Posted 30 December 2010 - 07:34 PM
I have checked the valves and they're all good, getting some new rockers on Saturday and then I'll have to see what happens after they're in.
I've got another Z mate trying to find out what's caused all this. I shall update as things happen.
Posted 30 December 2010 - 11:29 PM
Posted 31 December 2010 - 07:27 AM
How did you go with finding replacment rockers? I've got two complete L28 heads which I'd prefer not to separate but I could remove the rockers for you if you're desperate.
Posted 31 December 2010 - 09:49 AM
I've sourced replacement rockers from Paul in Brisbane, he has a Z graveyard which has helped me a lot in the past. So far I've only checked 2 rockers for their condition, hopefully they don't all have deep wipe patterns.
Posted 31 December 2010 - 10:04 AM
The lash pads "should" be directly under the cam lobes and you use feeler gauges to measure the gap. Clearance specs are in the gregories manual.
Posted 31 December 2010 - 10:54 AM
Your quote (The lash pads "should" be directly under the cam lobes)
As Gary Coleman would say:
"What chew talkin bout"
The Lash pads are on top of the valves. Directly under the cam lobes is the rocker wipe pad.
Valve clearences should be checked between the back of the cam lobe and the rocker wipe pad. That is with the lobe facing away from the rocker.
Also since you have a oiler cam, check with a thin piece of wire that the oil holes are not blocked on the lobes that have worn rockers. And as Salty has suggested check all the rockers for a wipe pattern that does not extend off the ends of the hardended wear area. The lash pads look to be reasonably tall so I presume this is an aftermarket camshaft. With standard valve spring retainers the maximum thickness of the lash pad should not exceed 170 thou.
Posted 31 December 2010 - 01:40 PM
I measured from the bottom to where the rocker sits in the lash pad and it's 6.76mm (0.266 inches [is this the measurement that shouldn't be exceeded?]). Another thing worth noting is that the lash pads spin freely, is this normal? The rockers are bouncing out so much that it's giving the lash pads time to spin.
Posted 31 December 2010 - 01:47 PM
Posted 31 December 2010 - 02:00 PM
Posted 31 December 2010 - 02:04 PM
I'm home the 1st and 2nd of Jan but work 9am - 1pm on the 3rd. I'm only 17, so, don't be surprised hahah.
The name's Zac.
Posted 31 December 2010 - 02:08 PM
Posted 31 December 2010 - 02:13 PM
Haha, enjoy your New Years, quiet night in for me
Posted 31 December 2010 - 09:23 PM
when i set up motors with ground cams i sometimes end up with 6 to 8 different size lash pads, that my friend is a good job, there are so many variations wouldnt it be nice if they were all the same , lash pads come in 10 thou increments , this is the idea ,adjustment, if there all the same obviously not much adjustment has been carried out , i have a kit that has 14 different size lash pads to juggle and set up cams with,, mind you checking each valve requires a somewhat patient attitude
Im more concerned about this " new cam grind " and the valve train as a whole, sounds like someone bit off more than they could chew and only did half the job required to match the new cam specs, driveway warranty at its best...Im also curious to read the verdict
Posted 31 December 2010 - 09:55 PM
The only sure way to determine the correct lash pad thickness is to check the cam lobe wipe pattern on the rocker arm rubbing pad.
Therefore it must centered other wise the wipe pattern will go off one end of the rubbing pad resulting in the destruction of the cam lobe and rocker arm.
There is all so other checks that help, i like to be sure that i have the same lift with a dial indicator if you have diffrent lift numbers you have not done it right. As your rocker arm ratio will not be right, the max variation between valves should not vary by more than 0.005 inch
Posted 31 December 2010 - 10:41 PM
Posted 31 December 2010 - 10:56 PM
so far you keep spitting out rockers , now your running out to get another set to spit out and , why dont you get a specialist to set it up properly so you can gain the maximum benefit from the cam and tune it up , another set of rockers will not help you.
No offence but I find your tone a little condescending. In no way do I intend to just swap my rockers out and think it's solved the problem, I'm not that ignorant. I intend to let Matt have a look at the head to determine what really needs to be done.
I don't want this thread to turn into an argument about personal setups, I will update everyone as I learn more about the head setup from Matt.
I appreciate most of your guys patience with me and my lack of knowledge but I would prefer to be treated with more respect by others.
Posted 01 January 2011 - 09:41 AM
Posted 01 January 2011 - 01:53 PM
Apologies Lurch. :-\
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