'77 CJ360T (Café SOS) - Calling it Done (for now...)

[crazypj]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

OK, what tools do you have?
Got a welder and bench grinder?
Harbor Freight Tools, mini lathe tool set, use 1/8" square tool steel and braze or weld it to valve head
Then, grind to the diameter you need
Do as I suggested, bolt on cylinder head, spin valve with power drill.
If your machinist usually does car stuff, he should be able to find correct diameter valve stem with a head bigger then your new valves

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Welder and bench grinder, check.

No lathe (mini or otherwise). I do have a hand drill, but it's not a good one and I have no stop.

I think I'll also need a valve larger than the one I already have. Is that right?

 

[crazypj]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Nope, you don't need lathe, just the high speed steel tool bits.
Weld so it overlaps edge of valve then grind back to cutting shape/diameter.
You know valve head size, you know how much clearance you need, just have it stick out 0.5~0.75mm

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Well... I sure got to feeling like Burt Munro this weekend. I ended up hand-cutting the reliefs in the pistons using a Dremel tool, die grinder, and half a dozen assorted bits. I masked everything off when I started, just in case the tools got away from me. It's a good thing I did as the Dremel decided to go for a stroll across the piston dome. No real harm done, though. It buffed right out.

I ended up taking .030" out of the cut, effectively increasing the diameter by about 1.5 mm.

Next step it to put everything back together and check clearances again to ensure the work that's been done is sufficient.

 

[teazer]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

That is how they are supposed to look. At least most of mine do, so that must be right...

Hope that gives you enough clearance now.

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

I got the engine assembled and this time I had clearance at TDC between (closed) valves and pistons and so I assembled the rest of the top end to give it a try. No go, but at least it's closer. There's still contact with the left intake and right exhaust valves and so everything came apart again and a Dremeled a bit more metal out of the piston pockets.

The pistons and jugs are back in place as of this post, but I haven't tested it again. Perhaps tonight or tomorrow as time permits.

 

[ducatiboy]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

There's still contact with the left intake and right exhaust valves and so everything came apart again and a Dremeled a bit more metal out of the piston pockets.

You must have the patience of a saint...

Funny how one of the intakes and one of the exhausts is ok. You'd think it would be both of one or the other not one of each???

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

I think it has to do with me not giving the crank a full rotation. I stopped once I felt too much resistance. I was only running with the weak springs at the time so as to keep resistance to a minimum. I'm operating under the assumption that I have clearance issues at all four points.

Next time I get it put back together I'm gonna break out the dial and get some real numbers with which to work.

 

[crazypj]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Are we having fun yet?

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

This stopped being fun about two months ago.

I just keep telling myself how good it'll be once I have a finished product. Not only will I (hopefully) have something worthy of the time and effort invested, but I'll actually be done and I won't have to do all of this again until I get the itch to make more changes.

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Seat upholstery is done. So there's one less thing to worry about.

Additionally, after two more assemble/disassemble cycles, my pistons and valves are getting along without getting too chummy. I'm now able to rotate the crank (with cam in place) and no contact occurs.

Next I'm going to actually measure the clearance to see if it's acceptable or if further modifications need to be made.

Maybe I'll actually have this thing assembled for real in the next week or two? Who knows...

Also, I found a bit of time to clean up the intake ports a bit. They had some pretty rough casting marks that the Dremel made short work of. I couldn't get all the way into the port with the attachments I currently have, but I ground out what I could. I followed it up with some 120 grit paper and the sanding is still in progress. You can see the new bronze valve guides, too. Maybe just my imagination, but they seem a bit shorter?

Left intake port

Left intake port

Right intake port

Right intake port

 

[JakubAnton]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

nice seat bro! that upholstery looks choice... 8)

 

[sxecafe]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Seat looks reeeeeeeeeallly awesome. I am working a diamond stich myself.

 

[teazer]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Ports don't look bad, but who cut the valve seats? The seat appears to be pitted and stained, but it may just be dust from working on the ports. I'd get those seats cut at 45 degrees again and have them use a larger diameter cutter on the 30 degree angle to blend the two cuts into one radius.

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

teaz,

I'll get some better pics of the seats so you can see the angles. The head isn't quite done at the machinist's yet as it's only with me for some test fitting. It's still going back to have the the base lapped. Also... the core is off tilt by about .005" and so that's getting corrected as well.

As for the "pitting", it's actually a bit of clay residue left from clearance checking and I hadn't wiped it off yet. The seats are as smooth as a baby's behind.

 

[crazypj]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

You should get the $40.00 long shank die grinder from Harbor Freight, a router speed controller and some 1/4" long shank carbide burrs from Enco.
The exhaust port is nasty on all 360's, usually a massive step between valve seat and radius of port where it was machined
Not really any need to open the pipe side, clean up top but don't touch floor
I put pics of combustion chamber/ports on page 1 of 360 build/blog

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Looks good. It seems you ended up deshrouding as well? Even around the exhaust valve?

 

[crazypj]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Nope, I just used some 120 grit on combustion chamber to smooth things out a bit.
total de-shrouding of valves looses a lot of torque at lower rpm plus lowers compression so I don't do it on 360 or XS650 (even though a lot of people recommend it on XS)
I think that head is skimmed 0.020"

 

[Sonreir]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

Thanks, pj. I was wondering about the compression bit, especially as I've been cutting on my pistons a little already.

 

[Dymass]

Re: '77 CJ360T (Café SOS) - Assemble, Measure, Modify, Repeat

That, mister, is the most beautifull seat ive ever saw in my life!