Topic: Top End job tips? flat sided cam chain? bent valves=damaged head?

[geoluv]

I'm about to do the top end on my cb550 and I have a few questions:

1. Im gunna bore it out to 605cc with the cruisinimage 61.5mm piston kit, port it, and throw a 650 cam in it.  I'm leaving the stock airbox and exhaust on it.  do i need to re-jet it?

2.What model aftermarket HD flat sided cam chain is compatible with this bike?   internet says 92-'95 750 gsxr.   I want whatever the "hd" aftermarket version of that chain is with its appropriate master link.

3. I bought this spare top end off eBay to do all these mods to so I could keep riding:
http://www.ebay.com/itm/162526334712
Despite the seller saying it all came off a running bike this stuff is all messed up.  3 of the exhaust valves were bent, I think 2 of the intake valves were bent.  They obviously didn't come off the same motor; the cylinders had a noticeable of wear from a loose cam chain and the head didn't.  My question about the bent valves is what do I have to do to check the head and the guides for damage?  I want to make sure I can use this head before I port it.    Also about how much $$$ is a 1mm intake valve enlargement?

Also any general tips for doing the top end job?

right now you can get nippon NOS cb550 intake valves on eBay for $6/e from a guy in Thailand http://www.ebay.com/itm/262541114022 and there is a person online selling the exhaust valves for $20 each.  If anyone is looking for 550 valves I suggest hitting up those sellers now because they have the goods for cheap ATM. 

[BomberMann650]

You wanna talk to the guys at cycle xchange 

[HondaMan]

With the 650 cam, a stock cam chain will be fine. Find an OEM NOS one for best results. The jetting: it depends more on the changes to intakes than on bore size: the jets still feed the same amount of gas to the passing-by air as they did when stock, so the ratio doesn't change. Most of the 550 engines were too rich to begin with (part of why they had #7 sparkplugs to keep 'em clean), so you're already rich at first.

[geoluv]

^I'm not going to change intake other than porting it and port matching it for optimal flow.  I'm just curious what the cost is for the valve job for the future maybe. 

Also I know the 550 is not hard on it's cam chain but I want a flat sided cam chain because it will be that much gentler on the expensive NOS cam chain tensioner I'm putting in it and i figure it will require less maintenance and stretch less being a cam chain thats 20 years newer.   I'm aware that "old school" chains of all varieties can be stronger than their lighter modern counterparts.  You're saying the NOS honda chain stretches less than the DID cam chain?  I thought the Honda chain was made by DID?

As far as jetting I'm mostly concerned about clip position because at some point in the future I'm going to do 4 into 1 exhaust with a muffler and pod filters. 

Here's a question; what assembly grease should I use?  for the stud threads etc?  The "Genuine Honda Moly Assembly Paste"?

here's another question; are HD engine studs worth it? 

[754]

If your valves are bent, better check prices for guides..

[calj737]

I'm about to do the top end on my cb550 and I have a few questions:

1. Im gunna bore it out to 605cc with the cruisinimage 61.5mm piston kit, port it, and throw a 650 cam in it.  I'm leaving the stock airbox and exhaust on it.  do i need to re-jet it? Probably. You might in fact need to lower your jets as you are about to lower the compression in your cylinders from stock and change the vacuum pressure.

2.What model aftermarket HD flat sided cam chain is compatible with this bike?   internet says 92-'95 750 gsxr.   I want whatever the "hd" aftermarket version of that chain is with its appropriate master link.

3. ...3 of the exhaust valves were bent, I think 2 of the intake valves were bent. The cost of the "prices" is not the expense, the cost of a machine shop pressing out the old ones, installing the new ones, and re-cutting your seats is. Changing the guides requires re-cutting the seats.
My question about the bent valves is what do I have to do to check the head and the guides for damage?  I want to make sure I can use this head before I port it. IF the valves were bent, the guides WILL need to be changed 99%

Also about how much $$$ is a 1mm intake valve enlargement? Very recently, I had a shop install 4 new exhaust guides, re-cut the seats, replace 4 new +1mm intakes, port, mill and replace 1 exhaust valve. Total invoice was right around $900. Thats 5 new valves, 4 new guides, labor, for $900

Also any general tips for doing the top end job? Take it to a competent machine shop.

[calj737]

Uh, by the way, if you opt for +1mm intakes, you may very well need to mill reliefs in the pistons. The ONLY way to know for sure is to assemble the engine, use machinist clay, and measure the piston-valve clearance with the cam rotating. If you do not undertake this step, anything and everything else you do is a complete waste of time.

[geoluv]

^ I'm not going to enlarge my intake valves I'm just curious how much that one job by itself is. 

I though boring increased compression ratio usually, not decrease.  I haven't calculated the CR ye even though I could because I have all the parts in front of me.  i was trying to find someone online who had already calculated it for this kit.  Should I deck it to get a high C/R?  I have access to 93 octane no ethanol, I'm going to have everything decked anyway. 

Stock its about 9.0:1, I thought this piston kit put it to 10ish:1 although I can't seem to find where I read that.   that's an increase in compression, not decrease, correct? 

I'm in the process of finding a machine shop that I can go to and watch while they bore it (i don't trust anyone after reading the machine shop horror stories on this site and others, I want to be there in person to make sure they clamp/brace it correctly before they bore it because these jugs are soft).  Any recommendations on a machine shop within driving distance of NYC?  I'll send it off if I have to but I don't want to. 

Is it 100% impossible to install guides at home?  Im pretty good at "seating" metal on metal things like this, like press fit bearings etc that need to be perfectly straight.  I'm a professional bicycle mechanic so I have experience in this area.  I have various small bearing pressing tools I could use.   Can I do it myself or am I going to mess something up?

$900 aint bad for a race head considering that they put $300+ of parts alone back in it plus all the work.

[Lostboy Steve]

^ I'm not going to enlarge my intake valves I'm just curious how much that one job by itself is. 

I though boring increased compression ratio usually, not decrease.  I haven't calculated the CR ye even though I could because I have all the parts in front of me.  i was trying to find someone online who had already calculated it for this kit.  Should I deck it to get a high C/R?  I have access to 93 octane no ethanol, I'm going to have everything decked anyway. 

Stock its about 9.0:1, I thought this piston kit put it to 10ish:1 although I can't seem to find where I read that.   that's an increase in compression, not decrease, correct? 

I'm in the process of finding a machine shop that I can go to and watch while they bore it (i don't trust anyone after reading the machine shop horror stories on this site and others, I want to be there in person to make sure they clamp/brace it correctly before they bore it because these jugs are soft).  Any recommendations on a machine shop within driving distance of NYC?  I'll send it off if I have to but I don't want to. 

That all depends on the design of the pistons.

Eddies valve grinding did my 550 top end. They are a good machine shop.


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[calj737]

Well, you've posted quite a few questions, so I'll give you my opinion/perspective on them as best I can:

C/R - depending upon which pistons you choose, they will either lower or raise your compression ratio due to their dome design. Many of the CI pistons are actually a lower CR than the stock pistons in your motor.

Decking to raise CR - That's an option, but that requires a fair bit of knowledge and proof-testing to confirm piston-valve clearances afterwards. And the pistons need to be viable if relief cuts are required.

Shadowing a machinist - If you choose a shop, leave them alone. If you believe you can stand over their shoulder and tell them how to do their job, I imagine they'd tell you to GFY and toss you and your parts out of their shop. Do you know how to machine a block? If not, stay out of their way and let them do their job.  Any competent automotive machine shop can bore a cylinder accurately given the correct information (i.e. piston-cylinder clearance, piston diameter, etc). Hand them your pistons, rings and cylinders. Provide them the details from the manufacturer about the clearances. Disregard "internet advice" about how much to use, or why to use it. You're not building a race motor as evidenced by your product choices.

DIY Machine work - Nope, nothing is impossible. The only real question is: can you do it? Do you have the equipment, knowledge, experience and competence to do it. If yes, then knock yourself out. If no, then pay up, Sucker (as the saying goes).

$900 - That's not a "race head". That's a rebuilt head. A "race spec" head would be about 2-3x times that amount of money. It would include new springs, retainers, all new guides, all new valves, extensive porting, machining, and flow bench testing.

Slapping larger pistons and a 650 cam into a 550 motor does not a "race motor" make. It will improve it's performance, but not sufficiently to equal the performance of any modern single cylinder 300cc japanese street bike. And not even within the same realm as a modern 500-600cc bike. So just be sure of your expectations. You may end up with mid-40s BHP after your efforts. Call it an additional 10BHP objectively. That's nothing to write home about, but also will make a vintage bike fun to ride. Just so you're aware...

[754]

Good luck finding a shop that lets you watch.
Your best bet, find one that specializes in bike or powersport work, and is known for it.

The crucial part of changing guides is getting all the carbon off.( I prefer to drill the tops off, then drive guide into the port .. Cleaner hole that way.)
 The guide removal tool is a stepped drift, easy to make, on a lathe.. Guides may need reaming.
The valves get damaged a lot, by improper head installation... Follow the manual.

Those piston kits are cheap, but for 750 the compression is low, not my choice for a hot cam.

[geoluv]

I don't have any delusions of this bike being "fast" in the modern sense, I'm well aware it's a dog I ride it daily.  But from what Iv'e read porting the head on a 550 really opens them up.  I know these pistons aren't going to do nearly as much to speed up the bike as porting it.  I just figured if I already have the engine half apart why not do the big bore?  If I can't get a decent price for the 3mm overbore at a shop I might just hold off on that for now and do all the other work.

The 650 cam in a 550 is more comparable to a "mild street cam" than a race or hot cam, so has been said.  Other people are running these pistons with a 650 cam ported head and stock valve set up so I should be fine although all the reports of these parts working together are along the lines of "yeh i installed that stuff it works i love it' but they never really get specific on cam lift or valve clearance or compression issues. 

Do you think there won't be enough compression for the 650 cam?  Should I choose between big bore and 650 cam?

[geoluv]

I'm just tired of loosing 0-60 races on the Williamsburg Bridge to stock 5 series beemers!!!!!

I feel the porting might fix this

[calj737]

I'm just tired of loosing 0-60 races on the Williamsburg Bridge to stock 5 series beemers!!!!!

I feel the porting might fix this

Not unless they spot you a 5 second head start.

[geoluv]

In all honesty I only loose if I miss a shift....     or I don't jump the light by half a second already winding up to 9,000rpm

[Lostboy Steve]

I'm just tired of loosing 0-60 races on the Williamsburg Bridge to stock 5 series beemers!!!!!

I feel the porting might fix this

Flagged for being jwilde!



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[calj737]

I'm just tired of loosing 0-60 races on the Williamsburg Bridge to stock 5 series beemers!!!!!

I feel the porting might fix this

Flagged for being jwilde!

And Scooterhead. 

[DaveBarbier]

I'm just tired of loosing 0-60 races on the Williamsburg Bridge to stock 5 series beemers!!!!!

I feel the porting might fix this

Flagged for being jwilde!



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Can't be, he hasn't mentioned his super model wife, half dozen perfectly restored classic cars that he did (although he asks how to change a tire) or the fact that cops let him run red lights because he's "known" in NYC.

[DaveBarbier]

Geoluv, for machine work that kind of close, you could PM MRiek. He's up in Ashland, MA. I'm in CT fairfield county and drove up there to him. Probably close to 3 hours for you. But he does great work. He did my 650-674 motor and ported head. Many members have used him and only have good things to say.


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[geoluv]

I also own a 2005 Vespa et4 150cc so I'm a scooter head in the most literal sense:)   The Vespa is pretty much just as fast up to 35mph off the line. 

No vintage cars, no where to store them that isn't hours away.  Last fall I was "this close" to driving out to long Island and buying a 1978 911SC hard top in very good condition for $13k, that's like half price.  I would have done low pressure turbo and wide body kit; a faux turbo.  I would have ended up spending 25k total for a vintage turbo Porsche that would be worth almost double that and look like a real $150,000 turbo model.  I didn't buy it because my dad has cancer and it seemed like a frivolous use of money at the time.  I should have bought it anyway.  My dad and I could have finished it by now and be enjoying it.  It haunts my dreams. 

I know how to change a tire with levers but HOLY HELL is it a PITA on moto tires.  There is a tire shop 200ft from my house that will change a moto tire for $10 total.  They rule.  I give them $15 and a sixer every time they change a tire for me. 

[HondaMan]

^I'm not going to change intake other than porting it and port matching it for optimal flow.  I'm just curious what the cost is for the valve job for the future maybe. 

Also I know the 550 is not hard on it's cam chain but I want a flat sided cam chain because it will be that much gentler on the expensive NOS cam chain tensioner I'm putting in it and i figure it will require less maintenance and stretch less being a cam chain thats 20 years newer.   I'm aware that "old school" chains of all varieties can be stronger than their lighter modern counterparts.  You're saying the NOS honda chain stretches less than the DID cam chain?  I thought the Honda chain was made by DID?

As far as jetting I'm mostly concerned about clip position because at some point in the future I'm going to do 4 into 1 exhaust with a muffler and pod filters. 

Here's a question; what assembly grease should I use?  for the stud threads etc?  The "Genuine Honda Moly Assembly Paste"?

here's another question; are HD engine studs worth it? 

Honda's OEM chains were made by RK of Japan, mostly. DID is not a top-quality chain, more of a 'consumer grade' sort of chain, inexpensive but usually effective with adequate maintenance. It the realm of 'riveted-together' masterlink cam chains, in my experience, these are the ones where the link let go, most often. Back in the days of the Twins with the masterlink'd cam chains (CB160/72/77 bikes), many of those were DID, with a clipped-on type master link.

Use the HD engine studs if you're going big-bore, or if installing high-dome type pistons with compression higher than about 10:1. Otherwise they are not really needed.

The jetting: the pipes do not affect this need much, the piston bore even less. If you realize that the larger bore causes the airflow thru the carb to be slightly higher at a given RPM than it was before, you'll soon realize this implies there will be no significant change in flow over the jets in the venturi: this results in the same mixture. This is a long-way-around to say, "No, bore change does not imply carb rejetting changes". Higher compression might, if going past 10:1 CR, to reduce ping: usually simply using higher octane does this better, and fouls fewer plugs in the process.