Im rebuilding a motor that bent two Push rods on #1 intake. Both valves on #1 were sticking in the valve guide. I believe thats the explanation for the bent push rods and Im moving on. The other thing that has me worried is the mark on the bore on #1 and the valve mark on top of the #1 piston (exhaust side). All the other pistons and bore look as new. This is a very very low mileage motor.





I have shown a couple of peeps the pics and they are suggesting a bent connecting rod.

 

The valve mark is probbly where it stuck open. Don't know about the scoring on the wall, but if you have a bent rod the piston would not go up as high so it wouldn't hit the valves. Also if the rod was bent Iin my experince you would have herd one hell of a knocking.

 

Only way to know for sure is to pull the pan and look.

 

yeh Dan it will be a complete tear down. Its just if Im looking for a bent rod I will pay more attention when I do it.

 

Measure the piston height and make sure it is the same as the others on that side. If the rod is bent it will not be the same height.

Jody

 

^Exactly...measure the deck to piston height and compare. The last rod and piston I re & re'd was .015" shorter than the rest, and it sounded like it had one dead hole...which was pretty much the case. The PO had sunk the front end in a creek and sucked in some water which bent the rod, but the bend was hardly noticeable.

 

Brian that looks like a broken top ring to me! I'm in agreement with Jody any discrepancy of .010" will indicate that rod is beyond useable length, but that broken ring cinched it for me! She's coming out for a rebuild! Sorry mate!
Jim

 

well the heads are ready to go to the shop. Im waiting for Clay to send me over some valves and guides. I will attack the block and let you know what I find.

 

Please do! Can you feel any grooving yet on that area?

 

smooth as silk.

 

how do I do this with the head off and all that gasket goo on the block

 

Good! The bore is probably ok just a ball hone t brake glaze, lucky you caught it early!

 

Not trying to hijack but, do you have pmr's or forged rods? And would a bent rod cause low compression? Reason asking is my number 8 cyl is a lil lower than the rest on compression and a while back before I did the comp test I attempted to start my truck after pulling the ds bank of injectors without cleaning out the cylinders. When I went to start it it went thunk and quit spinning. Pulled the gp's out, spun it over and voilà, it fired right up. Not that it is anything I can fix right bow just wondering. And the pmr ? Was my thinking that you would probably bend a forged rod and probably crack or break a pmr. However good luck with your findings!!

 

Both will bend Brian you're gonna have to clean off all that crap to check and record pre teardown deck heights and verify stroke anyway aren't you?

 

Its forged Bulla. This is not my original motor. I bought this one cheap as is (bent pushrod and all) so I could do what Im doing and learn as I go. My motor in my truck is running like a dream. But he has PMR's. So if I was to achieve my 500Hp goal I would have to strip it down anyways. So I decided to got this way. Once I have it sorted I will swap them out and sell my original. You wont believe what we can get over here for a good condition motor. I will have a strong, fresh, rebuilt motor with all the good bits for about 5000 AUD. (although my machining costs maybe more than I expected)
Maybe others will chime in regarding your compression issue cause Im not the one to ask. All I can tell you that both my valves were tights as in #1 which is what caused my pushrod to bend. With the pitting on #2 head and the lack of attention to the valves on #1 my conclusion is that the reman job was rubbish and I believe I cannot trust anything in regards to tolerances with this motor.