Post by cptkennykidna on Feb 11, 2018 12:26:25 GMT
a new rocker shaft i have just fitted part num 010114Z had no oil pressure and thinking that because the engine had been sitting for 20 years without a head on it the block gallery might be blocked, in Australia native bees - Hornets and other insects are known for nest making in any hole available e.g carburetors on your garden equipment etc and maybe this gallery was my problem so off with the recond head.
two batteries hooked together and a good cranking gave me oil out of the block so i blew compressed air through the head and all seemed well, head back on with another head gasket rocker gear etc, No oil pressure
?, answer was that these new shafts have smaller oil holes than the original [ old holes are about 7/64 inch and new ones are .100 thou size 40 drill bit or just over 2.5mm.
the Number 4 pedestal has a grub screw to stop the rocker shaft from rotating and also hold the shaft down against the No 4 pedestal oil feed hole.
that grub screw locking hole in the rocker shaft is in the wrong spot, just enough to move the shaft to the right and block the oil feed from the pedestal into the shaft, i experimented with another new shaft and ended up having to oversize that oil feed hole below grub screw to 15/64 inch.
that might seem a lot, but each time i went up a size i only gained half of the oversize, this solved the oil pressure problem but one other thing happened , the shaft moves to the right = front of engine and the spring and washer have no pressure, i had to put another washer on that end, the back washer and spring on the No 4 pedestal end becomes tight,it is a small issue that can be got over with thinner washers.
all reproduction shafts should be checked or your new shaft may be cactus with your bushes.it has been mentioned that pedestal shim 12h3960 can be used to lift the center two pedestals and get rid of some rattle, the rocker shaft does not rotate in the pedestals so it is possible to drill and tap the other three pedestals as per No 4 and lock it all down, you might need to think on that.
there are some performance mods with regards stiffening things up, out rigger pedestals AEH 762/3 = front and rear as a pair and spacer set instead of springs = AEH764/5 = 3 pieces and do not forget shims 12H3960.
CHECK YOUR NEW SHAFT.
two batteries hooked together and a good cranking gave me oil out of the block so i blew compressed air through the head and all seemed well, head back on with another head gasket rocker gear etc, No oil pressure
?, answer was that these new shafts have smaller oil holes than the original [ old holes are about 7/64 inch and new ones are .100 thou size 40 drill bit or just over 2.5mm.the Number 4 pedestal has a grub screw to stop the rocker shaft from rotating and also hold the shaft down against the No 4 pedestal oil feed hole.
that grub screw locking hole in the rocker shaft is in the wrong spot, just enough to move the shaft to the right and block the oil feed from the pedestal into the shaft, i experimented with another new shaft and ended up having to oversize that oil feed hole below grub screw to 15/64 inch.
that might seem a lot, but each time i went up a size i only gained half of the oversize, this solved the oil pressure problem but one other thing happened , the shaft moves to the right = front of engine and the spring and washer have no pressure, i had to put another washer on that end, the back washer and spring on the No 4 pedestal end becomes tight,it is a small issue that can be got over with thinner washers.
all reproduction shafts should be checked or your new shaft may be cactus with your bushes.it has been mentioned that pedestal shim 12h3960 can be used to lift the center two pedestals and get rid of some rattle, the rocker shaft does not rotate in the pedestals so it is possible to drill and tap the other three pedestals as per No 4 and lock it all down, you might need to think on that.
there are some performance mods with regards stiffening things up, out rigger pedestals AEH 762/3 = front and rear as a pair and spacer set instead of springs = AEH764/5 = 3 pieces and do not forget shims 12H3960.
CHECK YOUR NEW SHAFT.
