Cammer parts.

[rodneym]

The Kirkhams.
One of a kind.

[Barry_R]

OK
I'm am going into some dangerous territory here - - but I feel I might need to add a few things that are worth noting. Take the comments for what they are worth.

First is that I have no real personal nor business relationship with Keith. We talk once in a great while and I have sent him a pair of my heads to evaluate. He is a competitor and there is no incentive for me to defend him. I do however occasionally find myself in similar situations and feel the need to put a few things into the builder's perspective from an uninvolved but experienced third party position.

I have built several Cammer engines, and they are a very challenging combination to get really right. As a very much foreshortened program from Ford, they never saw the degree of development that would normally have addressed some areas of weakness. The timing drive system is the most problematic. Nobody - nobody anywhere - has an truly extensive history of hundreds street Cammer builds that they can develop from in the same way that we have evolved the wedge motors. Every single one is something of a prototype in that way.

I do not see the length of the chain as the real issue. I feel that there are genuine problems getting good front to rear chain alignment since each drive/driven item attaches to a different casting - including idlers and tensioners on the heads, the crank, the stub working on a cover mounted bearing, both cams being located by the heads - if anything is off by a minute amount it loads the chain, and many of these have no built in means of adjustment. Allowing some of these items to float on their respective axles rather than hard mounting them might actually work better even though it is counterintuitive. All of the drivel above means that even a slightly marginal chain could be driven beyond its ability by a seemingly minor issue that is nearly impossible to measure or control.

There are only a few chain suppliers for Cammers. The original was a company named Diamond, which provided a .222 pitch chain. There are either out of business or at least not interested in producing automotive chain these days. I believe that Munro has a .250 pitch chain that is likely the best option available, but it requires dedicated sprockets and is not always easily obtained here in the 'States. The two most readily available parts are from either Rolon (India) or Morse (USA or Mexico). I have broken a chain on a Cammer at 2000 RPM - it was a Rolon. I no longer use those parts as a result of the experience, but must admit that we subsequently found an alignment issue that may have been the true root cause of the failure.

As perhaps the only other person here who actually built several SOHC engines, and has broken a timing chain on a Cammer I can personally and absolutely guarantee that it can and will bend every freaking valve in the damn engine even when you have plenty of clearance. It will also bend several STEEL T&D rocker arms and can cause other damage as well. My exact same engine was repaired with the same cam, heads and pistons and subsequently went to 7200 RPM and made 870 HP.

A correctly designed piston will have valve notches that perfectly match the valves in terms of placement and angle. I can also absolutely and positively guarantee that the valve contact can deliver a perfect round imprint on the piston if contact occurs. A roller tip rocker or a rocker on an SOHC engine will not have any rotation force on the valve at all beyond the very small (10 degree?) partial movement cause by the spring winding as it compresses. There is nothing there to cause the valve to rotate. Nothing. The normal and proper wear pattern on the tip of a race valve is a nearly straight line with no indication of rotation.

The next item to address is the Coon heads. Bill Coon is at best a VERY CHALLENGING individual to do business with. I don't really like the guy, but I am able to deal with him. Most of the stories are true, and many others have not been published. With all that in the open I need to point out that I have sold many sets of the Coon Cammer heads, and despite the issues with "the man", there have NEVER been any problems with the parts at all. The only time I ever hit water was in a pair that we had so radically modified that they were almost beyond recognition to achieve 456 cfm. Bill is local to me, and I have been in the world's filthiest garage while he pressure tested his heads to 60 psi and have never had a leaker (except for that one pair that we brutalized with an insane amount of welding before porting into a completely different shape). I can't really say what you're looking at with the dye in the picture from a few thousand miles away, but can pretty well wager that it is not a destructive level of porosity as applied to aluminum casting.

I cannot and will not comment on the respective behaviors of the involved folks, but needed to point out some misinformation I saw posted here. Back to your regularly scheduled programming...

[RodKnock]

Originally Posted by Barry_R

The next item to address is the Coon heads. Bill Coon is at best a VERY CHALLENGING individual to do business with. I don't really like the guy, but I am able to deal with him. Most of the stories are true, and many others have not been published. With all that in the open I need to point out that I have sold many sets of the Coon Cammer heads, and despite the issues with "the man", there have NEVER been any problems with the parts at all.

With all due respect Barry, you're one of the leading engine builders and FE experts in the country, so if I were Bill Coon, I CERTAINLY wouldn't want to get on your bad side.

However, Jay Brown, another FE expert, one who has published at least one book on FE Intakes, had porosity problems with two pairs of Coon's Cammer heads:

August 26, 2012 - The Road to Drag Week 2012

"On the heads, they had to go back and forth to the welding guy four times before all the porosity got welded up; turned out that five of the exhaust ports and one intake port had serious porosity issues, with casting sand coming up out of the casting during the welding process. My machinist was driven nuts by these events, continually having to get the castings rewelded after one porous section was fixed, and the porosity just showed up in another spot. What a nightmare; so much for the quality of Bill Coon's head castings! These heads were worse than any of the Dove SOHC heads I've had problems with. On these heads I also had to have new guides put in, and the guides had to be custom machined because of the oddball guides used in the heads. The reason they had to be replaced was that the tops of the guides were significantly out of round; they appeared to have been hammered in during installation, and were distorted by nearly a thousandth at the top of the guide. You can't hone that out on a guide, so they had to be replaced. This is the second set of Coon heads I've had this problem with. Warning to the other guys out there who have Coon heads; check your valve guides! If your shop doesn't catch that during the valve job, you could be in for a nasty surprise when running the engine."

All it takes is a google search. No expertise required.