College engine build options for closing the case
September 27, 2013 Leave a comment
Back in January I wrote a 20 part series on getting started in engine building. The first milestone that builders are working for is closing the case. In the new numbering system, this covers groups 1000, 1100, and 1200. In these stories, we are also looking at 5th bearing options, so we are also looking at groups 3000 and in the case of the Eddie Easy engine, Roy’s bearing, which is group 3100. I named each of the engines in alphabetical order, in the older, pre-NATO code.
1) I later changed the numbering system slightly after these stories were written. For example, a crank is now part #1001, not 1000 as written in these stories. Small change, but I wanted no part to have the same number as the group it was in. Almost nothing else is changed, but as you are planning the details of your build, look for this number shift. The price sheet on our main products page has the final correct number system.
2) If you are going to build a 3,000 cc Corvair, the cases have to be bored out to accept the larger cylinders. If you would like to build your case at #27 as a 3,000 case, you need to mail your cases to me in advance of the college, (say by October 12 or 15th) and we will bore them out for $200. When you later purchase the piston/rod/cylinder kit, we will deduct this from the total kit price.
3) the most common short block that builders close at the college is a Gen 2 Dan bearing/ 2700 or 3,000 on a GM 8409 crank. Both reground and stock cams are common. Today builders interchangeably use OT-10 cams from Clarks Corvairs or CC-10 cams from California Corvairs. They both work.
4) I prefer that the cam gear clamp the thrust washer tight against the cam. A long time ago, Clark’s had a batch of thrust washers made that had no inner chamfer, which meant that if you pressed the cam gear tight, you would invariably introduce run out in the gears. I ruined 4 gears in the old Edgewater hangar in a single night working with Kevin before we spotted that the washers didn’t have a chamfer. A later inspection of Clarks installed gears showed that they had compensated by not putting the gear tight to the thrust washer. The correct fix, only took 60 seconds per washer….I put them in the lathe and cut the chamfer. After I told Clarks of the issue, they stuck to the story that they intentionally wanted the washer loose, but did later send out the washers in a revised form with the chamfer. Which is a long and old story that leads us to…….CC#26 where I ordered several washers from Clarks, and promptly got ones without the chamfer, and at the event I saw a Clarks installed gear with a loose thrust washer again. Since they didn’t really see this as a problem last time, perhaps the best solution is letting us put the cam gear on for you.
5) The California Corvairs and LS billet gears are made in the USA. A number of parts sold by Clarks are “GN brand” which is Chinese. This includes the stock gear. They switched them over years ago. The first ones they got were trash. Since then, I am forced to admit that these gears do work. The CC billet gear is very tight going on a cam, you must watch how far your key is sticking up, it can drag on the top of the keyway in the gear. I talk about avoiding Chinese parts, but I suspect that very few people really care. I recently got an EAA hat with the “heritage” logo on it. Yes you guessed it, made in China, sold by the EAA for $18.99. I was going to write something about it, how it told me that the EAA was interested in maximizing profit instead of exercising values, but I have been speaking of this stuff for years, and lets face it, very few people care. A friend just pointed out that the Chinese government is now a major shareholder in ICON aircraft. Read the press release that says they are going to be built by Cirrus, which itself is owned by the Chinese government….Yesterday brought news that Continental, owned by the Chinese government, was pressuring the FAA to issue a killer AD against their major competitor, the US founded and owned ECI. by my guess, less than 5% of the people in aviation care that this stuff is going on, so to whom am I speaking to anyway? I am convinced that 50% of Americans would see nothing wrong with buying a Chinese sewn American flag from Wal-Mart, just as long as it was a buck cheaper. I am happier when I don’t think about such things.
Below are the example short blocks. You can click on the links to the stories just below each listing. Write in with any question you may have, I am going pack to putting up all the mail sack comments in the next day or so.-ww
Engine options with 5th bearings:
Allan Able = $2,062
(See part #5)
Bob Baker = $2,516
(See part #6)
Chas, Charlie = $2,770
(See part #7)
Davie Dog = $4,270
(See part #8)