Rocker Damage
 

540 BBC Hyd rol cam.. #7 Intake Rocker seems to be damaged right where the Lockdown nut is.. Looks like the nut & rocker were scraping??? weird.. Just adjusted the valves about 2 months ago.. Did not notice it then.. Only difference this time went a tab tighter on the valves.. closer to 3/4 then 1/2 turn. did not notice anything out of the ordinary running wise.. no new noises.. ( i will post pic tonight when I can)..
Any ideas why the nut and rocker would meet? Other then I tightened it down a tad to tight.. Perhaps bad lifer? Spring??

rocker upside down?

maybe the stud backed out?

Needles left the fucrum?

pic?

Scratched the rocker with the wrench?

That last comment was a good one.. I will have to post a pic tonight.. The stud backing out sounds logical I assume..

I also assume a weak/broken spring as well as a worn cam lobe as well as a weak/broken lifter "could" result in this?? I would tend to think with any of the above scenarios, I would have noticed something running "weird"..

how big is the cam is there a chance the stud is rocking or flexing

Mike
have to check and take a pic tomorrow.. rain is crazy today..
I don’t think anything has flexed or changed.. I think it (more than likely) has something to do with my last valve adjustment.

One weird thing though.. The #7 plug was a little darker than the rest.. not much.. but noticeable.. all the other plugs looked perfect.

Perhaps a leak down test is in order?? I did a compression test back 2 months ago(when I did the valves). Each cyl was 150+- a few.. Looked good.

Some general shots of the valve train

More.. Closeups.. Number #7 Intake

More

Make sure the stud girdle is not to far down were the roller rockers can hit the back side of the girdle .

guess that could explain also..
I might have pushed it a bit too far down last time I adjusted..

Also.. Did an "On Head" spring test to test the seat pressure.. 140 all around.. nothing out of the ordinary on #7..

Aluminum heads? Maybe valve seat moved up into the port?

It seems as if a few of the rockers are nicked.. in the general area of where the stud bolts down..

it is posible they were too tight? Nothing looks as bad as #7 intake though.. Maybe I should try different rockers and nuts?

John i just saw this again i see you run a stud girdle so studs should not be moving, as was said make sure the girdle is not to low also have you checked the pushrod length if they are not right it can cause all kinds of problems

I would have thought the pushrods were checked by the builder.. I will order a checker and check them myself..
I was thinking of maybe (while I am in there) switching to a Jesel setup.. what do you think?

looks like they have the wrong nuts for those rockers. The nicks are from rocker hitting the nuts. Different length pushrods wont change it. I'm guessing those nuts came with the girdles,not the rockers. The fat part needs to be further from the top of rocker. Also check that rocker shafts are not upside down, that could also affect it.

tms,
I have often wondered about the nuts being "wrong"..
the shafts might be upside down also.. not sure.. they were installed like that from the builder.. canfield is out of business.. cannot ask them..

Do you think I should change the nuts only? or do the rockers need a change as well??

I have a great deal on a Jesel setup I can grab.. they are 30% off for the canfield heads right now.. as long as they are bolt on I might pull the trigger..

Here is another shot.. i always thought the nuts should be tappered like this?? with a girdle??

perhaps I should just remove the girdle and change the studs.

Not sure about these rocker shafts, i'ts been a while since I've done any HP engines. The original Merc 400 rockers had a flat side and a round side on the shaft. Had a customer put his back togeteher and had a few upside down. It caused the nut to loosen and set screw came out falling into camshaft. went between block and lobe and punched hole in the block.
Check the shaft and see if it has two different sides, one side may be rounded or higher than the other. If they are diff. check to see if any are upside down. Either way I would change them. Hitting the nuts may have done more damage than you can see and if they break you will really have a problem. Make sure either way you go you have more clearance between nuts and rockers.

Wow, nut has a shoulder on it at the top of the rocker! It appears that the shoulder is hitting the top of the rocker, I would go with a different design girdle that uses nuts without the shoulder on it and then make sure the girdle is not pushed down too low!

Just finished a leak down test on all 8.. results look fantastic.. from 3 % to 5% on all.. except #4.. 6-7%.. cold motor though.. either way I think the #7 cyl is looking good.. also.. got an “on head” spring tester today.. I just did #7 intake and #7 exhaust ( and the #1 intake and exhaust for comparison sake) . if I understand correctly ( and this is the first time ever using the tool), the “seat” pressure is right @ 200#.. on all..

I am using this definition of seat pressure: Seat pressure is the amount of pressure, as read on the gauge, to make the value stem “visibly” move just the slightest bit downward.

If I am using the tool correctly, then it appears the #7 springs “match” the #1 springs. In that case spring pressure did not cause the damage to the rocker. And since the leak down test was good I can only assume
a) I tightened the valves down too far
b) The stud girdle was installed incorrectly.
c) Something went wrong with the lifter???
d) ???????

Please correct me if I am wrong. But it appears this motor does not need to be disassembled. Perhaps a jesel setup or at least new rockers and stud ( minus a girdle ) are in order.

Thanks for the help
John

jesel is never a bad idea, stud girdle if you cant swing the jesel (they are expensive) . I think the correct adjustment on hyd roller is go to zero lash and then 1\4 to 1\3 turn.