shaving the head?
Moderator: Moderator
-
- Elite
- Posts: 722
- Joined: Thu Apr 19, 2007 6:40 pm
- Location: oregon coast
shaving the head?
I'm gonna try and make more power out of my motor, but i don't want to compromise the reliability of it. Will shaving the head make me need to worry about blowing a hole in the piston? Also, im wanting more midrange power, will shaving the head give me that, how about porting the intake. or port and polish the exhaust? any other suggestions?
thanks -Jimmy
thanks -Jimmy
-
- CBR1000RR
- Posts: 4957
- Joined: Sun Apr 16, 2006 11:51 am
- Location: Southern Michigan
Re: shaving the head?
Watch your CHT(buy a gauge!), watch your jets, use plenty of oil (25:1).PimpinSpree wrote:I'm gonna try and make more power out of my motor, but i don't want to compromise the reliability of it. Will shaving the head make me need to worry about blowing a hole in the piston? No, just wasier starts and more top end power Also, im wanting more midrange power, will shaving the head give me that, Nohow about porting the intake.gives ya low and mid or port and polish the exhaust?Higher RPM and more everything any other suggestions?
thanks -Jimmy
I am not a mechanic, nor do I play one on TV. Actually my advice is probably worth slightly less than what you pay to view it.
-
- Spree
- Posts: 240
- Joined: Sat Sep 27, 2008 2:09 am
- Location: Bathroom
Shaving the head will increase your compression, may give you more power but not sure if it'll be noticeable. If the compression's too high, your electric start may not have enough power to deal with that. Naturally you'd want to run higher octane fuel and like Kenny said a CHT gauge is definitely something I'd install.
Personally I wouldn't shave the head but that's up to you. It's more likely that you'd stand to notice and gain more midrange power with a ministroke setup but the problem with ministroke cranks is that all of them are made cheaply, we break a lot of them here.
Porting a Contessa is good stuff but you need to know how to port it. Some guys have polished the exhaust port and wondered why so much carbon sticks to it. I don't know if your block is ported but that's another area you could work on. The bore's intake and boost ports needs the rough casting removed and then the exhaust port can be worked on. Keep in mind that you'll likely have to re-tune after this with jets and weights again. There's some guys I know who run stock cranks that will beat ministrokes simply because they know how to port.
Personally I wouldn't shave the head but that's up to you. It's more likely that you'd stand to notice and gain more midrange power with a ministroke setup but the problem with ministroke cranks is that all of them are made cheaply, we break a lot of them here.
Porting a Contessa is good stuff but you need to know how to port it. Some guys have polished the exhaust port and wondered why so much carbon sticks to it. I don't know if your block is ported but that's another area you could work on. The bore's intake and boost ports needs the rough casting removed and then the exhaust port can be worked on. Keep in mind that you'll likely have to re-tune after this with jets and weights again. There's some guys I know who run stock cranks that will beat ministrokes simply because they know how to port.
Reliable and dependable tuning from 15+ years of experience.
-
- Elite
- Posts: 722
- Joined: Thu Apr 19, 2007 6:40 pm
- Location: oregon coast
-
- Spree
- Posts: 240
- Joined: Sat Sep 27, 2008 2:09 am
- Location: Bathroom
-
- CBR1000RR
- Posts: 4957
- Joined: Sun Apr 16, 2006 11:51 am
- Location: Southern Michigan
-
- Elite
- Posts: 722
- Joined: Thu Apr 19, 2007 6:40 pm
- Location: oregon coast
so i shaved the head. Instead of wasting 5 gallons of premix. I just added some octane booster too it, with bad results. After it got hot it started pinging, so i went to shut if off, and it had so much compression i couldn't shut it off, i pulled the spark plug boot and it did nothing. I had to stick my glove over the exhaust.
Would running premium fix my problems? I think im just gonna go back to a normal head.
Would running premium fix my problems? I think im just gonna go back to a normal head.
-
- Spree
- Posts: 240
- Joined: Sat Sep 27, 2008 2:09 am
- Location: Bathroom
Did you raise the compression on your 65cc kit? Those piston/bores are already running at higher compression than stock. Check your compression and report back; I'm interested in what your static compression is with that shaved head. With Spree, you're raising it from around 110 to 130-140 PSI.
You can probably keep using the shaved head if you run 2 head gaskets.
You can probably keep using the shaved head if you run 2 head gaskets.
Admin, Hondaspree.net
Buy air filters and gaskets here (Ebay): http://stores.ebay.com/noiseguysstore
Buy air filters and gaskets here (Amazon): www.amazon.com/shops/spreepower
Buy a t-shirt here: https://teespring.com/stores/spree-powersport-products
Buy air filters and gaskets here (Ebay): http://stores.ebay.com/noiseguysstore
Buy air filters and gaskets here (Amazon): www.amazon.com/shops/spreepower
Buy a t-shirt here: https://teespring.com/stores/spree-powersport-products
- scooter trash
- BMX
- Posts: 32
- Joined: Sun Nov 11, 2007 6:55 pm
- Location: CA