roller rocker install problem

jerry S

New Member
Sep 3, 2003
1,365
1
0
52.22N 5.12E
I am upgrading to Comp. Cams. Pro Magnum roller rockers. I decided to get the 7/16 studs to take advantage of the added strength. I first got ARP 1.75" overall length studs but these were too short. In other words, when the rocker was on the stud and the push rod on the back of the rocker, the nuts were too short by 8 mm.

So I got the comp. cams 1.900" overall length studs but the rockers do not go far enough down on the stud for me to get enough thread for the nut to screw down. That cannot be. Originally, the car was built with TF TW heads but the valve springs broke on the dyno tune so the shop swapped them out for Edelbrock RPM Performer cylinder heads. I know that the TF TW heads need a longer than stock push rod. Is it possible I have too long of a push rod on there and that this is why the 1.900" studs still are not long enough?
 
yep, I'd say the pushrods are too long. It seems like you have a knack for getting the wrong parts, LOL.... You should fab up an adjustable pushrod to see exactly what length you need. To get the appropriate length, you need to install the adj pushrod, mark the valve tip where the rocker rides, and observe the pattern it makes in its full range of motion. You want to adjust the pushrod so the rocker arm has the narrowest, most centered mark on the valve tip. Then remove the adj pushrod, measure length at that adjustment, order 16 pushrods of that length.
 
302 coupe said:
yep, I'd say the pushrods are too long. It seems like you have a knack for getting the wrong parts, LOL....

I am not getting the wrong parts as much as I am getting superfluous parts. Did I need a new ignition or dizzy to correct the rust from the fuel tank getting to the carb? No. Am I better off with a new ignition and dizzy at the end of the day? Yes. So far, the only things I had to exchange was the brake booster from MPBrakes.com (and that was only because they sent me the wrong one) and the rocker studs, which were prolly the right ones in the first place.

Please note that I did not select these push rods. It was the mechanic in PA and our agreement calls for him to make things right. Given our past dealings, I think he will. My current shop here is going to put a pushrod length checker in the engine tomorrow and see what is what. If I need new ones, the guy in PA is going to be the one to get them.

If these are too long, could I have done damage to the cam? They have only been in for 100 miles and 2 hours on a dyno.
 
maybe I worded that wrong, I didn't mean it like you keep on buying parts that don't fit. More of a case of parts incompatability. I, and probably most other hot rodders, have been through the same stuff before. Example, buy a set of heads to find that the headers no longer fit, so buy a new set of headers, find that the exhaust no longer fits, etc, etc. Its just the way it is. Anyway, good luck figuring it out. Hopefully its something simple/cheap to correct.
 
302 coupe said:
maybe I worded that wrong, I didn't mean it like you keep on buying parts that don't fit. More of a case of parts incompatability. I, and probably most other hot rodders, have been through the same stuff before. Example, buy a set of heads to find that the headers no longer fit, so buy a new set of headers, find that the exhaust no longer fits, etc, etc. Its just the way it is. Anyway, good luck figuring it out. Hopefully its something simple/cheap to correct.

I took no umbrage at your post. No worries friend. We are all Americans. :flag:
I will give you an example of the scenario you mentioned. When I thought it was the points in my dizzy that were going bad (instead of the rusted gas tank), I got a new HEI dizzy and ignition from MSD. The new HEI dizzy was now too high for the new Global West Monte Carlo Bar and new 14" air cleaner I had just put on. I had to get a new monte carlo bar and HEI offset air filter. Then, 6 months later, I swapped out the Torker II intake for the RPM Air gap. The new HEI offset air cleaner assembly with 25 miles on it, was too high to clear the hood. And since Summit was out of the K&N 1 1/4 inch dropped bases and Jegs would not ship one to my wife while she was stateside, I had to order an entire new assembly (for reasons that are unclear to you but clear to me). So yes, I know exactly what you are talking about. A little bit more of this and I will be able to build an engine from the spare parts lying about.
 
We pulled the push rods. 8.6" Trick Flow push rods for use with TF TW cylinder heads. Not to be used with Edelbrock RPM Performer heads. As I suspected, the shop that built my motor screwed up. Problem solved.
 
I feel your pain. I went through the same thing when I put on the AFR heads w/ FRPP Rockers. The adjustable pushrod is the key! Hey, BTW, are you in Hogering near Heerenveenpad? Google Earth is such a cool thing.
 
68converted said:
I feel your pain. I went through the same thing when I put on the AFR heads w/ FRPP Rockers. The adjustable pushrod is the key! Hey, BTW, are you in Hogering near Heerenveenpad? Google Earth is such a cool thing.

kinda close but the Hogering is about 5 mins by car. I am not sure where the HPad is though.