high compression setup

[gectek]

Fly. Cut.

[Superdave]

Valve clearance, or your actual cold quench?

geldartb's ABDC


I'll measure my clearance in a while...

[bszopi]

We've discussed dynamic compression before (I even built it into the CR calc), but pretty much decided that trying to calculate it still doesn't give you accurate information. So I wouldn't trust those numbers very much...

[IsaacHayes]

I found a calculator that computes DCR via cam specs without knowing the IVC, and it's showing your DCR to be way up there Brandon from 12.53:1. It's going to take more than 41.5* if that is what Dave was saying to drop 12.53 down to reasonable levels. I'm at 10.75:1 DCR which works on 93 octane, and I'll be running it on 91 come spring since that's all we have. I just hope it will run ok without pulling a ton of spark. I'll try TR6 plugs to help it out some if I need to and feed it the coldest possible intake charge I can get it.

[geldartb]

41.5

mine or yours?

[ForcedFirebird]

41.5

Valve clearance, or your actual cold quench?

[Superdave]

41.5

[geldartb]

sent him a PM so ill be waiting for the response.

damn should have asked him what the difference in power i would make at the higher cr vs what its putting out now. ah well ill ask him when he responds.

[IsaacHayes]

Ask him what it is, he was able to tell me for my cam, which was not on the grind chart.

[geldartb]

the only specs i have are the specs ben listed on the site. didnt get anything like a cam card.

i have the specs he had listed saved somewhere unfortunately there not on this computer.

227int 233exh
112lsa
108 int 116exh lobe center
322int 322exh lobe lift
.515int .515exh

found the excel file on here again but thats all i ever had for specs.

maybe i can see if Ben can throw something together in the program he's got or something from the old setup of cam's he had before.

[IsaacHayes]

Bradon, what is your intake valve closing ABDC ? I'm wondering what the 12.52:1 compression will be actual with your cam.

[geldartb]

iirc my limiter is set around 6500-6600 although i havent taken it much above 6200ish right now.

sacrificing the tootsie rolls for the engine.

cool looking forward to the numbers.

Lol at the pic.

[Superdave]

Lol...


my limiter is set to 7K, i usually shift a little before that.


I do have a lot of exhaust duration and the lift is pretty high. Maybe tonight i'll make a pair of solid lifters, toss one of the heads back on and a few tootsie rolls on the piston.


I'll post the numbers sometime soon.

[60dgrzbelow0]

...I just pulled the engine apart and there was a mark on the one "new" piston as well.. this time I was using stock head gaskets.

Well Dave ...there can only be one other answer as to why this is happening....

[geldartb]

yeah as noted Dave's issue is his duration and ramp rate on his cam plus the rpm and stretch of the rods at higher rpm's.

with that taking into consideration i should be all set.

im still gonna have to address the transmission too. its holding its own right now.