biketeacherdave
Well-Known Member
Badly worn rockers 1st to check but I'm betting worn can lobes saying that a couple of collapsed cups in the rockers would give the same issues
It gives him an excuse to bunk off childcare and get away for a few hours. Might have to get a 4.6 or two myself.
Rocker covers off, and measure the lobe loft with a dial gauge. Either that or do a coolant pressure test to see if anything is leaking inside ?
These from ebay are actually pretty good, and matched exactly the 50 year old versions I got from my father. Main benefit is they do multiple rotation & can be zero'd at any point. Also easy to make a bracket to mount on the rocker shaft studs or cover bolt holes.
These from ebay are actually pretty good, and matched exactly the 50 year old versions I got from my father. Main benefit is they do multiple rotation & can be zero'd at any point. Also easy to make a bracket to mount on the rocker shaft studs or cover bolt holes.
It's pretty amazing how many peeps will jump to help on here, this forum is pretty damn cool. 
Thats what makes this forum the best on the internet - yes we take the p!$$ a bit, but at the end of the day the knowledge is second to none!It's pretty amazing how many peeps will jump to help on here, this forum is pretty damn cool.
Thats this weekends job - just had permission from the other half to get mucky (oh er misses!)
martynv8
Well-Known Member
I'd say valvetrain related especially with the running issues. My liner was much more of a tap than a tick. Sometimes a double tap as the liner hit both the HG fire-ring & the bottom lip of the block (although your block wont have the bottom lip). Engine performed well apart from the noise.
So, update time (all be it a small update - and more vids!)
So had the chance to whip the drivers side rocker cover off....
Bonnet into service mode.
Looked at the mass of pipes and wiring for the LPG injectors
Whipped the rocker cover off, and ran the engine.....the vid below, you can just hear the faint ticking, but it appears to be at valve speed as it is in time with the rocker going up and down.
The pushrods are rotating as they should although there are two that are rotating at a much slower speed than the others - could be a sign, but when stationary, the rockers are tight and there is no movement between rocker, rod or follower, all nice and 'firm'.
Took the rocker shaft off to inspect the pads and the cups, and they all look as they should too, no missing cups, no worn pads, the shaft under the rockers is not ridged or pitted.
All the pushrods are straight and seated will into the follower, top of the valve stems are nice and clean, not rounded over (which would indicate a 'hammer' effect) all the valves have there collets in place. In fact it all looks very nice under there!
(Excuse the flakes of old paint and the odd bit of tree that fell in when I removed the cover!- all this was cleaned out before re-fitment obvs!)
I put the shaft back on and put the cover back on, with much dismay as i was hoping to spot something. The valves all move a decent amount and they match each other for movement - doesn't mean the cam is not worn, it may be worn by the same amount all over, but I would say it is not worn enough to cause an issue - admittedly, I have not seen the passanger side rocker movements, but assumptions are it would be the same! Next strip down will tell but I won't be able to run the engine with that side off as to get to it means taking quite a bit of the intake and throttle gubbins off!
So with it all back together a quick blat round the block a few times, I took the next video as the ticking had got louder....
As can be seen in the vid, when i close the bonnet and move the camera under the wheel arch, the ticking is quite pronounced - but still appears to be at valve speed (as compared to the first video rocker speed) so it could still be a dicky follower that is bouncing around and losing prime when the oil gets up to temp and thins out - I am hoping!!
The Ticking is quite loud, and if it was faster I would say liner, but it seems to be at valve speed and not piston speed - I have no other symptoms aside from the flat spot in accleration and a spot of popping and backfireunder hard (foot to the floor) acceleration.
What are your thoughts people?
In any case, it gave me chance to get all three together for the first time!
So had the chance to whip the drivers side rocker cover off....
Bonnet into service mode.
Looked at the mass of pipes and wiring for the LPG injectors
Whipped the rocker cover off, and ran the engine.....the vid below, you can just hear the faint ticking, but it appears to be at valve speed as it is in time with the rocker going up and down.
The pushrods are rotating as they should although there are two that are rotating at a much slower speed than the others - could be a sign, but when stationary, the rockers are tight and there is no movement between rocker, rod or follower, all nice and 'firm'.
Took the rocker shaft off to inspect the pads and the cups, and they all look as they should too, no missing cups, no worn pads, the shaft under the rockers is not ridged or pitted.
All the pushrods are straight and seated will into the follower, top of the valve stems are nice and clean, not rounded over (which would indicate a 'hammer' effect) all the valves have there collets in place. In fact it all looks very nice under there!
(Excuse the flakes of old paint and the odd bit of tree that fell in when I removed the cover!- all this was cleaned out before re-fitment obvs!)
I put the shaft back on and put the cover back on, with much dismay as i was hoping to spot something. The valves all move a decent amount and they match each other for movement - doesn't mean the cam is not worn, it may be worn by the same amount all over, but I would say it is not worn enough to cause an issue - admittedly, I have not seen the passanger side rocker movements, but assumptions are it would be the same! Next strip down will tell but I won't be able to run the engine with that side off as to get to it means taking quite a bit of the intake and throttle gubbins off!
So with it all back together a quick blat round the block a few times, I took the next video as the ticking had got louder....
As can be seen in the vid, when i close the bonnet and move the camera under the wheel arch, the ticking is quite pronounced - but still appears to be at valve speed (as compared to the first video rocker speed) so it could still be a dicky follower that is bouncing around and losing prime when the oil gets up to temp and thins out - I am hoping!!
The Ticking is quite loud, and if it was faster I would say liner, but it seems to be at valve speed and not piston speed - I have no other symptoms aside from the flat spot in accleration and a spot of popping and backfireunder hard (foot to the floor) acceleration.
What are your thoughts people?
In any case, it gave me chance to get all three together for the first time!
Exhaust gaskets appear to be fine, could be a HG blow between two pots, but could be a long shot!
Next weekend, I will look to pull the top off the engine down to the heads, i.e. just the plenum, and intake manifold off.... so I can take a gander down the valley so I can take a closer look at the followers and the cam.
If that yields nothing untoward, then I may pull the heads off too.
brianp38dse
Well-Known Member
Is it me or is there not a lot of oil coming up to the rockers, when I've run a push rod lump with out cover it splashes every ware.
If you move the rockers along the shaft slightly with a screwdriver as it is running, there is oil running out of the feed holes.....I have to admit, I would have expected more, but also more means the clearance between rocker and shaft is too great and the oil ****es out and losses oil pressure.
brianp38dse
Well-Known Member
Ant knows all about oil pumps and pressure, he has worn that T shirt out there`s a few vids about on that one
there`s a few vids about on that one
Good call, I will whip out the oil pressure kit next time and see what it reads.
The video is a little misleading - the tick on the first video is very faint - when revved, the noise of the engine and the fan drowns it out.....but it does go a tad quieter at speed.
