152 Flat Camshaft

J

John Hoffmann

New member
Working on a 152 engine that has about 1600 miles on complete overhaul , @ the time of overhaul it had a reman camshaft from IH parts & a new set of lifters from napa , used assembly lube in the face of the lifters & ran high zinc content oil , it took most of the lobe of # 1 intake & #2 exhaust , going with another reman camshaft new lifters , just looking for advice if im missing something that could be causing this !
 
How long between the overhaul and the first run?


1) liberally apply cam lube to the lifter faces and cam lobes only. Should be the ugly slimy black stuff. The other types work but can migrate away while sitting.

2) pre-oil by turning the pump through the distributor hole for a minimum 5 minutes. Recommend indexing the crank to a couple of different places during the pre-oiling process

3) before starting make sure all systems are perfect and able to run for 30 minutes at 2000-2500 rpm. This is a big deal to bed in the cam with large oil flow to all areas of the cam.

4) the oil needs to have 1300 ppm zinc and a good amount of phosphorus. Verify by investigating the manufacturers documentation/data sheet.

5) use IHPA's lifters. Through the years we have determined the best manufacturer of lifters for the IH cams to ensure proper lifter rotation. IHPA sells only those. All lifters are not the same.
 
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Robert , all things you listed above I feel were covered on original assembly, due to not knowing deck height & how May times the head has been surfaced over the years & the use of aftermarket lifters could it be possible that we could be bottoming out the lifters adding extra pressure on the camshaft ?
 
You can't really bottom the lifter once it pumps up. Only a valve spring compressed to coil bind or the keeper bottoming on the guide or valve seal can make enough loading to cause that damage.
Installed height for the stock spring is 1.850 and should have 80-90 # seat pressure.
You need to verify all of these numbers and clearances before sticking in a new cam.
 
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