Crane pushrods and rocker arm.

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djazzarello

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Hi everyone,
I bent a pushrod and nicked up a rocker arm. The parts were made by Crane (no longer in business). The pushrod part # is CRN-69690-16 and the rocker arm is CRN-69791-1.
The bare minimum I need is one pushrod. I could probably get away without replacing the rocker arm.

bent pushrod.jpg
 
You need a whole set of pushrods. The pushrods you have are too short. I can tell by how many threads you have the adjuster hanging out of the bottom of the rocker.

Clean up the rocker around the adjuster and replace the one adjuster. Then get the right length pushrods.
 
djazzarello said:
Hi everyone,
I bent a pushrod and nicked up a rocker arm. The parts were made by Crane (no longer in business). The pushrod part # is CRN-69690-16 and the rocker arm is CRN-69791-1.
The bare minimum I need is one pushrod. I could probably get away without replacing the rocker arm.

View attachment 1715888981
Click to expand...
What heads are you using? Are all the Adjusters set the same thread count below and above or are they different on each one and i mean drastically different?
 
Solid or hydraulic lifters? If solid, that may be part of why the extra threads showing. Solid lifter pushrods usually measure at 7.50" (OEM early 273) and I believe those Cranes may be advertised at around 7.33". OEM 340-6 had hydraulics with pushrods around 7.23". But I couldn't find that particular # in one of their last master catalogs. It is in their 1999 price sheet. Comp Cams sells a similar pushrod.
 
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First you should find out why the prod bent so that there is not a repeat performance....
 
Rat Bastid said:
You need a whole set of pushrods. The pushrods you have are too short. I can tell by how many threads you have the adjuster hanging out of the bottom of the rocker.

Clean up the rocker around the adjuster and replace the one adjuster. Then get the right length pushrods.
Click to expand...

Looking at the photo.. I don't see any threads out the bottom of the rocker. /scratch

I'd think the pushrods are too long... go a bit shorter as you want a few threads showing out the bottom and top correct?
 
74Scooter said:
Looking at the photo.. I don't see any threads out the bottom of the rocker. /scratch

I'd think the pushrods are too long... go a bit shorter as you want a few threads showing out the bottom and top correct?
Click to expand...
The pushrod cup gets splash oiling from the orifice in the rocker, having the adjusters too far up into the rocker body is not good. Gotta find the sweet spot when setting the adjusters for thread exposure so the oil gets there, but no more than necessary. Using thread exposure as an “in general” setting is ok, but I’d be checking it all mocked up (with a measuring pushrod) to make sure the orifice is above the cup and adjust as needed to get it ideal and then order pushrods.
 
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74Scooter said:
Looking at the photo.. I don't see any threads out the bottom of the rocker. /scratch

I'd think the pushrods are too long... go a bit shorter as you want a few threads showing out the bottom and top correct?
Click to expand...


There is an actual specification for adjuster protrusion. IIRC it is 9/32 +.050 -.0000 and that’s it.

I believe I see some threads showing. That oil feed hole and the relationship to the pushrod cup is critical.
 
Rat Bastid said:
There is an actual specification for adjuster protrusion. IIRC it is 9/32 +.050 -.0000 and that’s it.

I believe I see some threads showing. That oil feed hole and the relationship to the pushrod cup is critical.
Click to expand...


Could just be me, I'm not seeing any threads showing.
 
Lots on this one, no idea if it’s been retreaded down in after disassembly? but it’s down a good bit:

3718ABC5-458E-4BCC-AFC4-F4A02777F604.png
 
Only time i bent pushrods was with valve float, and never that bad. Was this from a over rev or maybe your springs are going away?
 
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