Installing Rockers

swooshdave · Jul 17, 2019

I installed the studs, put the old copper gasket on to act as a buffer and temporarily put the head on. Having the engine stand (thanks @comnoz!) has made a huge difference. I don’t have a proper workbench, just a service cart but it’s worked out so far.

I’ve never installed the rockers, only taken them out. I’ve got the shafts in the freezer and plan on heating the rocker box area up with a heat gun.

I’ve going give it a try and if I get stuck I’ll take it on Friday over to my friend. He’s restored countless bikes and that’s who I borrowed the puller from.

If everything works out the head will be done this weekend. Assuming nothing hits and everything still spins.

Then things will go pretty fast. Of course I’ve been saying that for a while.

acadian · Jul 17, 2019

It's fairly straightforward, just remember to get the flats aligned properly so the spindle caps seat correctly. Tweak the orientation while the area is still warm and use the spindle cap as a guide to ensure the bolt holes line up (easiest when the spindle is still about 1/4" proud).

swooshdave · Jul 17, 2019

It seems like it would be easy, flats to the outside. Several of the shims I've pulled out were either oblonged or worn. I have new shims going in.

Dances with Shrapnel · Jul 17, 2019

In this instance, I would not get too concerned about cooling the spindles as heating the alloy is the best bang for the buck. Aluminum has roughly twice the coefficient of thermal expansion of steel. Furthermore, unless you are using liquid nitrogen to cool the steel, the aluminum under a heat gun will most likely see the greatest delta temperature.

In the past, I've used a hot plate to evenly heat up the whole head, handle the head with welding gloves and go to town with getting the spindles in. Never messed with chilling the spindles, just used a light coating of oil on them. Better in my opinion to have more even heat across the head rather than trying to work heat into a quadrant of the head at a time.

seattle##gs · Jul 17, 2019

Here is some very good advice.....get some pipe or tube or whatever just slightly undersize of the spindles so it can slide in and out while cold.
I used a set of old spindles and made them undersize. Then assemble the rockers and spacers in the head and heat the whole thing up. It is MUCH easier to do cold than hot. When the whole thing reaches about 200 degrees, remove one tube at a time and slide in the spindle. The Thackeray washer holds everything in place.
#2...Warm up the spindle before you install it. Not too hot that it can't be handled easily. If it is 30 degrees the freezer what will happen is the spindle hole in the aluminum head will shrink immediately around the spindle and you lose all the advantage of heating the head.
try measuring a spindle at room temp and one at 30 degrees. There will be no change in the O.D. So there is nothing to be gained by freezing. Unless you get into nitrogen as mentioned above but that is something else entirely.

swooshdave · Jul 17, 2019

seattle##gs said:
Here is some very good advice.....get some pipe or tube or whatever just slightly undersize of the spindles so it can slide in and out while cold.
I used a set of old spindles and made them undersize. Then assemble the rockers and spacers in the head and heat the whole thing up. It is MUCH easier to do cold than hot. When the whole thing reaches about 200 degrees, remove one tube at a time and slide in the spindle. The Thackeray washer holds everything in place.
#2...Warm up the spindle before you install it. Not too hot that it can't be handled easily. If it is 30 degrees the freezer what will happen is the spindle hole in the aluminum head will shrink immediately around the spindle and you lose all the advantage of heating the head.
try measuring a spindle at room temp and one at 30 degrees. There will be no change in the O.D. So there is nothing to be gained by freezing. Unless you get into nitrogen as mentioned above but that is something else entirely.

That is the first time I’ve heard someone suggest putting it together with a proxy spindle, heating and then putting in the spindles.

It may have been a placebo effect but chilling get the wristpins seemed to help slightly. I think that’s what @comnoz suggested. Not sure what the effect will be on the spindles.

swooshdave · Jul 17, 2019

Dances with Shrapnel said:
In this instance, I would not get to concerned about cooling the spindles as heating the alloy is the best bang for the buck. Aluminum has roughly twice the coefficient of thermal expansion of steel. Furthermore, unless you are using liquid nitrogen to cool the steel, the aluminum under a heat gun will most likely see the greatest delta temperature.

In the past, I've used a hot plate to evenly heat up the whole head, handle the head with welding gloves and go to town with getting the spindles in. Never messed with chilling the spindles, just used a light coating of oil on them. Better in my opinion to have more even heat across the head rather than trying to work heat into a quadrant of the head at a time.

While I’ve shown that I could heat up the whole head I’m concerned it would cool too much by the time I got to the second rocker. Due to the distance between the rocker boxes and the bottom of the head heating up that area shouldn’t have much affect on the other parts.

I’m always game to trying a method and if it doesn’t work try something else.

seattle##gs · Jul 17, 2019

I use a hot plate myself. Using my method of pre-assembly, it will give you a bit more working time but even then you will have to re-heat to make the spindles slide. It takes time to align the spindle slots correctly and the head cools rapidly.
Another tip...turn the head upside down on the hotplate so you heat the rocker area first. Ideally I would have a motor home propane oven and do it all at once.

swooshdave · Jul 17, 2019

For those of you who use the hot plate method have you also tried the localized method?

Torontonian · Jul 17, 2019

Heat gun for me , works well enough.

swooshdave · Jul 17, 2019

It was easier than I thought. The first one took a while but then when I got the hang of it the rest went easy. I checked the alignment but putting the plate up to it. All looked good. I think I did it. Flats all face out.

I used a heat gun on high. The exhaust took longer to warm up. The intakes were easy.

So now the question is what do you put on the gaskets? Dry? The copper spray? Something else?

gortnipper · Jul 18, 2019

Like I said on FB, if you have the JS silicone gaskets, nothing.

One piece rocker covers are the thing.

With two piece covers and paper I used copper spray.

Fast Eddie · Jul 18, 2019

I had these shafts turned up, nice sliding fit, extended and knurled ends. Made the repeated fitting and removal during my pre assembly checking and measuring and re checking and re measuring, slightly less painful!

triumph2 · Jul 18, 2019

seattle##gs said:
...snip....
try measuring a spindle at room temp and one at 30 degrees. There will be no change in the O.D. So there is nothing to be gained by freezing. Unless you get into nitrogen as mentioned above but that is something else entirely.

I'm not sure what you are using to measure the spindle O/D ? Maybe a tape measure? Using a micrometer will show a definite change. Basic physics.

Hortons Norton · Jul 18, 2019

^ Test underway ^ Hell I'm retired.

swooshdave · Jul 18, 2019

So the spindles were definitely frozen and they started to warm immediately going into the hot head. But I assume the cold spindle has some affect. I didn’t do the scientific thing and try a room temperature spindle.

Hortons Norton · Jul 18, 2019

I cannot see any difference between 77 and out of the freezer, gotta go into town so i'll leave it in a little longer.

dynodave · Jul 18, 2019

My ice box freezer is closer to 0 f. However doing any head work like guides or seats, I use dry ice for the guides/seats and there is a tiny bit of shrink. The head goes in my industrial oven which uses a thermocouple controller and I set it typically to 375 f. I check if it is ready with a Infared gun.
Doing rockers, I don't need to do anything to the rocker shaft, just install in the hot head...

Hortons Norton · Jul 18, 2019

Well over an hour in the freezer and still maybe at the most it's maybe .0001 or 2 at most. Only reason I was curious is I am going to be doing this this winter also.

comnoz · Jul 18, 2019

Actually cooling the spindles is counterproductive. [counter to most claims]

Since the steel is higher density than the aluminum it will absorb heat from the aluminum faster when it is cold. So a cold spindle will make the hole in the head shrink faster than a warm spindle will.

The same applies to bearings in an aluminum bore. The bearing will stay loose in a hot bore longer if the bearing is installed at 100 degrees F than it will if the bearing is cooled in the freezer first.

Try it some time, I have.

Installing Rockers

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