Bent Pushrods

[Extremecor]

Hello

First i'd like to itroduce myself.
My name Cornald Nuiten and i am a mechanic in The Netherlands.
We have now in total 15 srt-10 pick-up's imported from the USA.
Its a very nice car but we have some technical problems with it,and now i hope someone can help.
I have 2 srt-10's that have the pushrods bent.
The first one it is a quad cab automatic transmission and it was cilinder 6 (the intake), i changed him and drive it was ok.
When i started the car 2 minutes later the problem was ther again, but now cilinder 5(also the intake). I replaced it and the man has now driven 10.000mls with it without problems.
The other one was a single cab manual transmission it was cil 3 (the exhaust)
replaced him and 3 weeks later he had the same problem but now it was cil 9(intake).
Is it possible that the fuel is the problem?Both of the cars are driven on propane,but 11 other srt-10's are also driving on propane without problems.

Any suggestions?

(sorry for my bad englisch)

Regards
Cornald Nuiten

 

[eddie102870]

hardened push rods might help. probably just as cheap.

 

[Floor]

neem ze naar een DODGE Dealer?

 

[nycstev]

Ik wens dit ik u kon helpen!

 

[Prof]

Could be the fuel...any signs of detonation? Any of these trucks running an air/fuel gauge? Years ago we used to assume pre-ignition problems when we had bent push rods...build up of deposits from poor fuel that ignite air fuel in the cylinder before/or after cylinder reaching TDC...

FstJack, Muzzy, Silverback, Stingray....any opinions?

 

[FSTJACK]

There is a very small chance that detonation caused the bent pushrods.

Assuming that over reving is not the cause of the problem. And that the valve springs are in tolerance with regards to seat pressure at closed (valve on the seat) and full lift pressure (valve fully open).

Propane is a very dry fuel which can cause the stem to stick in the guide.
In some applications we have had to put an extra 1/2 a thousandth on the stem to guide clearance.

You might also need to use a silicone bronze valve guide (less chance of gaulling under dry heat) with a berrylium valve seat for better heat transfer.

Without more information it is difficult to diagnose your problems. I hope this helps and will give you something to look at to correct the situation.