noobie cylinder question
noobie cylinder question
ok i have a 91 with a 90.5 weisco piston. it is a super freash rebuild. it has no relief on the bridge and no holes in the piston. it does appear that the piston has a bit of side play. what is the max play side to side and what would happen if you dont relief the bridge? and if i have to relief how deep do i go? also it has no scallops and i might want to have them machined in where do they go and how deep and how tall. is there any directions? havent ran the motor just wanta make sure it's right the first time. also i check my cylinder and came out with 90.5 id. and it's a 90.5 piston. still seems to have a few thousands play.
updat piston number is 636m09050 all i know is that it is 90.50. i did mic it and it came out to 90.00 so all i can guess is taht 90.50 is with rings. it is not drilled. so should i take the cylinder to the machine shop and have them drill the piston and relieve the bridge. and if so while im there should i get the scallops put in or is it borded too much over. where is the directions for all of this. thanks and : bling : guys. boy im coming along fast for a 4 stroker. hahah
Scallops are for eating, not putting in engines. (I dont even like eating them)
Yah, I'm from Saskatchetoon!
MRE 02 250/500 conversion, pulse injector, twirp porting, coolhead, MRE ignition, blah blah blah blah... www.millarengines.com
MRE 02 250/500 conversion, pulse injector, twirp porting, coolhead, MRE ignition, blah blah blah blah... www.millarengines.com
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- Posts: 1898
- Joined: June 23rd, 2007, 12:47 pm
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Scallops exsist in the stock bore, and end up getting honed away when the cylinder is refinished. They allow for less compression when starting the bike. Have a good engine builder do them, GSS would be a good choice. If you send him the jug, piston and head and tell him to make your bike fast and streetable, he will set you up right.
Don't Clyde it, ride it!
- iggys-amsoil
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- Location: Just North of March Airfield CA
http://bannedcr500riders.com/board/viewtopic.php?t=606aloha450x wrote:who is gss?
Money ain't got no owners, only spenders - Omar Little
If the exhaust bridge isnt relieved and you have no holes drilled in the piston expect to squeek it within the first 5 gallons of gas.. You need to relieve the bridge properly and or have the piston drilled. My bridge was relieved properly and i didnt drill the holes in my piston.. Been goin great since my last rebuild
97 Steel 500 that wants to be an AFC
- iggys-amsoil
- Posts: 3602
- Joined: June 1st, 2007, 6:09 pm
- Location: Just North of March Airfield CA
Removing the bridge is for full on race. Not a good idea for the street.aloha450x wrote:ok got the directions on relieving the bridge and scallops. what is the cons of scallops? alos could i run with no bridge. i have read of few people that just machine that shit out. remember this is a street bike that will be seeing lots of revs and being beat up like a hooker. lol
Dont bother with the scallops, they decompress the cylinder during starting. Have the bridge PROPERLY relieved per the manual. Drill the holes, they hurt nothing and could save the motor.
If you havnt had the motor ported for mid/top end revving the snot outta it is only gonna make you go SLOWER and over heat. Oh ya, and look stupid...
If you havnt had the motor ported for mid/top end revving the snot outta it is only gonna make you go SLOWER and over heat. Oh ya, and look stupid...
Faster then Speedy Gonzalez, slower then the Road Runner!!! MEEP MEEP
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
Use a spring loaded center punch, the curve of the piston makes it real easy for the drill bit to "walk"...aloha450x wrote:shit nevermind thanks for the help. im gonna drop it off in the morning. and ill drill the piston myself.
Faster then Speedy Gonzalez, slower then the Road Runner!!! MEEP MEEP
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
Don't be scared.........AlisoBob wrote:Those are pretty big...
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LIVIN THE DREAM!!!
NOTHING BUT GREEN LABEL BLENDZALL!!!
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http://www.pro-hillclimbers.org/
I'm not scared, but I think their defeating the thought..pstoffers wrote:Don't be scared.........AlisoBob wrote:Those are pretty big...
Smaller holes allow lube onto the majority of surface area.
Bigger hole reduce the amount of surface area, increasing load on the remaining area.
Also, primary compression is going out those holes too.
I know Glen drills em' big, but I dont agree with it.
With proper relief you "shouldnt" need the holes. They are a "back-up" and dont hurt anything to have. Can you say FREEBIE!!Caseys500 wrote:the diagram does show smaller holes...i didnt even put any holes in mine. I could tell there was a good relief on the bridge...no problems and I have put 20-30 hrs on it.
Rick, those things are HOOOOOG!! I thought that was a picture of a pen/pencil holder at first!! HAHA
Faster then Speedy Gonzalez, slower then the Road Runner!!! MEEP MEEP
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
I think the reasoning for the bigger holes is better "cooling" from the raw fuel contact on the bridge. But I think that greater contact area with the piston may offer better cooling??AlisoBob wrote:I'm not scared, but I think their defeating the thought..pstoffers wrote:Don't be scared.........AlisoBob wrote:Those are pretty big...
Smaller holes allow lube onto the majority of surface area.
Bigger hole reduce the amount of surface area, increasing load on the remaining area.
Also, primary compression is going out those holes too.
I know Glen drills em' big, but I dont agree with it.
Faster then Speedy Gonzalez, slower then the Road Runner!!! MEEP MEEP
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee