Discussion
Started engine yesterday with the intention for sorting out a bit of cold start and idle tuning but ran into a problem, engine sounds like it has broken a spring I have had a quick look in the rocker covers and can't see anything broken so have decided to remove the engine and investigate further, what a pain
I would at least be stripping the valve train before pulling the engine.
Are they solid or hydraulic lifters? could just be a stuck lifter if hydraulic.
have you identified the suspect cylinder? Without doing this you will have great difficulty finding the problem even with the engine stripped.
Steve
Are they solid or hydraulic lifters? could just be a stuck lifter if hydraulic.
have you identified the suspect cylinder? Without doing this you will have great difficulty finding the problem even with the engine stripped.
Steve
Just done a couple of rotations of each bank and checked all rockers and springs, no broken springs or clearance between rocker to valve, the only thing I can find is slightly less preload on the inlets with no3 easily the worst , all the exhausts are good so its looking like a lifter problem on cylinder 3 inlet. I spent a lot of time making sure all the lifter pre loads were correct as there is a very small window for preload with the short travel lifters (engine has 4 different pushrod lengths to achieve this) and this is not how they were originally so looks like I will be stripping more. Maybe the lifters not pumping up.
The good thing about preloads is you set them once and that's it. Your preload measurements now could, I expect be all over the place due to some lifters being primed more then others. What preloads have you measured and are they within tolerance? If you have no slack in the valvetrain then maybe the oil bled out and the lifters were tapping because they hadn't filled. How long did you run the engine?
Are the valve stems all the same height?
Are the valve stems all the same height?
Haven’t remeasured the preloads again only from what I can feel at the tip of the roller rocker, can’t remember what the preload was but was set to lifter recommendations. When they were set there wasn’t the movement that is in cylinder 3 inlet, engine was running for 2 mins max up to 2k rpm maybe it needed more time and now I know nothing is broken I should reassemble and try again
I would run it again to let the lifters fill properly.
Have had a couple of engines (although rover v8s) which made lots of noise but because they were in their cam break-in cycle we had to keep going. Above the din we planned to go back in and strip down but within 10 mins. they were silent (as much as they can be at 2500 revs for 20 mins).
Steve
Have had a couple of engines (although rover v8s) which made lots of noise but because they were in their cam break-in cycle we had to keep going. Above the din we planned to go back in and strip down but within 10 mins. they were silent (as much as they can be at 2500 revs for 20 mins).
Steve
Started the engine this morning, new oil and filter, noise still there until about 2k rpm and then disappeared and ran quietly again so looks like it was a lifter not pumping up. Next problem was loss of engine sync and engine cut out, looks like I have disturbed something looking for the tapping noise so that's tomorrows job sorted and if I can find it quickly maybe a bit off tuning in the afternoon. 
Almost finished the exhaust tips, just need to be cut to length, a couple of clamps and a polish
Almost finished the exhaust tips, just need to be cut to length, a couple of clamps and a polish
Sorted the sync problem, engine running but loud tapping is back and won't clear with rpm, engine is running smooth almost constant rpm at idle but the sound seems to speeding up and slowing down in a rhythmical fashion almost like a belt or pulley is hitting something but nothing touching, Seems to be coming from top end/ front of the engine. Engine out this time
Removed the drive belt which only runs the alternator, checked for any obstruction again for the crank pulley, alternator pulley and Belt, found nothing, alternator turns smooth, dry sump pulleys and belts no obstructions, will run the water pump tonight (electric) and check for noise and then restart and check with stethoscope, still got a sneaky feeling it’s a spring problem
I have 2 belts fitted at the moment, the main belt only drives the alternator via a shorter belt, the only thing that could make that noise is the alternator itself or something close touching, the alternator is smooth and no obstructions anywhere near. The second belt from the crank pulley is driving the dry sump pump so can only run engine with the alternator belt removed and I figured after rechecking the alternator and belt that the noise cant be coming from there. Will run the water pump with the laptop tonight and then start engine and check with stethoscope.
Thank for the advise will let you know what I find
Thank for the advise will let you know what I find
Boosted you were right, Brother in law came round to give me a hand with his stethoscope. Noise was not from top end so belt removed and no noise, turns out it was the belt slapping on the crank pulley. Belt tightened as far as I dare and no noise, can't believe that the belt could make that noise with the tension that was on it originally. Even better a problem solved without costing me money.
Thanks to all
Thanks to all
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