In our new manual numbering system, the camshaft group is #1100. Below are the numbers in the group. This story is about buying our cam package that includes all the parts listed below, ready to drop in your engine.
Cam group (1100)
1102- Thrust washer
1103- Key, hardened
1104- Cam gear
1105- Hydraulic lifter set -12 total-
1106- Cam lubricant
1107- ZDDP oil additive
Above, the elements of the #1100-ww Camshaft group package. It contains every required part in the 1100 group in the new manual numbering system. Everything in this picture is made in the United States.
I have put the cam that Harvey Crane designed for us in 1997 put back in production, because I have found a respected national manufacturer who can grind the pattern on original GM cam cores.
The cam is Parkerized, checked for straightness and magnafluxed after processing. These cams come with a new billet made in the USA gear already installed (#1104). The gear is correctly mated so there is zero play in the thrust washer (#1102), it is clamped tight and will not rotate. A new set of HT-817 sealed power lifters (#1105) The moly lube (#1106) and a bottle of ZDDP (#1107) all come wrapped up in one box that a builder can buy, and then just check “Camshaft Group 1100″ off his list.
We extensively flight tested this cam pattern more than 15 years ago. In performance testing, this cam has a slight edge on an OT-10. I was motivated to do this because we kept having builders show up at colleges with cams they paid to have the gears put on which has the thrust washers sloppy loose. None of them wanted to hear that their brand new gear had to be trashed and a correct thrust washer and new gear had to be installed. Having the whole 1100 Group done, correctly and available precludes this from happening.
I have had this project in mind for more than a year, and have had the actual cams here for several months going through testing and verification of the grinder’s ability to get the pattern right on the money. I had them independently magnafluxed here. I assembled about 10 of these into engines so far, and they work very well. They will be in every production engine we build from here on.
To illustrate how long I have been having an issue with car parts suppliers who don’t put the cam gear down tight enough to capture the thrust washer as GM designed it to be, below is a 2008 post from our traditional website. It shows that the reason why car people could not put the thrust washer down tight is that they substituted a Chinese made thrust washer, that didn’t have the required bevel on it. It took about 60 seconds to correct this on a lathe, but if you don’t do it, and try to press the gear on tight, it knocks the gear out of alignment. I pointed this out to car people, they corrected it for a while, but in the last two years the problem has come right back. I am done with trying to have car people take this seriously.
Discovering and solving that single issue and being able to type that short sentence about it cost me about $500 in cam gears and four days in the shop to learn, almost ten years ago. If you spent a weekend in my shop, I could literally show you 100 more items about Corvairs like this, all of which went into the knowledgebase in the new manual.
At Oshkosh this year I had a guy stand in my booth and tell me he was part of an on line discussion group about Corvairs, and they were using an idea called “crowd sourcing” to come up with “new answers.” Because of my superior anger management training, I was able to calmly explain that 50 people who have never built a running Corvair speaking to each other on line is a form of the blind leading the blind, and it doesn’t work any better in Cyberville than it does in reality. I also said that Cyberville may seem great because everyone gets to have their own unicorn, but he should remember that even if he brings a lot of he video game “extra lives” from Cyberville when he heads to the airport, “Game over” has a different meaning in reality than it does in his pals in the Sony Play station world. He made a hurt face when I said “You can go ahead and press “reset” but me and my friends Physics Chemistry and gravity will still be here. Reality works like that.”
(2008) Above are two cam thrust washers for a Corvair. On the lathe, I’ve cut a slight bevel to provide clearance on the side of the washer that touches the cam. My research into building Corvair engines is continuous and ongoing. The unbeveled washer is an aftermarket part supplied by several of the Corvair parts houses. When pressing on a new cam gear, this will make the cam gear walk slightly out of square at the last moment. After years of installing countless cam gears without problem, we’d recently had trouble getting several of them to seat on their cams and hold tight their washers. Ignoring this problem, people selling cams with gears on had been leaving the washer loose as a really poor fix. It took a while to determine what was causing this issue, but a slight relief on the washer makes the difference.
(back to 2006 ) Cams are made of cast iron. They should never be subjected to compressive forces down their length. This tool holds the cam by the first bearing when the heated cam gear is pressed in place. In our shop, we always make sure the thrust washer is clamped tight by the cam gear. This requires holding it under pressure while it cools. I had a recent tech discussion with the staff at Clark’s Corvairs about this. They said that many car people prefer the thrust washer to be loose and rotate on the cam. I explained to them that for every aircraft engine, I want the washer tight.
9 Replies to “1100-WW Camshaft Group”
I’m tempted to remind you there is a theory, oh, excuse me, hypothesis that states a room full of the smartest monkeys you can find, given word processors, will, if they live long enough, produce, by the operations of the mechanics of odds and statistics, every great book ever written in the history of mankind. Pretty sure your man was ascribing to this one. Reminds me of the hypothesis, i.e., not proven beyond a shadow of a doubt, as many times as asked for it, in a ‘non-biased’ laboratory – every time, regarding genesis and evolution cross species. As for me, I go with the empirical, lab tested, flight proven Fly Corvair group. Not interested in smart monkeys designing ANYTHING on my plane. Merry Christmas!
I recently put my block together on my 95hp corvair and i noticed there was a lot of play rougly .002 -.004 axial play between the cam gear teeth and the crank gear upon further notice i found the cam gears to be worn. im ordering the new stock gear and washer and key from clark’s however i was looking at the key selection and noticed they also had a 2 and 4 degree offset key. which key do you recommend for use in a aircraft conversion. I was planning on going with stock key
Dewayne, If you order a new washer from Clarks, it will come without a bevel, and it will be loose after you press the gear on. You are better off using the stock one if it is not cracked.I you really have .004″ vertical travel of the cam in the case, you may have too much wear. I really don’t suggest using old cams, and not old gears ever.
the engine i received was a one off a zenith airplane that had a sudden stoppage it only flew 5 hours and was ground run and tested for a total of 10-15 hours max. I tore the engine down and sent the crank and cam out to be magnafluxed and checked for warpage and bending. at the time it all checked good. I mic;d the lobes and they all measured with in tolerance per the shop manual. I was thinking of just getting a new cam gear and key and having it pressed on at the local race shop. can a cam wear that much within that few of hours. # how does the cam gear wear, does it rub on the case or is it more than likely a improper installation of the gear to the cam
In a sudden stop the cam gear is junk, it must be replaced, even if it looks good
thanks, what about the cam replace that too.
Is it possible to purchase just the cam and gear assembly from your company because i have already bought the lube, lifiters and zdp from clarks. if so How much
How do you determine if you have a reverse rotational engine
They are rare, something people made for half a percent of planes and dune buggies. Send me a picture of the end of the cam without the gear on it. It can still be in the case