head volume
Thread Starter
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Tourer
Joined: Jan 2008
Posts: 359
Likes: 21
From: Midland Tx.
stock is suppose to be 83cc but it can be anywhere from 81cc to 85cc. if yours are 74 they have been cut thats the volume that most hot rod builders shoot for. with 74cc heads .030 head gasket wiseco 10:1 pistons .003 in the hole and a wood w-9 cam will give you 11:1 static compression and 9.67:1 corrected that's as high as you can go on pump gas.
with flat top pistons and ev51 cam your static would be 9.3:1 and corrected is 8.4:1
with flat top pistons and ev51 cam your static would be 9.3:1 and corrected is 8.4:1
I'm not looking to race, just have some over stock so I don't get lost behind the newer bikes.
I hade an evo with the headquarters system 85 setup and that ran well, this Andrews cam seems a bit bigger, but not a huge amount.
Road Master
Joined: Feb 2014
Posts: 913
Likes: 5
From: indiana
Glad you brought that up, because I'm not clear, when Andrews recommends 9 or better comp. for this cam, are they referring to static or corrected? I'm assuming static; corrected seems to be referred to less.
I'm not looking to race, just have some over stock so I don't get lost behind the newer bikes.
I hade an evo with the headquarters system 85 setup and that ran well, this Andrews cam seems a bit bigger, but not a huge amount.
I'm not looking to race, just have some over stock so I don't get lost behind the newer bikes.
I hade an evo with the headquarters system 85 setup and that ran well, this Andrews cam seems a bit bigger, but not a huge amount.
the magic number is 9.6:1 corrected if you put 10:1 wiseco in it and a .045 head gasket you will be at 9.6:1 corrected the bike will be a beast.
right now your motor has to big of a cam its probably a little soft on the bottom end. go with a ev27 or wood w6
or more compression.
Dirt don't hurt
Joined: Jan 2011
Posts: 21,059
Likes: 4,534
From: Haslet Texas
the magic number is 9.6:1 corrected if you put 10:1 wiseco in it and a .045 head gasket you will be at 9.6:1 corrected the bike will be a beast.
right now your motor has to big of a cam its probably a little soft on the bottom end. go with a ev27 or wood w6
or more compression.
right now your motor has to big of a cam its probably a little soft on the bottom end. go with a ev27 or wood w6
or more compression.
Thread Starter
|
Tourer
Joined: Jan 2008
Posts: 359
Likes: 21
From: Midland Tx.
the magic number is 9.6:1 corrected if you put 10:1 wiseco in it and a .045 head gasket you will be at 9.6:1 corrected the bike will be a beast.
right now your motor has to big of a cam its probably a little soft on the bottom end. go with a ev27 or wood w6
or more compression.
right now your motor has to big of a cam its probably a little soft on the bottom end. go with a ev27 or wood w6
or more compression.
Road Master
Joined: Feb 2014
Posts: 913
Likes: 5
From: indiana
make sure and check your deck height before you buy head gaskets so you can get the correct compression ratio you don't want to go over 9.6 corrected or you will have detonation problems and never run anything lower than 92 octane.
if you want to be safe you could buy james .060 head gaskets with the 10:1 pistons and that cam you would still be at 9.3:1 corrected.
Thread Starter
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Tourer
Joined: Jan 2008
Posts: 359
Likes: 21
From: Midland Tx.
make sure and check your deck height before you buy head gaskets so you can get the correct compression ratio you don't want to go over 9.6 corrected or you will have detonation problems and never run anything lower than 92 octane.
if you want to be safe you could buy james .060 head gaskets with the 10:1 pistons and that cam you would still be at 9.3:1 corrected.
if you want to be safe you could buy james .060 head gaskets with the 10:1 pistons and that cam you would still be at 9.3:1 corrected.
I have a friend with a stroked shovel that's running 10:1 with a big cam and he always has to add. Oh, and rebuild often too!
Road Master
Joined: Feb 2014
Posts: 913
Likes: 5
From: indiana
I'm measuring .009 below so I don't think the .040 is any problem, and maybe a 9.5:1 piston might be a safer choice. Granted, it's not the motors "full potential" but will probably suit me. It's hard to find even 91 octane around here, and I don't want to have to carry additive with me everywhere I go.
I have a friend with a stroked shovel that's running 10:1 with a big cam and he always has to add. Oh, and rebuild often too!
I have a friend with a stroked shovel that's running 10:1 with a big cam and he always has to add. Oh, and rebuild often too!
yes a 9.5 would be better but wiseco doesn't have one and they are the only pistons I will buy. they are a superior product
Road Captain
Joined: Aug 2012
Posts: 625
Likes: 102
From: New Albany, Ms.
Hey D,
One question. All info that I have found, says to keep the corrected compression around 8.9:1 to 9.1:1 for a good streetable motor. I'm at a measly 8.56:1 right now, and have had a couple hard starts, this past summer & harder starts , this winter, with compression bumped to what it is now. Added new battery, new AllBalls starter, BDL 84/10 ring gear kit, new Terry battery cables. Not a real problem in warm weather, but is when temps get below 55. Went to lighter weight oil, & helped some. So I pulled the heads, couple of weeks ago, & put Compression release's in them to help, & had my indy cc the heads to give me a 9.0:1 corrected. My question to you is , where did the magic number of 9.6:1 come from? Not saying thats wrong, just trying to learn. Got a link to a article?
Sorry to the OP for the hijack.
Ride Safe,
Harold
One question. All info that I have found, says to keep the corrected compression around 8.9:1 to 9.1:1 for a good streetable motor. I'm at a measly 8.56:1 right now, and have had a couple hard starts, this past summer & harder starts , this winter, with compression bumped to what it is now. Added new battery, new AllBalls starter, BDL 84/10 ring gear kit, new Terry battery cables. Not a real problem in warm weather, but is when temps get below 55. Went to lighter weight oil, & helped some. So I pulled the heads, couple of weeks ago, & put Compression release's in them to help, & had my indy cc the heads to give me a 9.0:1 corrected. My question to you is , where did the magic number of 9.6:1 come from? Not saying thats wrong, just trying to learn. Got a link to a article?
Sorry to the OP for the hijack.
Ride Safe,
Harold
Thread Starter
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Tourer
Joined: Jan 2008
Posts: 359
Likes: 21
From: Midland Tx.
Hey D,
One question. All info that I have found, says to keep the corrected compression around 8.9:1 to 9.1:1 for a good streetable motor. I'm at a measly 8.56:1 right now, and have had a couple hard starts, this past summer & harder starts , this winter, with compression bumped to what it is now. Added new battery, new AllBalls starter, BDL 84/10 ring gear kit, new Terry battery cables. Not a real problem in warm weather, but is when temps get below 55. Went to lighter weight oil, & helped some. So I pulled the heads, couple of weeks ago, & put Compression release's in them to help, & had my indy cc the heads to give me a 9.0:1 corrected. My question to you is , where did the magic number of 9.6:1 come from? Not saying thats wrong, just trying to learn. Got a link to a article?
Sorry to the OP for the hijack.
Ride Safe,
Harold
One question. All info that I have found, says to keep the corrected compression around 8.9:1 to 9.1:1 for a good streetable motor. I'm at a measly 8.56:1 right now, and have had a couple hard starts, this past summer & harder starts , this winter, with compression bumped to what it is now. Added new battery, new AllBalls starter, BDL 84/10 ring gear kit, new Terry battery cables. Not a real problem in warm weather, but is when temps get below 55. Went to lighter weight oil, & helped some. So I pulled the heads, couple of weeks ago, & put Compression release's in them to help, & had my indy cc the heads to give me a 9.0:1 corrected. My question to you is , where did the magic number of 9.6:1 come from? Not saying thats wrong, just trying to learn. Got a link to a article?
Sorry to the OP for the hijack.
Ride Safe,
Harold