Topic: Bored out CB500/4 engine rebuild - need a ring source!!

[rustbucket]

Hey all,

I'm in the process of rebuilding a '72 500/4 engine I picked up cheap. It was bored out to a claimed 562cc back in the day, and looks to have a reground cam and aftermarket valve springs as well. It's turning out that it didn't really need the rebuild, but it had been sitting for 10 years or so, so I wanted to see what I was working with. I've got it apart, but I have a few questions on what I should check while it's in a million pieces, and where to source some parts.

1.) I have a good set of calipers, so I've checked everything in the manual that I can with those, but I don't have a dial gauge or a bore gauge. I'm wondering if I should pack it all up and bring it to a shop that can check the things that require those tools, if I should purchase the tools, or what... Off the top of my head, it's things like the valve/camshaft/crankshaft runout, and checking the round and size of the bearing seats for the crank. Advice?

2.) I'd like to get away with just a hone if possible. Is there a way to check if that's practical at home? Here's a pic of the cylinders - I'm happy to get more shots if it would help.

The complete album with all I pics I've taken is here: http://s4.photobucket.com/albums/y144/AnotherSoul4Sale/Engine%20Teardown/
A lot of those pics are for my reference, though...



A few more pics:
Pistons:


Piston Size:


Crank: I was told the engine was blueprinted, which I thought meant the crank was balanced... Doesn't look modified to me...


Cam chain & primary chain:

[rustbucket]

I'm also looking for a source for some parts. I bought a gasket set off eBay, which I'm hoping will take care of most of my needs (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=380269281776&viewitem=&sspagename=STRK:MEWNX:IT#ht_500wt_1182)

3.)I'm assuming I'll need a different headgasket for the 59mm pistons.

4.)Piston ring side clearances are all very good (less than .038mm, my thinnest feeler gauge), except the top ring on cylinder #4, which is .120. That's within the published service limit of .180; should I look to replace this ring?

5.) My clutch discs are 3.17 - 3.29 in thickness. The factory lists the standard as 2.7mm. Are there aftermarket discs that are thicker? Is this likely to cause a problem? Clutch disks aren't cheap, so I'd like to use these if I can.

6.) Does anyone make heavy duty head studs for a 550? I'm gonna need to get new ones, so I figured I'd get better ones if they're out there.

7.) Primary chain - should it be replaced? How about the cam chain? How about the cam chain tensioner & guide?

Finally, any recommendations for additional parts I should source, or things I should look out for?

Thanks for any help guys! I'm really excited to get this back together.

[JBMorse]

I have a link to Dynoman for studs, but I'm not sure that they're heavy duty or not. 
http://dynoman.net/engine/studs.html
Perhaps someone else knows.  As far as your cam chain tensioner, I am not going to replace mine as it looks to be in very good shape and functions properly.  I believe there is a spec for the cam chain and primary chain you could check for though.  I've heard a light honing can be just fine, but I suppose you'd want to measure the cylinders.  The tools are expensive, maybe you could borrow them?  Or if you're planning to do this a few times, just buy them.  That's what I am finding myself doing with my stuff.
David Silver Spares should have the primary and cam chains, and tensioners, if you do decide to replace them.
Good luck with your build!  Hopefully you'll get some others to chime in, there's a lot of knowledge here.  I'm new to this whole engine rebuilding business.

[Lavis500]

Im at the same point in the rebuild of my 500.  I'd say since you're in there it would be a good idea to replace the primary.  If you dont know how old it is or how many miles it has on it, then you also don't know when it's going to stretch and begin to eat through your cases.  That would make me toss and turn at night.  You could replace your cam chain if you want, though I dont think that one stretches as much as the primary.  Don't quote me on that, though.  I believe I've heard it preached that if you replace one ring then you should replace them all.  I could be wrong, though.  As for your cam chain tensioner, check for excessive wear and condition of the rubber.  If it feels like a rock then definitely replace it!  However, if it is still supple and there aren't massive grooves, then you SHOULD be fine.

Stupid question:  How did you pull your generator?  I tried to pull mine for a while and I couldn't get it to budge at all.

Good luck on the headgasket.  Dunno where you'll find that one.

[rustbucket]

Lavis -

I've heard the same about the rings. I'm a bit concerned about the cost of them, and where to source the darn things. I'm pretty broke, but I do want to do it right...

For the generator, you just need an M16 X 1.5 bolt. I got mine from Bolt Depot, since they're not too far from me (http://www.boltdepot.com/product.aspx?cc=20&cs=77&cm=21&cd=1385). Unfortunately it's an uncommon size. I just threaded it in and hit it with an impact wrench.

[JBMorse]

Lavis -

I've heard the same about the rings. I'm a bit concerned about the cost of them, and where to source the darn things. I'm pretty broke, but I do want to do it right...

For the generator, you just need an M16 X 1.5 bolt. I got mine from Bolt Depot, since they're not too far from me (http://www.boltdepot.com/product.aspx?cc=20&cs=77&cm=21&cd=1385). Unfortunately it's an uncommon size. I just threaded it in and hit it with an impact wrench.

You can also buy a puller, which is nothing more than a bolt in that size, with a bigger hex head:

http://www.z1enterprises.com/detail.aspx?ID=2176
They list it as a flywheel puller.  I bought mine at my local dealer, they had one in stock.

[Lavis500]

Not to be simultaneously dense AND a thread jacker, but how does this work?  You just keep screwing the bolt in and it pushes the generator off?  I thought it would be considered a flywheel puller, but I had tried the puller found at my local automotive shop...  COMPLETELY different.  Ah well, now I know what works, and knowing is half the battle!  

Since your pistons are bigger, I'm not 100% on where you could source the proper rings.  I think I paid about $80 for all 4 of my sets of STD rings and 8 new wrist pin clips.

[rustbucket]

No worries man. The hole in the center of the rotor is threaded for a larger bolt than the one that normally holds it on. so, when you thread in the larger bolt, it bottoms on the crank, and pushes off the rotor.

[dave500]

hone and re ring it,be sure to get all the carbon from the ring grooves out,you can snap an old ring and fashion a scrapping tool from it.

[fantino]

Easy way to check primary chain stretch is to hold it between two fingers, horizontally on its side and see how much side to side flex the chain allows. A new chain is quite rigid and will appear straight even when held this way. I had a chain that was worn and sawing its way through the crankcases, it probably had ~20 degrees of flex. You can also just see if you have marks near the main oil gallery where the chain runs. If you're cutting through, definitely time to replace.

[rustbucket]

Thanks for the insight fantino - my primary chain looks like it's in good shape. The cam chain tensioner seems like it's seen better days, so I'll replace that.

I just read your build thread - looks like you're a ways ahead of me!

Still need a source for a headgasket and rings, if anyone can help.

[rustbucket]

MReick kindly responded to a PM suggesting I call Total Seal for rings. I called 'em up, but they weren't able to offer anything. 

Per their reccomendation, I also contacted Grant & Wiseco, who also don't have the rings available... I'm beginning to think I'm screwed here. The cylinder bore is 59.4mm, top & middle rings are 1.5mm and the oil ring is 2.5mm, for reference.

I did a little searching for other pistons that might match that bore, but no luck so far.

I also have a '76 550 parts motor that I haven't torn down yet. Perhaps I should just give up and build that engine with the cam, valve springs and such from this one... 

Or can I get away without doing new rings? I haven't removed them from the pistons yet, FWIW.

Thanks!

[Lavis500]

Grant couldn't help you?  It says on their website that they can make custom rings from just samples and drawings.  Perhaps another call to a different department or something?

Just my $0.02

[bryanj]

When a 500 is that far appart ALLWAYS fit a NEW primary chain

59mm is 2nd oversize 550 pistons so try for those rings

[rustbucket]

Yeah I spoke with Grant about custom rings - they're prohibitively expensive. 

I'll check out the 550 rings - thanks man!!