iv had a rew issues with the type 4 engine that came with my bus, iv had the rocker arm assembly for cylinder one with sheared nuts and mangled studs which i have just repaired and set the rocker clearance up so i was thinking all was good, moved around to the other side to set the clearances round there and found this with these bits sitting in the rocker cover once i removed it my questions are: how could this have happened? are all the rocker arms the same for inlet and exhaust? should i now take the heads off to have a look to see if there has been any internal damage? does anyone want to give me a new type 4 engine for free? this is an engine that i was assured was a good runner, DAM YOU AGAIN P/O :rant:
I think its vital you take the heads off and see what valve damage (if any) has happened and also check for piston crown damage too..looks nasty Good luck!
And check the push rods to see if they are bent (roll them on a sheet of glass) If you get stuck for some new rockers, I have some spares on the shelf!!
i would throw a used rocker on it leave a fairly big gap, turn it over by hand, if it looks ok run it again.
Ok, I think I'm going to take the heads off to see if there is a reason why these have failed, Seems to much of a coincidence that there have been problems with 3 of the 4 rocker arm pairs. Could it be an engine timing problem, broken camshaft? Or maybe someone playing with the engine and setting the valve clearances wrong,
could've possibly had the push rods out, and not relocated them back into the lifters properly... then pistons impacted on the valves if they didn't reset the gaps before firing up the engine!! I think you're taking the correct approach, and taking the heads off is the most sensible thing to do!!
I agree, I suspect that the rockers were tightened up by a numpty who had no idea what he was doing and got timing completely wrong, and then the push rods snapped off the rocker arms. OR someone hit the assembly with something heavy and smashed them off. In the first case the push rods would be bent, and possibly the pistons damaged, but in the second they would be fine. Heads have to come off to check push rods as mentioned earlier, and pistons. You will need new rocker assemblies or decent used ones, anyhow.
Ok that confirms it, the heads are coming off, as the engine is out of the van. And I really need to find out what's going on here Cheers for the replays guys
Unless the valves are flopping about springless they won't have hit the pistons judging by the the settings on the broken off bits on your picture. It's a mystery though - never seen that I have to admit!.
ok i have had another look at it today, i removed the rocker arms and used the base of a hammer to press on the valves, they all push in and return nicley. the pushrod on inlet of No3 had a very slight bend in it, you can see a tiny bit of day light when i rolled it across a flat surface, is there a tollerance on these or is it a case of bin that and get another? on a positive note, there were no sheared nuts or studs this side
best to get a new one... I`ve never seen that either ,the rockers must have had some pressure usually it is the valves or push rods go... [if you measure the pushrod I may have one]
Lol sounds interesting I'll measure the rod tomorrow, I put it all back together loosely tonight so I didn't loose any bits, Cheers
This is quite impressive as the force required to break those is huge .... Something major must be wrong somewhere . You could put one breaking down to dodgy forging but not two ...
Just an odd thought...have you got a fancy camshaft installed? If the valve springs fully compress so they're binding, something will snap. I think this has happened anyway, to snap your rockers off.
