Broken push rod

[pussywuped]

I was making a pass on Saturday 11/4 and could get only about 5400 rpms. I came off plane and noticed I had lost one cylinder. While I was being towed in, we looked @ the plugs all good, Then we removed the valve cover and all the springs were good ,Then found number 2 exhaust rocker arm loose and the push rod missing the ball on the end. The push rod was still in place and under the rocker arm. As you can see in the attached pictures the top of the rod was damaged and the rocker arm was also. The question is what do you think caused this? Hopefully the damage in confined to the push rod and rocker. 489 procharged 5 lbs boost ran 5800 on lunch run 10/20 ran fine until yesterday.http://www.***boat.com/image_center/data/520/2457valve_springs-med.jpg http://www.***boat.com/image_center/data/520/2457rocker_arm_damage-med.jpg http://www.***boat.com/image_center/data/520/2457push_rod-med.jpg

[MikeF]

Who is the maker of the pushrod?

[MikeF]

Similar threads as of late......
http://www.***boat.com/forums/showthread.php?t=124489&highlight=pushrod
http://www.***boat.com/forums/showthread.php?t=126073&highlight=pushrod

[pussywuped]

Who is the maker of the pushrod?
I have no idea, I will talk to the guy who built the motor and get back with the info. Would it be possible to replace all of the push rods without replacing the lifters? The motor has about 80 hours since rebuild.

[MikeF]

I have no idea, I will talk to the guy who built the motor and get back with the info. Would it be possible to replace all of the push rods without replacing the lifters? The motor has about 80 hours since rebuild.
Yes, you can replace the pushrods w/o replacing the lifters. Replace that rocker though too.
Looks like it did not run long enough w/ the broken pushrod to do alot of damage (i.e. alot of shiney stuff on the head from the rocker and pushrod) so there is a good chance that you won't need to tear the engine down too.:clover:

[vee-driven]

did you over rev it.

[pussywuped]

did you over rev it.
No, The water was flat and no wakes.
I don,t know if this was a symptom of somthing else wrong or the cause.
I am going to take the parts into Boatmaster today and see what they think.
Hopefully just replace the parts change the oil and filter turn over without plugs and see if the valve works. I may have a bad lifter we'll see. I am trying to figure what else would cause the pushrod to do this.

[motormonkey]

Its hard to tell from the pics but the pushrods look small. Blower motors will like a bigger pushrod, some stud girdles, and you might want to check pushrod length.

[Morg]

BTW- I no longer use the chromemolly rockers. Broke an ex this summer. I was lucky, no other damage.
Where the rocker broke, there happened to be an air pocket in the casting.

[GUGS102]

I had a guide get hot on me and cause the same problem. Roller motor? I'd say replace the pushrod and rocker compression and leak down test to make sure you did not hurt a valve. Solid guides or inserts?
Gugs

[pussywuped]

Boat is still on the hoist about a hour away. I will check comperssion and do a leak down test after I get the parts. This is a roller motor,I donot know about the guides. Thx for all of the info it is very helpful.

[VDRIVERACING]

Not sure how long you've been running this motor, but if it's a fresh piece don't overlook the possibility of valve-piston contact. Sometimes it bends the valve stem, sometimes you get lucky and the push rod goes first.
Sometimes push rods just bend, but it sounds like you have an expensive piece so it's worth taking the time to find the cause and fix it. I had all kinds of problems with those chromemolly rockers, so if you have canned them that could be the ticket.