LSCha0s

iTrader: (4)

Long story short my car went lean at idle. I lost a spring and bent the push rod on the #1 intake valve. I looked with a bore scope and the valve never made contact with the piston. I'm hoping a new push rod and spring will get me going but I'm worried I could have a bent piston rod. Is there a way to check without taking the head off?

wildcamaro

iTrader: (15)

I would at least pull the head and check the pushrod and valve guide for damage, you can check if your rod twisted by seeing if the dot on the piston is still at 9 o'clock...

LSCha0s

iTrader: (4)

Actually I have been thinking if the cylinder holds pleasure I may replace the spring and push rod and see how it goes.
What do you think?

Darkman

iTrader: (2)

Not sure about a cylinder holding pleasure, but if the valve never made contact with the piston, why would the rod be bent anyway?

2 Stroke Racer

iTrader: (11)

So your not sure if you have a bent pushrod or a bent connecting rod??
What is the car doing? It went lean at idle?? Sounds like good luck. Lol

LSCha0s

iTrader: (4)

The car went lean at idle while being tuned by someone I don't want to get into that. It has been flashed back to the original tune. Right now I know the piston did not make contact with the valve because I used a bore scope. I do have a bent push rod and the spring broken in two. I have no experience with this.. never had a car go lean. Are you guys saying if the piston never made contact with the valve the connecting rod will not bend from detonation alone? If so I'm happy to hear that.

I Confederate I

If you are truly worried about a bent con. rod, jack up the car as high as you safely can. Drain and pull the oil pan. Then rotate the engine 360 degrees. The #1 piston should move down to the point where you can unbolt it from the crank. Rotate the crank so you can get it out of the way, and pull the piston out. Make sure you line everything back up to TDC when you put it back together. If you have trouble rotating the crank, pull the spark plugs and pushrods. It will relieve the pressure on the crank. You might also have to pull the serpentine belt. I know its a lot of work, but it answers your question.

I can't remember if you can pull the piston completely out from underneath on the ls1, but you should be able to get it far enough out to inspect the con. rod.

bww3588

iTrader: (49)

If the head and everything checks out, a simple compression test will tell you part of the story. If that particular cylinder is low, chances are you bent the rod. If it went lean, I doubt you washed the ring.

Z28Drifter348

I can assure you that this will not work. after you screw around enough to even get the oil pan, pickup tube, windage tray down and unbolt #1. You will only be able to drop it down to Bdc and there is no way to tell if it's out or twisted by the naked eye and shining a flashlight in there. The motor needs to come out and be disassembled and the rod needs to be measured. My advice is replace the spring and pushrod and compression test. I'm Thinking it's going to be fine. If it leaned at 6k it would be a different story.

MPFD

iTrader: (5)

Did the car have stock pistons?

SSpdDmon

iTrader: (10)

The valve never contacted the piston, but the pushrod and valve spring are both bent/broken AND this happened at idle? Even if it went lean for a moment, I can't imagine this happening at a low RPM or idle. What was he doing???


Either way, I doubt that a pushrod and valve spring would break/bend without the valve making contact. It might not have left a major mark on the piston.... I'd be more concerned with the valve being bent and as mentioned the guide being damaged before thinking the connecting rod was bent/twisted.

MPFD

iTrader: (5)

If the car did not have forged pistons, then you would have had a piston in a million pieces in the bottom of the pan. A cast piston will shatter at about the same force required to bend a sintered rod. But i would pull a plug and look at the cylinder with a bore scope to make sure the top ring land isn't cracked or fractured.

LSCha0s

iTrader: (4)

I already looked in the bore with a bore scope and the piston looks good. I bought the engine from a totaled Camaro. It is supposed to have forged internals. The push rod is a thunder racing 7.400 .080 rod. It has dual springs but IDK how to Identify the make. The valve I was not able to see IDK if it is bent or not. But there are no marks on the piston.That is why I say it never made contact.

MPFD

iTrader: (5)

It had to have hit the piston. Knowing now that its aftermarket internals I would pull the head and check piston protrusion, if your that worried about it.

LSCha0s

iTrader: (4)

I just uploaded the video I made with the bore scope .. I think I see it better now on the PC after youtube enhanced the lighting. It looks like a small half rin on one of the the valve reliefs.The sqiggly marks on the cylinder wall are from the bore scope its kinda hard to get in there.

oberth1

iTrader: (6)

i dont see anything in the video. that thing would be pretty marked up if the valve hit it...but i am not claiming to be a mechanic.

Just to throw it out there anyways, whos to say the person that built it before it went to the junkyard didn't throw a bent rod in there without checking? Or thats even the correct rod length? Downside of buying junkyard parts. New rod, new spring check the retainer and all the hardware good and run a compression test.

LSCha0s

iTrader: (4)

That is what everyone keeps telling me. I think Ill do that. Im going to call TPS and order it now.BTW I bought the engine from the guy not the junk yard. It was built before he totaled it..its not a junk yard engine.

Gray86hatch

iTrader: (83)

Push rods don't bend unless the valve hits something or the rocker arm fails or valve gets stuck in the guide. I don't care what you see on the piston.

With the parts that are damaged I would pull the head and see if anything else is damaged. It dosn't take much to bend a valve or crack a guide.

Tim

LSCha0s

iTrader: (4)

So you don't think putting a new spring and push rod on and doing a compression test is a good idea?

edub80

iTrader: (2)

so going lean at idle caused this problem? how lean did it get? was it tuner mistake or some other problem?