rocker shaft goes off..

oyk · Mar 25, 2005

hi all folks,
while rebuilding my engine i noticed that the exhaust rocker shaft had a radial play more than 1mm. i removed it and saw that it was very worn.
the place that it rests(dont know the right word) from the one side is the endplug, right? its hole turned into oval and so did the aluminium hole on the other side(there is no bushing).
i thought that it was a good idea to overbore the two holes, put a set of apropriate of bronze bushings and a new shaft.
do you thing it is a good idea? would it be less reliable?
any one has a better suggestion?

Taffy · Mar 25, 2005

great idea and the best in my opinion.

regards

Taffy

oyk · Mar 25, 2005

rocker shaft

i also noticed that the shaft is not hardened at all, you can mark it just with a butter knife, is there a reason for it?

would it be good to make my own shaft using hardened steel or it would cause something bad?

oldberger · Mar 25, 2005

Am I reading this right, rocker shaft (steel) into aluminium bore?

WTF :evil:

This is a serious breech of engneering principles IF the rocker shaft is able to rotate.

It may never be the first thing to go when an engine fails but may well be the root cause of several other top end failing parts.

When I replace the rocker bearings (soon) I'll look at this mod.

Does anyone know the rocker shaft diameter and tolerance?

oyk · Mar 25, 2005

rocker shaft

the shaft doesn't rotate, it has a hole where a bolt engages it not to spin.

the outer diameter is 12mm, the inside is 5mm and the maximum radial play is 0.15mm.

i thing that newer models (mine is a 95' fe 600) have bushings but i am not quite sure

oldberger · Mar 25, 2005

Re: rocker shaft

oyk said:
the shaft doesn't rotate, it has a hole where a bolt engages it not to spin.

the outer diameter is 12mm, the inside is 5mm and the maximum radial play is 0.15mm.

i thing that newer models (mine is a 95' fe 600) have bushings but i am not quite sure

0.15mm (0.006") is a lot of play, It's been a long time since I looked in my Zeus book but I reckon that makes the hole tolerance greater than H8. I'd deffo go for the bushing mod. I've not had the top end apart yet so I hope you're right about the later models being bushed. 2002 on anyway :wink:

berger_king · Apr 2, 2005

i would recomend getting a new or second hand rocker cover but if you want to try the bushings it would work but for how long?

oldberger · Apr 2, 2005

berger_king said:
i would recomend getting a new or second hand rocker cover but if you want to try the bushings it would work but for how long?

berger_king

If the bushing mod is done properly it'll be better than new.

oldberger :roll:

oyk · Apr 2, 2005

rocker shaft

well, the mod is done. i made a new shaft from a harder steel than the original which was rather soft as butter and put a pair of steel bushings.
i thing that it will be MUCH more reliable than the original set

Search

Search

rocker shaft goes off..

oyk

Taffy

oyk

oldberger

oyk

oldberger

berger_king

oldberger

oyk

Similar threads

Register CTA

Recent Discussions