A-65 spider

Ron Babos · Post by **Ron Babos** » Tue Oct 17, 2006 22:16

Has anyone either ported and polished the spider for the 65 or used an 85 spider and gotten a few more takeoff rpms. If so how much more?
Ron

Nathan K. Hammond · Post by **Nathan K. Hammond** » Tue Oct 17, 2006 22:30

Don Swords swears by the 65 spider. He takes one, hogs out the inside so it forms a venturi. He claims 12 extra h/p when you do that, along with a port and polish.

When you hold the 2 spiders up, the 65 is smaller in diameter. But I don't know which is better; larger, more open 85 or a venturi'ed 65.

For what it's worth, I've got a hogged out 65 spider and don't seem to have any porblems. But I don't have any data on what an 85 spider would do.

nkh

Ron Babos · Post by **Ron Babos** » Tue Oct 17, 2006 22:40

Nathan: I've heard of using it on the bigger engines , but would like to know any benifits on the 65. Hell I'd be happy with 25-50 more rpm if it will help.
Ron

Paul Agaliotis · Post by **Paul Agaliotis** » Wed Oct 18, 2006 00:35

Ron,
I clean and polish the spiders and the result is a nice idle. I dont have any measurable RPM increase. This is a very low speed/low power engine and porting is most common on higher performance engines.
The 85 spider when used on 65,s have had some problems in the past and is not a good match.
Paul

Ron Babos · Post by **Ron Babos** » Sun Oct 22, 2006 21:42

Paul: What kind of problems could that cause? I can see too large of a venturi creating bog and detonation, but the spider is after the venturi.
Ron

Paul Agaliotis · Post by **Paul Agaliotis** » Mon Oct 23, 2006 00:14

Ron,
I had two cases where the engine would quit on roll-out. It didn,t happen every time, but it was too often for the owners. In both cases the engines (A65) had the C series spiders installed. After I replaced them with the correct spider they had no more problems with the engines. I dont know the science behind this but it cured the problem.
Paul