a machined pump cover. IIRC.

People run it without machining the gears. but the angle is off, and it will wear FAST. clearance wise some people get away with just 2 gaskets. But with something as crucial as valves and timing on an interference engine, on a high HP/crazy cam setup to require a double roller, how much you wanna leave to chance is up to you.

Not only does it wear, I have seen a few posts where the gear will snap right in half.

Right, it'll run for awhile, but who knows how long. I wouldn't trust it without the proper machining. You run whatever you want.

I would prefer to run the stock chain and keep my harmonic balancer. From what I read around the boards is that without the harmonic balancer you should use zzp 8 rib SFI balancer. But yes. I haven't had any luck with finding a properly configured double roller

Originally Posted by SnowFlake

Get a sandpaper roll/dremel and just clean up the exhaust ports.

Will be a better setup than anything off the shelf.

I agree with this but if you wanna do a serious port job I suggest using deburring bits with a die grinder.
Something like this.

Forney 60125 Tungsten Carbide Burr with 1/4-Inch Shank, Tree Radius, 3/8-Inch https://www.amazon.com/dp/B003X3W30G..._Mkhiub0XV0Q7J


The sand drums are good for smoothing. Then I use scotch brite wheels to polish.

Right from a thread here

Double roller timing chains, I personally don't believe they help make the setup more durable. The Rollmaster chains in particular had a tendancy to stretch and I've seen some setups jump/chip a gear tooth because of chain stretch. I've heard of a Cloyes chain fitting but have no personal experience. I used to prefer the JP timing setups, before Rollmaster bought them out, because they had a stronger chain. I've seen some stock tensioners like the above picture after a year or two, and I've had others upgrade to double roller after a year or two and their tensioners looked fine. With a double roller, you also must must must machine the proper lip at the back of the crank gear, and ensure that the gears line up with a straight edge without the camshaft being pulled all the way forward. All this business with double front cover gaskets, machined pump covers etc, it's all an issue with the crank gear sitting too far forward from the block. This is why you will occasionally see the cam retaining plate crack and the cam gear kiss the front cover like I saw in my own GTP, the crank gear pulls the cam gear forward as the chain tries to align the gears.

Originally Posted by crazyguy03

I would prefer to run the stock chain and keep my harmonic balancer. From what I read around the boards is that without the harmonic balancer you should use zzp 8 rib SFI balancer. But yes. I haven't had any luck with finding a properly configured double roller

All you need to do is bring the crank or cam gear(cant remember which) and the double roller and ask the machine shop to make them match

Easier said then done lol
that's why I order things online from zzp expecting the vendor to have corrected this before selling
they are quite capable of many things just curious why they don't offer it ?