Originally Posted by nw_guy4_fun
I would think this is simple just use the parts they suggest, all of them, and it should work fine. Sorry haven't seen them yet but they haven't lied to us about the performance of the standard release, so based on that would be inclined to use their cam, heads and 12/1 pistons.
I hear ya Don.
let me put it a diff way.
I am sure using the 12.1 pistons .267 cams and the hurricane heads, would work as they described. this would be a high rpm hp build no doubt.
my thinking is..... most likely I will end up with a shorter cam than even the 266 E although it might just work out. I advanced the 266 E in the 120r crate motor 4 deg. the graph didnt show much of a change in the curve actual it didnt change the curve at all, just the peak HP/TQ. swapped around. it made slightly more hp than tq (straight up) after the 4 deg advance it made slightly more tq than hp. SOP riding was ...the bike felt good all over. a lot more responsive than with the cams straight up. I didnt have the time to do any partial throttle pulls before and after,because of clutch problems ,and the owner let me have it for a week and wanted it back (cant blame him for that).
so anyway back to what I am wondering.....why not use the hurricane heads on the crate motor with stock 10.5 advertised comp. the MVA heads are advertised as 95 cc heads. "IF" the hurricanes are 95 cc also (is my understanding they are but cant find the specs) why wouldnt they come in at the same compression ,and just work better "they flow better" or so they are advertised as such.
I cant help but think they (Hurricanes) would be better even without the 12.1 pistons and 267 cams.
the 267 cams will bleed off comp. with the 12.1's, not sure how much they will bleed off with the 12.1, in comparison to the 10.5 with 266E's.
on the crate motor if you just swapped the 266's to 267's it would bleed of 14.5 ccp. I dont know the dome of the 12.1 pistons ,so I cant see exactly how much they bleed off,to compare the ccp of the two.
I know this, the ccp on the 120 R crate motor was 195 with the 4 deg advance.
what I would like to do is cc the hurricanes to achieve about 205 ccp either with the 266's straight up or whatever shorter cam I would use.
red shift 658
sorry Steve I was typing when you posted. thanks for the math ccp on the xtreme would be 210?
I am considering something like you doing also. that's why I haven't made the calls yet LOL!