Anyone running 10:1 comp with andrews 37g cams? I'm starting to second guess my set-up. Nothing installed yet, but I don't want a ping monster. The SE catalog says with se cast flat tops and se pro mcr heads with 95" will give 10:1 (this is what I have) They also say that stock 88" is 9.0:1 comp which I hear it isn't. Maybe their 10:1 is also high? Any thoughts/advice?

 

I am. Just went up to a 103" yesterday and that brings compression to 10:1. Just breaking it in, so haven't pushed it hard enough to ping yet, but I'm also at 6500 altitude so I need the extra compression up here. So far, feels real strong. Dealer ran it through the dyno after putting it back together - 90 hp and 103 tq - that is untuned. I may be able to get close to 100/110 when done. The torque curve is fairly broad, which is what I was after.

The recommendations I got prior were 9.5 - 9.8 in general; 9.8 - 10.2 at my altitude.

Mark

 

You can never assume what compression ratio at, or go by what they say in the catalog. You have to measure your deck height and have your head's chambers CC'ed in order to know what you have for a compression ratio.

Andrews 37 cams like no more then 9.8:1 compression or else they will ping like crazy.

Steve

 

UC is correct also those # are a little low for that build wait till you get it tuned.
9.8 compression and you will be pushing it for a 37g. 10.1 with a woods 6 cam but also go with compressiion releases for those hot days.
got some 95 in running 105hp/tq sae with Baisley heads with 37g cams fat cat and they are strong bikes. mostly bagger builds. real popular and they run for miles.

 

nothing but sound advice so far, I would also recomend after you blueprint your parts and setting the quench to get a Dayton twin tec igntion if your carburated, this way you have some timming adjustabiltiy to help dail it in. it is possibe to run your setup between 190 and 200 lbs of cyilder presure if your diligent at tuning.

 

Thanks everyone...I guess I should have givin more details. I live in eastern Canada and the bike is an 03 carbed wide glide. I'll be using the .055 head gasket that comes in the hd kit. What would be a good gear drive cam choice now that I have these heads? Thanks again for the honest answers and keep em coming. I still may try this combo fo the summer and start saving for a better matched set of cams.

 

with that compression woods tw6 cam ... if you could keep it at 10.0 you might get away without releases.

 

The SE MCR heads are machined for releases and I have a set, so I'm good there. Just hope that the catalog is over-rating the comp ratio by a bit. It certainly wouldn't be a stretch to find out they are. 9.7-9.8:1 would be great. I don't think there is anyone around here to cc my heads for me. But I'm gonna look around.

 

i beleive some of the guys on the HTT site checked the MCR heads. they are the bath tub design.
i think they were about 83cc not to sure tho.
how stuck on those heads are you?????
g

 

Pretty struck on them. I think givin the choice I'd change cams rather than heads...Where is the HTT site you mentioned?