Att eh drags the other night with an old friend we were discussing the problems with flat tappet cams since the demize of the zinc content in most
oil.
We have had a number of people we know who have wiped lobes despite using additives and proper break in. ONce they are broken in the failure rate
seems to go down.
Mind you in most of these cases they were high performance cams with much higher than stock spring pressure. Conventional wisdom is to break the cam
in with lighter springs [I believe the original DZ Z28 engines came with these and the high presure springs in the trunk] but lets face it... thats a
PITA
Anyway, he has had good results breaking in engines with reduced ratio [1.3] rocker arms that lighten the initial load. In fact, Im going to borrow
his set for my next SBC build. But they are pricey and not a good option for most. also, AFAIK they are only made for small bock chevy
Go to thinking about problems with hte olds engines in our community. I dont claim much olds spesific knowledge, but wondering if this migh tbe a n
idea to try.
looking at the olds system it seems similar to a ford style rocker. Was thinking someone with a mill and tig welder could modify something like these
rockers and relocate the roller to acheive a lower ratio for break in. and then sell them to the next person inthe community who might need them. It
may be tricky to get the geometry right.
https://www.ebay.com/itm/PRW-Rocker-Arm-Kit-0830201-Sportsman-1-6-Roller-Tip-for-AMC-Ford-Oldsmobile/281791398834?epid=630642887&hash=item419c1383b2:m:m6JVM47QaQjBHP9eLUAKBng&vxp=mtr
Obviously this doent help long time durabilty issues and it is still a pain to chnnge rockers and reset the valves. But its far lesss of a pain then
if you wipe the cam lobes, and I would think the better break in would help down the road
THe roller cam set up is the better way, but an expensive option
Knock on wood, I havent had any problems with my flat tappet cam vehicles yet, but if I ever need to do the GMC I might put this to the test
--
76 Glenbrook
oil.
We have had a number of people we know who have wiped lobes despite using additives and proper break in. ONce they are broken in the failure rate
seems to go down.
Mind you in most of these cases they were high performance cams with much higher than stock spring pressure. Conventional wisdom is to break the cam
in with lighter springs [I believe the original DZ Z28 engines came with these and the high presure springs in the trunk] but lets face it... thats a
PITA
Anyway, he has had good results breaking in engines with reduced ratio [1.3] rocker arms that lighten the initial load. In fact, Im going to borrow
his set for my next SBC build. But they are pricey and not a good option for most. also, AFAIK they are only made for small bock chevy
Go to thinking about problems with hte olds engines in our community. I dont claim much olds spesific knowledge, but wondering if this migh tbe a n
idea to try.
looking at the olds system it seems similar to a ford style rocker. Was thinking someone with a mill and tig welder could modify something like these
rockers and relocate the roller to acheive a lower ratio for break in. and then sell them to the next person inthe community who might need them. It
may be tricky to get the geometry right.
https://www.ebay.com/itm/PRW-Rocker-Arm-Kit-0830201-Sportsman-1-6-Roller-Tip-for-AMC-Ford-Oldsmobile/281791398834?epid=630642887&hash=item419c1383b2:m:m6JVM47QaQjBHP9eLUAKBng&vxp=mtr
Obviously this doent help long time durabilty issues and it is still a pain to chnnge rockers and reset the valves. But its far lesss of a pain then
if you wipe the cam lobes, and I would think the better break in would help down the road
THe roller cam set up is the better way, but an expensive option
Knock on wood, I havent had any problems with my flat tappet cam vehicles yet, but if I ever need to do the GMC I might put this to the test
--
76 Glenbrook
