340 Rockers

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americal

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Has anyone used Comp Cams 1622-16 roller rocker arms on a 340? Are they good and worth the price?
 
Just bought a set 2 weeks ago.

20170813_140131.jpg
 
americal said:
If the pushrods need to be shorter what length do they need to be?
Click to expand...

you need to measure on your motor....blocks get decked and heads get milled over the years...no one knows what you have.....only you.....buy a push rod length checker tool....set it to where it needs to be, then measure the length of the tool....then buy the closest push rod you can buy....I used comp cams 7958 push rods which are 7.550
 
americal said:
If the pushrods need to be shorter what length do they need to be?
Click to expand...

Take an existing push rod and cut 1 inch out of the top portion leaving about an inch of end piece , get a piece of all thread that will fit inside the 2 push rod ends... and 2 nuts that screw onto the all thread.
Now you have an adjustable push rod.
Set the adjuster to give about an even number of adjuster threads top and bottom of the nut and rocker, no more than 3 threads above adjuster nut. Take the adjustable push rod and set it in place on lifter, turn the nuts to shorten it enough to clear the rockers on shaft to bolt it down....now adjust the push rod longer, screw the nuts away from each other to lengthen and contact the adjuster. Now adjust the push rod to what ever lash is called for, "read below"
Do this on all 4 corner cylinders 1,7,2,8 to get the average length between them all, that's the length push rods you order up.

Hyd cam, tighten 3/4 or .030 lifter cup depression.
Solid cam, what ever the cam maker calls for , I like .018 open lash

When I do mine this way, once the length is set....i take another push rod cut and weld it to that exact length and set it up on every rocker, adjust it and rotate to check clearance, adjuster threads etc, any stem height issues will show then if anyone screwed up early in the machining part.
 
bbrroowwnn said:
you need to measure on your motor....blocks get decked and heads get milled over the years...no one knows what you have.....only you.....buy a push rod length checker tool....set it to where it needs to be, then measure the length of the tool....then buy the closest push rod you can buy....I used comp cams 7958 push rods which are 7.550
Click to expand...
Had to do the same thing here, but it was several years ago and I don't have a record as to what I bought. But they were in stock at Summit, made by Comp.
 
MOPAROFFICIAL said:
Take an existing push rod and cut 1 inch out of the top portion leaving about an inch of end piece , get a piece of all thread that will fit inside the 2 push rod ends... and 2 nuts that screw onto the all thread.
Now you have an adjustable push rod.
Set the adjuster to give about an even number of adjuster threads top and bottom of the nut and rocker, no more than 3 threads above adjuster nut. Take the adjustable push rod and set it in place on lifter, turn the nuts to shorten it enough to clear the rockers on shaft to bolt it down....now adjust the push rod longer, screw the nuts away from each other to lengthen and contact the adjuster. Now adjust the push rod to what ever lash is called for, "read below"
Do this on all 4 corner cylinders 1,7,2,8 to get the average length between them all, that's the length push rods you order up.

Hyd cam, tighten 3/4 or .030 lifter cup depression.
Solid cam, what ever the cam maker calls for , I like .018 open lash

When I do mine this way, once the length is set....i take another push rod cut and weld it to that exact length and set it up on every rocker, adjust it and rotate to check clearance, adjuster threads etc, any stem height issues will show then if anyone screwed up early in the machining part.
Click to expand...
You forgot: The lifter must be on the base circle of the cam.
 
I got my new Comp rockers 1622-16 yesterday. My pushrod adjuster will hopefully be in today. I tried to make my own but my old 340 pushrods are solid. It looks like I may need a longer pushrod than the stock 7.500. I have been looking at Comp cams pushrods to see available sizes when I get the correct length. My question is can I use a oiling pushrod in place of my non oilers? Most of them are listed as oilers. Thanks.
 
Yes, use any type pushrod you want. It does not matter. Depending on the lifters, the oil may or may not get up the pushrod, but there is really no place for it to go once it hits the surface of the adjusting screw.
 
Smith bros pushrods. They will make whatever length/end you want. Pretty reasonable.
 
I run the last generation of those rockers for years. Very happy with them
 
bbrroowwnn said:
you need to measure on your motor....blocks get decked and heads get milled over the years...no one knows what you have.....only you.....buy a push rod length checker tool....set it to where it needs to be, then measure the length of the tool....then buy the closest push rod you can buy....I used comp cams 7958 push rods which are 7.550
Click to expand...

This is VERY good advice:thumbsup::thumbsup:
 
Been using those rockers on 2 different engines for 7 seasons now have performed flawlessly very happy with them..
 
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