So the Bronze went through a bit of a retro grade this past week.
First up - there's very little time in my life at the moment - likely my own doing, but just the same. So I have had this head, which I bought from Hainz many years ago (for a good deal then, I might add - thanks Hainz if you’re still out there). At any rate, this was supposed to be the head that went on the Bronze with the EFI conversion in 2006/7. It never happened, the head ended up having the rockers and lash pads removed, bagged and tagged and well preserved in wax oil on all surfaces before being wrapped up and placed in a box in 2007... ‘til this past Monday.
The head was brought home, disassembled and assessed. There was funky shimming under the valve springs, the valve springs are not stock and are also unknown, the valve installed depth was all over the map (.040" variance), and the camshaft is still a complete mystery - other than I measure .483" lift at the valve, lobe measures .320" lift.
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So I measured the installed height of the valves, had a guy at the local Lordco machine shop determine the valve spring pressures both closed and open (118/256 lbs intake, 133/269 lbs Exhaust) and I then determined that the funky valve spring shimming was to compensate for the fact that the exhaust vales are installed deeper - which corresponded to the different thickness lash pads as well - so that all came together.
The intake and exhaust valves are new, upgraded to 44mm from the stock 42, stock 25mm on the exhaust - but brand not known. The guides have been sleeved and are quite snug on the valve. I lacked in the small hole gauges at home so I couldn't mic the difference between the vale and guides, but it's pretty snug, to that's good. The rockers had been resurfaced, and a ground finish at 90 degrees to the lobe operation was clearly visible. The rocker wipe pattern was perfectly centered on all rockers, so that was good. The head and manifold surfaces had both been planed, the head is missing .015" off its factory nominal thickness of 108mm, that's livable. I cc'd the chambers just for fun, they were 43-44 cc's.
So the head pretty much checked out good. I port matched a manifold, ground an intake gasket to fit, tapped out all the holes. I tossed the valve seals and installed new ones, and reassembled the head yesterday.
But I decided that I would not modify this head for EFI, instead making the decision to install the 44 Mikuni's which Chad borrowed and used for a couple years on his car. This meant that I would have to make a new throttle cable, and figure out fuel. So I port matched the manifold and made it ready to install (or so I thought)...
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