Rocker Shafts

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 2:31 pm

I thought I had taken great care to make sure I had put my rocker shafts on the right way around.

But looking at the base of the shaft last night I found there was a lot of wear from the ally roller tip rockers. Then I noticed the oil hole was not lined up with the oiling groove in the rocker.

I am right in thinking these should line up with each other yes??

Anonymous · Post by **Anonymous** » Wed Mar 23, 05 3:46 pm

Would have thought to Dave, at least partially anyway.

Is the width of the Ally rockers / spacers any greater than the stock items? If there is a minor difference, over the length of the shaft it might add up to a significant missalignment.
Have you got springs or spacers between the rockers?

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 4:44 pm

They are spaced with billet spacers mate. I have a pet hate of those spring types.

Valvetrain geometry is spot on. Both visually and by checking the wear pattern in the valve stem tip.

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 4:47 pm

I will have another look at it tonight and see if I can work out what has happened.

You can get 'banana groove' versions of the shafts which oil better. It might just be a case of swapping to those.

Funny engough the rockers themselves don't show any wear? I will check them again to make sure though.

Jeff · Post by **Jeff** » Wed Mar 23, 05 6:00 pm

Dave left a trail of blood round mine, while working on the rocker shafts.... He looked like trhis when he left!

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 6:02 pm

Damn you and your razor blade shims Brown!

Alex · Post by **Alex** » Wed Mar 23, 05 6:37 pm

Dave they should line up mate,I can see where they have been missing the hole.. I have tried turning the shafts round before and found they lined up better, i.e front of the shaft to the rear, don't ask me why there should be a difference !

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 10:29 pm

Nope. They can't line up. It's impossible.

The oil holes are closer together than the valve stems.

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 10:35 pm

It could be damage from when I had trouble getting quick oil pressure at fire-up a couple of years ago.

Or it could be damage from loosing two lifters on the track at the last Nats and running up the strip and back to the pits with zero oil pressure.

Or it could be normal wear and tear with this type of rocker?

I don't know if I should get new shafts or re-use these old shafts.

There is some minor wear inside the rockers now that I look closer.

Mmmm.

If i do get new shafts they will be like these ones I think

Dave-R · Post by **Dave-R** » Wed Mar 23, 05 10:35 pm

Or I might just take the angle grinder to the ones i have?

Alex · Post by **Alex** » Wed Mar 23, 05 10:36 pm

Thats weird, looking at the markings on the shaft the rockers look indexed spot on to the valves.. are they O.E shafts?? the holes look to be exposed an equal amount on each rocker so maybe they use the rocker as a flow restrictor?

Alex · Post by **Alex** » Wed Mar 23, 05 10:39 pm

I like the slotted shafts but I wonder if the slots would be exposed at one end if the rockers are offset to the centre line like you have now? I would think about custom cutting yours so the grooves are indexed to your set up. The holes on the slotted shafts appear smaller in the pic, that makes me think the hole in your current shafts may be set up to be partly restricted?

latil · Post by **latil** » Wed Mar 23, 05 10:59 pm

My original 70 manual clearly shows the rocker arms (stamped steel) as offset by around the same as your valve stems are to the oil holes.The rockers are l/h &r/h offset arranged from front ex port l,r,l,r,l,r,l,r
This is for 383/440 engine.It says "install rocker shafts so that 3/16 inch dia rocker arm lube holes point downward into the rocker arm so that the 15 degree angle of these holes point outward towards the valve end of the rocker arms. The 15 deg angle is measured from the centre line of the rocker shaft mounting bolts"

Dave-R · Post by **Dave-R** » Thu Mar 24, 05 9:31 am

Yeah I was very careful to make sure I had the shaft on the head the right way around as that is critical for the oiling.

Dave-R · Post by **Dave-R** » Thu Mar 24, 05 9:38 am

latil wrote:My original 70 manual clearly shows the rocker arms (stamped steel) as offset by around the same as your valve stems are to the oil holes.

My rockers have no offset on them....

I bought the shafts and the rockers from Indy Cylinder head. I would have thought that if the rocker oiling holes needed to be offset on the rockers they would have thought of that?

Lots of things over the last few years have got me pretty angry about Yank "engineering".