L92 heads - LS3 intake with 228/232 cam in a LS2 GTO?
08-30-2008, 04:57 PM
#24
OK, First off, you're probably checking it wrong. You need to use checker springs installed in place of the valve springs. Then, you need to use a checker pushrod and carefully adjust it until there is ZERO PRELOAD, AND ZERO LASH. THEN you check your PTV.
If you're not doing this set first, you are most likely either preloading the lifter, or holding the valve open slightly to start with. Either one will skew your results.
That cam, should not be too big for that application. Although it does depend on the ICL, and the type of lobe. But, all that being said, it shouldnt be too big. Trust me on this one.
OK, to elaborate, without the head gasket, and depending on the length of the pushrod, you may be hanging the valve open to begin with, effective subtracting however much its open, from your true PTV.
Additionally, the valve spring can slowly collapse the lifter, as you're turning the engine over by hand, collapsing it even more, if its not already bottomed out.
The bestest, most accurate way, is to use the head gasket (either one, its only a dif of a .001 or .002, dont both torquing) checker springs, and a checker pushrod, adjusted so there is ZERO PRELOAD AND ZERO LASH.
Once you've determined your PTV, the lifter preload has no impact on it, once you final assemble it.
HTH. If you need personal assistance call my shop, I'll be here for a while. Or leave a message and I'll get back to ya later today.
757-424-1740
If you're not doing this set first, you are most likely either preloading the lifter, or holding the valve open slightly to start with. Either one will skew your results.
That cam, should not be too big for that application. Although it does depend on the ICL, and the type of lobe. But, all that being said, it shouldnt be too big. Trust me on this one.
OK, to elaborate, without the head gasket, and depending on the length of the pushrod, you may be hanging the valve open to begin with, effective subtracting however much its open, from your true PTV.
Additionally, the valve spring can slowly collapse the lifter, as you're turning the engine over by hand, collapsing it even more, if its not already bottomed out.
The bestest, most accurate way, is to use the head gasket (either one, its only a dif of a .001 or .002, dont both torquing) checker springs, and a checker pushrod, adjusted so there is ZERO PRELOAD AND ZERO LASH.
Once you've determined your PTV, the lifter preload has no impact on it, once you final assemble it.
HTH. If you need personal assistance call my shop, I'll be here for a while. Or leave a message and I'll get back to ya later today.
757-424-1740
This time...I used my adjustable pushrod to set zero lash. I was using solid lifters I'd fabricated, so preload wasn't the issue.
What took forever was getting my adjustable pushrod to the proper length. The first time I did it with no gasket, but didn't think about the fact that when I snugged down the rockers, I was already opening the valve a bit.
So...I tried cleaning up my old head gasket, and realized that would take hours it was so messy. Since I'd spent all morning cleaning the block and it was pristine (along with new heads) I just used the new head gasket...torqued to specs in sequence, and then installed my adjustable pushrod until it was JUST tight, but not opening the valve. Had to repeat that for the exhaust, and took her all back apart.
The claying was easy...read somewhere that the cleaner you have the piston the better it will stick. It did...also put oil on top, and the valves didn't stick at all. I used a straight razor and sliced strait down, pulled away...measured the piece that "broke loose" with the micrometer, then used the depth micrometer to verify the part still stuck to the piston.
Intake : 0.080" Exhaust: 0.110 Whew.
Gerry
08-30-2008, 06:42 PM
#28
Staging Lane
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glad you sorted it out,great to hear you enjoy working on aussie muscle is easier than f-body,haha,let us all know how it performs it should hammer with right tune in her,
cheers dave.
vn commodore,dd,iron 427,waiting on l92 street warrior..
cheers dave.
vn commodore,dd,iron 427,waiting on l92 street warrior..
08-31-2008, 04:51 AM
#30
TECH Apprentice
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id be running more comp with that cam. it will make numbers but not much area under the curve. i had a 226 232 114 in a 6.0l with l92 heads with 10.4 to 1 comp and it was soft on the bottom. i am trying another cam and raising the compression.
09-01-2008, 01:30 PM
#36
Launching!
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Don't miss it a damned bit!
09-01-2008, 02:48 PM
#40
I wish I could answer that question. After installing the head and drivetrain, I was rotating the crank by hand to check the valvetrain geometry when I heard a loud crack. So, I removed the head, inspected everything, and was on the last pass torquing #8 bolt. Just when I thought it was about to snap the torque wrench, I felt it release an POP! That's all she wrote.
I know the bolt was not hydralocked, as I blew out all of them very well with 90 psi air, and I run them all down by hand. I was a helicopter mechanic for 10 years, so I know what doesn't feel right, and there was nothing that felt wrong.
The only "problem" is that I was lubing them with 30 wt Penzoil instead of the ARP molly lube since nobody bothered to tell me that they do not include the lube in the box. Other than that, your guess is as good as mine. I just hope I didn't mess the thread up too bad in my block...don't feel like making this my first helicoil installation attempt.
Gerry
I know the bolt was not hydralocked, as I blew out all of them very well with 90 psi air, and I run them all down by hand. I was a helicopter mechanic for 10 years, so I know what doesn't feel right, and there was nothing that felt wrong.
The only "problem" is that I was lubing them with 30 wt Penzoil instead of the ARP molly lube since nobody bothered to tell me that they do not include the lube in the box. Other than that, your guess is as good as mine. I just hope I didn't mess the thread up too bad in my block...don't feel like making this my first helicoil installation attempt.
Gerry