Can I rebush rockers and not redo faces or cams?

[gregwils]

I probably deserve the flaming I will get for this, but money is tight so I need to ask.

I disassembled and resealed my motor a few years ago and replace some stuff that really needed it - valve guides, seals, intakes, etc. It was a low budget job. I chose not to redo my cams or rockers, they looked perfect minus #1 exhaust rocker which was replaced because of some pitting.

However, it seems like I can't get my valves completely quiet with sound coming I out of #3. The rocker shafts were in spec, but with measurable wear. Plus, I could see some wear marks in the rocker bushings. There was no radial play when on the shaft, but they moved so freely on the shaft - rotation and axial, I am wondering if they don't need rebushed.

If it is completely ill-advised to rebush only, then I won't and will manage to scrape together enough to fully redo the cams and rockers. However, I have lots of other places on the car to spend the money, I will get more bang for my limited buck doing other projects.

Thanks.

I was considering Cgarrs bushings. Refurbished rockers?

Here were my cams and rocker bushings at the time...

[nocarrier]

Cgarr did an awesome job on mine.

You have to regrind the rockers (a very small amount) to insure the wear pad is exactly parrallel with the rocker bore as it rides on the rocker shaft.

[gregwils]

Originally Posted by nocarrier

Cgarr did an awesome job on mine.

You have to regrind the rockers (a very small amount) to insure the wear pad is exactly parrallel with the rocker bore as it rides on the rocker shaft.

That does make sense. Thanks.

PS - He did my heads, so will probably send rockers to him.

[cgarr]

Some I grind are pretty close with the new bushings and some are off a lot, all depends on how bad the original bushings are. Best thing to do is send in the feet with them so they can be surfaced too. Sometimes they will get a ridge in them which makes adjusting the valves with a feeler gauge pretty hard to do.

[KTL]

How sure are you of your valve adjust ability? I don't mean that in a "you suck at adjusting valves" sort of way. Just asking if you have been able to get them quiet after previous valve adjustments. I ask because I always thought I did a good job of adjusting mine and they always ended up clackety- because I had them quite loose.

Considering that the process of adjusting by feeler gauge involves bending the gauge, it's easy to end up with loose valves (not necessarily a bad thing). Once I forced myself to adjust them tighter than the typical "light drag on the feeler" rule of thumb, I would have a quieter valvetrain. I adjust them now so that there is a good amount of drag on the feeler, but not so much that it requires effort to slip the feeler gauge in/out of the gap, nor does it deform the flat/unbent area of the feeler.

[burgermeister]

I rebushed mine myself, without refacing the rockers, for the staggering cost of $35 in parts and a few hours of my time. However, the bushings do not wear evenly, and the faces will wear to match the off-kilter old bushing, and will thus be off a bit when the arms are re-bushed. The rocker faces will wear in to the new orientation eventually, which produces a bit more oil glitter than one would like to see. And there is a fair bunch of clacking that accompanies this wearing in, presumably from axial movement of the rockers caused by the uneven contact. It slowly goes away, and after 5k it was gone completely (or at least it was on my engine). If you have the money & time, it's probably a good idea to have them refaced.

[gregwils]

Originally Posted by cgarr

Some I grind are pretty close with the new bushings and some are off a lot, all depends on how bad the original bushings are. Best thing to do is send in the feet with them so they can be surfaced too. Sometimes they will get a ridge in them which makes adjusting the valves with a feeler gauge pretty hard to do.

Are you by any chance doing cams yet Craig?

[gregwils]

Originally Posted by KTL

How sure are you of your valve adjust ability? I don't mean that in a "you suck at adjusting valves" sort of way. Just asking if you have been able to get them quiet after previous valve adjustments. I ask because I always thought I did a good job of adjusting mine and they always ended up clackety- because I had them quite loose.

Considering that the process of adjusting by feeler gauge involves bending the gauge, it's easy to end up with loose valves (not necessarily a bad thing). Once I forced myself to adjust them tighter than the typical "light drag on the feeler" rule of thumb, I would have a quieter valvetrain. I adjust them now so that there is a good amount of drag on the feeler, but not so much that it requires effort to slip the feeler gauge in/out of the gap, nor does it deform the flat/unbent area of the feeler.

That's a fair question. I am by no means an expert, but have probably adjusted them a half-dozen times, with definite improvement along the way. Most of my valves are pretty quiet, but #3 in particular likes to talk to me regardless of what I do. Plus, I bought the valve adjusting tool with the two 36 degree markers which has helped me a lot, so I am pretty comfortable that my valves are not loose.

[gregwils]

Originally Posted by burgermeister

I rebushed mine myself, without refacing the rockers, for the staggering cost of $35 in parts and a few hours of my time. However, the bushings do not wear evenly, and the faces will wear to match the off-kilter old bushing, and will thus be off a bit when the arms are re-bushed. The rocker faces will wear in to the new orientation eventually, which produces a bit more oil glitter than one would like to see. And there is a fair bunch of clacking that accompanies this wearing in, presumably from axial movement of the rockers caused by the uneven contact. It slowly goes away, and after 5k it was gone completely (or at least it was on my engine). If you have the money & time, it's probably a good idea to have them refaced.

Thanks. That is exactly what I was going to do and hearing your experience will probably cause me to just pull the cams and rockers this winter. I need to have my chain tensioners rebushed too, so I will knock them all out at once. Hopefully, my motor will then be good for another 100k w/o further work on the internals.

[burgermeister]

The idlers & sprockets (the tensioners themselves don't really move) you can do yourself with impunity.
idler arm bushing replacement

[burgermeister]

I had the chance to inspect my rebushed rockers, idlers, and idler sprockets today due to an unrelated issue with my engine.

The rockers had some serious wear - +0.18mm for the worst of them, which is wayyy out of spec. I did these myself, I did not reface the rockers (and they were off, very visible from the cam wear), I did not micropolish the shafts, or do anything else to help them out. One can conclude that the DU bushings when just pressed in and reinstalled as-is are a rather shortlived replacement (14,000 miles & 13 track days).

The idler bushings had some wear - the teflon coating is almost gone in one spot.

The idler sprocket bushings look like new. So that one seems a good application even for the homebrew mechanic.

[larrym]

guys - there is a much better and easier to use feeler gage - double ended 004 - 006 so you can do go/no-go easily

it's thin, rigid, much easier to poke into those head crevices, easier to "feel"

find it at motorcycle, etc, shops - picture attached

maybe Pelican should stock em, eh?

Originally Posted by KTL

Considering that the process of adjusting by feeler gauge involves bending the gauge, it's easy to end up with loose valves (not necessarily a bad thing). Once I forced myself to adjust them tighter than the typical "light drag on the feeler" rule of thumb, I would have a quieter valvetrain. I adjust them now so that there is a good amount of drag on the feeler, but not so much that it requires effort to slip the feeler gauge in/out of the gap, nor does it deform the flat/unbent area of the feeler.

.

[KTL]

I'm not a big fan of the "factory" tool with the tiny pieces of feeler gauge that screw onto the tool & need to be bent. I got one of these back in the day from island911 and i'm very pleased with it.

That Cool Valve Adjustment tool - New Source