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View Full Version : Turbo Camshaft specs/cam gears



jeff1234
03-11-2024, 10:07 AM
Hello All, I am having no luck at finding the cam numbers for the #4387721 roller or its replacement, such as lobe separation angle, intake/exhaust duration and intake centerline.
I also wonder if there is a difference between round tooth and square tooth cam gears? Specifically, relative to the cam gear key slot, are the two gears teeth identical in spacing or are the key slots machined a couple of degrees different from each other.
Jeff

2.216VTurbo
03-11-2024, 01:05 PM
It's all here fromhttp://www.turbo-mopar.com/forums/showthread.php?74750-slider-cam-with-round-tooth-sprocket-what-would-timing-do&highlight=Cam+gear+timing the good Ole days

jeff1234
03-11-2024, 08:53 PM
Thanks, I'll check it out.

jeff1234
03-11-2024, 09:34 PM
Interesting article, I've got a 557 on my cam which I got from Jackson, probably 89-92 vintage. But I still need the cam specs. Does any one have them.

jeff1234
03-12-2024, 05:57 PM
I found an old post of mine, (2014) T/U cam spec's

jeff1234
03-14-2024, 11:15 AM
Here is detailed stock cam information from 4 l-bodies. Might I suggest that because this info is hard to find, make a copy for your records. Thanks to Todd.
Hi Jeff,
Okay I have some measurements for a 89 2.5 turbo cam. All rollers had .433 lift.
Installed intake centerline is 114. Lobe separation angle is 113. duration @ .050 is 212° on intake and 210° on exhaust. Overlap @ .050" is -17° (negative). Intake valve opens @ .050 8 ATDC closes @ 40 ABDC. Exhaust valves opens @ .050 38 BBDC and closes @ 9 BTDC. These #'s are almost exactly what I've seen posted years ago on Dennis Doza's website which is long, long gone. These were actual measurements I took.
The TBI early 2.5 TD and 89 TBI roller camshafts had almost the same exact duration. Supposedly the 88 square tooth 2.2 roller had 224 intake and 210 exhaust (but I've never been able to confirm that). So quite a bit more intake duration @ .050 and the same exhaust duration. I've also seen other NA rollers listed at 208° duration @ .050 instead of 210°.

BTW the turbo slider camshafts had 218.5° Intake and 214° exhaust @ .050. So they were a slightly more aggressive profile, at the cost of more frictional loses. They also had a 110 installed centerline and a much tighter LSA of 107.