cam timing

[jeepboy45]

I mentioned this in a different thread , and thought it would be more appropriate to post it in a different thread.

I picked up my 360 from the machine shop last week.. I got the pistons and crank installed yesterday and wanted to get the cam, and timing set, and heads on today.

I cant find the cam specs right now, but when I ordered it, I wanted one with short duration and a bit more lift to keep the torque and HP band lower. (Using an auto tranny)

Anyway, the timing set allows for stock, advance, and retarded cam timing. If I advance it, I believe the HP band will be even further down in the rpm range. Retarding it brings the HP band into a hight rpm band.

I was going to use the advance positions on the timing set to have even better throttle response, but another member said "Do not put the cam gear on in the advance position. I repeat, do not do this. Install in the zero position. There is not enough adjustment in stock valve train to compensate. You can impact valves even with dish pistons."
(BTW: thanks priceg)

So I decided to start this tread to keep the topic together and consise.

Any imput would be greatly appreciated.

thanks
brian

 

[priceg]

Did not mean to scare you. Their is a big difference in degreeing the camshaft and jumping a full 10 degrees of advance. When you degree the cam you are basically indexing the cam and cam gear to each other. When you purchased your camshaft it cam with a spec card. With stock timing components it is almost impossible to achieve the true relationship that the camshaft is speced to. However, if you install the gears in the stock location, the variance is not enough to cause a problem with achieving your static and dynamic specs. Not knowing the specs of your build, I.E., block deck height, head surface height, piston compression height, cam specs, head gasket thickness, naturally I got concerned when you suggested the advance of the cam gear. Carry on and good luck.

 

[jeepboy45]

Did not mean to scare you.

well you DID dammit !!! LOL

I'm glad you spoke up. you seem to be knowledgeable and I appreciate the imput.

MTA-1 cam is
Degrees @.050
intake: 204 / exhaust: 214

Degrees ADV
intake: 280 / exhaust: 290

Lift:
intake: .448 / exhaust: .472

You are correct in saying I wont be degreeing in my cam. I have never done that nor do I really want to get that involved. If there are significant gains by using the "advance" marks as opposed to the "stock" marks, then I'd like to do so. But if it really isnt worth doing, or questionable to do, then I wont.

thanks again

 

[johnbilt]

Excellent question! I pondered this when I built my 360. I set mine to the standard position which I believe would give me the cam timing in the specs. I didn't figure I could really gain anything for my uses in a Jeep.

I guess most guys that are moving the cam timing are building a race engine. Like the other poster noted, there are many factors to consider when you do this. I suppose rotating the eingine through by hand would be a good practice to verify that the valves don't hit the pistons. John

 

[CJ]

Brian, just put the cam in to print. You will be fine...

 

[jeepboy45]

Brian, just put the cam in to print. You will be fine...

"to print"? I assume you mean to the stock position...

I know it will be fine... I wanna be BETTER than fine!! LOL

 

[CJ]

If you want to better then fine you need to purchase a degree wheel...

 

[jeepboy45]

If you want to better then fine you need to purchase a degree wheel...

CJ, I wouldnt know what to do with a degree wheel..!! I got it...come down here, bring your degree wheel, and help me out!! I'll buy you dinner at Ale House like we talked about !!!

 

[CJ]

Lol! Just put the cam in... I,ll explain degreeing in a cam when I get to O town and we have beer or ten!