Went to pleasant saturday and had a good day for the most part. On the way back to the dock, i noticed my lifters were making noise. Thank god i was done for the day. When i got home i took apart the valve cover and found the last rocker on the driver side with no push rod. Took the intake out and found the push rod broke in two pieces. WTF! Ive seen push rod bent but not broken. And the lifter was in its hole but the guts of it was missing. Found those too.
What could have done this. Any help is greatly appreciated.
has the engine over revved at some point? That same exact thing happened to me a few years ago. I hit one of those invisible rollers and launched the boat, over revved the engine and heard some noise. I shut it all down for a few minutes and on the restart all was well. Next trip out I heard the noisy lifters again and found that #8 lifter had come apart with a broken pushrod.
I guess the other thing that could have happened is the rocker arm nut loosened up enough to cause that.
No it didnt over rev at all. I was just criuzin around with the family. what did you do to yours? Did you replace all the rods and lifters? Thanks again.
I kind of lucked out because all 5 pieces of the broken lifter were in the valley, including the retaining spring. I just replaced the lifter and broken pushrod and away it went. If you do the same, make sure you use a lot of assembly lube where all the parts come in contact with each other. I even got some red assembly lube, heated it up so it would run onto the cam lobe.
how long have you been running this engine? weeks, months, years?
Stock pushrods can just break. If you're running performance springs, a higher than stock lift cam, higher RPM than designed for, and especially if the P/R is hardened (you don't have to have guide plates to have hardened pushrods) they can flex under load, and just like bending a piece of wire back and forth, finally break. This is why part of a good valve train upgrade is a good performance pusrod. It dosen't have to be a race motor to justify...just break a few and you'll see why.
Cas= I just got the boat 2 months ago. The seller said the motor was rebuilt last year. Its a BBC with twin turbos. She ran great then all of a sudden this happened. Im gonna replace the lifter and push rod as well. Red assembly lube? What is that? Can i get that at checkers or do i have to go to a performance shop? Thanks a lot.
Steel comp=Im not sure if its performance spring or not. Like i told Cas, i just got the boat. How would i tell if it was.
I would kind of assume that a twin turbo set-up was done properly but I'd still have the need to check it all out. Do you know what size the pushrods are?
Also, are the push rods directional? Some manufacturers have a hardened metal in the area where the push rod comes in contact with the guide plates. If that happened to be installed upside down, it'll wear out and break.
Steel also made a real good point in the fact if the push rods weren't matched up for heavier springs, breakage will occur.
Now is the time to dig in and do some real good investigation.
...just my 2 cents...if the guts of the lifter are gone...broken push rod.......what caused the the rod to go through the lifter???...A seized valve????...how???...maybe water in the cylinder head???...was it an exhaust side??...maybe reversion caused by the cam???.....just some thoughts ....I had this happen to me....
...just my 2 cents...if the guts of the lifter are gone...broken push rod.......what caused the the rod to go through the lifter???...A seized valve????...how???...maybe water in the cylinder head???...was it an exhaust side??...maybe reversion caused by the cam???.....just some thoughts ....I had this happen to me....
I was wondering this as well. There was no water in the cylinder heads. I believe it was on the intake side. Im guessing of course. Im gonna tear into it this weekend and see what else i find.
I would kind of assume that a twin turbo set-up was done properly but I'd still have the need to check it all out. Do you know what size the pushrods are?
Also, are the push rods directional? Some manufacturers have a hardened metal in the area where the push rod comes in contact with the guide plates. If that happened to be installed upside down, it'll wear out and break.
Steel also made a real good point in the fact if the push rods weren't matched up for heavier springs, breakage will occur.
Now is the time to dig in and do some real good investigation.
Im not sure what the exact measurements the push rod is but it about 8 5\16 inches long. And i dont think its stock because when i went to buy some the parts they gave me were thinner in diameter. It also has roller rockers as well.The turbo seems to do its job fine. I had it running at 4500rpm with no problem 3 weeks ago. I am gonna do some investigating though. Thanks for the advise.
Posting Permissions
Reply With Quote