Well this is depressing....I pulled off the factory intake off the factory 302 heads on my 73 Grabber to replace with an aluminum intake and Carb and noticed 3 push rods were bent almost to a 45 degree angle. The block was purchased in 98 as a rebuilt block so i am not sure what year block it is,and i cant see above the starter to tell the year until i can get it on stands. Is there any way of knowing if it caused any damage to the cast iron heads or would i be safe just replacing the push rods? The motor has been setting up for 5-7 yrs and the mechanic said it was missing, i guess that could have been why. What size rods should I go with? And is there a specific one I should go with? Should I upgrade to roller rockers or stick with the ones I got? I can get complete H.O mustang heads for 75 bucks, should i just swap them? Would they be better than the stock ones I got? Isnt having cast heads rebuilt pretty expensive? Sorry for all the questions but it was 30 min ago when I found the problem so I am full of questions.
Jeremy...Its possible the engine has a few bent valves and maybe some piston damage.Pull the valve cover on the side with the damage and look to see if any of the valves are hung open on the rockers with the bent push rods.If not... remove the rockers on those that are suspect and rap the valves with a hammer(not too hard) just enough to make the valves open and close.If they open and close ok get a couple of push rods...put em in...give everything a good visual inspection(pull all the plugs) and turn the engine through a few times by hand.If it turns with out locking up/binding.Do a cranking compression test.If the test checks good...then you can try to fire it up and see how it runs.Put fresh gas and oil/filter in it first.New plugs wouldnt hurt either.Main thing is to try and figure out what caused the push rods to bend in the first place and correct that problem.Could be wrong cam....Timing chain jumped at RPM...improper rocker adustment...push rods too long or short for app...rocker arm geometry is just wrong for application.There is more but some specifics are needed to go further.Start with this stuff and see where it takes you.Good luck!!!
I dont know if this will matter but I drove the car up the driveway and back the day before but at an idle it runs great, it only misses when you give it gas. Would that mean that pistons and valves are ok? When I had the intake off i pushed on the piece the rod touches on and they moved in and out. What are those called and does that mean anything.
That would be the lifters...in the block...that you were pushing on with the push rods...If I read your statement correctly.They are round...have a small cup the pushrod sits in...They shouldnt pump too easily when you push on the push rod.You said it runs good at idle??? with 2 severely bent push rods???can you take pics??? of the carnage???
Yeah it runs at an idle fine with 3 rods that were off the lifters, 2 which were bent. I will get the pics up tomorrow. Sounds like I am going to have to pull the motor to see what all is damaged huh?
No engine pulling yet,perhaps a head though.Get a good pic if the valvetrain that showes all 8 valvesprings/rockers as well as those bent pushrods.
If I am able to push down on the lifters does that mean there is a problem. It doesnt just drop when i push but if i put a little weight on my thumb it will go in without coming back up. I will get a pic of the intake off to view the lifters and rods and also of the rockers when i get the valve covers off.
But with bent rods you would think I would have heard some noise but it sounded fine with no ticking.Or maybe thats not always the case i guess
You may have some collapsed lifters,Or a lack of oil delivery to em.They should pump up and hold for a while not just collapse and not return. Yes you would think...makes me wonder if the rockers were over adjusted or the pushrods are too long??? You really need to figure out what year that engine is.It makes a difference for pushrod length. let us know what you find.
If engine ran before any amount of time,,, I'm thinking water or gas got in cylinder an in cranking over the push rods got bent. If I'm getting the story right, I would double check that valve move up an down without sticking (raps of hammer should move them freely) Take out good push rods and measure, do couple to make sure same length-all would be best, replace bent with new an fire up to check condition of engine. I don't think you will really hurt engine anymore doing this. Run engine to warm up, check for water vapor in exhaust, oil or oil in water. check compression on each cylinder an go from there. Good Luck!
Sorry for the delay but today was the first time it quit raining long enough for me to get to my valve covers off. I am not sure of the lenght due to it being bent but it was around 6 3/4 give or take if that helps? One of the rods wasnt coming out so I may have to pull my head after all. The debris may be from the gasket while removing the cover but cant be 100%. I had a friend tell me the burr on the rods meant they were cheap and that is what grabbed and bent them, and that i should be ok to just replace the rods. Not sure how true that is. Any suggestions on that idea or should i go ahead with pulling the heads to look for piston damage. I wouldnt see any hesitation in turning the motor to check for it hanging cause it cranks and idles fine...right???
Sorry for the delay but today was the first time it quit raining long enough for me to get to my valve covers off. I am not sure of the lenght due to it being bent but it was around 6 3/4 give or take if that helps? One of the rods wasnt coming out so I may have to pull my head after all. The debris may be from the gasket while removing the cover but cant be 100%. I had a friend tell me the burr on the rods meant they were cheap and that is what grabbed and bent them, and that i should be ok to just replace the rods. Not sure how true that is. Any suggestions on that idea or should i go ahead with pulling the heads to look for piston damage. I wouldnt see any hesitation in turning the motor to check for it hanging cause it cranks and idles fine...right???And what does raps the valves mean?
I couldnt help but notice that there seem to be no intake manifold bolts on the right side.Did you remove them or were they just not there???If they just werent there...that would explain the poor running (Vacuum leak)Big one...between the head and intake.(This has nothing to do with the bent pushrods)Those burrs your freind was talking about wouldnt happen to be the gouges in the side of the bent push rod in the pic by any chance???those marks were caused by that pushrod getting bent against the head each time the cam cycled that particular push rod.
No i had removed the intake to swap for the other and i just left the bolts off until i figure out if i have to remove the heads or not. My friend said if i saw where it was rubbing on the rod that it could cause it to burr and bend. I havent shown him the rods yet so not sure what he would say about it, but I am looking for someone that knows what they are talking about and not sure he does. These are stock heads from the original 302 73 maverick grabber it is on now. I read there might should be a guide plate for the rods and i did not see one. The motor was a rebuilt block, could the stock rods be a problem if the same was used in the original block? I havent had the opportunity to pull my block numbers yet due to tryin to get the starter off while on the ground. Going to get it on a solid surface and jack up to pull it off. I guess that needs to be my next step right? Other than pullin some good rods to get a closer measurement?
