Bent intake pushrods on 1st start up of build!!!
Bent intake pushrods on 1st start up of build!!! A friend of mine just called me and told me that all of his pushrods bent on the intake side when he started up his car for the 1st time after the build. I'm completely clueless as to what could cause this. I'll give a known list of what he did. They're still stock pushrods. The heads are unused but they sat for a couple years so I don't know if the valves could be sticking or what.
Patriot LS6 Stage 3 heads/ with duel spring valve springs
228/230 duration with .585 lift cam
Pacesetter LT's
Stock lifters
Double roller timing chain.
It doesn't make any sense to me as to what could have caused this and he's wanting to find the problem as soon as possible.
Any help is appreciated
Patriot LS6 Stage 3 heads/ with duel spring valve springs
228/230 duration with .585 lift cam
Pacesetter LT's
Stock lifters
Double roller timing chain.
It doesn't make any sense to me as to what could have caused this and he's wanting to find the problem as soon as possible.
Any help is appreciated
Last edited by Benner; Mar 12, 2008 at 07:23 PM.
I guess it's a possibility but the guy that helped him build it has built several cars so it doesn't make sense that he'd make such a simple mistake. But again it's possible i guess
Last edited by Benner; Mar 12, 2008 at 07:23 PM.
its actually my car.. the heads were not milled any.. the timing chain is adjustable but the degree mark was put to 0 and the dots were lined up according to the guy that helped me with the build. i wasnt there when he put the timing chain on b/c i had to work. im cluless.. if the timing is right what else could it be??? weak pushrods?? please chime in and let me know what you guys are thinking... thanks
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Verdad Gallardo The only thing that i can think of that would bend a pushrod, even a stock one, on first start up would be cam timing off. It takes a lot of force to bend a pushrod and pistons against valves is a perfect force to do it.
Cam would have to be huge-normous and the heads decked a ridiculous amount to have NO piston to valve clearance.....HIGHLY unlikely. And the OP states the cam is only a 228 so there goes that.
What is highly likely is what others have touched on and that is the cam is installed a tooth off (or more) opening the valves at the wrong time allowing them to collide into the pistons....and the fact that ALL your intake valves hit backs up that possible (and likely) scenario.
Ask him what your piston to valve clearance was? Did he degree and check the cams installed position?
Its easy to put in a camshaft a tooth off if your working in the engine bay of a car doing the install (ask me how I know....but upon degreeing the cam found what would have been a potential problem). While an engine stand build (motor out of the car) its more unlikely to miss a tooth, its still not out of the question (its easier to look straight at the timing marks with engine sitting directly in front of you on the stand).
My advice at this point is to check the cam's installed position....always check whats most likely to be the problem first....then start eliminating variables from there.
Good luck...let us know what you find.
Tony
What is highly likely is what others have touched on and that is the cam is installed a tooth off (or more) opening the valves at the wrong time allowing them to collide into the pistons....and the fact that ALL your intake valves hit backs up that possible (and likely) scenario.
Ask him what your piston to valve clearance was? Did he degree and check the cams installed position?
Its easy to put in a camshaft a tooth off if your working in the engine bay of a car doing the install (ask me how I know....but upon degreeing the cam found what would have been a potential problem). While an engine stand build (motor out of the car) its more unlikely to miss a tooth, its still not out of the question (its easier to look straight at the timing marks with engine sitting directly in front of you on the stand).
My advice at this point is to check the cam's installed position....always check whats most likely to be the problem first....then start eliminating variables from there.
Good luck...let us know what you find.
Tony
well guys we pulled the timing cover off and on inspection found that when he set the timing at 0 on the crank gear he looked at the wrong 0.. the zero on the teeth of the gear is what he should have went by. he went by the 0 on the face of the gear. which was 2 degree off.. that explains everything.. i know that more than likely the valves are bent.. but i am hoping they are not.. the perdicament i am in right now is that it was my best friend doing the job.. he probably doesnt have the money to fix it.. and im tapped out on a 2500 build.. so basically im screwed at the moment.. looks like the stock heads will be going back on... chime in and let me know if anyone has had this happen and were the valves bent when it did happen.. thanks guys
You might be in luck since you had stock pushrods, they may have have absorbed the brunt of the force and spared the valves if you are really lucky. Try replacing the pushrods and getting the cam timing squared away, then run a leakdown test on each cylinder to see if the valves are leaking. That will get you started and wont really cost much at all.
I would pull the heads and check the valves, as long as the seats aren't damaged you can contact Gunnar and just get valves. Shouldn't be too much money and if you have a valve spring tool the swap is easy and won't take long.
I imagine your friend feels like crap too. I helped someone with a cam last summer and my biggest fear was messing up and doing something bad to his motor.
Good luck on the fix.
I imagine your friend feels like crap too. I helped someone with a cam last summer and my biggest fear was messing up and doing something bad to his motor.
Good luck on the fix.
it is amazing how much force a starter really has.. b/c the car never fired.. it just hit once and that was it.. then there was no compression what so ever.. im still in disblief really.. but it will be this weekend before we can start tearing it back down.. thanks for all the info guys. you have no idea how much i really appreciate it
Another thread that should encourage people to degree their cams or at the least check P to V with clay (basic procedure). That would have alerted you to this mess long before you cranked the motor saving you alot of time, money, and aggravation.
Good luck on getting her back togther....you probably only have pushrod damage but a leakdown test would verify any bent valves.
Tony
Good luck on getting her back togther....you probably only have pushrod damage but a leakdown test would verify any bent valves.
Tony
Another thread that should encourage people to degree their cams or at the least check P to V with clay (basic procedure). That would have alerted you to this mess long before you cranked the motor saving you alot of time, money, and aggravation.
Good luck on getting her back togther....you probably only have pushrod damage but a leakdown test would verify any bent valves.
Tony
Good luck on getting her back togther....you probably only have pushrod damage but a leakdown test would verify any bent valves.
Tony
My roommate did that to a buddy's car. When he installed the cam, someone took the flashlight and he didn't get the timing marks lined up exactly and bent a couple of rods. That would be my guess as to what happened with your friends car too
