Yes, if you have stiff valve spring and rev over 8,000 RPM it distorts the shaft.

the vale springs were quite soft considering the application, you could spin them with your finger when captive. Clapped out valve springs would soften up like that wouldn't they?

I had the same issue. It was with my A14.

Replace the shaft I'd say. Unless you have the time and cash to machine it down and replace the sleeves in the rocker arm void with thicker sorts.

This wouldn't happen to be on an A14 would it?

Why indeed it is, h75 head, h72 block

The out of round you talk of is usually caused by over tightening the riser that supports the shaft. because the shaft is hollow it just follows the shape of the bore in the riser. If you have good standard oil pressure at the rocker then there is something you can do to increase the oil pressure where the rocker bore meets the rocker shaft. I used to race these engines pretty hard and had similar problems. What you can do is machine up some spacers that fit where the end float springs normally fit. Make them a neat fit on both the bore diameter and the lenght. once made and fitted properly they increase the oil pressure at the rocker bore because the oil cant just squeeze out of the rocker bore then just dribble back down into the sump. the oil has to be forced out from the spacers thus maintaining better oil pressure for longer.
I did this to my injected 1200 and it fixed the problems with the rocker shaft drying of oil at 8000rpm.

Well, well, well I have a H75 head and here is a picture of my engine block. Definitely H72.



I wonder if this is a common thing?

What 1200 coupe says is very logical as well. Thanks for the 'sleeve spacer' advice!

I may have had trouble with over-tightening. I had an inaccurately calibrated P.O.S torque wrench when I first started the build.

LittleD-O,

Did you find the engine was very tight when cranking it over? Or did you not notice.

Chris

the noticable symptoms this motor had were:

distinct loss of power after a super long burnout in 2nd\3rd, never felt as strong
hard to idle
then the whole ringlands thing

mind you the space between the first and second things was like a year, Atually I may have had to change a starter motor over in that time I can't remember.

I didn't like the look of another shaft I found in the shed but it may just be the old grease, I'll look a little harder tomorro. Also I bought a set of rocker spacers from Dundee for this motor, dont want to leave the rocker spacing up to a couple of piddly springs, mabey if I used the old valve springs..... :)