bent pushrods do I need to pull my head

[tistan2]

I was running my car last night when it started making a awfull knocking noise. The car was firing back through the intake runner on the number 4 cylinder. It bent the exhast valve on #4 real bad and it also bent the intake, but the intake was still opening enough for the air to fire back out of it. I am not sure what caused this. I have had the heads on the car for about 3 months now with no problems. The the lifters are still working and I think that if a valve hit a piston it would have happened alot sooner than this. Has anyone else had this problem. I would appreciate any information.

 

[00 Red SS]

If you know you bent the valves then you need to pull the anyways. Id start by pulling the valve covers checking the pushrods and see if you broke a valvespring then onto pulling the head checking the valves and look at the pistons for contact.

 

[Rick 91GT]

Your title syas bent pushrods, but you say you bent the intake and exhaust valves????

If the valves are bent then the head needs to come off, you also need to figure out what happened. If you over rev'd the car of the valves floated you could have hit the pistons. Whats the combo?

 

[tistan2]

My bad the push rod on the intake and exhaust valve is bent. The valve itself does not appear to be bent. I am just running a b cam also so I really do not have that much lift. So I do not think that it was a pistion to valve clearance problem and like I said earlier I have been running this setup for about 3 months with quite a few trips down the drag strip. I did not know that floating the valve could cause it to hit the piston. I have a stock computer so it will only let me rev to 6200. I did not think I could float the valves before that.
bbk cold air
pro-m 75 mm mas air
ford motorsport 65mm throttle body
cobra intake
ford 24# injectors
afr 165s
scorpion 1.6 rockers
aeromotive fuel pressure regulator
190 lph fuel pump
b303 camshaft
msd billet distributor
underdrive pulleys
mac headers
mac xpipe
mac catback
king cobra clutch
mclead adjustable clutch qaudrant and fire wall adjuster
pro 5.0 shifter
ford motorsport aluminum driveshaft
ford motorsport 3.73 gearset
eaton limited slip differential
moser 31 spline axles
Kyb shock and struts
steeda caster camber plates

 

[00 Red SS]

If you float your alves it could hang open til TDC and the piston would smack it but w/ 165's i would think its plenty of valvespring for a Bcam. Id say if its just a bent pushrod it was over revv'd. Its pretty common on LS1's not heard alot about it on 5.0's though.

 

[Rick 91GT]

You can over rev a 5,0 and get them to float and it doesn't take much to bend a pushrod.

How was the geometry on the rockers and pushrods?

 

[tistan2]

How was the geometry on the rockers and pushrods?

They seemed to have good clearance between the valvespring and the were centered up pretty good on the top of the spring. Are chromemoly alot stronger than the standard hardened push rods?

 

[SmockDoiley]

as long as you didnt have 2.02 valves, I dont see how you could hit your pistons with a Bcam. Furthermore, you shouldnt be running your engine out to 6200 with a Bcam since it peaks before that. You probably didnt have your rockers tightened enough or something. As for pushrods, any hardened pushrod should do the trick though I tend to use trickflow pushrods because they are milled from a solid piece of steel so they have no pressed on or welded on tips.

 

[DaBoss302]

Bent Pushrods

I had a popping noise on my car checked rockers and found 2 bent pushrods. and 2 worn HYD Flattap Lifters .equaled to a worn lobe on cam.

I am thinking it has something to do with guys that had engine before me not breaking in cam the correct way.

Needless to say I am converting block to hyd roller with craneLifter Retro LinkLifters. with a Roller cam.

The question I have is it has GT40x heads 1.6 Bolton Rockers I was told 2.02 valves cam was a A 351. on the bent pushrod cyl no damage on pistion. But 1 cyl had a very small mark on pistion look like valve hit.

I am going to go with Victor Jr heads now since I am doing a complete head and valvetrain swap.
Heads
VICTOR JR
Cam
Comp XtremeEng 282. ...232/240 565/574 112lobe.
Rockers
Adjustable 1.6


Should I have any P/V issues anymore. I believe most of my problem was worn lifters but.....

anyway to check P/V????????

thanks

 

[88 5.0 hi perf]

put clay in the valve reliefs on the piston. assemble the cam and heads and cycle the crank a couple of full rotations, take off the heads and see if there is clearance where the valves hit the clay.

 

[DJTR]

If you have run 3 months without problems then I don't think you should have to pull the heads just pull the rocker covers repace the push-rods (all of them) with a new set of hardened pushrods and see if the problem goes away, if not then pull the head. Why over complicate something that may just be a small issue?