Re: C-1 '61 solid lifter adjustment
Read post #10.
Read post #10.
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Re: C-1 '61 solid lifter adjustment
Duke and John,
What's best way to find top dead center to start with? Assume you verify it rather than just relying on mark on balancer?
Thanks in advanceComment
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Re: C-1 '61 solid lifter adjustment
Duke thanks but you are way over my head. I have read your report 3 times. All I want to know is why do you start your adjustments with #2 intake first when you begin by setting up the process with #1 at TDC according to your report. why dont you start with #1 intake?? I think this way because all other threads that I can find say to start at #1 intake I just want to make sure that there was not a misprint. Keep it simple for me if you will. do I start with the #2 or #1 intake. Thanks, MIkeComment
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Re: C-1 '61 solid lifter adjustment
Mike,
Sometimes we split hairs here on the forum and ALL the posts are good but if you want to make it simple and in black & white go to your manual and it spells it out simply and it has worked good for us till we found better ways but you will be just FINE using your manual.
DOMComment
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Re: C-1 '61 solid lifter adjustment
You have a Duntov cam, so you can index the engine at #1 TDC of the compression stroke and adjust both valves of THAT cylinder. Then go in the firing order sequence.
I explained as best I could why you CANNOT use this indexing method for the 30-30 and LT-1 cams. It's my hope that all can understand the explanation, but it's not absolutely necessary to do so. You don't need to understand Quantum Mechanics to use a computer or smart phone. You just follow the instructions to do what you want to do. If you follow the instructions for the Duntov cam including the optional indexing method as given above, you will be okay.
I'll give it one more try. At TDC of any cylinder the inlet valve lifter of THAT cylinder is still on the closing clearance ramp of the 30-30 cam - about .002-.003" above the base circle. If you continue to rotate the engine in the normal clockwise direction as viewed from the front it will be on the base circle in about 20 more degrees of rotation and will still be on the base circle at 70 degrees further rotation, which is TDC #8, so it's okay to adjust #1 intake at this crank indexing position, which is 90 deg. after TDC #1. The same argument applies to the other inlet valves, and a similar argument applies to all the exhaust valve since all the exhaust lifters are about .002-.003" above the base circle at the BEGINNING of the clearance ramp, so they can be adjusted at 90 deg. BTC which is TDC of the preceeding cylinder in the firing order.
DukeComment
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Re: C-1 '61 solid lifter adjustment
If the balancer is out of true it will have a much bigger effect on spark advance than valve adjustment. As I said, the crank only needs to be indexed within about 10 degrees either way of the various TDC points to ensure that the lifter is on the base circle.
If you suspect the balancer is off you can verify TDC with a piston stop, which has been discussed in many threads.
DukeComment
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Re: C-1 '61 solid lifter adjustment
On a manual transmission car, just put the trans in fourth and push on the front tire to rotate the crank. Easy and quick to adjust the crank exactly on the marks.Comment
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Re: C-1 '61 solid lifter adjustment
Duke, thank you. It has been an education. It just took me awhile. But you did throw me a curve by you first sentence of your thread by being able to adjust both valves of "THAT" cylinder starting with #1 and doing both valves of each in the firing order. Never saw that option in any of my research. No need to explain the finer points of that option. I will stay with the report and start with 2I and 8E. Thanks again, MikeComment
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Re: C-1 '61 solid lifter adjustment
Guys Just a question about the use of roller rocker arms with a solid lifter camshaft. any benfits? I would think the rocker adjustments may vary some.New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.Comment
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Re: C-1 '61 solid lifter adjustment
Roller tip rocker arms are probably the biggest waste of money the aftermarket offers, and it's amazing how many guys get sucked into parting with the 150 bucks that a set typically costs. I have no idea what their ratio characteristics are. My recommended lash settings apply to the OE rockers.
Even modern LS rockers DO NOT have roller tips. They have roller trunnions, which are useful for reducing internal engine friction with the high rate valve springs necessary for modern, aggressive roller lifter cam lobes, but that's a different deal.
The OE rockers both for vintage and modern Chevrolet engine have a curved tip, which, if the valvetrain geometry is not totally out of whack, ROLLS over the valve strem tip. It does not slide, so roller tips are basically useless other than adding mass to the valve train, which will reduce valve train limiting speed.
DukeComment
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Re: C-1 '61 solid lifter adjustment
I recall they were off-the-shelf Crane parts, and that was the only engine Chevrolet ever used them on. I suspect it was for "bling" as that was a low volume engine that was a stop-gap until the LS went into production.
It's also interesting that they didn't use the "reverse flow" cooling of the LT1/4 design on the LS. On paper it looked good, but GM abandoned it, and I never heard why they did so.
Then there was the Opti-spark system... oh, never mind!
DukeComment
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Re: C-1 '61 solid lifter adjustment
they also used a mixed ratio 1.5 and 1.6 so i guess that was the only way that could do that by using roller rockers. the reverse flow was to cut down on detonation by cooling the head first before the block but i would guess the all aluminum LS series that was not a problem.Comment
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