Pushrod rubbing against head, picture inside

[Falco]

Howdy,

I just picked up the passenger's side valve cover to check everything is fine after the initial startup of truck with the new heads. It seems to be fine so far, however the pushrods (all of them) are excentric and are very near to the pushrods holes' wall at one side. Is this normal? My pushrods are crane chromemoly ones, and bit shorter then the stock. Otherwise the valvetrain geometry seems to be fine. Checked the contact points of the valve stems with the rocker arms and it's good. Pls chime in if you can...

TIA,

 

[sytydvr]

hey falco those pushrods are definately rubbing the heads.. I had the same problem before even starting the engine I noticed it .... You need to but the louis tool from jegs or summit.... this tool elongates the hole so the pushrod wont rub... Im surprised it rubs with 1.52 ratio rockers, I used 1.6 and a few were rubbing but for insrance purposes I elongated all the holes...

good luck falco

Joe
sy#682
ty@2351

 

[Falco]

Thanks Joe, I've a Louis tool. Can I enlarge the holes with it without removing the heads? Don't think so... The metal chips would be everywhere. BTW, in the meantime I checked my new pushrods and they are short by 0.7". I ordered the wrong set I belive. I'll put back the stock length ones this weekend and will check it again.

Later,

 

[E-Rue]

this is the same thing that happened when we put 1.6 rockers on my mccoy motor. after running it for a few weeks i checked the pushrods, and it turned out about 4 of them were rubbing a little bit. i really wish as much money as the mccoy motors cost, that they would elongate the pushrod holes. ive "heard" that 1.6's will work on the stock engine/cam without rubbing, but i guess my mccoy motor is a little different.

e

 

[Falco]

E-RUE,

What happend after you discovered this? I remember this thread, but not that well. Is this caused any damage?

Later,

 

[E-Rue]

i dont think so. i didnt run them for very long, and they were not rubbing much at all. only a couple of them had marks from rubbing. i have installed a bigger cam now, and have gone back to 1.5's. still trying to get this chipping thing figured out.

e

 

[Falco]

One more question E. Did you enlarge the holes with the heads in the truck?

Thanks,

 

[jwaller]

those look like adjustable rockers on a non adjustable stud...is that right?

 

[sytydvr]

hey falco I enlarged the pushrod holes with the heads in. I just sorrounded the hole with a few magnets. then I used a vaccum to remove all the debris. good luck if you have anymore questions let me know... i have 1000 miles on my engine and its running perfect.

another thing if there are signs of rubbing on the pushrods most likely they are bent I suggest new ones... you can check them by rolling them on glass or a flat table.


Joe
sy#682
ty#2351

 

[warmpancakes]

Guide plates, adjustable, they have been on mine for some time with no problems, every 4.3 head builder recommends them when you have rollers.

 

[Falco]

those look like adjustable rockers on a non adjustable stud...is that right?

Yep, they are screw-in studs if that's what you mean. I thought I can use them in this configuration. Is this right? I should use a specific torque and not the '1/2 turn down after zero lash' method if I'm right, However I don't now this torque, so I'm just planned to try the usual stuff.

Ken,

As far as I know adjustable rockers with guide plates is not a good idea.

Thanks the replies...

Later,

 

[Falco]

Ok. After a little search over at s-series.org I realized what John meant. Sh*t! I've to convert to adjustable rocker studs if I wanna run the roller tip rockers.

Crane cams has a conversion studs, which doesn't require machining. CRN-99148-2 at summit, I'd need six of these. As far as I see the only other way to go is to use the OEM stamped rockers since I don't want to pick out my heads to drill them up properly to standart 3/8" studs. I don't know.

John! Thanks! And pls confirm the above if you can.

Later,

 

[jwaller]

yes you have the complete wrong setup going there....and the wrong length pushrod...

get that conversion stud you stated....it comes in a pack of 2 and it's expensive....23-25 bucks.

then you have to set your lash just as you would on a stock sy...1/2 turn down from zero. there is more to it than that though. ask me if your unsure when its time for that.

now I hope those are self aligning, if they are then all you'll need is the correct stud and pushrod. if they are not self aligning then you will need guide plates too.

 

[Falco]

Thanks again John,

I use the following roller tip rockers:

http://store.summitracing.com/partdetail.asp?part=9406

They supposed to be self-aligning. What do ya think?

I've the correct sized pushrods at hand, so I've to order the converting studs only if no guideplates required.

Hopefully I'm getting out from the labirinth of the different kinda 4.3 head configurations. :-?

Later,

 

[jwaller]

yes those are self aligning so you wont need guide plates....

y did you get 1.52's and not 1.6's?

 

[Falco]

Was affraid because of pushrod-pushrod hole clearence... No comment. :-?

Anyway, it seems to be I'm learning from my own mistakes.

Going to order the studs from summit. I appreciate your help, thanks once again.

Peace,