10-02-2020, 09:12 PM
I was going to run this engine with standard bores and 1 1/8” crank but chatting it over with some friends last weekend persuaded me to get the block cleaned up and re-bored. Having made that decision, I went for a poke about in the shed last weekend and look what I found!
I’ve had this Phoenix crank for more years than I can remember so now it’s time to use it.
Next, I needed to get some rods re-metaled, so I sorted out four 1 5/16” rods, cleaned them up and dispatched them to David Kirkby for attention.
Now, fitting a 1 5/16” crank to a mag (or early coil) crankcase is straightforward but there are three modifications that need to be made.
1) A 7/32” drain hole is needed to return oil back to the sump from the main bearing.
2) The inside of the front lip has to be bevelled to allow room for the front of the crank
3) The camshaft centre roller bearing housing needs to be relieved to allow the larger crank to have clearance.
I made a tool for jobs 2 and 3 above, it’s a length of 1 1/8” bar with two old rear main roller bearings (early, 1 1/8” type) loctited on. These allow the bar to move through as needed. There are two holes for two pieces of tool steel; I use 5/16” silver steel, hardened and tempered. It’s only cutting aluminium. I guess I could add a cutter for relieving the front lip to fit a repair plate but I haven’t needed to yet.
All those have been done so now I can thoroughly clean the crankcase to remove all the swarf before assembly starts.
Meanwhile, the block is away being bored, having been cleaned electrostatically (see the thread on 1 shot drain cleaner for details).
BTW, I've sorted out and helicoiled where necessary the sump and oil tray bolts. They were in a real bad way, having the wrong bolts forced into many of them!
More to follow when assembly starts.
I’ve had this Phoenix crank for more years than I can remember so now it’s time to use it.
Next, I needed to get some rods re-metaled, so I sorted out four 1 5/16” rods, cleaned them up and dispatched them to David Kirkby for attention.
Now, fitting a 1 5/16” crank to a mag (or early coil) crankcase is straightforward but there are three modifications that need to be made.
1) A 7/32” drain hole is needed to return oil back to the sump from the main bearing.
2) The inside of the front lip has to be bevelled to allow room for the front of the crank
3) The camshaft centre roller bearing housing needs to be relieved to allow the larger crank to have clearance.
I made a tool for jobs 2 and 3 above, it’s a length of 1 1/8” bar with two old rear main roller bearings (early, 1 1/8” type) loctited on. These allow the bar to move through as needed. There are two holes for two pieces of tool steel; I use 5/16” silver steel, hardened and tempered. It’s only cutting aluminium. I guess I could add a cutter for relieving the front lip to fit a repair plate but I haven’t needed to yet.
All those have been done so now I can thoroughly clean the crankcase to remove all the swarf before assembly starts.
Meanwhile, the block is away being bored, having been cleaned electrostatically (see the thread on 1 shot drain cleaner for details).
BTW, I've sorted out and helicoiled where necessary the sump and oil tray bolts. They were in a real bad way, having the wrong bolts forced into many of them!
More to follow when assembly starts.