Kohler Command CH25S rocker installation

[macindude]

Hi all,

I was watching a YouTube video about this engine and they talked about how there's a little depression in the cylinder head where the bumps on the rocker pivots go, and showed using a wrench to twist the pivot while torquing the bolt so that it sits correctly in the head and stays aligned.

I am just building up a new cylinder head, and my pivots have the bumps (either side of the bolt):



However, the head is perfectly smooth, with nowhere for those bumps to sit:



How should the rocker arm pivots be installed so that they don't twist around? What is the method used to correctly align the rockers?

FWIW, I grabbed the old cylinder head and it didn't have the depressions in the head either. Given how it practically fell apart as soon as I took the head off, I'm wondering if a twisted rocker pivot is part of the reason my push rod bent.

Thanks!

Kent

 

[RandyT]

I have always just eyeballed the alignment and torqued the rocker bolt to spec. the older Commands had a trough that the rocker sat in to keep it straight.

 

[tomplum]

So, you never found the reason why your pushrod bent? If that is the case, a set of lifters would be in order I'd think.

 

[macindude]

So, you never found the reason why your pushrod bent? If that is the case, a set of lifters would be in order I'd think.

Yep, totally new head, valves, lifters, etc.

 

[macindude]

FWIW, here is what I'm talking about:

I don't have the slot, so looking for what I should be doing instead.

 

[tomplum]

I saw what he did there in regards to locating the rocker and securing it. That looks fine to me. There's give there but I suppose one could get a thin straight edge across the square base of the pivots and they should be aligned. I looked down for a bit and then noticed he was using RTV, kinda lost me there. So I didn't really watch more. Bleeding the lifters I hope?

 

[macindude]

I saw what he did there in regards to locating the rocker and securing it. That looks fine to me. There's give there but I suppose one could get a thin straight edge across the square base of the pivots and they should be aligned. I looked down for a bit and then noticed he was using RTV, kinda lost me there. So I didn't really watch more. Bleeding the lifters I hope?

Ah, that's a good idea. So the two rocker pivots should be parallel? Or is there a slight V to them? Looked like the latter to me, but I'd also prefer something more precise than "well, that seems about right".

As far as the lifters, I got new ones. Nothing to bleed. Local dealer's head mechanic said *not* to soak and bleed, but just to install them dry.

 

[macindude]

Just popped the other valve cover off again for a look and the rocker pivots on that side are circular. There’s also a slight V between the rocker arms.

 

[tomplum]

 

[macindude]

Right, but I’m not reinstalling any lifters. I installed two new ones on the side I opened up. They’re dry, so there’s nothing in them to bleed. Right?