Lifter Preload

[68r/t]

Can someone please tell me what the factory lifter preload specs are for a Big Block?
I have a Crower hdp282 cam  and Crower say I may need a longer pushrod, but with milling of my heads etc I am getting .070-.075 thou preload on my lifters with the standard pushrods which indicates that I should use a .050 thou shorter pushrod..
I know .020-.050 thou is what is recommend by Crower and I am curious as to what the factory specs are.

[firefighter3931]

The factory spec was .020-.040  These engines weren't exactly blueprinted from the factory...deckheight was all over the place and chamber volumes varied considerably. As long as you're in that range, you're good to go. The HDP282 is an excellent cam....i had one of those in my old 440 


Ron

[68r/t]

I will get .050 shorter pushrods,   Does anyone know who may stock .050  shorter 440 pushrods?
All I can find is stock and +.050 and .100.

[frederick]

Comp cams lists standard length for RB as 9.300"
so you would need 9.250"
Summit has them:

http://www.summitracing.com/search/Department/Engines-Components/Part-Type/Pushrods-Assembled/Tubing-Diameter-in/5-16-in/Top-Tip-Style/Ball/Intake-Overall-Length-in/9-250-in/Brand/COMP-Cams/?Ns=Rank%7cAsc


But it might be cheaper to get them custom made at Smith Brothers
http://www.pushrods.net/
If you order from them, measure your own pushrods before ordering, as there are different measurement methods:
http://www.pushrods.net/terminology.html


Cheers,

F.

[68r/t]

Thanks for that, I searched Summits the other day but was searching  440 pushrods, these are a universal with oiling holes which should be O.K.
I did email Smith Brothers a couple of days ago also but have not had a  reply yet.
Summits it will be.

Thanks

[68wedge]

Just had to do the same thing. Put new top end in my motor and needed a custom length. You can also try hughes engines- thats where I got mine made. They stock a 9.25 & 9.5- But go figure I needed a 9.225. Easiest way is to get yourself a pushrod measuring tool...