Vid

[rockiedog2]

sent Casler a link to the 4050 rpm vid and the climb angle vid. asked him if i had voided the warranty. havent heard back
spencer

[Steve]

Reading in Steve Witman racing lore, the O-200 would hold together at 4200 rpm - the Corvair boyz (I was one) would run down the eways at 4500 rpm on a stock engine... It has a lot to do with the quality of the performance balance job at higher rpm's...

[rockiedog2]

SC told me the bottom end of a 45 is good for 6K. we didnt talk about the top end. what do you old VDub heads think?

[Steve]

I think the valves will start floating at 5k...

[Dan_]

~~I think the valves will start floating at 5k...~~

Yap, and right about there is where it might start eating valve sammidges...

[rockiedog2]

i felt fine with it at 4K+...smooth, sounded busy as hell but happy...
one thing i'm thinking about is it takes it so long to wind out. suspecting the high drag frame. also that prop has a thick camber which is a little draggy. but nice and stiff. have given a little thought to the breathing possibility somebody mentioned yday. at 4K it shud be making maybe up near 50 hp. havent looked at the mikuni chart but wouldn't be surprised if that called out a bigger carb

[Dan_]

Joe,
The plane is dam near perfect...  Every time you make something a littler better, there is always going to be the next thing that is holding it back in some small way.  You are down to splitin hairs, and have been for a while. 


If it is running short of breath, it could be the carb bore, or it could be the porting on the heads, or...     I'd say you are just about there on getting much more out of the plane...
Except maybe a light weight JATO.  :pee:

[Dan_]

asked him if i had voided the warranty

Joe,
I notice the right cylinder has noexhaust pipe.   I'd ask him about that...  Even too short a stack can warp valves.  They cool off too quickly.

[rockiedog2]

i thank theres another 100 fpm in it. just gotta keep tweaking. combination of things. prop probably #1. the breathing question has interested me. think i'll do the can behind the carb thing first
since the 2 carb setup have run i dunno about a half dozen props on it all seemingly what should have been more a climb prop than turned out to be. they all top out at 3350-3450 at 45 mph climb. interesting. got a couple 32s borrowed from Hugh.
on the short stacks...both sides have sink drains. when i saw you said the right cyl didnt have a tailpipe i jumped up and ran out in the hangar and checked. theres a sink drain on there. i thought it'd fallen off. i asked casler about those short stacks years ago and he said yeah thats no prob. so far i got about 300 hours with those stacks and no valve probs yet. but thx for the headsup