After a recent valve grind, I've discoverd that my pushrods are now too long. The block has been decked .050" and with the now removed material from both the seats and valve faces, the valves are opening up as I tighten the rocker shaft down.

Before the grind, if I ran down the interstate at 65-70 MPH, about 25 miles into the trip I'd develop a miss, guessing that one or more of the valves was hanging open due to heat expansion of lifter pump-up. Letting it idle for a couple minutes would correct itself and all would be good.

The stock pushrod measures 9.985 and the length checker is 9.760 at zero lash. The FSM says the dry lash is .060 to .210

The question is, what length should I have made up since I have .150" to play with? It's an 85 D-150 hydraulic head engine that is my daily driver with the ocasional 60 mile highway use. It does have a Comp Cams 260H RV cam in it, but the base circle is still the same.

I'm thinking aroud 9.800" will fill the bill but just wondering if I've done my math right with the length minus the decking and adding the dry lash(s).

Troy

.150" lifter travel seems like a lot. I would measure the plunger travel in the lifter so you know what the true travel is rather than relying on the manual. Send your adjustable checking pushrod set to zero lash to Smith Brothers and tell them you want that pushrod length plus 1/2 of the lifter travel. That way Smith Bros can measure the pushrod and deliver the proper length.

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Joshua

The dry lifter travel is measuring somewhere around .285 acording to my dial calipers. Half that (.1425) and we're back to close to the .150.

With these new measurements, I'm coming up with somewhere between 9.879 and 9.910.

Does anyone know what Smith Brothers charge for a set of pushrod?

Troy

Wow, that's a bunch of travel. Smith Brothers is quite reasonable and they are fast. Call them. http://www.pushrods.net/ 800-367-1533

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Joshua