Right, the purpose in my case is to check..

 

Actually, since I have a couple of dial indicators, I used a second dial indicator to determine TDC. What I did to hold the crank in position was to fabricate a piece of 1/4" steel plate with teeth that matched the teeth in the flywheel. Then I welded up a bracket such that it would bolt into the starter motor location. I move the crank to any position that I want, slip the tool into position, and bolt it down. No crank movement; very handy for crank hub R&R and flywheel/clutch R&R.

No, I haven't visited pbfbody, but you and I have talked at Moroso. I haven't been up there in awhile; but, I'm the old guy with the black Formula convertible.

If you find your cam is off a couple of degrees or more, like I did with mine, you can bring it back in pretty close with an offset crank sprocket key. AFAIK, you cannot use an adjustable cam sprocket because the ignition events in the PCM are tied to the cam position, and changing that relation will screw up your ignition timing. The PCM doesn't look at the position of the crankshaft relative to the camshaft to determine the ignition timing so changing that relation doesn't matter. Anyway, I used the offset crank key and it worked out just fine. Actually, since I upgraded the crank hub to a keyed hub that I got from Thunder Racing, I used another offset key on that as well to keep the pointer on the hub in the original relationship to the crank sprocket (not that it matters). Lot of relationships going on here.

One other thing I did that you might want to consider, was a suggestion that I think Racerdude mentioned once on this board. More Performance sells a steel reinforcing plate that fits over the plastic oil pump gear drive assy. I understand that the plastic drive has been known to crack and pop up out of position and thus, no longer drives the oil pump. This thing keeps that from happening. I think it's like $20. I got one, but once I saw what it was, it would be simple to make yourself, but figuring what your time is worth and the safety factor it provides, $20 isn't too bad.
Chris



Chris

 

Thanks for the heads up Chris, check your PM's

 

Do I check my cam to see if it's to spec?

Yes... better to check than wonder what the hell is off.

-Mindgame

 

my machine shop did it for 50 bucks....much easier than doing it yourself.

 

I would, but the engine is in the car.

 

I'm glad to see there are so many guys who do it the right way. I've been on other boards where they think it's a waste of time to degree a cam. IMHO a waste of time is to do all this work and not know what is and what isin't right and just pray that it all is.

Bret

 

I've got a 306 comp cam. the advertised #s are 230/244 & 510/544. I called comp tech, read him the #s engraved on the cam and he gave me the actuall #s for this particular cam = 229/245 & 544/577. Quite a difference. Also he stated that Comp generally makes their cams with 4 degrees advanced machined in it so i should install it straight up 0*.

 

Nope, that's actually pretty good for what it's supposed to be and what it is.

Install that cam +4, you really cant retard it 4 degs and have the computer like it.

Bret

 

Maybe it's not a far off as you think.

The Comp catalog quotes: 230/244 @ .050 with .510/.540 lift with 1.5 RAR

With 1.6 RAR rated lifts are .544/.576.

http://compcams.com/Technical/Curren...ML/198-199.asp

That's within 1 degree and .001 lift. Either you mentioned you had 1.6s or he thought you did. Actually +/- 1 degree is very good for durations quoted in whole degrees. We have seen some Comp cams with designed durations at some fraction of a degree, but they quote whole degrees.

My $.02

 

That's what I was thinking, #'s seemed way too off and sounded right with a 1.6 rocker on a 306.

 

My cam was set up at 102 degrees ICL straight up dot to dot. I was suppose to have a 105. So mine was off 3 degrees. I don't know how much of a difference that is but i didn't want to find out. I used the LT4 ED chain and the bushing trick

 

Well I figured I'd post up my results.

Mine is off about 2* retarded. I know TDC is 100% dead on, I used the piston stop method first, then verified it against my dial indicator.

It seems tough to get the same reading everytime, but the *least* off I got was 1.5* off, the most was 2.5* off. Prolly did it about 6 or 7 times.

Both Lloyd and Bret have suggested I run a 2* offset crank key, so I need to find one locally and hope for the best. From what I understand this will not affect the tuning of the car any, so we'll go from there.

 

cool, I am glad you took the time to do it the right way.

The people that "DO" degree their cams are also the same people that check PR geometry and length, use sealant on rocker studs and head bolts, correctly adjust rocker arms, checking opti pin length, spend a lil more $$$ on tuning, etc, etc. These same people are the ones that end up making 10-20 more HP than "others" running the same heads and cam and have alot fewer probelms in the long run.

These LT1 engines are not the easiest thing to work on and just "assembling" the parts and TQing the parts down is not the best way to do these things. U have to be mechanically inclined as well for the best results and to not have any problems. If the person doing head an cam install in NOT mechanically inclined, he really needs to have someone that is do all of this work and just pay them for the work. "AT LEAST" get some help from someone that is mechanically inclined and experienced with these engine if you are gonna dive in and do the work yourself.

I try and give alot of advice and a good parts list but there is only so much I can do over the phone and at some point the customers need to know what they are doing.

 

I found the right keys locally Lloyd.. I'm screwed on the Mr. Gasket gaskets though, noone has them.