Hitchcocks Forum

I'm slowly getting to the bottom of the rebuild of my basket case '61 Bullet. I've spent the week making sure I have everything I need and my crankcase now has shiny new bearings in both sides. However, I've reached a couple of show stoppers and I could do with some advice:

1. On the timing side, my crankcase has a very narrow aperture where the crank exits onto the timing pinion. There are two grooves machined in it which I presume to be for oil seals or o rings but I can't find a reference to them in the parts lists. Is this correct? Is there a seal on this end of the crank and where do I find reference to the part number?

2. I've read a lot about lubrication and I am of the opinion that a crankcase gasket might be a good idea. Am I wrong? Do the Redditch bikes leak through the crankcase face joints and is a gasket a good plan?

Hi Jamie

I am not fully conversant with your paticular engine but I have never worked on any British bike with an oil seal between the crankcase and the timing case. As for a gasket between the mating crankcase faces, definitely not the best way to seal these faces providing they are not damaged it to coat both faces with Welseal and allow to dry for ten to fifteen minutes prior to assembly.

Is one for a circlip and the outer for an oil seal lip? As Dennis says wealseal will do the trick if its important to preserve clearances..

Indian motors are most often rebuilt with a gasket because mating surfaces can be iffy…
Not sure about reditch...

Really? I thought a crankcase gasket was a pretty standard piece of kit. My bullet has one as does my Ducati. Thin but soft paper gasket. I have put cases together with a flange sealant (loctite make a good one) but have cursed people who use silicone or shellac based goo as it can make future disassembly bloody difficult.

The other reason for a gasket is that it lets you do a trial close to establish end float.

I've just realised I'm missing the thrust washers off the end of the crank so I can't set up end float anyway. I'll buy those tomorrow and I think I'll use gasket sealant as the crankcase faces are pretty good.

I was reading about oil leaks into the crankcase on early Bullets and I found it odd that there wasn't a seal between the timing case and crankcase, but the clearance in my case around the crank is so small it could only really be an o ring type seal.

Hi Jamie. No gasket is used between the crankcase halves of the Redditch engines, just a suitable gasket 'goo' from a tube is all you need. The Indian engines use quite a thick gasket, but if this were used on a Redditch engine, the clamping effect of the crankcases around the bottom of the cylinder liner would be largely lost and the conrod would be off centre to the crankcase join, the timing pinion might end up too close to the mainshaft boss, preventing easy removal in future by use of the special pullers available, although you could shim the crank over from the drive side a little, to compensate for all of this. There is no seal inboard of the timing pinion on Redditch engines, there will either be a close fitting 'hole' through which the timing side mainshaft mainshaft will pass, or a bronze bush doing the same. In either case, bush or plain hole, they will have scrolled grooves cut in them, to allow a small amount of oil through to the timing side main bearing. Regards, Paul.

Perfect answer, thank you.