Gasket material for PeeWee conversion?
 

Does any one have any advice on what gasket material to use in converted PeeWees?

The teflon ones get pinched of right away so I've tried using a thin aluminium one from a soda can. I got several good runs in today, getting about 10000rpm on a graupner 6x3 when fully leaned out, and the engines sounded really strong. That's on my regular diesel fuel with 33% ether, 25% castor and 1.5%DII, so nothing special, and had very easy starts when priming the piston.

But eventually that gasket was broken too, after about 4-5 tanks. I'm not sure that it gets pinched of, it might actually get bent off (?) right next to where it is clamped. Any ideas? Thicker aluminium or brass instead?

RE: Gasket material for PeeWee conversion?
 

Okay, I take it not everyone are running PeeWees on diesel that often...

I made a new gasket out of .005 Brass rather than the previous .004 aluminium, it fired right up but I will have to make a longlivety test.
The performance on diesel seems really nice though, just have to find a gasket that last a little longer.

10000 rpm on a 6x3 will pull my 4oz cub into orbit...

RE: Gasket material for PeeWee conversion?
 

I am sure that using aluminiuim would be fine here but the toughness grade of a drink can may leave something to be desired and the gauge is rather thin.

And perhaps you could make the next alloy gasket to a larger outside diameter to help prevent spreading under the compressive loads.

Hope this helps.

RE: Gasket material for PeeWee conversion?
 

Ran the brass gasket today and it seems to hold up fine. Got consistent runs at about 9500 rpm on a graupner 6x3, and runtimes of about 2 minutes. When fully warmed, up the compression screw can be backed out and it actually looses contact with the counter piston, may have to shave off a bit more from that one.

The case seems to wear quite a lot, it is already quite sloppy but I guess it is time to get this one into the air...

[youtube]http://www.youtube.com/watch?v=mMJlI0rgXVo&feature=channel[/youtube]

RE: Gasket material for PeeWee conversion?
 

Okey, it has now been in the air for four tanks and is still running strong. The exhaust oil is barely coloured.
Very easy handstarts (no spring starter needed) when priming the side of the piston and backing off the compression screw about 1/8 of a turn. It fires each time and it has only started in the wrong direction once.
Might try to add an exhaust throttle also as it flies more like a clipped wing cub at the moment...

RE: Gasket material for PeeWee conversion?
 

In my Baby Bee with Davis head (and crankshaft), I found the teflon gaskets to last not much more than 10 flights.
I changed for beer can aluminium which is much better: about 30 flights so far.
One of my clubmates swears by soft copper sheet, says it lasts forever.

RE: Gasket material for PeeWee conversion?
 

Not everyone checks the forum every day. ;)

Metal is not going to be a good material for a diesel conversion like Davis makes because it flutters back and forth every revolution. Metal will only withstand that for so long, regardless how minute the movement. Brass should last longer than Aluminum though.

RE: Gasket material for PeeWee conversion?
 

Have tried Pop can aluminium and thin copper to make new disks, copper is the longer lasting material (TD .049/Davis head). I made myself a punch to make 12mm disks easily so I can try many material types. Surprised the Pee-Wee cranck can survive diesel conversion at all!