JRed 670 Impulse quandry

[SuperII]

Somebody was full of bright ideas!!! Did the cyl base gasket look stock? They are fairly thick. Like in the 0.030" range compressed. I've never seen a piston or cyl like that. As Bob (Spike60) would say....."You've got a puzzler right there!"

The base gasket was very thin with a slathering of silicone. I pulled the rubber boot last night and will post a pic of the internal and external pulse ports. Maybe i have the proverbial unicorn of the week.

 

[SuperII]

This, to me, looks like it was made this way. Not sure what their thing was. If this is a very early saw and were moving from internal to external, why would they go to the extra work. Maybe it was transition and they were using up old cylinders and just added the external port.

 

[SuperII]

The only thing I can think of and this is just a thought, can you tell if the cyl base has been cut down? They may have cut it to far and did not have the ability to cut the squish band so trimed the piston top instead.

The Cyl. Base does not look like it has been cut. It has the casting texture and cast edges.

 

[SuperII]

Hard to tell but looks uncut. I found a NOS piston and a squish test will tell me i guess. And i can get a repro boot, without the moulded in pulse passage, so as to abandon the internal pulse port. Only thing is, what to do with the internal pulse nipple on the intake manifold. Cut off and epoxy??

 

[SuperII]

By the way, if anyone has the proper clamp for the boot to cylinder area that they would part with that would be a bonus. Although from what I read, the early ones used a wire, which is what it had on it. That could be done as well, thanks.