• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Worn valve rocker shaft.....

Share this page

K

karls59tr

Obi Wan
Bronze
Country flag
Offline
If a valve rocker shaft was somewhat worn but everything else in the valve train was OK what effect would that have on engine performance?
 
Likely very little short term . Long term ,unusual wear will be likely on the valve stems and guides.
The major issue is getting valve lash set up correctly. A fresh shaft is cheap but take a picture
or two as you disassemble it and dont be shocked if some of the rockers are shot.
IMHO refresh all the rockers to 1.55 to 1 This will pick up 2 or 3 HP.
Mad dog
 
Thanks for the info on the rocker shaft. (Have you had a chance to ship out the TR3 horn turn signal button we talked about? I can pay in advance for freight if you like?) Karl
 
Assuming you set your valve clearance regularly, wear will only have the affect of slightly reduced oil to the front rockers on the shaft. Since it's already worn...the reduced oil may speed further shaft wear slightly.

I have noted that the steel rocker shaft wears much faster than the bronze rocker bushings. I have never figured that one out?!? Also, if you think about it, as the rockers rise with shaft wear, the valves will also be slowly rising with gradual valve seat wear. So...in the end they will keep the designed tappet to valve geometry. I really don't think rocker shaft wear will hurt anything, so long as you adjust the valve clearance to keep up with the wear.
 
CJD said:
Assuming you set your valve clearance regularly, wear will only have the affect of slightly reduced oil to the front rockers on the shaft. Since it's already worn...the reduced oil may speed further shaft wear slightly.

I have noted that the steel rocker shaft wears much faster than the bronze rocker bushings. I have never figured that one out?!? Also, if you think about it, as the rockers rise with shaft wear, the valves will also be slowly rising with gradual valve seat wear. So...in the end they will keep the designed tappet to valve geometry. I really don't think rocker shaft wear will hurt anything, so long as you adjust the valve clearance to keep up with the wear.
Click to expand...
That's good to know. Since your familiar with my efforts in regard to replacing the head gasket here are a few other things I should have done when I had the head off but I wanted to drive the car for the short summer months here. The car runs great ,rings and valves good compression etc.When the head was off I noticed that one tappet had some slight groove on top which probably is not doing the cam lobe any good? Also I should have bought new push rods and had the guides replaced when I was in there...and may as well replace the rockers too.:rolleyes: It will be winter here soon and no garage so that might have to wait until Spring.
 
The best trick is to install new valves and knurl the old guides. This cures oil consumption as it acts like
a valve guide seal. New valves are always good as they dont "drop" later. (total destruction event)
The cam and the lifters wear together, if one is bad you must replace it all.Putting a new lifter on an old cam
is suicide (in my experience). The most critical breakin on a new motor is breaking in the new cam and lifters
All engine builders are quite careful in this procedure.Usually setting the valves at .015 for the first 30 minutes
only the
Mark
 
I sent my whole rocker shaft out to a specialty shop in California and they installed new rockers and new shaft. I think it was 300.00.

Steve
 
Going through this now on my TR6. The issue on the worn rockers is the oil feeding the gallery. The movement causes the oil to flow out the shaft instead of the weep holes. Will be sending a set to CA for a rebuild.
Does anyone have a review for them?
 
Ripper01 said:
Going through this now on my TR6. The issue on the worn rockers is the oil feeding the gallery. The movement causes the oil to flow out the shaft instead of the weep holes. Will be sending a set to CA for a rebuild.
Does anyone have a review for them?
Click to expand...
I dealt with them about 10 years ago, Rip. They did a satisfactory job.

About Rocker Arms Unlimited

Long history of rocker arms 25 years experienced employee owned.
rockerarms.com
 
Ripper01 said:
Going through this now on my TR6. The issue on the worn rockers is the oil feeding the gallery. The movement causes the oil to flow out the shaft instead of the weep holes. Will be sending a set to CA for a rebuild.
Does anyone have a review for them?
Click to expand...
I have 3 TRs and have used Rocker Arms Unlimited for about 20 years even about a year ago. They ( now just a he) have done a good job every time. This was the company that TRF used to send the rocker arms to when they were doing engine rebuilding. I also live only a few miles from their shop.
Charley
 
On a Tr6 it is VERY helpful to add an oil feed line to the rockers.They rarely oil well, and this fix takes 5 minutes.
Mad dog
 
The stock system uses a partial slot in the rear cam bearing to highly restrict the oil going upstairs. The oil comes into the bottom of the rear cam bearing, but can't get around the cam to the drilling in the top of the bearing, which goes upstairs to the rear rocker stand. The partial slot in the cam allows oil pressure for a very limited time to bypass the cam and make it up to the rockers.

The racing mod taps a line into the rear oil gallery plug hole, and runs an external line up and to the rocker shaft. Personally, if I were building a race engine, I would fully slot the rear cam bearing journal to accomplish the same thing without a lot of external piping. Keep it simple!!

IMHO...the stock system has proven itself for any street application. Plus, any oil that goes up...has to come back down. So a lot of extra oil is thrown against the cylinder walls and work the rings harder. This is good in a race engine...but will likely increase oil consumption on a street engine for a slight improvement in rocker shaft wear.
 
How would one notice if the rocker shaft were going bad? Every time I adjust my valves I take a good hard look, but I’m never sure what to look for. If my engine is running great, can I sleep tight without worrying about my rocker shaft assembly?
 
Back
Top