View Full Version : Key and Dowel the Harmonic Balancer to the Crank Shaft
JB91710
02-01-2018, 10:11 AM
Has anybody Doweled the Harmonic Balancer to the Crank Shaft. This is a video of what I mean. https://www.youtube.com/watch?v=pkvXHGvbMko&index=1&t=63s&list=FLFsNbu_AalilSMdtgmxsiPA I'd like to see if anybody has done it to the Subaru cranks so I can find a place to buy the kit and discuss the process.
Thanks,
Jack
STiPWRD
02-01-2018, 10:45 AM
There's already a keyway lock on all the EJ crankshafts I've every seen, which prevent the timing gear and balancer from rotating. So there's really no need for drilling dowel pins. I just looked up an EZ30 crankshaft and noticed the keyway is a bit more recessed. Does it not lock your balancer?
Mechie3
02-01-2018, 04:53 PM
Side note, FWIW. Subaru has claimed the crank pulley is not a harmonic balancer, just a crank pulley.
UnhipPopano
02-02-2018, 08:16 AM
If the key is properly designed, it is the week link and designed to brake if the torque between the balancer and the crankshaft is too great. Protects the crankshaft if something seizes up and the belt does not slip.
That said, what has been gained by adding the dowels? If you replace the pulley / balancer, would you be able to get the holes to line up 100 %? At high RPM could the dowels make the balance induce vibration?
JB91710
02-02-2018, 12:16 PM
They add the dowels to make the connection stronger for racing or adding a supercharger. I'm doing it because I am connecting the two engines that way. My car will not be for racing and the two engines will run off one computer and fire a cylinder in each engine at the same time on opposite sides. The major torque transfer will be when the rear engine has to turn over the front engine when I start it. It shouldn't be doing that for a long duration with modern engines and computers.
I'm going to have an adapter made that will be like the pulley but will accept the eight bolt holes for a torque converter flex plate. The front engine also has a flex plate and they will touch rim to rim and have the four torque converter holes to connect them. Lining up the rims of the plates by adjusting the engines will align the cranks. The Flex plates will absorb any deviation.
We'll see anyway.