45mm bbk compression
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45mm bbk compression
i finally got my rings on my piston and everything back together. i did a compression test and it was 139. i was wanting some input from the scooter gurus. is this compression ok?
Thanks:
TJ
Thanks:
TJ
Re: 45mm bbk compression
Iceman, are you using the stock head, with what gasket? It's the kit from Patrick?
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Re: 45mm bbk compression
sorry i got in a rush posting.bonesv wrote:Iceman, are you using the stock head, with what gasket? It's the kit from Patrick?
yes stock head and i'm using the gasket that came w/ the kit from patrick.
TJ
Re: 45mm bbk compression
you may want to order an aftermarket 45mm head to match or take your stock head to a machine shop to have them match it to your cylinder. You can probably run it like that but I wouldnt
1986 Spree/ Eve af16 swapped 65cc Prodigy vari 8g 9:1 Ruima gears
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
Re: 45mm bbk compression
Mystic wrote:you may want to order an aftermarket 45mm head to match or take your stock head to a machine shop to have them match it to your cylinder. You can probably run it like that but I wouldnt
just curious what issues it would have if i ran it w/ the stock head?
thanks:
TJ
Re: 45mm bbk compression
the area around the spark plug is your combustion chamber and the area around the edge is the squish band. The squish band reduces the chance of detotation by concentrating most of your fuel mixture within the combustion chamber, the rest of the mixture helps with cooling the cylinder basically. There is more to it I am sure but that is my understanding of it. With higher compression and a larger mismatched squish area you increase the risk of detonation and overheating
1986 Spree/ Eve af16 swapped 65cc Prodigy vari 8g 9:1 Ruima gears
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
Re: 45mm bbk compression
Mystic wrote:the area around the spark plug is your combustion chamber and the area around the edge is the squish band. The squish band reduces the chance of detotation by concentrating most of your fuel mixture within the combustion chamber, the rest of the mixture helps with cooling the cylinder basically. There is more to it I am sure but that is my understanding of it. With higher compression and a larger mismatched squish area you increase the risk of detonation and overheating
got ya. thanks for the input. i diff don't want over heating.
thanks:
TJ
Re: 45mm bbk compression
THere are other that should be able to explain it better like Bear or bakaracer
1986 Spree/ Eve af16 swapped 65cc Prodigy vari 8g 9:1 Ruima gears
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
21mm OKO 42/100 32:1 45mph kymco zx exhaust
1994 Elite S 17.5mm Arreche, Daytona reeds, SEF ramp, pump plugged
1987 Elite SE50 af16 swapped
1989 Elite E SB50p
2003 Yamaha Zuma
Re: 45mm bbk compression
Find a malossi or polini head. The squish band angle is already set and the diameter cutout will be really close to what you need it to be.
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Re: 45mm bbk compression
got ya.
but for now i have the stock head on and the compression is 139. will i be ok to run it?
thanks:
TJ
but for now i have the stock head on and the compression is 139. will i be ok to run it?
thanks:
TJ
Re: 45mm bbk compression
I wouldn't run it like that. The stock head is to small and the flat area that sticks out into the cylinder area will cause flow turbulance which will cause lower power then should and over heating issues from engine knock. The squish band prevents that from happening.
Nothing like getting stroked!
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Re: 45mm bbk compression
bakaracer wrote:I wouldn't run it like that. The stock head is to small and the flat area that sticks out into the cylinder area will cause flow turbulance which will cause lower power then should and over heating issues from engine knock. The squish band prevents that from happening.
ok... i have a head from a 51mm ruima bore. would that be ok to use?
TJ
Re: 45mm bbk compression
Probably not going to have enough compression with that. I have the same cylinder kit, the stock head was not allowing good enough power without the excess heat. It just wouldn't cool enough AND run well. I had it apart at least 5 different times and did not see any abuse or noticable wear.
I now use a malossi 47mm aluminum head with an o-ring gasket AND an aluminum head gasket which keeps the compression at 125 psi.
I am also running a PG Short exhaust pipe. A small but usable 19mm oko carb, jetting at 120 main/42 pilot, clip in the middle. No posted speeds yet.
The set up I run currently max. rpm at 8600 which is far above what this is rated for but I've done some port work and polishing.
Check with Keith and order a new head, you won't regret it: http://www.hondaspree.net/phpBB3/viewto ... =2&t=19538 He is FAST shipper!
You won't ruin your motor running it like it is but at least put a cht gauge on it so you know when to adjust it. Happy Trails!
I now use a malossi 47mm aluminum head with an o-ring gasket AND an aluminum head gasket which keeps the compression at 125 psi.
I am also running a PG Short exhaust pipe. A small but usable 19mm oko carb, jetting at 120 main/42 pilot, clip in the middle. No posted speeds yet.
The set up I run currently max. rpm at 8600 which is far above what this is rated for but I've done some port work and polishing.
Check with Keith and order a new head, you won't regret it: http://www.hondaspree.net/phpBB3/viewto ... =2&t=19538 He is FAST shipper!
You won't ruin your motor running it like it is but at least put a cht gauge on it so you know when to adjust it. Happy Trails!
Honda Elite SR
Honda Elite-Dio ZX
Dio ZX Headlight/Disc Brake Mod: http://hondaspree.net/phpBB3/viewtopic.php?t=30861
Honda Elite-Dio ZX
Dio ZX Headlight/Disc Brake Mod: http://hondaspree.net/phpBB3/viewtopic.php?t=30861
- kingkamehameha
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Re: 45mm bbk compression
Dont fool around with the stock head or mismatched heads. Get the one thats designed for the bore or go pay a machine shop to cut the head to the right size. Either way your gonna have to shell out 30 bucks to get the right size
ua mau ke 'ea o ka aina i ka pono o hawaii