Clattering Lifters 48 V-12

I started this project over a year and a half ago and unfortunately am dissapointed with my reults. The engine was pulled, bearings - rod and mains, new cam, rebuilt pump,lifter housings reground, fuel pump bushing & rod replaced, relief valves(oil) replaced. When I went to reassemble engine and raised question about clearance between lifter and valve stem. I have some question as to was it necessary to have the .030-.050 using hydraulics. I tried to make measurement but could not get good readings. Finally gave up and think this may have been my downfall. HELP Note! Lifters were were taken apart and cleaned, oil pressure good, rear wheels jacked up and ran for an hour, all to no avail.

I think that your problem was that you did not fill the lifters with oil before assembling them in the lifter bodies. Eventually they will fill up with oil but will be noisy in the meantime. I have also found that elevating the rear or parking the car on a steep grade rear high but not so high the oil pump will not pick up oil in the sump, and idling at a fast idle will help to quiet down the lifters. I know that I read somewhere not to oil the lifters before assembly, but I have on a couple occasions started up fresh rebuilds with oil in the piston and cylinder portion of the lifter and had no problems.

Bill

You mentioned that you had the lifter bodies reground but what was done to the hydraulic push rod assemblies? Were these carefully taken apart, cleaned and checked for leaking ball checks and excessive clearance between the piston and cylinder? During your attempt to check clearances did the pistons in the assemblies move away from the valve stem when you forced them down? I assume you also checked and or replaced the bypass valve at the back of the engine next to the fuel pump push rod. Any malfunction/blockage at this valve will limit or cut off oil to the tappets.

Thanks for the reply on the lifters. I have done everything you

have suggested, except putting in oil in the cleaned lifters. It appears there is two schools of thought on this and the factory repair manual says they should be dry on reassembly. My next step is to pull heads and manifold and try to find some new (rebuilt) lifters. Should I replace gaskets or could I use the new ones I recently put on? Also, must I try to do the .030 - . 050 gap measurement. THX

Before you do anything. Add 1 pint of ATF to the oil. The ATF will clean out the lifters. Run it for about 100 miles then change the oil. This has worked everytime for me. It is an old trick that my grandfather knew. He was with GM from 1949-1996.

You should really use new gaskets on the cylinder heads. The clearance on the tappets should be between .030" and .070". One more thing to check before tearing those heads and valves loose; Was the spring and ball check relief put back into place under the cap at the front of the valve galley? If this was left out there would be almost no oil pressure in the lifter feed passages.

Has anyone recently bought lifters? (new or reconditioned) I am currently looking as this is my next step to solve my propblem. THX.