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Wiped cam/dead lifter/s?
Posted: Sat Jun 23, 07 2:00 pm
by MilesnMiles
Here we go again. Last Saturday I had a ticking lifter, so i decided to do my annual check and adjust the lifter preload. Car ran nicely for an hour or so before one of the lifters decided to go noisy.
I drove back (another 45 mins) and decided to have another go.
Yesterday it started chttering again so i turned the car 'round and drove back
Lifter chatter stopped for 10 mins then came back and worse.
Today. did it all (the adjustment) again.
Clattering from lifter/s also, the car was very lumpy and wouldnt tick over, felt like it was running on 7 cylinders.
If I take off the inlet manifold, is there a way of checking if a lifter is knackered. I'm assuming a wiped cam would be obcvious to see.
Posted: Sat Jun 23, 07 2:07 pm
by Dave-R
Yes. You would see it. Compare all the cam lobes to each other. Look for signs of metal removal from the lobes.
Posted: Sat Jun 23, 07 2:23 pm
by MilesnMiles
Just about to start the teardown.
One question, if i'd wiped a lifter, the problem could'nt be intermittant surely?
When i drove it yesterday it suddenly went from a bag of nails to smoothe and back again. Thats the bit i dont get.
Posted: Sat Jun 23, 07 3:06 pm
by Dave-R
No I wouldn't expect that.
What weight and type of oil are you using?
Posted: Sat Jun 23, 07 3:27 pm
by latil
A bit of muck/sealant/gasket floating around in the oil gallery?
Posted: Sat Jun 23, 07 3:28 pm
by MilesnMiles
Dave, looks a bit better now that i've awarded myself the top

rse of the day award.
Having reconnected the hose from the breather to the carb, my smooth running/tickover was restored.
BUT quick 15 min drive and the tappety sound comes back and stays.....until i get the car in the garage and stops, presumably, ready to come back later
Oil is 15/40, havent changed it for a while (3,000miles)because its still clean.
Posted: Sat Jun 23, 07 3:47 pm
by Kev
Are you running a hyd cam and adjustable rocker gear? Could be that the hyd lifter has crap in it and it's not getting enough oil. Take the rocker covers off and turn the engine over by hand and see if all the valves open. This may allay your fears of a wiped lifter. A compression test before you strip it may be in order. You'll get unusually high figures from the dodgey cylinder if it's an exhaust problem or low readings if it's inlet. (Is that correct or have I just thought it all up for nowt?

). You can run the engine with the rocker covers off to have a look as well. Not too messy if you rag the head just above the exhausts (NOT petrol soaked rag, by the way

)
Posted: Sat Jun 23, 07 4:04 pm
by MilesnMiles
Kev, i'm going to take the inlet manifold off and have agood stare at the internals, i'll be able to see very clearly then if the lifters rae able to turn and whether the cam is good.
Overall, when the ticking isnt there normal service is resumed. I really need to sort this before the nats. The lifters got a bit of a hammering due to preload issues when i first built the motor, so i need to conduct a visual, I reckon.
Posted: Sat Jun 23, 07 4:05 pm
by MilesnMiles
Oh yeh. Comp cams hydraulic jobby with adjustable pushrods to allow for preload. Original pushrods are too short.
Posted: Sat Jun 23, 07 4:32 pm
by Anonymous
If you need to pull the lifters.... if they are concave they are wiped and so is the cam
Posted: Sat Jun 23, 07 6:48 pm
by Anonymous
This all sounds failiar
How comes your stock push rods are too short ?
Posted: Sun Jun 24, 07 12:12 pm
by MilesnMiles
Long story Steve, but any of the following
cam may have smaller circle than stock versions
machined head faces
new valve seats
head gasket thickness
+ sods law!
Posted: Sun Jun 24, 07 2:11 pm
by Anonymous
If you are going that far in, pop the lifters out and check the heel for concaveness.
Posted: Sun Jun 24, 07 4:20 pm
by MilesnMiles
Ok folks,
Just had a good inspection. The lifters are good in that they are not concave. However, i think i've found the problem in that two of the lifters have possibly collapsed. I can push them in with my finger whilst the remaider of the lifters provide solid resistance.
Thinking, new lifters and new pushrods and try again.
I can upload pics if anyone needs a look see!
Posted: Sun Jun 24, 07 4:57 pm
by Dave-R
If you get two new lifters you don't have to change the pushrods.