88 cam 04387850 centerline spec needed

[wheming]

I guess i should have asked earlier, but at Brian's shop and need a definitive answer to what cam centerline spec for stock 88 turb cam. Mopar # 04387850

If you can help, i owe you a beverage.
Thanks!

[wheming]

I found this, can someone verify post #11 is accurate? Says 122 degrees.

http://www.turbododge.com/forums/f4/.../798266?page=2

[sdac guy]

According to the 1988 parts manual, 4387850 was used until 3-1-88, that would make it a square tooth sprocket. 4387721 was used after 3-1-88 making it a round tooth sprocket cam.

So, put a square tooth sprocket on the cam and go through the steps to centerline it. What you measure will be the correct intended centerline for the cam (stock sprocket, installed straight up, should = correct centerline).

What Ed Peters suggested (122 degrees) may or may not have been the correct intended centerline, it may have just been his suggested centerline. And since it has been almost 20 years since he has appeared at any Shelby/Turbo Dodge event, who knows if that 122 degrees was really what he suggested, after all, memories fade ...


Barry

[GLHS60]

Did you get any info Wayne??

Todd would know for sure, typically the centerline straight up is the same as the LSA.

From memory, the LSA is 112 or 113, so 122 would be considerably retarded which is good for high RPM operation, especially on a 2.5, but I'm sure Brian knows this.

Thanks
Randy

[Chris W]

According to the 1988 parts manual, 4387850 was used until 3-1-88, that would make it a square tooth sprocket. 4387721 was used after 3-1-88 making it a round tooth sprocket cam.

So, put a square tooth sprocket on the cam and go through the steps to centerline it. What you measure will be the correct intended centerline for the cam (stock sprocket, installed straight up, should = correct centerline).

What Ed Peters suggested (122 degrees) may or may not have been the correct intended centerline, it may have just been his suggested centerline. And since it has been almost 20 years since he has appeared at any Shelby/Turbo Dodge event, who knows if that 122 degrees was really what he suggested, after all, memories fade ...


Barry

I am fairly certain that number is correct. From what I remember it was his suggested centerline for the '88 TBI cam. I have been reviewing 6 hours of the Phoenix '97 Convention videos to confirm.

Chris-TU

[wheming]

Curiously enough, when Brian set the 88 cam up to 122 degrees, it was virtually identical cam gear setting to when he set up the R5 cam at (whatever Brian had previously mention in the R5 cam specs thread, iirc 112 deg? ? )

This is where the R5 was set:


And this is the 88 turbo cam at 122 deg:


With the difference of the square tooth gear being set at a different key orientation, and the different centerline suggested, i don't know if anyone would have guessed the cam gear would be set that close.

[puppet]

https://web.archive.org/web/20030311.../camshaft.html

Here is a link to an archived page that contains a lot of the cams our engines used over the years.
On that page there are links to some really good articles/theories concerning cams in general.

[wheming]

That's good info. Thanks!
I think i have seen that page before, but it should be saved in the knowledge base somewhere.
There might be a few more options out there now too.