273 adjustable rocker conundrum..

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I have a whole set of the Crane ones.

But they are already installed on the rockers I'm going to run on my new slant build. I think I got the last set Summit had. The next day after I ordered them, they weren't showing available and they've not been available since.
 
RustyRatRod said:
I have a whole set of the Crane ones.

But they are already installed on the rockers I'm going to run on my new slant build. I think I got the last set Summit had. The next day after I ordered them, they weren't showing available and they've not been available since.
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No you need one of these:

press.jpg
 
RustyRatRod said:
Take the rockers and put them on your anvil on the bottom corner and gently tap the opposite bottom corner with a hammer. You only want to close the bottom side of the holes just a very small amount. That'll do it.
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You've seen the adjusters on the crane rockers that I have and how far out they are... On these Factory ones I've taken up almost all of the adjustment within a couple threads so I should be able to booger them up kind of high so I get lots of thread in there before they start getting tight and not just boogering it up all the way through..
 
j par said:
Appreciate you trying to derail this the best you can but some actual help here would be nice..
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Just trying to help. We weren't getting very far. I'll remind you of that next time you do it to someone elses thread.
 
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j par said:
You've seen the adjusters on the crane rockers that I have and how far out they are... On these Factory ones I've taken up almost all of the adjustment within a couple threads so I should be able to booger them up kind of high so I get lots of thread in there before they start getting tight and not just boogering it up all the way through..
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You don't want to booger threads up. That's not how you make an interference fit. You close the holes up just a little.
 
j par said:
You've seen the adjusters on the crane rockers that I have and how far out they are... On these Factory ones I've taken up almost all of the adjustment within a couple threads so I should be able to booger them up kind of high so I get lots of thread in there before they start getting tight and not just boogering it up all the way through..
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And about the Crane rockers.....what size are THOSE adjusters?
 
RustyRatRod said:
And about the Crane rockers.....what size are THOSE adjusters?
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Trust me the first thing I looked at LOL they're bigger..
Which would bring up another conundrum first if I drill and tap the factory 273 to fit those I might lose that oiling slot... And then the crane rockers become kind of useless and not sellable..
 
j par said:
Trust me the first thing I looked at LOL they're bigger..
Which would bring up another conundrum first if I drill and tap the factory 273 to fit those I might lose that oiling slot... And then the crane rockers become kind of useless and not sellable..
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Yeah I wouldn't even think about doing that. Then you end up with two sets of useless rockers. There's not enough meat in the 273 rockers to get them out to 7/16.
 
I have a "spare" set of complete adjustables destined for my build. To be safe I would like to add locknuts, I dont tink I need adjusters too. I'll chk Summit and Mancini, altho I havent been impressed with the shackles I bought from Mancini.
 
RustyRatRod said:
Yeah I wouldn't even think about doing that. Then you end up with two sets of useless rockers. There's not enough meat in the 273 rockers to get them out to 7/16.
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My eyeball is way off and I completely lied to you... It's getting late here but I still went out to the garage and pulled one of those adjusters off the crane and screwed it right into the factory 273!!!..
BAZINGA! SCORE!...
Now just like the advice I took from you on my first set of 273s back in 2014 when I first built the stroker for the Duster I need to take a file to the top side of those and smooth them out like I did the last set that I foolishly sold. But then I have to grind the inside face so they don't touch the Springs like the machine shop did for me the last time...
I'm good to go..
 
j par said:
My eyeball is way off and I completely lied to you... It's getting late here but I still went out to the garage and pulled one of those adjusters off the crane and screwed it right into the factory 273!!!..
BAZINGA! SCORE!...
Now just like the advice I took from you on my first set of 273s back in 2014 when I first built the stroker for the Duster I need to take a file to the top side of those and smooth them out like I did the last set that I foolishly sold. But then I have to grind the inside face so they don't touch the Springs like the machine shop did for me the last time...
I'm good to go..
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I had to do a little grinding too.
I have the wrong springs but they are set up and they work.

100_5227.JPG
 
toolmanmike said:
I had to do a little grinding too.
I have the wrong springs but they are set up and they work.

View attachment 1715807521
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These are Crower Springs that the engine builder put on 7 years ago. The 596 heads were completely rebuilt and I really don't have many miles on them. They had the clearance the 273 rockers that I gave them originally but when they shut the engine up they said some of the adjusters weren't holding and that's when I had to take them off and put locking adjusters on.. that was 7 years ago though when parts were plentiful and like I said I foolishly sold that set...
I tried to slip a .030 piece of welding wire behind the spring and it wouldn't pass..
 
toolmanmike said:
I had to do a little grinding too.
I have the wrong springs but they are set up and they work.

View attachment 1715807521
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I need to take one cylinder apart and see if Comp 901's would be better. The machine shop had to put a real thick shim under those to make them work. The springs are too short or I got ahold of some long stem valves.
 
Grinding on the rockers isn't the "correct" way, but for what you're doing, it'll work ok. Just do a neat job and avoid any sharp corners. Grind it smoothly and neat so as not to make any stress risers that might induce cracks.
 
RustyRatRod said:
Grinding on the rockers isn't the "correct" way, but for what you're doing, it'll work ok. Just do a neat job and avoid any sharp corners. Grind it smoothly and neat so as not to make any stress risers that might induce cracks.
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They need very little and as you know these are cast and random...
 
instead of grinding the bottoms of the rockers, like we've all done. I think using beehive valve springs would be the way to go.
 
lemondana said:
instead of grinding the bottoms of the rockers, like we've all done. I think using beehive valve springs would be the way to go.
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That's certainly a real option. The real reason though is because the geometry needs correcting by relocating the rocker shaft. But the beehive option or rocker shaft spacers are equally expensive and I really don't think it's worth doing with what he's doing with the engine. Were it a high RPM hot street or race motor, yeah.
 
Almost positive the thread 'interference' in the original design was in the adjuster, not the rocker. The adjuster was hollow, & slightly oversize. When screwed into the rocker, the adjuster thread was able to 'compress' slightly because of the hollow centre. This kept the adjuster tight enough to stop it changing position. The thread in the rocker may well be a standard 3/8" NF thread, in which case adjusters with a locknut are probably available.
 
Thanks Bewy, I'll see about getting a jam nut locally and giving it a try.
Thanks.
Bewy said:
Almost positive the thread 'interference' in the original design was in the adjuster, not the rocker. The adjuster was hollow, & slightly oversize. When screwed into the rocker, the adjuster thread was able to 'compress' slightly because of the hollow centre. This kept the adjuster tight enough to stop it changing position. The thread in the rocker may well be a standard 3/8" NF thread, in which case adjusters with a locknut are probably available.
Click to expand...
 
Bewy said:
Almost positive the thread 'interference' in the original design was in the adjuster, not the rocker. The adjuster was hollow, & slightly oversize. When screwed into the rocker, the adjuster thread was able to 'compress' slightly because of the hollow centre. This kept the adjuster tight enough to stop it changing position. The thread in the rocker may well be a standard 3/8" NF thread, in which case adjusters with a locknut are probably available.
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I thought so to until............I actually did the mod and added the Crane adjusters to a set. The interference is in the rockers. With the Crane adjusters, you don't want the interference fit. The Crane adjusters were tight like the factory adjusters until I ran a 3/8-24 tap through all of them. Several times in fact. Loosened them right up. But I was like you. I thought it was in the adjusters too, but it's not.

Now......on the slant 6, it's different. The interference IS in the adjusters. I believe it's because the rockers are made only of folded sheet metal and are not strong enough to hold that interference fit for long. I was able to screw my Crane adjusters in my slant 6 rockers with my fingers. There's also enough room on the slant 6 rockers for the adjuster nut to fully seat without having to face the top of the rocker holes. I'll have pictures before much longer when I am able to get my camshaft in. Then I can assemble the head on the engine.
 
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