383 Pushrod length?

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Dart_440

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Over the weekend, I built a pushrod length checker & solid lifter from an old pushrod and hyd lifter. I installed my 1.5 crane roller rockers on my stock 383 heads with a .019 steel shim head gasket.

I proceeded to check the length by marking the valve tip, adjusting the rocker so 1-2 threads are showing, installing the pushrod and adjusting till there is zero lash at the base lobe. Then I rotated the engine a couple turns and removed the rocker shaft. The wear mark on the valve stem was centered.

I have measured my overall pushrod and then subtracted the top cup to get my effective pushrod length.

I came up with 8.002". Does this sound correct? I guess I thought it would be a little longer?

Summit sells pushrods designed for the 383, with hyd lifters and roller rockers and they are 8.25". The only difference I have is my steel shims, but that's not much.

Maybe I measured wrong?

Thanks Bryan
 
I don't know, but I have questions:

Why do you think you need non stock length, that is, are the heads/ deck milled?

When you "made" your lifter, is the plunger in the (hydraulic) lifter at operating height, or is it bottomed out?
 
Well I bought the motor used.. It had already been recently rebuilt. I am not sure if anything has been decked or milled.

The only thing I know for sure that is different is the .019" steel head gasket I put in.

I pulled out the plunger from the lifter and inserted a stack of washers until I could just barely get the lifter cap and snap ring back in place.
 
I believe lifter preload on a hydraulic is on the order of .030"-.060", so that would be added to the length you got. That still doesn't add up to 8.25" though.
 
bOb shingler said:
i'm sure the length is measure from the ball to the top of the cup.
Click to expand...
Some pushrod manufacures measure overall length (tip of ball to top of cup) and some go by effective length (tip of ball to bottom of cup) make sure you clarify before you order. When you are ready to order call Manton Pushrods they will make sure you get the right pushrods for your application.
 
I would call the manufacturer your going to use and see what measurement they use. My guess would be ball end to inside cup. Your method is right on, don't worry about what summit has listed. It could be the difference between rocker setups, gaskets, deck thickness, etc.
 
Per an older post on the "other" board...http://board.moparts.org/ubbthreads...n=6929066&Words=+cjs69mope&topic=&Search=true "... The old Mopar performace book says B eng push rod length w stock rocker hyd. lifter 8.593 inches. w/adjustble rocker 8.375inches ...."
That being said, I have a set of OLD stock Mopar 383 B&S pushrods (spot welded on cup end) that are 8 9/16 (cup top to tip) They look like hydro cam to a mechanical rocker ala 340 TA? Who knows, Im not using them..no more B's.
 
pishta said:
Per an older post on the "other" board...http://board.moparts.org/ubbthreads...n=6929066&Words=+cjs69mope&topic=&Search=true "... The old Mopar performace book says B eng push rod length w stock rocker hyd. lifter 8.593 inches. w/adjustble rocker 8.375inches ...."
That being said, I have a set of OLD stock Mopar 383 B&S pushrods (spot welded on cup end) that are 8 9/16 (cup top to tip) They look like hydro cam to a mechanical rocker ala 340 TA? Who knows, Im not using them..no more B's.
Click to expand...

I'd like to know why the OP welded up a HYD. lifter to make it solid to check pushrod length ? If one is checking pushrod length they should be using the actual lifter they plan to use and not all ifters are the same , especially hyd to solid .
 
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