Author Topic: Marissa's 1972 CB500  (Read 92825 times)

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Offline DaveBarbier

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Re: Marissa's 1972 CB500
« Reply #125 on: November 17, 2017, 06:20:59 AM »
Dave - you can hear the head and drive out the guide, but with new guides you must recut the seats anyway. Off to the machine shop you go...
Ah ok, that makes sense.

Offline HondaMan

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Re: Marissa's 1972 CB500
« Reply #126 on: November 19, 2017, 11:18:09 AM »
Valve lapping, especially with a new valve, is straightforward and simple. Most of the CB500/550 heads live a LONG time with their guides because the angles are straighter and the side loads lower than on the 750 engine: it is rare that I have to replace the guides in these heads. The exhaust side wears out first, mostly due to ethanol fuels today.

Maybe check with PartsNmore for valves, less expense than OEM.
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Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #127 on: November 26, 2017, 03:58:26 PM »
I got started on relapping the valves, so far it seems really straightforward, but I have a couple of things I want to run by those with experience;

On cylinder 4, the intake valve looks like its wearing along the area above the seat (the black "polished" ring is what I'm referring to), is this something I should be concerned about? On all the other valves, that section is more like a thin stripe than anything else. Looking at them from the side, the valve on cylinder 4 did seem more voluminous above the seat, and it does have the same stamping on the face of the valve as all the others. Is this like a flaw with OEM valves? Am I overthinking this? Should I get a new valve for this one?



Also, does anyone here use bounce tests to verify the concavity of the valves? I want to bounce test them but I don't know if there's a special technique to do so, whenever I insert the valves into the guides there's not enough slack to allow them to fall into place, giving them the inertia to bounce if they were right. If no one here ever bounce tests the heads, then I guess I will trust a leak down test to tell me. I know there are some people though that don't like to go by that method alone. 

I currently have the Vesrah valve seals installed, does anyone think it's a good idea to change to the Viton seals while I'm in here? These seals are new and were installed by the machine shop. They look fine but if it's better to upgrade to Viton with factory spec internals then I guess I will, it is pretty cheap to do so.



I'm using CTA lapping compound, which comes with a "Coarse compound" and "Fine compound". It seems to do the trick well. I'm also using Permatex "Ultra Slick" engine assembly lubricant to lubricate the valve stems while I'm lapping the seats.

1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline HondaMan

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Re: Marissa's 1972 CB500
« Reply #128 on: November 26, 2017, 07:19:27 PM »
The 'bounce test' only works on valves with more than 0.0030" stem-to-guide clearance, which is too much for this engine. This one uses 0.0008" to 0.0012" intake side, 0.0014"-0.0022" (new numbers) clearance. If yours has bronze guides, use the tighter numbers.

The valve 'margin', which is the unground portion outside of the newly-ground face & seat, should not be less than 0.25mm. When new, this space is about 1.2mm on the 500/550 valves. If this goes to 0, then either the valve must be replaced (if it was previously ground) or the seat recut, in which case all 4 should be recut together. The OEM valve seats, according to Honda's manuals, were 3- angle seats: in the 500/550 engine this was never true. Most of them come with a 2-angle seat, the inner 60-degree one being sort of molded into the valve seat itself, not cut in. Making new 3-angle seats with 1.25-1.50mm 45-degree seat faces will improve breathing and cooling, if you're going for more HP.
;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
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Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

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Offline Davez134

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Re: Marissa's 1972 CB500
« Reply #129 on: November 26, 2017, 09:14:07 PM »
Just read through most of the thread. Good on you for trying to do things the right way. I know it can be disheartening every time you open something else up and find something wrong. The payoff of a reliable, good running bike in the end is worth the effort!

Offline DaveBarbier

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Re: Marissa's 1972 CB500
« Reply #130 on: November 29, 2017, 04:38:07 AM »
I may have missed it, but are you replacing the guide(s) and getting a valve job? Or maybe just trying to see how lapping goes?

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #131 on: January 04, 2018, 12:10:11 PM »
I may have missed it, but are you replacing the guide(s) and getting a valve job? Or maybe just trying to see how lapping goes?

Back from the depths of winter with an update.

Originally Dave, it was just seeing how lapping was going to go, and to replace one valve guide that was cracked. I had to drill out the old guide, but it got to a point where I was off a drill bit size by just a hair, so I couldn't remove the rest of the guide, and I certainly did not want to go over a size or else the head wouldn't be useable. I didn't know what to do next and I was getting hesitant to go further with that, which is when I stumbled upon a used head on eBay for $50. It had perfect fins and looked to be completely solid, so I went for it and bought it.

Turned out to be in pretty good shape. A lot more dirtier on the outside than mine was, but cosmetics are easily fixable. The inside was fairly decent, and turns out all of the studs were replaced at least in the past couple of years, so they almost look new. All threads are in great shape, no damage. So I went ahead and started to disassemble this head and look for issues. Since the first time my original top end was rebuilt by a shop, I have no internal comparison to make, but I could tell this head ran with ethanol fuel for a while. The exhaust valves were pretty ugly and took a while to clean, really caked stuff. I wish I took more pictures of the outside because it was pretty ugly, but here's a couple from the job. All valves, guides, and even seals seemed to be decent, so it was a really straightforward cleaning and lapping job. I bought Viton seals for it as well and put those on, and sprayed the head with a coat of VHT's Flat Aluminum Header paint.



So clean and pretty!

A glimpse of the work during a quick 400 grit sanding of the mating surface. It wasn't uneven really, but there was a tad bit of pitting from the corrosion you can see in the photo. After a nice cross cutting sand, the corrosion was still visible, but you can't feel it in the surface, even with a fingernail. So I didn't worry much, just not the prettiest surface, which is A ok in my book.
 

An old seal. I eventually cleaned out as much as possible on this head after soaking it in a 50/50 solution of Purple Power and water for a couple of days, since it's been so cold I was allowed to work inside the kitchen a couple of nights, so I grabbed some nail polish remover while I was in the house and started to clean up any hard to reach areas with cotton swabs. And yes, the alcohol content in nail polish remover does a really nice job of cleaning. I highly recommend it since it also does not have as strong of fumes as some of the typical solvents and cleaners.



Coming together. You can see I wasn't able to get the face of the exhaust valves to look completely smooth and new, but that seems to be of no issue. You can also see the array of tools and materials used, as well as the teddy bear sheet (which adds like 10 extra horsepower and a blessing to this build, of course.)

Very dirty exhaust port.

Very dirty intake valve. I wish I had remembered to take a photo of all 4 at once to compare to everyone the appearance of them. I could tell there was AFR issues in some valves, I think it was cylinders 2 & 3 that looked like they were running richer, which I believe could make sense if they were running a different intake style as 1 & 4 always get more air from the physics behind them, and likely the bike was tuned to the AFR of 1 & 4. Just a speculation I guess.

The cleanest valve!

Intake before:

After:

Nice and clean seat:

Nothing looks brand spanking new internally, nor am I using new oversized cool valve train components, but it was still exciting to see it come together

After cleaning up the valves and putting the new seals on, I went to reassemble and I noticed some of the retainers were more worn than others. I'm thinking at some point valve lash was incorrectly measured and maybe a couple of times it was ran a tad low on oil or there was some other oil issue. So I went ahead and swapped out the worn ones with good ones from my original head. It pays to have an extra after all.

Borrowed a leak down tester from work, and after working to about 4am, it was going to be ready to test the next morning. Quite frankly I was so tired that I didn't even realize how much the results we saw in that moment were going to matter. I had no idea how this was going to go.

1 & 2 were absolutely perfect. 3 was at about 20%, but that one is likely due to the fact that I kept spinning it over TDC by 10 degrees, every single time(it let air out through the exhaust port as well which is why I'm thinking there is no issue with the cylinder, but mainly user error  :) ). 4 was a bit sad, because it showed results that need attention:

The good news is, absolutely none of this was leaking from the head. Which means that I finally solved the top end issue, once and for all. This was monumental for me!

The bad news is, this was crankcase pressure, so likely, I cracked a ring when placing the cylinder jug back on. I'm not really surprised since I had to do that twice, I probably cracked the ring the second time on and considering I used my hands to compress each ring, one at a time, and slowly lower the jug onto it going from side to side. I essentially was asking for a ring to fail, haha. So all in all, I am not upset. I actually was able to find a leak as well from the kickstarter area, which I referenced a few months ago when the kickstarter spring (at some unknown point in its life) kicked off the perch by the clutch basket and squeezed itself between the cover and the gasket. Now I know that it needs a little bit of RTV on that side and it should be good to go after. Quite frankly I'm happy that issue showed itself now and not when the bike was on the road and spilling oil every where!

I also used the rubber band trick as prevention when installing the valve cover on, and although I thought it would do little to nothing, it truly helped a lot more than expected and made installation a breeze. It only takes about a minute to put the rubber bands on as well so it's really not out of the way.

So, disassembly will be needed one more time, I'm going to wait until I can inspect the rings on 4 to order any parts or ring compressors. In the meantime, I did order an EK cam chain and master link, so I will need to break the old chain, break the new chain, remove a link, install chain with new master link and link tool. I know endless is always preferred but I didn't want to go down to the crankshaft and I think the advantage over master link will be negligible for a stock rebuild. All thoughts welcome on this however, if it's unanimous that this isn't the best chain brand or option, then I can still return it and swap it!

Right now it's just a waiting game, it's been single digits and diving into negatives for the past couple of days and weekends which is really upsetting since the next semester starts in two weeks. I really wanted to make some progress between now and then, but it's just too cold and I don't have a heater in the garage. I also know I make stupid mistakes when it's that cold, so I think it was a perfect time for an update.

I also made an electrical box about a month ago. It's pretty big because initially I was trying to fit a stock sized battery into it, but I've read that I'm going to need a lithium battery once it's running because of the extra CCA the electronic ignition is going to want along with a higher AMP per hour. This is fine because I had my eyes on a small Antigravity 8 cell anyways, so once I'm done with everything else I can modify the box further since the Antigravity battery reduces battery size pretty much in half. I was thinking about trimming an inch off the height and then creating a lip around the top of the box to give it a more refined finish look and feel, and hopefully save my fingers from getting cut on the rough edges haha. At that point everything will look so much more clean and tucked, even though it's still using original harness. After I get a season of riding time into this thing I would love to convert to a motogadget unit and create a new harness from scratch.





Thank you all for your support and telling me about similar instances many of you have had. I know I don't reply to most comments on here (I feel like it really lengthens posts an excessive amount, and I'm trying to keep it straightforward for anyone who reads this for any insight for whatever reason) but I read every single one and I try to respond to most of them in mass updates like this. Or, I hope that my updates help answer the previous question stated without having to reiterate it.
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline calj737

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Re: Marissa's 1972 CB500
« Reply #132 on: January 04, 2018, 01:14:30 PM »
You don’t “need” a lithium battery for any reason other than space requirements. A quality AGM has all the CCA and Am/Hr resources you need.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline MauiK3

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Re: Marissa's 1972 CB500
« Reply #133 on: January 04, 2018, 01:43:47 PM »
In addition I'll say a battery tender is a must.
Looks like a great project.
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10/72 build Z1 Kawasaki

Offline HondaMan

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Re: Marissa's 1972 CB500
« Reply #134 on: January 07, 2018, 08:48:36 AM »
The color difference on the valves (and chambers) when oriented as 1-4 and 2-3 usually comes from the ignition timing having been off a little bit on one of them. ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

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Offline PeWe

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Re: Marissa's 1972 CB500
« Reply #135 on: January 07, 2018, 10:15:20 AM »
My bike has no problem with a cheap GEL battery.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #136 on: January 14, 2018, 07:04:58 PM »
I was able to tear the engine down this Friday, a random heat wave of 50 degrees came through!

Expecting to see a cracked ring, I pulled the jug off carefully, and surprisingly, no damage to any rings.

It looks like this may have been a potential indexing issue, as everything is in good spec and I didn't set the gaps 120 from another. I took multiple measurements, some of which I have photos for.









Here are some of the measurements I took. I'd love to get a second opinion on these measurements, I just have a hard time believing that improper ring indexing could really cut compressions in half.

Cylinder wear:
2.185 in.

Cylinder wear limit: 2.207 in. Therefore in spec.

Piston diameter: 2.2001 in.

Piston diameter limit: 2.199 in. Therefore in spec.

Piston ring end gap: (Top Ring) .015 in. (Second Ring) .010 in.

Piston ring end gap limit: .030 in. Therefore in spec. (Second Ring limit): .020 in. Therefore in spec.

Piston Ring Side Clearance: (Top Ring) .12mm (Second Ring) .10mm

Piston Ring Side Clearance Limit: (Top Ring) .18mm (Second Ring) .15mm

Keep in mind, I know the air is passing through the rings because the leak down test revealed pressure being released from the oil breather (which means crankcase pressure) and I had another leak all the way at the side of the clutch basket cover.

I'm hesitant to put everything back together on an assumption that it's ring orientation. Is there anything else I'm not thinking of that could lead to this issue? Either way, I have to order a new base gasket and head gasket, so nothing is going together until next weekend, at the earliest.

Thanks in advance!



1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

Instagram- marissasimos

Offline HondaMan

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Re: Marissa's 1972 CB500
« Reply #137 on: January 14, 2018, 08:03:53 PM »
There is both a minimum and a maximum ring-end gap: max for this bike is 0.026" for the top 2 rings. I'm a little curious: did you get 0.030" top gap in a new set of rings, or are these used rings? Usually new rings come at 0 or the minimum gaps, requiring fitting during installation. Most of the 500/550 pistons I've done fall into the 0.008"-0.010" range, larger being for the overbores like 600cc kits: on those the top rings can go out to 0.012" gap.

If the top ring gap is more than 0.020" then there will be quite a bit of compression leakage, at least until possibly some carbon fills it in somewhat. That may take up to 1000 miles with today's super-clean-burn gasolines, though.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #138 on: January 14, 2018, 09:23:40 PM »
There is both a minimum and a maximum ring-end gap: max for this bike is 0.026" for the top 2 rings. I'm a little curious: did you get 0.030" top gap in a new set of rings, or are these used rings? Usually new rings come at 0 or the minimum gaps, requiring fitting during installation. Most of the 500/550 pistons I've done fall into the 0.008"-0.010" range, larger being for the overbores like 600cc kits: on those the top rings can go out to 0.012" gap.

If the top ring gap is more than 0.020" then there will be quite a bit of compression leakage, at least until possibly some carbon fills it in somewhat. That may take up to 1000 miles with today's super-clean-burn gasolines, though.

Hey HondaMan,

I should clarify, the last measurements (where I state they are in spec) are the maximum wear limits provided by the Clymer Manual. Here in the book it says the top ring limit is .030 in. and the second ring is .020 in.



The rings installed are new rings, measured at .015 in. for the top, and .010 in. for the second ring. Those were measured by placing them in the cylinder jug and measuring with a feeler gauge.
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

Instagram- marissasimos

Offline calj737

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Re: Marissa's 1972 CB500
« Reply #139 on: January 15, 2018, 03:53:52 AM »
Those were measured by placing them in the cylinder jug and measuring with a feeler gauge.
If I may ask, Marissa, where within the cylinder? Only at the top edge, or midway down the sleeve? I ask this because I have seen many times the cylinders "ovate" well below the deck due to rocking on the wrist pin causing the piston-cylinder clearance to be much larger along its stroke than at TDC.

I shove the ring midway down, then measure for "anecdotal proof" when I do it.

And, did you put a good hone on those cylinders?
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline HondaMan

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Re: Marissa's 1972 CB500
« Reply #140 on: January 15, 2018, 01:23:41 PM »
There is both a minimum and a maximum ring-end gap: max for this bike is 0.026" for the top 2 rings. I'm a little curious: did you get 0.030" top gap in a new set of rings, or are these used rings? Usually new rings come at 0 or the minimum gaps, requiring fitting during installation. Most of the 500/550 pistons I've done fall into the 0.008"-0.010" range, larger being for the overbores like 600cc kits: on those the top rings can go out to 0.012" gap.

If the top ring gap is more than 0.020" then there will be quite a bit of compression leakage, at least until possibly some carbon fills it in somewhat. That may take up to 1000 miles with today's super-clean-burn gasolines, though.

Hey HondaMan,

I should clarify, the last measurements (where I state they are in spec) are the maximum wear limits provided by the Clymer Manual. Here in the book it says the top ring limit is .030 in. and the second ring is .020 in.



The rings installed are new rings, measured at .015 in. for the top, and .010 in. for the second ring. Those were measured by placing them in the cylinder jug and measuring with a feeler gauge.

Ah, yes, Clymer strikes again...their errors in their various versions of their CB750 manuals were one of the things that pushed me to make my book...

Your actual ring numbers are good, though, at less than 0.016" and more than 0.007".
To get off into the weeds a little for a moment:
RING WEAR is measured by putting the ring at the bottom of the cylinder bore where the hole is most likely still its original size.
BORE WEAR is measured just below the site where the top ring's travel marks are/were. The bore above that site is also still un-worn.
WEAR LIMIT is measured with the used ring(s) placed at the most-worn site at the top of the bore, usually about 1/4" down from the top.

Thoughts about the compression numbers:
if the ring gaps of the top 2 rings are closer than about 60 degrees to each other, it makes a noticeable "number difference" at cranking speeds. This often fills itself in with a little run-time and carbon build-up, though. In really-worn (750) engines I have torn down before, I've seen all 3 gaps aligned vertically (on pistons with 1-piece oil rings) from cylinders where compression was OK, but rings worn enough to let oil slip by. This happens on these engines mostly on the 1-4 cylinders, with the gaps aligning toward the outside-front (11 o'clock on #1, 1 o'clock on #4) zones where the bore is largest. But...I'm speaking about engines with nearly 100k miles on them, certainly not in this one's arena.

The leakdown problem can also come from a loose-fitting valve guide: the most common culprit here is the exhaust guide clearance-to-stem. Reason: if the clearance is too loose, the valve closes just slightly off-angle after being pushed open-closed slowly (cold, especially) and doesn't completely seal. If the clearance is a bit too tight, and especially if the valve is new (Parkerized stem), it will not seat well until it wears into both the seat and the guide.

Too-much clearance is about 0.0032" wiggle of the valve face when lifted about 5mm off the seat: the greatest movement is toward the center of the chamber and the front of the engine, back-and-forth. Too-little clearance is less than 0.0006", or if the stems are still Parkerized, 0.0004". In this case, I have sometimes polished the offending stem somewhat, or reamed the [new] guide 0.0004" extra to set them up.

Once in a while, I have also found a slightly-warped valve stem! These can be hard to find, but one way is to roll the stem slowly along a flat plate (I use a piece of picture frame glass I that haven't broken yet) while watching closely for the face to wiggle, or else put the valve in the head sans spring, look at it from the port, and shine a bright light at the chamber while slowly spinning the valve against the seat to see if light shows up around an edge. If warped, light will peek in for about 30-45 degrees around the edge of the valve now and again while twirling it, trying to hold it tight to the seat.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #141 on: February 02, 2018, 06:51:11 PM »
Kinda wanted to keep it hush hush until I made uphill progress, but I reached a point where I really want to get multiple sets of eyes on what I'm seeing and ensure I make the right decisions.

I got a cb550 engine for a good deal and wanted to grab it to learn more about disassembly and potentially swap it into my 500. I figured if anything else I could part it out and make more money on it vs. what I spent. I split the cases the other day and I'm a little concerned about two things:

1: This engine needs a new primary chain, it is rubbing a tad on the bottom casing and has lots of side to side play. The crankshaft appears to have heat discoloration near it from contact I would guess?

Has anyone seen this, and how bad is it?







Second concern is the bearing seats for the transmission gear shafts, they are all worn irregularly and I'm not sure how much of a threat this is. I'm assuming you treat them similar to the cam seats and the crankshaft bearings, which would mean this is not good. Does this mean I can't use these crankcases?

Thanks in advance!







1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline 754

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Re: Marissa's 1972 CB500
« Reply #142 on: February 02, 2018, 07:04:33 PM »
Check the crank for runout on V blocks. The only reason I can think of for that heated area is  maybe  cutting off a primary chain, or maybe trying to straighten a crank? Cant think of other reasons.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline wolf550

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Re: Marissa's 1972 CB500
« Reply #143 on: February 02, 2018, 07:50:58 PM »
hope it all works out in the end.
have a 500 and 550 engine going to start pulling apart to understand how to put back together myself.
74' CB550 (Sold)
71' CB500/550 (Sold)

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #144 on: February 03, 2018, 11:39:16 AM »
Check the crank for runout on V blocks. The only reason I can think of for that heated area is  maybe  cutting off a primary chain, or maybe trying to straighten a crank? Cant think of other reasons.

Those are both good points actually. Thanks, I'll check for run out.

Anyone have any thoughts on those transmission bearing seats? Should I just try to find new ball bearings and run it? I can't find anything on the shop manual or the Clymer manual that discuss them other than talking about putting in the bearing set rings and the dowel pins.

Thanks.
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #145 on: February 03, 2018, 11:49:24 AM »
hope it all works out in the end.
have a 500 and 550 engine going to start pulling apart to understand how to put back together myself.

Thanks, you as well! I'm hoping by the time I'm done with the 550 motor (if I don't part it out) I can swap it in and use that with my bike, and then practice more with the 500 engine. After taking this thing apart I am fairly certain that the buildup of grey stuff in my original engine is crankcase material from a sloppy primary chain. Obviously I won't know for certain until I take the cases apart but the 500 engine looked to be completely original (based on my comparison with the 550) and had that buildup, which tells me it's possible for the primary chain to be original, and with 23,000 miles on it, I would definitely believe it would have enough slack to do that damage.

Someone has very clearly been in the 550 engine before. So we will see what we find!
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #146 on: February 04, 2018, 08:16:46 AM »
More nice finds. I can’t tell how this damage came to be on this primary shaft but I guess if all else fails I can pull parts from my 500.

UPDATE: looks like this is apparently normal on the primary shaft? I looked at primary shafts for sale on eBay and every single one had this awful hole in it. It didn't look like it was intentionally put there at all but I'm guessing this has a purpose since every single other primary shaft I found has this. It looks pretty scary though, I won't lie. I have no idea why this was designed in such a manner.

Got a better view of the discoloration on the crankshaft now. Looks like it affects two sides, not sure the cutting idea fits now. I haven't seen this on any of the previous build threads I've read on here. I work at an automotive performance shop and have seen this on a couple Audi 2.7T cranks, should I disregard this as normal? I just want to make sure I'm not overlooking anything that might need attention.



« Last Edit: February 05, 2018, 06:59:12 PM by Marissa »
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

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Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #147 on: February 05, 2018, 08:53:45 PM »
Since this is now out there, I should back track it while it will still make sense to any of those reading.

Here's how I got the engine! It was actually a solid deal (Note: potentially my first solid deal with anything relating to this bike???  ;) ) And the guy who sold it to me gave me a nice back story. The garage was filled with rock and roll memorabilia, a 74 Trans Am, a 750 motor, and a bunch of photos of his dads old hot rods and projects.

I forget roughly how many years this motor has been sitting, but it's been quite a while.


This thing fit perfectly in the trunk of my Fiesta ST!













First off, let's do a little comparison here. The oil filter housing on the CB550:



Oil filter housing on the 500 (Original motor) ((After already cleaning out the oil))



Oil pan on the 550: Comment referencing to the pieces of gasket found in pan.



Oil pan on the 500:





Valve cover off! Was a bit hesitant around this point because 3 of the breather cover bolts seized and stripped. This was kinda scarring me as I was using my typically successful technique. Luckily, it's been smooth sailing from that point on and I haven't come close to stripping anything since, except....





I knew once I saw this that the PO definitely romped on this thing...




This time I got around to checking ring orientation. Cylinder 1 was the only one with a more ideal ring orientation. The rest of them were pretty off or just gaps right on top of each other.



A little leaky! Later on I found a piece of gasket wedged in there; potentially got in there when it was sitting and was wedged into place? Was a bit odd but either way valve lapping is pretty easy for me at this point so I would be doing this regardless.





You can see a "recent" rebuild was done, the valves were pretty darn clean or at least the buildup was quite little. Definitely was running rich though for the time after the rebuild. I want to note how flawless the valve stems were, too, as comparing to the ones on the first 500 head, they had horizontal fine scratches from spinning and I guess overall wear. The valves, valve springs, and the retainers on the 550 head seem really new and in great condition. Sometimes you don't realize how bad and out of shape things were until you see new right in front of your own eyes.



This washer though... Don't know how many times this was reused...




While I was disassembling this, I went ahead and purchased a cheap bore gauge and a honing tool. I took some readings on my CB500 jugs, and decided to practice honing on it. Luckily, the readings were consistent and the cylinders were just barely out of round. I have yet to take readings on the honed version, but hopefully this weekend I can get back to tackling that.



Here's a pic of the current result, you can see there's still staining at TDC, so I still have a ways to go!



*Back to the CB550***

Cylinder jug off, finally seeing some cross hatching! But there is also some scoring marks, a TDC ring, and a couple of areas where the oil ring pattern can be seen on the cylinder wall. Still, let's compare it to the CB500 so we can see the difference:






I did something I knew would be quite risky, but I also knew many people have used this method with success, so I bent the studs and broke them free this way. All went well, except the short stud in the corner of cylinder 1 completely split itself in half and broke apart, except for what's left of it in the case. Luckily, I know I will be able to get it out, I'm soaking it in penetrating oil and I'm going to put it through a dozen heat cycles to help free it. That is something I will jump back to with patience.



You can see the bit that's left here:


My trick for splitting the cases? Excessive amounts of razor blades. Dave saw a couple photos of this engine beforehand and immediately noticed how much sealant I was dealing with. If you take a look back at the head studs you can see red streaks on them from some other sealant used on the head. Sealant everywhere.





Looks solid...

My started break down space. The teddy bears add 5hp.



This has accumulated many more parts now.









I would say next step is removing the rest of the bits from the bottom case, including the kick starter shaft, and then from there go into the soda blasting process. Need to save up money for the primary chain.

1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

Instagram- marissasimos

Offline 754

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Re: Marissa's 1972 CB500
« Reply #148 on: February 05, 2018, 09:30:45 PM »
I just read the whole page,
 Think I have good news, your crank likely has no issues once I saw the pic with the primary gear the lightbulb went on...I now Think the heat marks are maybe  from hardening the primary gear , that would make sense.

Also in the other head pics of the second head, I would say it's been surfaced once already, you can see the marks, not usually a problem unless they took lots off.
 If I may ask, don't have to answer, what do you do at the engine shop?  Sure should help you I would think.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Marissa

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Re: Marissa's 1972 CB500
« Reply #149 on: February 05, 2018, 11:10:06 PM »
I just read the whole page,
 Think I have good news, your crank likely has no issues once I saw the pic with the primary gear the lightbulb went on...I now Think the heat marks are maybe  from hardening the primary gear , that would make sense.

Also in the other head pics of the second head, I would say it's been surfaced once already, you can see the marks, not usually a problem unless they took lots off.
 If I may ask, don't have to answer, what do you do at the engine shop?  Sure should help you I would think.

Hey 754,

It’s not an engine shop, it’s an auto repair/performance shop. We specialize in servicing European and Japanese vehicles, anything from scheduled maintenance to builds. We send all of the engine parts out to a machine shop we have been working with for 15 years. We disassemble them but typically everything goes to the machine shop. I do marketing and data for the company, so I track our online sales and web traffic. We sell aftermarket parts online like APR and AWE Tuning. We work on a lot of GTIs, Golf R’s, S4s, etc. typically if there is engine work it’s moreso fabrication and adapting the oiling system on a 2.7T to fit a 3.0 oil pan I believe. I’m not into Euro that much so I don’t remember as much of that. We do a lot of suspension work, clutch jobs, turbo upgrades, etc.
1984 Nissan 300zx - sold
2016 Ford Fiesta ST - daily
1972 Honda CB500 - infinite work in progress

Instagram- marissasimos