[chuckies76ta]

Curious: Has anyone every used these rockers in a Pontiac. I guess a better question is, What determines which Rocker is used in a Pontiac? I'm thinking the pivot points from the trunnion to the center of the roller tip.



https://www.compcams.com/ford-7-16-s...ker-arm-1.html




Thanks.

[PAUL K]

Yes we have a few times in the past. They will require a different length pushrod and pull the pushrod quite a bit more towards the rocker stud than a typical Pontiac rocker arm.

What determines a "Pontiac rocker";

A ..... The rocker arm was made by Pontiac

B ..... The box says it's for a Pontiac, which usually means it will fit a Pontiac with the correct pushrod and clearance. When the aftermarket started coining in on the Pontiac pushrod market they would use existing rocker bodies they already had for a different application and modify them to work for a Pontiac. Some companies did a better job than others. One thing for sure is most individuals will not be able to tell how the rocker arm will fit by comparing the looks of an original OEM Pontiac rocker arm.

[Formulas]

Center trunion to valve tip is one consideration another is placement of pushrod cup

Not talking placement that changes ratio talking 90° from that
Looking at a rocker from the side imagine a straight line from center trunion to center roller tip carry that over to pushrod cup where the cup is on a rotational axis to that line that's where Ford rockers are often different

And I will add that even different manufacturers often come up with different placement of pushrod cups for same engine

You may want to buy a single for moc up then go from there

[Murf]

I have HS 1.6 Ford rockers on my wife’s car. I haven’t had any problems with them. I suppose they would use a different length pushrod but I used them when I put it together. So I had to check length & buy correct length pushrods anyway. I think whenever you use aftermarket parts, the pushrod length is likely different & should be check & adjusted accordingly.

["QUICK-SILVER"]

Originally Posted by chuckies76ta

Curious: Has anyone every used these rockers in a Pontiac. I guess a better question is, What determines which Rocker is used in a Pontiac? I'm thinking the pivot points from the trunnion to the center of the roller tip. .

Taller/longer than stock valves moves the valve stem tip closer to the rocker stud. Taller enuff requires a shorter rocker arm to get a better (closer to center) contact pattern on the valve stem tip.

With stock length valves, the ford rocker will move the contact pattern towards the rocker stud when compared to a Pontiac length rocker.

Get what best fits the job
Clay

[77 TRASHCAN]

I remember Cliff used some ford rockers on a engine.

I wonder how close the ford rocker to Pontiac rockers?

[Steve C.]

"Comp does make a really nice aluminum full roller rocker. Their 1.6 Ford rocker will fit perfectly on a Pontiac engine, have several sets in use....Cliff

Also Old Man Taylor used Crower Ford rocker arms on his Pontiac.


http://forums.maxperformanceinc.com/...5358&p=1889147
.

[pastry_chef]

The old Comp 1332-16 worked fine with 670 Iron and E-heads.
Buddy called Comp, they basically said. "we can't say they will fit" but they wouldn't deny it either.

Thousands of street miles on those rockers now.

Comp replaced the old part with Ultra Pro Magnum style, how well the newer would work I can't say.

[Steve C.]

To mirror Paul K's remarks above, this posted on another site....

"Ford roller rockers (small block) fit a Pontiac. But they're ever so slightly different...might cause the pushrod to be in the wrong position. Usually not a big deal, as long as your heads were clearance to allow them to fit."


.

[Skip Fix]

When I was playing with different rockers to get a higher ratio I bought a Crower SS 1.6 Ford. The trunnion to roller tip is way shorter than your average Harland Sharp roller rocker. I did use SBF 1.33 break in rockers with a very short pushrod on my 455 in the 78 TA for the HFT. 8.95".

[mrennie]

I tried Comp's Ultra Pro Magnum (not XD) Ford 1.6 rockers on my KRE heads, wouldn't work for me. They were part #1632-16

Pushrods needed to be super long to even get close to a good contact pattern and even then the pattern was too close to the edge of the valve.

Then tried Crower Pontiac 1.65 Enduro rockers and everything was perfect, good pattern, "normal" pushrod length for KRE heads, etc.

[chuckies76ta]

Well, I must say a big Thank you to you guys for taking the time to post. I really appreciate it.. Was looking at the Ford Ultra Pro Magnum™ XD Rocker Arms. looks like a nice rocker arm. Like was said would have to purchase one to see how they fit. The Crower 1.6 Rockers are couple hundred more but are made for Pontiac.

Thanks again everyone.
Charles

[Scott65]

I've been hoping for years that Comp would offer a Pontiac version of the Pro Magnum rockers. Looks unlikely. I've used them on Chevrolets and thought they were really nice, and were priced very reasonably for the quality. That's been many years ago though...

[chuckies76ta]

Ya that was my exact thoughts. There listed as good for springs up to 1000 pounds.

[Skip Fix]

Norris Cams used to make a Potniac SS rocker HO Racing sold and you could buy direct from Norris in 1.5, 1.6 ,1.65. I ran the 1.6s on my RAIV 400.

Here is a picture of a Crower 1.65 Pontiac, 1.6 Norris, 1.65 HS, and a Crower 1.6 Ford(stamped on the rocker) Although the Part number in Crower's current online catalog shows it as a 1.6 Pontiac rocker #73623 on the box. The ruller is under the middle of the roller tips and all are lined up on trunnions and you can see how much shorter the Ford rocker is, the rest about the same. Crower SS by far have the largest trunnion bearing of any rock I have seen including Comp's SS.

I have the Comp BBC 1.7s on my 409,eventhough 409s are actuall 1.75 factory ratio.

[chuckies76ta]

Thanks skip for the info and pic. Much appreciated. Nice for comparison side by side.

[PAUL K]

Picture of the Comp Pro Magnum 1632 next to a Harland Sharp Pontiac 1.65 ..... You will notice the Comp trunnion bearing means business ��

[chuckies76ta]

Thanks Paul for posting pics. The Comp looks alot like the Crower ones in trunnion area.