johnnyc14 said:
Thanks Bill, yeah it's definitely a Heinz 57. The frame number is CB450-4101737. I was wondering what that thing on the output shaft was. Is that the chain oiler? I love the look of the bike too, that's why I paid too much for a bike with a sick engine. The seat hinges at the rear and it has a 19" front wheel. I did some measuring on the crank and rods today and it looks like the crank is OK. I thought there was too much wrist pin to rod small end clearance but when I measured the small ends they are .6710" and .6708". The Honda manual says replace if over .6721". I found no radial clearance in the main bearings or the rod big ends. The "rod tilt" measures .037" and .039". The rod big end side clearance is .013" and .012". Is there a spec for crankshaft end play? Mine seems to have a lot. Do you know if there is a recommended place on the piston skirt to measure the diameter? These seem very barrel shaped and the largest measurement is about 1/2" from the bottom of the skirt. Do you know what the recommended piston the cylinder clearance is for new pistons? The manual does not seem to have a spec for piston to cylinder clearance. These both measure .0055". I have a new set of 1.0 mm over pistons and rings and all the gaskets and seals but I'll need a cam chain and some wrist pins and circlips. I also have 4 new valves and valve seals and I have a good head with the seats already refaced with a 3 angle valve grind. So I'm just about ready to go after the cylinders are bored. I'm looking forward to getting it back together, hope to be riding it in the spring.
The piston to cylinder clearance you measured is a bit much, though Honda lists no values for it - Terry Naughton has mentioned 0.0015"-0.002", which is what I've always heard as a standard value. Just as important is the cylinder "taper", or the difference between the bore at the top and bottom of the cylinder - the manual lists a very small spec for this, less than 0.0002". That's the reason I bored my own 450 out.
When you get it bored out, take a copy of the manual pages with you and the machinist will know how to bore them for proper clearance.
Incidentally, the con rods do not connect to the pistons dead center either - they're off set by 1 mm towards the intake side, so that the momentum carries it through the top of the stroke.
The pistons are not supposed to be round - they are "thicker" facing front and rear, to make up for the expansion of the extra metal around the con rod pins on the sides.
I have never seen a spec for crankshaft sideplay anywhere. If you have significant sideplay even with the oil filter and alternator attached and the cases together, I'd think about a different crank myself. Been there, done that.
With that said, if the pictures are accurate, it's still a pretty darned nice bike. No rust, great exhaust and seat, and generally in real good shape, very clean.
I'd say if you paid $800 or less, you did well. You can fix the engine and still have about $1,000 in it, which is pretty good.
And that K1 tank is a killer, dude !!
By the way, the frame is a CBK4, like the engine.
And I was wrong - those are K4 air cleaner covers.
So looks like someone spliced in a bunch of CL parts to a CBK4 - that seat is also proper for a K4.
Yeah, that's the chain oiler there in the end of the countershaft. I replaced my countershaft with one from a K2, which had no chain oiler. In the past, I've just removed the whole thing, sprayed the inside of the countershaft with carb cleaner to get oil out of it, then plugged it with silicon.
The chain oiler is a huge, messy pain in the butt, I have no idea why Honda did it.