[TransAm 474]

We have been putting our 455 together today, and we just got through degreeing the camshaft with out JP Performance billet timing set. I wanted to see what y'all thought of our results. We first set the chain dot to dot "straight up" to check and see where we were at, and it came out at 113.75* Intake Centerline. The cam card states to degree it to 108*. So we took our JP billet timing set and switched the crank gear to the +6 keyway and rechecked it. This time it's coming out 106.5* Intake Centerline, so it's acually 1.5* advanced from where the camcard says to install it, but if we use the +4 keyway on our crank gear, it would be retarded. So I'm thinking about just leaving it as is, and figure the new chain will stretch a little and it will get closer to where it's suppose to be. We also checked the intake opening and closing points to double check our results, and it shows the intake opens at 7.5* BTDC....the camcard states it should be 6*....and the intake closes at 42* ABDC....which is exactly what the camcard says it should close at.

So....what do yall think of our results? Leave at the 106.5* and let chain stretch compensate? This is 100% street driver.......

Thanks!

[gtofreek]

I would leave it. That's almost 230° @ .050 and 7.5 BTDC is not a bad place for a cam that size to be. You're not big enough, cam wise to worry about piston to valve clearance.

I have seen these crank gear timing marks all over the place. The last Roll Master I used was way off. I needed to advance the cam 1.5°, but had to use the +6 slot and timing mark to get there. Each 2° advance, actually only advanced the cam .5°. I would rather it be like this though as it gives you better resolution for degreeing it in.

[TransAm 474]

Thanks Paul.....we went ahead and checked it again with the crank keyway at the 4* advance slot....and it comes out perfect at 108* .....and the intake opens at the 6* it's suppose to now...but the intake closes at 43.5* instead of the 42 the camcard says.....i think we will leave it right where it's at...

Thanks for the help Paul.... i appreciate it

Brian

[Blued and Painted]

I used the JPP 9 way chain set on the same cam on a 461. I had to use the 4 degree key way to get the ICL to 107.5.. All the @.050 events were dead nuts on, minus the .5 degree.

Took a few tries to get the carb dialed in but its running like a scalded dog now.

11 inches of vacuum at idle.

[TransAm 474]

Thanks Blued and Painted! I am interested in more details about your engine.... heads, compression, rocker ratio... ect..... how well does the 60243 perform in your 461? How does it sound at idle? 1.5 or 1.65 rockers?

Thanks! Brian

[Cliff R]

I've posted this before, but ALL of the 60916, 60243, and 60919 cams we've installed here have been close to 112-114 ICL "dot to dot".

I started advancing them 4 degrees before even checking them, and in most cases haven't had to touch anything.

I would NOT under any circumstances put any of them lower than 108ICL, 109-110 would be better. They do not work quite as well at 106-107, this comes from DIRECT testing in several different set-ups.......FWIW.....Cliff

[TransAm 474]

Thanks for the great info Cliff!!

[PONTIAC DUDE]

I have yet to find a 9 keyway Billet timing set that is marked correctly. Have had some up to 8 degrees off.

[Blued and Painted]

230 cfm @.500 6x-4 mill to 93 cc.. 72 Iron intake with Q jet. Dougs headers to 2 1/2 pipes to dynomax turbos. HEI. TH400 w/continental 13".. 3.08 gear.
A little attitude at idle but easy to drive around town.
Im still working on the front suspension and ride height so i have not been over 60 mph. But it don't take long to get there.
I'll be taking it to Bandimere for time trials once i get her dialed in and safe.