|09-25-2011 05:07 AM|
|zenchal26||Not sure did not pull them out and check.|
|09-24-2011 09:07 PM|
|cobalt327||So the lifters are hydraulic after all?|
|09-24-2011 06:50 PM|
|zenchal26||Ran it today with the therom in and no overheating issues hovered around 180-190. Adjusted the valves hot today and now it starts harder than before. Adjusting valves with eng running back off till clatter tighten till no noise then 1/2 turn more. When following this same procedure cold I would bump the key and she would fire now I have to hold it and feather the throttle. Not sure the year of the eng but it is not org. Best quess is 283 and it has a th350 trans.|
|09-23-2011 09:13 PM|
The exact reason for why yours is missing may never be known, but overheating is a common reason.
Some guys think removing the thermostat is going to help an overheating problem or make the engine run better. This is false.
You need to see if the lifters are solid or hydraulic. If they're solid, there will be valve lash on all the valves when the lifter is on the base circle, and the lifters will not compress if the rocker adjustment nut is tightened down enough to lift the valve slightly off its seat (also w/the lifter on the base circle). If they're hydraulic, the lifter will bleed down from the valve spring pressure, allowing the valve to close again. This bleeding down can take several minutes, so if you do this go have a coke and come back to see if the lifter has bled down or not.
Hydraulic lifters can be adjusted cold or hot. Factory settings were often 1 to 1-1/2 turns down from zero lash. Nowadays, we usually use less preload- on the order of 1/2 to 1 turn down from zero lash.
Most specs for solid lifters call for the engine being hot. The problem you may be facing if this is a solid lifter set-up, is you do not have any specs on the valve lash. You can start at 0.020" and go from there.
Too loose is harder on the valve train than too tight- until you are so tight that the valve doesn't rest on its seat long enough to rid itself of enough heat. When that happens, you risk burning the valve and eroding the seat.
If this is an original engine, there's a very good chance the cylinder head needs to be rebuilt. These engines were made to be run w/leaded fuel, if it's been driven extensively on lead free gas, the seats and valves can be worn out. The valve guides will always be worn, too. Along w/the valve stem seals being bad as well.
|09-23-2011 08:18 PM|
|zenchal26||OK so I put a thermostat in the truck and around 150-180 she quieted down a bunch. Going to readjust the valves tomorrow and see what happens. Better to adjust hot or cold? Biggest question now is why was there no thermo? Have to test drive after valve adjustment and see if it over heats.|
|09-22-2011 10:07 AM|
|zenchal26||no termostat in eng would being too cold cause any issues.|
|09-22-2011 08:05 AM|
|zenchal26||yes the psi is the same|
|09-21-2011 07:46 PM|
|va4cqd||is the pressure still the same when the ticking changes?|
|09-21-2011 07:00 PM|
|zenchal26||pressures good around 40-50lbs on the stock gauge|
|09-21-2011 06:36 PM|
|va4cqd||hows the oil pressure?|
|09-21-2011 06:35 PM|
|zenchal26||took it out today seems like at certin speeds/rpm the ticking goes away. Then when I let off or get on the gas it starts back up.|
|09-19-2011 07:09 PM|
The cam and lifters are directly beneath the intake. You'd expect to hear valve train noise from collapsed or out of adjustment lifters up top- but there is no guarantee it's something else because all there is besides the valve train is loose wrist pin noise or piston slap. I suppose the cam bearings might be suspect, but that's a long shot. The distributor wouldn't make that type of noise and you'd hear it through the distributor body if it was.
|09-19-2011 07:03 PM|
|zenchal26||If I do go with a new cam and lifters what lift and duration should I go with? I know next to nothing about this subject. I like the lopey lope sound but this 57 3100 will be a street/cruser machine.|
|09-19-2011 06:55 PM|
|zenchal26||The noise does not sound like it is coming from under the valve covers more under the intake man. If the valves were out of adj would they be more likely to make noise at the rocker or at the cam/lifter.|
|09-19-2011 06:46 PM|
Once you know what it has (my money would be on hydraulic), readjust the valves to see if that quiets it down, or if the cam/lifters are too worn and need replaced. If you replace the cam and lifters (replace them both), use a hydraulic cam and do a search here for guidelines on breaking in a new cam/lifters.
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