Small Block & Big Block Chevy Specific - Hyd CAM - Preload on Lifters
04-16-2007, 01:56 PM
I have a problem with my friends 57 chevy. I has a SBC 383 with a CAM that I have been trying to set the valve / Lifters on. The engine (as we were told by the seller, that the engine was assembled by one of Reggie Jackson dealers, but we are unable to find any information on it, phone is now disconnected(?) and the seller can not provide any more info). We have no spec's on the cam other that it is a Hyd flat tapped and most likely high in the duration and over .500" lift
Well... on setting the valves to zero lash and then pre-loading them with a 1/2 turn.. the engine will not have any compression and just spin freely. We had to set them to zero lash to get the car running again.. I can not figure this out.. Do you think someone used Solid lifters ? (I know this has/can been done before).
Are there any CAM/Lifter setup that you know of that use Zero lash ?
04-16-2007, 02:35 PM
What about hydraulic lifters that the oil has bled off?
Just an idea!
04-16-2007, 03:07 PM
I have tried setting them with both the engine hot and cold.. anytime I put a turn of preload on the adjuster, the engine would start to die or run badly.
It seem like it is a solid lifter and if the adjuster nub is turned, the valve would be open and the lifter would not compress any (solid lifter ?).
Thanks.. anyone else ??
04-16-2007, 03:56 PM
What year is the block from? Sounds like you need to pull the intake and check out what kind of lifters are in the car.
04-16-2007, 04:48 PM
As far as I can tell.. it is a early Gen I block. Oil level tube is on the driver side. we are trying not to tear into it if we don't have to.. we had just did a Manifold swap, installed a Vintage Air front runner setup on it over the winter.
The Lifters are Flat Tap's, not Roller. But at this time, If we have to tear it down to check the CAM, we will just stick a new one in. But we would like to get through the Summer if possible.
04-16-2007, 04:52 PM
If it's hydraulic you set it to zero lash, give it one turn, the valve will open and slowly bleed down a little. If it's solid it will open and stay open.
I'd adjust them to about .022 and run it. If it's real noisey it might be hydraulic but it doesn't seem like it going by your description of the problem.
04-17-2007, 09:43 AM
After some research, I think these lifter may be the Rhoads V-Max lifter that are Hyd... but set like Solid lifter. You use a feeler gauge (.010-.040) and tighten until the valve starts to open, then you loosen the adjuster until the feeler guague has the required clearence. I will have to do some more resarch to see if in fact these are in the engine.
Currently the engine will not run if any preload is left on the valve... no compression and the engine spins freely. Once I return the adjustment to zero lash, it run ok.
At this point, I am thinking they are the Rhoads.
Any one have any experience with them ?
04-17-2007, 10:01 AM
Never heard of the VMAX until now.
Found a link for others who don't know about them. http://www.rhoadslifters.com/Pages/VFlatTappet.html
Sounds like you're on the right track.
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