Rocker Arm (upgrade) suggestion for A-460 Heads

This past weekend,.....

I was short-track racing my truck and on my 2nd test pass,.....something didn't feel/sound right,.....so I let out of it. Got back to my pit,.... pulled the Valve Covers and found the #3 intake rocker arm BROKE.

After closer inspection,......I found stress cracks in two more rockers,......both on the intake side.

FWIW,...
My heads are the 18-bolt A-460's,...part # 5451T802-87,....with the stock spring package.
Cam lift,...IIRC,....is .815 on the intake,....... .780 on the exhaust.
The Rockers are just standard Aluminum TFS 1.73's,....part # 53400621,....utilizing a Jomar Stud-Girdle. Only spinning the engine 6500-6600 rpm.

I'm wanting to upgrade to a better set of Rockers,......and I'm leaning toward a higher end set of steel ones,....such as the COMP Cams Ultra Pro Magnum XD's,..... OR,.......possibly a set of Crower Enduro S/S series,.... BUT,....
What I'm finding out is,.....a lot of Rockers are limited to a Max spring diameter. These such Rockers I'm looking at have a limit of 1.55 / 1.56",.....and according to the specs on the heads,...the springs have on O.D. of 1.64".

I don't want to get into any clearance issues,.....nor,... am I interested in changing springs,...pushrods,....or machining parts to fit. I just want a good set of Rockers I can bolt on & go,.....and not have to worry about breaking,... like these Cast ones are doing.



Suggestions,..... ?

Both the steel rockers you mention will work with the 1.640" dia. springs. If it's published otherwise it is a misprint.

Lem Evans wrote:Both the steel rockers you mention will work with the 1.640" dia. springs. If it's published otherwise it is a misprint.

Good deal Lem,.........

I appreciate the info.

How much time is on the springs?

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

dfree383 wrote:

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

I'm curious,.......

What is a good, affordable (on-head) tool to check Valve Seat / Spring pressures ?



I was looking at one from LSM Racing Products,.....Part # PC-100SLC

I usually take them off and check them on my bench top checker when the time comes, I can look at seat and open pressure easier. On the car stuff is cool for at the track but I don't feel they are as good as the bench testers

Copperhead wrote:

dfree383 wrote:

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

I'm curious,.......

What is a good, affordable (on-head) tool to check Valve Seat / Spring pressures ?  



I was looking at one from LSM Racing Products,.....Part # PC-100SLC

I can tell you for damn sure that low spring pressure did not kill that rocker arm.

I switched from a set of FRPP blue rockers to the Comp XDs. Nice pieces. Beware though that due to their design I had to get different length pushrods to keep my geometry in check...

Not cheap but I have a Buxton Engineering, in my own opinion none nicer for on the head checking. Id say any of them would work even if the reading is off 20# across the board from a bench tester. Your looking for a weak spring and as long as you keep track of readings from new its not going to matter much. Id read all the springs, record them and check them regularly to see if one is falling off. If you have one 20# light id be looking at getting it off there.

TravisRice wrote:Not cheap but I have a Buxton Engineering, in my own opinion none nicer for on the head checking. Id say any of them would work even if the reading is off 20# across the board from a bench tester. Your looking for a weak spring and as long as you keep track of readings from new its not going to matter much. Id read all the springs, record them and check them regularly to see if one is falling off. If you have one 20# light id be looking at getting it off there.

Brad Buxton set the standard for testers long ago.....cool guy.

LSM tools are good stuff. I have the tool to change valve springs on the engine

Lem Evans wrote:Both the steel rockers you mention will work with the 1.640" dia. springs. If it's published otherwise it is a misprint.

Lem, does the same go for the Comp ultra pro magnum NON xd model? Will fit the 1.64 springs? Looking in the catalog it hard see much difference other than the bigger trunnion and of course the rating. They don't list a weight.

stanger68 wrote:

Lem Evans wrote:Both the steel rockers you mention will work with the 1.640" dia. springs. If it's published otherwise it is a misprint.

Lem, does the same go for the Comp ultra pro magnum NON xd model? Will fit the 1.64 springs? Looking in the catalog it hard see much difference other than the bigger trunnion and of course the rating. They don't list a weight.

I have installed the XD but not the non so I will not address that. I will say that if I was using a big roller cam spring I'd use the XD. It has a hard push rod cup insert that the non does not.

Lem Evans wrote:

Copperhead wrote:

dfree383 wrote:

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

I'm curious,.......

What is a good, affordable (on-head) tool to check Valve Seat / Spring pressures ?  



I was looking at one from LSM Racing Products,.....Part # PC-100SLC

I can tell you for damn sure that low spring pressure did not kill that rocker arm.

lack of pressure sure can........

Lem Evans wrote:

Copperhead wrote:

dfree383 wrote:

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

I'm curious,.......

What is a good, affordable (on-head) tool to check Valve Seat / Spring pressures ?  



I was looking at one from LSM Racing Products,.....Part # PC-100SLC

I can tell you for damn sure that low spring pressure did not kill that rocker arm.

Scott Foxwell wrote:

Lem Evans wrote:

Copperhead wrote:

dfree383 wrote:

Copperhead wrote:

dfree383 wrote:How much time is on the springs?

Mmmm,.....

Time wise,.... about 2yrs,........BUT,.......a lot was short track (300') racing,.....and not spinning the piss out it.

Make sure to check them and keep track of the time on them, weak springs will break parts and they do need replaced from time to time.

I'm curious,.......

What is a good, affordable (on-head) tool to check Valve Seat / Spring pressures ?  



I was looking at one from LSM Racing Products,.....Part # PC-100SLC

I can tell you for damn sure that low spring pressure did not kill that rocker arm.

The rockers broke because of who TFS had produce those rockers. They are not a good bet with big roller cam springs.

Doing burnouts do as much or more damage to the springs as doing full quarter mile passes.
The quit up and down rpm change is what kills them.
Harmonics ....