Cam and Crank Dot question,???
Thread Starter
Staging Lane
Joined: Jan 2015
Posts: 81
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From: Portland, TX
Cam and Crank Dot question,??? So im in the process , of installing tsp 233/239 cam in my 02 ls1 ss... ive been reading ls1 how to for this but also had some questions... i bought springs,pushrods,lifters and the trunion upgrade,and ls2 timing chain.. my question was ,since i dont have adjustable timing chain no need to degree the cam..? just make dam sure to have the cam and crank dots lined up right.. ? crank at 12oclock,cam at six o clock.. ? just really dont wanna mess this up... ive done old school sbc and bbc cam swaps but this is my first ls swap and wanna make sure everthing goes smoothly...any input is greatly appreciated!!!!
Teching In
Joined: Apr 2013
Posts: 40
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From: Central CA
I'm in the middle of the same process and that sounds like what I found when I took it apart, what I read and what I have done going back together. Probably wont have it all the way together until tomorrow night or Saturday morning!
Fingers crossed!
Doug
Fingers crossed!
Doug
Yes, 6 o'clock for the cam, 12 o'clock on the crank. Make sure you verify PTV clearance. You CAN degree it without an adjustable timing set, you would just use an offset bushing to change timing. Personally, I would just install it dot-to-dot and let it eat.
When the dots are aligned, (crank @ 12, cam @ 6,), the number 6 cylinder is at TDC.
Number 1 is TDC when the crank is @ 12, and the cam is at 12.
Most people don't know this, and it only occurs this way on the LS series, as far as I know.
You can prove this to yourself by rotating the assembly while watching the opening and closing of valves.
Number 1 is TDC when the crank is @ 12, and the cam is at 12.
Most people don't know this, and it only occurs this way on the LS series, as far as I know.
You can prove this to yourself by rotating the assembly while watching the opening and closing of valves.
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When the dots are aligned, (crank @ 12, cam @ 6,), the number 6 cylinder is at TDC.
Number 1 is TDC when the crank is @ 12, and the cam is at 12.
Most people don't know this, and it only occurs this way on the LS series, as far as I know.
You can prove this to yourself by rotating the assembly while watching the opening and closing of valves.
Number 1 is TDC when the crank is @ 12, and the cam is at 12.
Most people don't know this, and it only occurs this way on the LS series, as far as I know.
You can prove this to yourself by rotating the assembly while watching the opening and closing of valves.
The main reason for degreeing is to make sure the cam is ground correctly. They sometime aren't as well as chain stretch, etc.
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Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
TDC is CRANK at 12 o clock, period. It has nothing to do with the cam in any way shape or form. There are two times the crank and cam are "aligned" (12 and 12 or 12 and 6). TDC on compression, and TDC exhaust. Whether it's compression or exhaust is determined by cam position. 6 or 12 o clock. So, crank at 12, cam at 6 OR 12 and you're money. Remember the cam turns half speed so a full rotation of the crank take the cam half, so you're always coming from or going to 12 and 12 or 12 and 6.
TDC is CRANK at 12 o clock, period. It has nothing to do with the cam in any way shape or form. There are two times the crank and cam are "aligned" (12 and 12 or 12 and 6). TDC on compression, and TDC exhaust. Whether it's compression or exhaust is determined by cam position. 6 or 12 o clock. So, crank at 12, cam at 6 OR 12 and you're money. Remember the cam turns half speed so a full rotation of the crank take the cam half, so you're always coming from or going to 12 and 12 or 12 and 6.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
Its just some terms get so loosely thrown around that it starts getting confusing for the newer folks. Sometimes we just half to clarify and get it all out in the open.