Lifter/Pushrod problem

[HoustonScout2]

I have a 345 ci that has less then 1000 miles on the a professional rebuild. The rebuild was about 6 or 7 years agos and have had trouble tuning the motor ever since. It has had a sure miss since we got it back. It was my fathers and he gave up on it and sold it to me. Well after having 4 or 5 friends come over and try to tune it it had a new rattle. So we pulled the valve covers and noticed that the #2 and #4 intake pushrods were missing. So we pulled the intake manifold and the pushrods and lifters were in the valley under the intake manifold. So my question is what can cause the pushrods to come out? I was told by one guy that the lifters might be siezed. Can that be the case? Or can this be much worse? And if this is the problem where is a good place to get lifters and pushrods cheap? Thanks for reading and sorry about giving the long life story.

 

[Robert Kenney]

I'd suspect when the engine was built the valve stems did not get the right oiling. Common for shops to miss install the #2 and 4 cam bearings. Those two supply the valve train with oil and if indexed wrong the oil holes can be blocked or partialy blocked.

 

[Robert Kenney]

Michael mayben has a great write up on test and verification routine for your condition.

Another cause I have found is that if the stems are not lubed correctly upon initial assembly they can stick during the cam break-in thus causing a tossed pushrod.

First I guess the valves associated with the missing/loose pushrods are stuck or sticky. Not the lifters. Once the lifters pop out of the bores the oil gallery looses pressure and the other lifters will start clacking. In my opinion you can do some checks and verify root cause before tearing it down.

http://www.forums.IHPartsAmerica.co...I-4-sv-engine-non-oiling-rocker-assembly.html

 

[Michael Mayben]

And...I deal with this exact scenario onna daily basis, those are cases that are not documented in this forum.

Engines supposedly "rebuilt 30 years ago and never run, and engines rebuilt last month that have the same condition. But we only hear about/get involved with the problem children that are posted here, the vast majority of these engine builds do not have any valve train lubrication issues whatsoever.

Robert has provided the link ya need to start your education and diagnosis. We have by far the most extensive amount of information regarding the "lifter" (a total misnomer) subject and valve train lubrication regarding the ihc-produced I-4 and sv engines to be found anywhere on the 'net. And that information is continuously being updated when we find new solutions or techniques.

Proper cylinder head assembly/installed valve height is critical on any engine which uses a non-adjustable valve train assembly.

What you have/had is two valves that seized either momentarily or continuously in their respective guides. That in turn allowed their dedicated pushrods to jump out and are most likely bent. Since the engine continued to rotate, the associated lifters jumped out of their bores, when that happened the lifter galleries lost oil pressure/flow...that is a cascade effect. But, it's easily rectified without tearing down the engine or removing the intake manifold/lifter chamber cover.

Once the motor is whole again, then you must do the observation of rocker assembly oiling as described in the link provided, and it must be done for at least a two hour runtime to watch what is going on. A valve May "stick" in five minutes, it May take two hours, but it will stick again unless the issue is resolved by repair.

All parts needed for making this repair are available right here at ihon. Take the time to read through every thread in the "engine tech" sub-forum and you will find the answers.