Adjustable Front Starter Bracket


Below are photos of our latest evolution on front starters. Since 2002, the only starter arrangement that we have worked with is the front starter. Originally we used hand prop engines, moved to front starters in 1992, Developed and flew the rear starter in 1998-2001, and then came back full circle. In the last 10 years we have refined the front starter several times to make it lower profile (2003), use machined brackets instead of welded ones (2006), switched from welded on ears to bolted on ones (2010), and now we have changed the ear to a single piece bracket with an adjustable slot which eliminates the previous drilled aluminum link. installing a starter now takes a few minutes with three wrenches. No drilling or fitting. If you crank it up and it doesn’t mesh with the sound of prefect engagement, a minute of loosening the bolts and resetting the adjustable bracket will make it correct in no time.

Above, the new bracket bolted on a starter mounted on a 3,000cc Corvair equipped with a Dan Bearing. In the last two years, starters we have sent out have had the front ear bolted on instead of welded on. any of the bolt on ear starters can be retrofitted with the new bracket. The above photo is of the same engine we had on display at Sun n Fun. A number of builders asked about the starter, saying it looked smaller than previous models. It was an illusion; This is the same EA-81 based ND starter we have used for the last 10 years. The main visual difference was that I painted this one black and spent 15 minutes on the band saw removing the shroud around the starter gear. The new bracket has a cleaner look than the previous system, but the concept is the same one that has started 100’s of Corvair builds in the last 10 years. The improvements have been small and evolutionary. I have had much better experiences with things in aviation that are refined and slowly evolved to be what the are rather than things that are new and revolutionary. We can all think of things that are revolutionary success stories like the Vari-eze, but you have to remember that it was the exception. In the 1970s there were dozens of other new revolutiary airframes that didn’t work out, like the BD-5. I like to read about new and exciting things, but I have been much better served by things that are old and proven.

Above is a photo of two dozen of the new brackets. They are CNC machined for accuracy from 1/4″ 6061-T6 plate. At the bottom of the photo are two different spacers. These move the starter forward slightly when installing a Dan bearing. If you look at the top photo, you can see the small spacer between the new bracket and the left hand side gold anodized starter bracket. We have these spacers and pre-machined tail brackets for engines that are assembled with Dan bearings. The tail bracket is visible in the top photo.


Distributor Detail


There are a lot of little details on Corvair installations that are best shared in a picture and a few sentences. Below is a distributor clamp, installed as we prefer, on a 3,000cc corvair that we built.

Above, the proper orientation of the three parts of the distributor hold down.

Every now and then I inspect a Corvair engine assembly where the builder has the incorrect clamp, or has it improperly installed.  First the nut; the stud thread is 3/8″-24. In its stock form, the nut is a regular fine thread nut. In the car it is unlikely to back off because the little wire clamp effectively spring loads it. In the plane we are not going to count on this. The best nut for the job is an MS21042-6, something you can get from any aircraft catalog. A regular all metal lock nut will often have it locking feature above the top of the stud. The MS nut is low profile and the fact it takes a 7/16″ wrench makes it easier to tighten. (This is the same nut we use on the hybrid studs to hold down the prop hub.)

 Under it is the stock GM square washer. It has two little ears that face down to keep the wire from spreading when you tighten the nut. A regular washer will not work here.

Under it is the GM wire style clamp. These are far better than any other type of distributor clamp. When you put the pressure on them the two ends of the clamp make very firm contact with the distributor housing, and then the wire deflects as a little spring. I have never seen one of these move once it is tightened down. The reason why the two parts look shiny is that we have the ones on engines we build nickel-plated for corrosion resistance.  A quick shot of spray paint will have the same effect on engines assembled in home shops.