First start after cam change ls1
hey, just started the clubby after changing the cam, lifters, pushrods, DR timing chain, valve springs, locks, retainers, seats. started first time and idled fine, but DAMN the valve train is noisy! the oil pressure light was on but went away when it was revved 1/2k rpm then it would come back on at idle. my brother in law is going to bring home a oil pressure tester tomorrow night so ill keep you posted and ill post a vid aswell.
looking forward to it. you do all the work yourself?
Donati..Whoa Green
Mate I wouldn't start it (or especially rev it) until the oil pressure problem is fixed. You might have accidentally buggered something up around the oil pump area.
If you have the time, pull all the timing gear and oil pump back off and go over everything there with a fine tooth comb.
A few more hours work is better than scrapping your engine I say. Good luck.
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on holiday
did you start the balancer onto the crank with a hammer untill you could get the bolt in that tends to do bad things to the pump
I tune the oldschool way fear on the passengers face and knuckle colour cant go wrong
tabbacco is still my favorite vegetable
How long have you run it for? You should'nt let a fresh cam and lifters idle until they're 'broken in'. Did you crank it with no fuel pump relay first until you had oil pressure?
What pushrods have you used? Did you check you have the correct lifter preload?
Yea I gently knocked it on with a hammer a few taps either side til I could get the bolt started, how is that bad for the oil pump it doesn't touch it?Originally Posted by delcowizzid
I got my brother in law over who is a mechanic at holdens, we ran it for a few minutes with a few revs. I turned the motor over for about 15 seconds with coil packs unplugged. I was told you don't need to check lifter preload as there hydraulic
Made sure everything oil pump was ok, took quite a while getting it right. I filled sump up with new oil past full because of new lifters etc and it has come back down to add now, there are also some small bubbles on dipstick which my brother in law said it must be oil pressure. The ticking is nearly the exact same noise I has before the cam swap which I thought was a noisy lifter. My mech/bro said it would be Soooo much noisier if it had oil problems, and it probably would of seized already right?
Yeah I did all the work myself following a great write up from jmx. It took a few weeks as getting new head gaskets and new intake seals took a bit longer, I also replaced all springs with king superlows and Monroe gt sport, and replaced whole front end with nolathane bushes.
Comp 222/224 @ 112 lsa so only a mild one, I didn't wana go too big for my first change. But I'm sure I can get some decent power out of this when I take it to be tuned.
Last edited by johnno010684; 20-06-2011 at 02:31 PM.
If its an off the shelf cam with all the bits provided to go into an otherwise stock motor, its probably fine. But, this should always be checked as your new cam is likely running a different radius base circle on the lobes to stock, and can therefore require shorter or longer pushrods to suit. Idealy, you want about 0.030" of preload on the lifters. From the rocker bolt tightening point which just takes up the slack on the pushrod so you can just spin it in your fingers, this is approx 1/2 - 3/4 turn crush. Not enough preload will give noisy valvetrain and too much preload will give low oil pressure feed to the rockers.
This may not be your problem at all, but something to be aware of as you dive deeper to find the source of the noise.
Very unlikely, but did you check all the pushrods tubes were free of any obstruction/foreign material that would prevent oil flow?
Cheers.
yea it was a complete cam package all the bits to suit the cam, i blew thru all the pushrods to make sure and soaked them in oil before i put them in, same with the lifters.
how do i tell if its running a different size base circle than stock?
ok so i just took off the pass side rocker cover, theres plenty of oil in there sitting by the head bolts. some of the rockers i can wiggle a little bit with my hand, when i installed them i just torqued them up at 22/lb ft, should i have torqued them up when the lifter was on the base cirle of the lobe?
Thanks heaps for all your help so far guys.
That link doesn't work for me for some reason, but the specs provided by the manufacturer often don't give this detail. Usually though they match the base circle to stock if it's ground from a new billet. A reground cam will use a smaller base circle. Your pushrod length 'should' be fine though if this was a specifit kit for your application.
Wiggle how? They should be pretty solid. I don't know the rocker bolt torque figure off the top of my head, but they should be a torque to yield i.e. tension to a specified torque, plus an additional Xdegrees.
Yes it is more accurate to torque the rocker bolts when the respective lifter is on the base circle. This way you are only tensioning against the lifter preload pressure, and not compressing the valve spring aswell.
i can lift a couple of them up off the valve stem a few cms! i "think" this was when no 1 cylinder valves were both closed
With both valves closed the lifters will be running on the base circle (or there abouts anyway) for that respective cylinder. This is when there will be the least tension on the lifter. Um, do you really mean 'cms'??? Have you re-checked the rocker bolt torque? With new lifters fitted it is not uncommon to momentarily have a little lifter compression by hand, until they pump up, say, 1mm on the compression stroke. This should have happened long ago though with the amount of time you've run the motor for.
my bro took the torque wrench back to work today, hopefully he brings it home tonight. i reckon we might have found the problem. and yes i mean a few cms!
Well that would certainly seem to be the source of your valve train noise! But, unless the rocker bolt has loosened several turns, I don't know how this is physically possible, short of a collapsed lifter. With everything asembled and the lifters pumped up, you shouldn't be able to move anything by hand.
In the interim, just check the tension of each rocker bolt with a ratchet. You'll quicky determine if they've come loose or not.
Pushrods are definitely correctly seated in the cup of both the lifter and rocker arm?
yeah when i can lift the rocker arm off the valve stem the pushrod gets pushed down into the head.
Possible to get some pics? Sounding like you lifters are yet to 'pump up' which they should have by now.
Take it out/Take it Back
Did you bleed all the lifters before you put them in?
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