How bent is a bent pushrod
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Teching In
Joined: Oct 2007
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From: Land O Lakes Fl.
How bent is a bent pushrod I have a knock in a used LS1 that probably sat for about 3 yrs. I was told the motor came out of a wrecked car with about 15K mi.Well I just spent the last six months putting the motor in 73' Camaro.CAR IS FINISHED motors knocking!
Sounds like rod bearing but oil pressure seems descent (35-40 @ idle)The knock goes with RPM change as well as oil pressure.How can you check for spun rod bearing?
Valve springs, rocker arms seem good but I pulled pushrods on one bank & rolled them on glass & they all have a slight bend. No more than a 1/16 more like a 32nd. This must be normal?
What a bummer! Hopefully someone has good news. Thanks
Sounds like rod bearing but oil pressure seems descent (35-40 @ idle)The knock goes with RPM change as well as oil pressure.How can you check for spun rod bearing?
Valve springs, rocker arms seem good but I pulled pushrods on one bank & rolled them on glass & they all have a slight bend. No more than a 1/16 more like a 32nd. This must be normal?
What a bummer! Hopefully someone has good news. Thanks
You can get a good set of used hardened pushrods for 60$. If they are all bent, it was probably a mechanical over-rev that caused it. Since it is capable of that I would install the hardened ones to prevent it from doing it again. I would just assume that the ones you have are bent or you have a slight hiccup in the glass. Any slight bend will cause a bit of a ticking.
Thread Starter
Teching In
Joined: Oct 2007
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From: Land O Lakes Fl.
I put new oil & filter when it went back in the car but I may have old filter to cut open.
I will put new push rods in & hope for the best.I'll repost later if I don't shoot myself.I appreciate your time.
I will put new push rods in & hope for the best.I'll repost later if I don't shoot myself.I appreciate your time.
TECH Enthusiast
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From: OHIO
I bent a few of my stock ones on a miss shift a few years back. One of them was bent so bad it enlarged the hole in the head. If you are a guy who constantly miss shifts I would leave stock pushrods in so they will be a cushion. If you replace them, with ones that won't bend then something much more expensive is gonna take the force.
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Thread Starter
Teching In
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From: Land O Lakes Fl.
Learned not to check all of pushrod on glass because the end ***** are not true,just check shaft.Mine seem to be straight.Absolutly no metal in old filter so with that I wonder if I have colapsed lifter.This motor sat for a long time!
Is there anyway to check or re-prime lifter?
Is there anyway to check or re-prime lifter?
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It could be piston slap. If you don't see any shavings in the oil/filter then it's probably not a bearing. Have you let the motor fully warm up yet? If so does the noise quite down when it's hot? As for a collapsed lifter, I have had good luck with a can of seafoam in the oil to clear the gunk out of the galleys. Good luck finding the problem and I hope it's not bearing troubles.
I have a set of stock pushrods. You pay for an envelope and shipping and they are yours for free.
I like to help people out. I imagine you'd get a set of 16 good stock pushrods for $5-$10. PM me if you want these as they are just sitting in the back seat of my car.
I like to help people out. I imagine you'd get a set of 16 good stock pushrods for $5-$10. PM me if you want these as they are just sitting in the back seat of my car.
Thread Starter
Teching In
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From: Land O Lakes Fl.
Thanks for all the above info: My pushrods seem to be fine.I pulled plug wire one at a time & the knock didnt seem to change.So we think it may be a lifter because it sat so long.I will try some thinner oil or seafoam & run it up to temp a couple of times.The motor is very clean & low mileage I just hope its not a rod.I can't tell which side if it is a lifter , it sounds centered.BLK WS6 thanks for the push rod offer.
I'd get chromemoly, why getting stock pushrods again? If he's geting an aftermarket cam installed he'd be ready at least with pushrods and if not he'll be sure about the quality of those pushrods. But that's just me, I like getting quality parts for my engine as its not a joke. But you wanna go the cheap way? Then go the cheap way
Call me old fashioned, but, I'd call a .005" reduction in push rod length a bent push rod. If you can see 1/32" to 1/16" of an inch bow, uneven end ***** or not, I'd call that kinked.The post regarding removing the plugs was related to removing the spark plugs while running, not just the plug wires.
Good-luck, hope everything works out
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The pushrods were not designed to be a fusible link in the valvetrain. If you want to protect your engine, run a valvetrain that can handle the rpm AND learn to shift properly dammit. If one is over revving their engine on a regular basis, the answer is not get stock pushrods so they can bend. The answer lies in the driver and to a small extent his link to the car via the shifter, the stick and the ****.
To keep that valve train safe run springs that won't float in the upper rpm. Get pushrods that won't bend under high rpm load. Simple as that. The only thing to worry about in a mechanical over rev scenario is rod bolts and that's only in the 7krpm scenario on the older 98 cars.
To keep that valve train safe run springs that won't float in the upper rpm. Get pushrods that won't bend under high rpm load. Simple as that. The only thing to worry about in a mechanical over rev scenario is rod bolts and that's only in the 7krpm scenario on the older 98 cars.
Thread Starter
Teching In
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From: Land O Lakes Fl.
LS-1 450 all the push rods seem to have this slight imperfection in the ***** but shafts seem straight .Is there a chance they all have damage. I'm going to pull each plug to check rod under no compression & check compression while I,m at it. Thanks
I can't tell without looking, but, if there is question as to the condition of the push rods, as was indicated by your comment that you see 1/32" to 1/16" of daylight when you roll them on glass, then they should be changed, IMO. Other thing you can do is get a caliper & measure the lengths, if they're shorter than they should be, then they are bent.
The only complaint that I have regarding the LSX when compared to its' Grandaddy, the Chevy 350, is that in the 350, push rods can be changed without pulling the heads. It's a real PITA to have to pull the heads in order to change simple items like lifters & push rods in the LSX motors.
I'd get chromemoly, why getting stock pushrods again? If he's geting an aftermarket cam installed he'd be ready at least with pushrods and if not he'll be sure about the quality of those pushrods. But that's just me, I like getting quality parts for my engine as its not a joke. But you wanna go the cheap way? Then go the cheap way