Cam Advance and Retard... which do i do to make this change?

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Oct 28, 2003 | 02:35 PM

T/A Medic

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From: The Thin Air

Cam Advance and Retard... which do i do to make this change?

my tsp 231/237 is on a 112 +2

do i advance it or retard it 2deg to get it to 110 +2 ?

Normally Installed it looks like this...

Intake Valve opens - IVO 5.5 BTDC (- indicates ATDC)
Intake Valve closes - IVC 45.5 ABDC
Exhaust Valve Opens - EVO 52.5 BBDC
Exhaust Valve Closes - EVC 4.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 114
Overalap 10 degrees

I want it to look like this 110 lsa +2

Intake Valve opens - IVO 7.5 BTDC (- indicates ATDC)
Intake Valve closes - IVC 43.5 ABDC
Exhaust Valve Opens - EVO 50.5 BBDC
Exhaust Valve Closes - EVC 6.5 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 112
Overalap 14 degrees

Oct 28, 2003 | 03:55 PM

Reboot

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From: Sacramento

Quote:

Originally Posted by T/A Medic

You can't change the LSA by advancing or retarding the cam. A 112+2 would mean the quoted cam specs are accurate when installing at a 110ICL. To reach your target valve events you would install the cam at a 108ICL or +4. It would still be a 112 LSA.

Don

Oct 28, 2003 | 04:00 PM

Jabroni

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From: Orlando

LSA is ground in. Unfortunately, you're stuck with it.

Oct 28, 2003 | 04:25 PM

Gage

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Quote:

Originally Posted by Jabroni

LSA is ground in. Unfortunately, you're stuck with it.

Yes and NO
you ARE stuck with the LSA but you CAN retard to get your desired VEs if you wish. what he is asking here how much mest he retard to get the desired VEs,altho not perfectly he can get Verry close..

Oct 28, 2003 | 05:30 PM

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From: Sacramento

Quote:

Originally Posted by Gage

He has to advance an additional 2 degrees to get the desired VE's. Retarding the cam will move the VE's in the opposite direction of what he's looking for.

Oct 28, 2003 | 07:44 PM

Gage

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Quote:

Originally Posted by Reboot

He has to advance an additional 2 degrees to get the desired VE's. Retarding the cam will move the VE's in the opposite direction of what he's looking for.

DOH, ya thats what i ment, lol
this retarded 2deg.
IVO 3.5
IVC 47.5
EVO 50.5
EVC 6.5

and this is advanced 2deg(to make it +4 from the original)
IVO 7.5
IVC 43.5
EVO 54.5
EVC 2.5

Last edited by Gage; Oct 28, 2003 at 07:50 PM.

Oct 28, 2003 | 08:25 PM

Reboot

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From: Sacramento

Quote:

Originally Posted by Gage

DOH, ya thats what i ment, lol
this retarded 2deg.
IVO 3.5
IVC 47.5
EVO 50.5
EVC 6.5

and this is advanced 2deg(to make it +4 from the original)
IVO 7.5
IVC 43.5
EVO 54.5
EVC 2.5

Hehe! I would actually retard that cam. I like those VE's better.

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