Can I rotate the cams

[Hollowdweller]

With no timing chains attached can I put a socket on the cam bolt and rotate the cam? I’m trying to do the timing chains but worry if I spin the cams to line up the dots a valve may hit a piston. I don’t really see that happening but have no clue so thought I’d ask

 

[07 Boss]

Yes you can but you have to be careful as there are a number of things to consider.

Is your cam stock or is it a higher lift cam?

How is your crankshaft positioned? If you rotate the crank to where it is at top dead center then rotate it 22*-23* the pistons should all be centered in their travel and there should be no valve to piston contact. I believe with stock cams you hve about 5* of cranshaft rotation before and after center where there is the danger of any contact. Not positive on the 5* but it's what's in my head.

These are interference motors so if you're not careful you will damage a piston or valve.

 

[Hollowdweller]

I think I got it….hell I don’t know!?!? I ended up having to unbolt the cams, install the chains, then use the towers to pull the cams down (haven’t finished yet, other issues). Currently the chains are around the gears with dots matching and I have bolts started on cam tower caps.


With no chains attached I did spin the crank a few times and rotated the pass side cam 1 time….that was a mistake lol! I didn’t think about the spring pressure with it coming off the high lobe and it POPPED and scared the crap outta me. The crank spins effortlessly and I don’t think the cam rotation had enough force to bend or damage anything so I don’t think I screwed anything up.

Called Comp Cams today and the guy that answered the phone said this about cam phaser lockouts….

“We us lockouts on all the cams we sell but since yours is a cam we build for MMR you need to call them”

….I thought this was odd bcz surely I would’ve seen somewhere in all my research that all Comp Cams need lockouts

 

[Hollowdweller]

Called MMR and he said….

“Personally I would run them but it’s really up to your tuner”

 

[Midlife Crises]

….I thought this was odd bcz surely I would’ve seen somewhere in all my research that all Comp Cams need lockouts

That is very odd because Comp Cams does not recommend lockouts for all the 3 valve cams. I have run the 127350 cams for several years and one of their features is the variable cam timing is still active. Comp categorizes their cams in the catalog by wether they need springs, limiters or both.

 

[Midlife Crises]

Called MMR and he said….

“Personally I would run them but it’s really up to your tuner”

I would not relay on the tuner alone to prevent the valves from kissing the pistons. The man said he would run them locked!!!

 

[Hollowdweller]

That is very odd because Comp Cams does not recommend lockouts for all the 3 valve cams. I have run the 127350 cams for several years and one of their features is the variable cam timing is still active. Comp categorizes their cams in the catalog by wether they need springs, limiters or both.

I got the impression the guy was just trying to get off the phone. I was on hold for 40mins then when he picked up he seemed confused and distracted so I didn’t put much stock in what he said.

I would not relay on the tuner alone to prevent the valves from kissing the pistons. The man said he would run them locked!!!

Yeah I’m just going down the chain…forum said call comp, comp said call MMR, MMR said call tuner lol….MMR guy did say tuner may not want lockouts for timing control…