Compression release question.
Thread Starter
|
Tourer
Joined: Jan 2011
Posts: 376
Likes: 27
From: Ontario
Compression release question.
Hello
Would it be beneficial to put in the compression release at 10.5:1 CR
The heads already are machined for the valves
I'm looking to bore out to 98"
Weisco pistons ..(called weisco to ensure I get right pistons for that compression ratio)
Rienhart 2 into 1 exhaust
Converting bike over to carb from MM EFI
Daytona twin tec tc88 ignition module
Heads are SE performance heads
Cam SE 257
Intake open 24
Closed 48
Exhaust open 51
Closed 21
Intake duration 252
Exhaust 260
Overlap 45
Intake lobe centre 102
Exhaust 109
Lobe Sep. Angle 105.5
Lift .569
Intake lift TDC .213
Exhaust TDC .200
Would it be beneficial to put in the compression release at 10.5:1 CR
The heads already are machined for the valves
I'm looking to bore out to 98"
Weisco pistons ..(called weisco to ensure I get right pistons for that compression ratio)
Rienhart 2 into 1 exhaust
Converting bike over to carb from MM EFI
Daytona twin tec tc88 ignition module
Heads are SE performance heads
Cam SE 257
Intake open 24
Closed 48
Exhaust open 51
Closed 21
Intake duration 252
Exhaust 260
Overlap 45
Intake lobe centre 102
Exhaust 109
Lobe Sep. Angle 105.5
Lift .569
Intake lift TDC .213
Exhaust TDC .200
Seasoned HDF Member
Joined: Oct 2019
Posts: 10,864
Likes: 7,499
From: OH
Previously there was an unanswered question as to whether your S.E. heads were 72 or 76 cc
Did you have them measured ? Find the part # to answer this question ?
Short answer : I`d have them installed while the heads are off. ( you say the machine work for C/R "valves" is already done ?
EDIT: FWIW, I have a VERY similar 98" and use them every time.
Would it crank well HOT w/o them ? Maybe, don`t know , haven`t tried it
Did you have them measured ? Find the part # to answer this question ?
Short answer : I`d have them installed while the heads are off. ( you say the machine work for C/R "valves" is already done ?
EDIT: FWIW, I have a VERY similar 98" and use them every time.
Would it crank well HOT w/o them ? Maybe, don`t know , haven`t tried it
Last edited by eighteight; Dec 22, 2020 at 12:42 PM.
Thread Starter
|
Tourer
Joined: Jan 2011
Posts: 376
Likes: 27
From: Ontario
Previously there was an unanswered question as to whether your S.E. heads were 72 or 76 cc
Did you have them measured ? Find the part # to answer this question ?
Short answer : I`d have them installed while the heads are off. ( you say the machine work for C/R "valves" is already done ?
EDIT: FWIW, I have a VERY similar 98" and use them every time.
Would it crank well HOT w/o them ? Maybe, don`t know , haven`t tried it
Did you have them measured ? Find the part # to answer this question ?
Short answer : I`d have them installed while the heads are off. ( you say the machine work for C/R "valves" is already done ?
EDIT: FWIW, I have a VERY similar 98" and use them every time.
Would it crank well HOT w/o them ? Maybe, don`t know , haven`t tried it
They are 76cc
But I will have them cc'd otherwise
Yes the heads already machined to install the valves
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,754
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From: Snow Hill, NC
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HDF Community Team
Joined: Jun 2006
Posts: 12,782
Likes: 2,610
From: san antonio
Don't disagree with installing compression releases; they extend battery and starter life. However, static CR is really not the criteria for deciding if CRs are "needed" or not; the criteria is CCP. In the OPs case, even with 10.5 static, CCP is about 9.3 if his listed specs are correct. At 9.3CCP, IMHO, CRs are not "needed" but they certainly won't hurt particularly since the heads are already prepped for them.
