Can you identify the Issue here?

[HeliPilot71]

I bought this engine a little over a year ago. It's suppose to be a fresh build. I took it into the shop to put it on the dyno. There was an issue with the push rods rubbing; long story short, pull the heads and grind a little of the area needed for clearance. Popped the heads off and bingo. Can you spot the issue?

 

[PurpleBeeper]

Hard to see in the picture if you had any piston/valve interference, but at first glance.... it 'looks' like old TRW L2295 440 pistons "installed backwards"... or the really, the rods put on the wrong side of the motor. Am I right?

 

[WileE]

It depends on how I hold my tablet.

 

[HeliPilot71]

Hard to see in the picture if you had any piston/valve interference, but at first glance.... it 'looks' like old TRW L2295 440 pistons "installed backwards"... or the really, the rods put on the wrong side of the motor. Am I right?

You are correct...bought this motor from a guy named Ron Burger up in Spokane, WA. BTW, he is ignoring my calls.

 

[PurpleBeeper]

You are correct...bought this motor from a guy named Ron Burger up in Spokane, WA. BTW, he is ignoring my calls.

Dang.... well, did the pistons hit the valves? If not, you could swap the rods/pistons side-to-side and you'd be OK....PIA though....just looking at the bright side.

Nevermind, just turn the rods around, same piston in the same hole....it's got me dizzy trying to think this through.

 

[HeliPilot71]

Dang.... well, did the pistons hit the valves? If not, you could swap the rods/pistons side-to-side and you'd be OK....PIA though....just looking at the bright side.

Nevermind, just turn the rods around, same piston in the same hole....it's got me dizzy trying to think this through.

The good news is I have not yet ran the engine. But, it makes me question the rest of the assembly.

 

[1967coronet440]

Ya I think that warrants a tear down

 

[Mike67]

Those look like the KB 236s...step piston

 

[mopar 3 B]

Dang.... well, did the pistons hit the valves? If not, you could swap the rods/pistons side-to-side and you'd be OK....PIA though....just looking at the bright side.

Nevermind, just turn the rods around, same piston in the same hole....it's got me dizzy trying to think this through.

Rods need to be positioned correctly or the cylinders will not lub.

 

[threewood]

Those look like the KB 236s...step piston

I'm pretty sure you are correct. I have the 237's and the reliefs are the same, symmetrical cuts.

 

[69Bee]

Rod/piston assy must be swapped side for side, and piston arrow or dot forward. You can NOT just rotate them in the same hole as the rod chamfer will interfere with the crank radius and lock up the crank. The rod numbers (if there are any) do not matter. Just ensure that the bearing tangs face OUT towards the pan rail, and the chamfer will be positioned correctly.

As far as the oiling hole goes, replacement bearings have not had the notch in them for the oil to go to the squirt hole for years. It has been eliminated to reduce the number of part numbers they have to make, thus reducing manufacturing costs... This does not have any great effect on the motor, so no big deal.

 

[lewtot184]

pistons upside down,...lol.

 

[mopar 3 B]

Other than the valve releafs pistons never cared which direction they went in. The notch was placed so people would not intall the rod backwards. But the assembly had to be correct to begin with.

 

[lewtot184]

Other than the valve releafs pistons never cared which direction they went in. The notch was placed so people would not intall the rod backwards. But the assembly had to be correct to begin with.

the notches were there so the piston would be in the bore correctly for the offset in the pin. no offset, then no notch or arrows.

 

[mopar 3 B]

Then why would Chrysler have recommended rotating the pistons 180° on high mileage engines on low buck rebuilds to place the skirt thrust on the other side of the piston if the pins were off set in the bore? Such a move would place the piston eather higher or lower in the cylinder if the pin was offset. Possible causing rod to shirt problems.

 

[dvw]

Piston offset for HP stuff doesn't exist anymore. It's possible the rods are backward the way it sits right now. You won't know until you disassemble it. If you are leary of the build you have 2 options. Take it all apart and check it yourself. If you don't have the skill, then take it to someone who does. I personally would never run a hot rod engine I didn't personally inspect.
Doug

 

[lewtot184]

Then why would Chrysler have recommended rotating the pistons 180° on high mileage engines on low buck rebuilds to place the skirt thrust on the other side of the piston if the pins were off set in the bore? Such a move would place the piston eather higher or lower in the cylinder if the pin was offset. Possible causing rod to shirt problems.

never heard of mopar telling people to put the pistons in backwards on high mileage engines. this would make piston noise worse. they did recommend, back in the day, to install the pistons backwards for a performance increase. it was all about getting the offset in the "power direction" to reduce friction.

 

[lewtot184]

Piston offset for HP stuff doesn't exist anymore. It's possible the rods are backward the way it sits right now. You won't know until you disassemble it. If you are leary of the build you have 2 options. Take it all apart and check it yourself. If you don't have the skill, then take it to someone who does. I personally would never run a hot rod engine I didn't personally inspect.
Doug

I was thinking maybe the pistons are installed correctly on the rods but the builder just put the piston/rod assembly in backwards. either way the engine has to come apart.