Didn’t get as much done as I had planned. Was ‘mowing’ the leaves in the yards and on the drive. Not that I truly care how the yard looks up here, but it is a safety precaution. Wildfire season, and a nice bed of leaves can move fire quicklike. But the drive belt to the mower deck took one hit too many or something (it was old so there is that.) and
It’s Sunday. TSC didn’t have one in stock. Ace Hardware didn’t have one in stock, and I tossed hands in air at that point. Went ahead and had Ace order one in. Should be in this week around Wednesday.
SOooossssss
I came home and piddled a bit. Used the blower to clear more leaves off spaces to protect the areas I’m most concerned with, then, over to Buffalo’s stall to piddle some more.
Looking over things, realized that there are more changes between engines other than emissions hardware. Not a deal killer, but that I completely missed the differences, and I was the one doing the tear down and inspections, humored me a bit.
See, the donor engine, the one with A.I.R. (air injection along with EGR functions.) was also on the front end of a design change internally. It was the last of the vortec4.3’s with rocker arm assemblies. Later that same year, they started making them with roller rockers. And thats what Buffalos old block has. So I went digging even further,,,,
Exhaust ports (at the manifold, not the valve face) are slightly smaller in the donor heads. about 1/8″ side to side. Not sure if that means more back pressure in the manifold or less. Smaller passage usually moves gases faster, but larger moves more in the long run. 1/8″ may not mean doodly either,,, dunno.)
Heads are fully interchangable on the blocks.
Roller rocker heads are cleaner by far.
Roller rocker parts are not interchangable between heads. its either roller rocker head, or made for standard rocker arms.
and I am of the mind, since I’m sending heads out anyway, to use the roller rocker heads from Buffs engine on the short block of the donor.
And thats the reason for the late post. Been online reading forums for research as to “should I bother”. other than the rocker arms, all other parts are same. Rod lengths are identical, valve parts are identical. Roller Hydraulic lifters identical.
But the roller rockers don’t wear like the rocker arms. And that has me leaning that direction. Some say its a HP increase as well, but I can’t see that as GM touts both engine makes at 190HP (measured at the flywheel, not true dyno test.) Not that I would notice much of change; going from 350k worn out engine to something fresher, I’ll notice something and what could be due to that alone.
Anywhooos,,, if any of ya gear heads have any input on this, I am 5 days out from taking heads to the machine shop and not settled on any one direction yet. If ya think its a bad idea, let me know: heck, if you think its a great idea, let me know that too. If indifferent, same. I have room to work and parts to work with, but not a lot of money to be blowing on shop services. its one or the other, and once one is up, its going in no matter what.
Thats all I’ve got for the night.
Love y’all
Stay curious.
Live
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Learn
LOAD!!!
