Post by: Cb750r on November 26, 2023, 05:23:57 PM
I’m on a new major phase with my CB. I’ve owned it since roughly 2004, it was a poorly researched purchase and I got scammed. The seller slapped together a bike/motor with a hodgepodge of parts and the head gasket blew a day or so after I purchased it, then the engine itself blew up after I replaced it. Long story long there was high domed F2 pistons in a K5 head that had been also milled down below specs because the idiot had wire wheeled the head and damaged the surface. (Could still see wire wheel marks in the old head under close examination.)
I couldn’t afford a new motorcycle, let alone a high horsepower build, I rebuilt the motor with used head, cylinders, eBay, used con rod, new stock size pistons etc. I also discovered that the engine cases had previously lost a fight with the drive chain and was welded back up. Glad to report my collection of new and used parts did turn into a well functioning engine for many years and lots throttle cable stretching action. However I have had to deal with oil weeping from the case halves where the damaged case was repaired due to unperfect mating surfaces. I made various attempts of repair over the years with RTV but obviously it never lasted. Last winter I pulled the motor out with the goal of repairing and rebuilding the engine.
I originally attempted to repair the cases I had, and used some specialized aluminum epoxy to build up the case as well as re drill and heli coil a damaged thread near the area where I had over tightened it to try and reduce the oil leak. The repair is better than it was but I could still see light between the gap when I mated the upper and lower cases. So project sat… until I found a Cb750f2 "parts bike" for sale randomly on marketplace! I started on tearing down and inspecting the "new" motor that came out of the back of a motorcycle shop where it sat for many many years after it had rear ended someone and broke its fork stem. Carbs and exhaust robbed but otherwise just left for dead. The motor tuned over so was stored "properly" but the oil left in the pistons had left the chat in subsequent decades and this engine top end needed a rebuild, however the bottom end and the cases look great.
So I contacted Mike Rieck in the USA, and outlined my goal of wanting to build up just about the strongest street motor I could with stock F2 rods… Even though I had a good 410 core, due to shipping costs Mike sold me a good core and then went to work doing his magic. A full stage 3 port new valves and seats, and spec’d a mega cycle cam that he’s used on several bikes to much success. I ordered, a set of high domed 836cc JE pistons designed to retain compression ratio on the F2 heads…. And for insurance a set of Carillo rods! So much for the Stock rods as my self limiting measure!
I have my crank and and rotating assembly as well as my cylinders and pistons at the local hot rod shop for balance polish cylinder boring and ring gap filing.
I’m painting case halves and just rebuilt the oil pump, and have welded in a set of the frame adapters to give access to the top end with engine in frame. Hope to keep a log of the progress here to share my progress
Post by: Cb750r on November 26, 2023, 05:27:17 PM
Post by: Cb750r on November 26, 2023, 05:57:06 PM
[attachimg=1]
Post by: K2-K6 on November 27, 2023, 08:41:45 AM
Head work looks good, any more pictures of it from combustion side too ?
Post by: Laverda Dave on November 27, 2023, 09:08:11 AM
What's all the white powdery stuff under the front wheel, snow already 😱
Post by: SteveD CB500K0 on November 27, 2023, 10:23:45 AM
And it’s the end of November.
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Post by: Cb750r on November 27, 2023, 05:14:13 PM
Here’s a couple more shots of the head detail
JMR heads are quite well known on the US SOHC forum. MRieck is a long term member over there and does great custom work.
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attachimg=2]
Post by: Bryanj on November 27, 2023, 05:58:56 PM
Post by: Laverda Dave on November 27, 2023, 09:47:22 PM
Post by: K2-K6 on November 27, 2023, 10:05:46 PM
Post by: Laverda Dave on November 27, 2023, 10:43:44 PM
Post by: K2-K6 on November 27, 2023, 11:04:49 PM
Is that the reason why the F2 suffered with premature valve guide wear Nigel? I assume if the valve was higher in the head this would have an effect on the cam/rocker to valve stem geometry compared the earlier models unless of course Honda accounted for this in the design of the F2 head?
Yes, the geometry didn't change as far as I understand it. The rocker arc is compromised in its contact with the valve to give slightly more sideways loading through it's initial travel, coupled with raised spring rate for higher rpm too. Tgey deleted some of the oil drainage holes from head too, this to keep more oil around the valve gear prior to going back down into sump.
Honda realised this with development of endurance race 16 valve head onto CB 750 bottom end with the first "RCB" motor in 1976, I think. Then development of the road going twin cam motor.
Post by: Cb750r on November 28, 2023, 05:18:09 AM
Unfortunately for my pocket book it also means I have a head and cam that will allow more airflow than my stock carbs will allow for so it seems I’m also in the market for a larger bank of carbs.I will cross that bridge a little later but I’m leaning towards a set of Mikini RS34. I have the case haves a coat of paint over the weekend.
[attachimg=1]
Post by: Cb750r on December 08, 2023, 04:36:31 AM
Post by: andy120t on December 08, 2023, 06:37:19 AM
Post by: Cb750r on December 08, 2023, 04:11:35 PM
Looking good . I like your headlight/screen brackets - did you make/mill them?
Thank you, I did mill them. I have a small CNC machine and have made a few bits. I left the pocket not fully milled out on the left bracket so I can eventually drill it out for the choke. However I may end up with carbs with the choke down on the body of the carbs so may end up milling out the pocket fully.
Post by: Oddjob on December 08, 2023, 05:22:00 PM
Could be an optical illusion though.
Post by: McCabe-Thiele (Ted) on December 08, 2023, 05:57:23 PM
Your fork stanchions look uneven, one of the top nuts is sitting slightly lower in the top yoke than the other, might not make a great deal of difference but worth fixing IMO as it costs nothing.
Could be an optical illusion though.
Hawkeye Ken strikes again,
yep the right one looks as thought it's clamped on lower so the top nut is sitting higher - could be camera angle.
Post by: Cb750r on December 08, 2023, 06:32:55 PM
Your fork stanchions look uneven, one of the top nuts is sitting slightly lower in the top yoke than the other, might not make a great deal of difference but worth fixing IMO as it costs nothing.
Could be an optical illusion though.
Hawkeye Ken strikes again,
yep the right one looks as thought it's clamped on lower so the top nut is sitting higher - could be camera angle.
No kidding! It’s all just hand tight in the photos. the top clamp is <1mm askew left to right in the photo, but the lowers are tightened still so same fork length left and right. I want to swap the black pinch bolts for bright hardware so left it all loose for now.
Post by: Skoti on December 09, 2023, 12:19:16 PM
Rubber or soft plastic sleeve between your headlight bracket clamps and fork legs may suffice.
If not you may have problems with blown headlight bulbs.
I found this out by doing the same as you've done, mounting the brackets directly to the fork legs.
Your project looks good, please keep posting photos.
Good luck
Skoti
Post by: Cb750r on December 09, 2023, 04:10:10 PM
Headlight assembly should be rubber mounted just like the original F2 was.
Rubber or soft plastic sleeve between your headlight bracket clamps and fork legs may suffice.
If not you may have problems with blown headlight bulbs.
I found this out by doing the same as you've done, mounting the brackets directly to the fork legs.
Your project looks good, please keep posting photos.
Good luck
Skoti
Thanks for your input, I’ve had the headlight ridged mounted in one form or another since 2015, this bike has an H4 conversion and I can’t recall going through more than one bulb in 25000km.
Do you use a sealed beam headlight? Maybe they’re more sensitive than an H4?
I’m going to try and put an h4 LED conversion to help reduce wattage draw, this would likely also reduce vibration issues
I live in an area with an abundance of wildlife so I don’t ride at night on any of my bikes, if I can avoid it.
Post by: Cb750r on January 22, 2024, 02:30:32 AM
Post by: Laverdaroo on January 22, 2024, 10:42:18 AM
Post by: McCabe-Thiele (Ted) on January 22, 2024, 11:42:55 AM
Post by: Cb750r on January 22, 2024, 02:34:50 PM
Your newly coated frame does looks great - I'm slightly confused when you say it was a 600 km round trip has Canada gone metric to annoy the USA?
Yes we did go metric in 1975…
We’re stuck with a bit of a hybrid system as most construction materials are sold in inches.
Post by: Cb750r on January 22, 2024, 04:10:52 PM
Post by: Oddjob on January 22, 2024, 06:44:58 PM
Post by: Cb750r on January 22, 2024, 07:38:05 PM
What colour is the silver, it's a close match to OE.
I can find out. I just saw a sample of the colour and went with it. I had stripped and polished my plate’s previously but as all raw aluminum it kinda dulls over time.
Post by: Cb750r on January 30, 2024, 03:07:49 AM
I zinc plated the hardware that’s not powder coated black and gave the old rubber a good scrub.
Post by: Skoti on January 30, 2024, 07:38:46 AM
All looking nice, please keep posting photos.
Post by: Oddjob on January 30, 2024, 07:57:31 AM
Zinc plating turned out really dull, you sure it took?
I've done a few of these now and found the holes for the pin had started to elongate, this allows the peg to rattle and ends up making it worse. Due to no doubt Honda not greasing them from the factory and of course we never think to grease them until it's too late.
Same for the tunnel the pin runs through on the peg, I ended up going slightly bigger on the pin size and replacing them with stainless steel pins, washers and split pins.
I think for the 6mm pins (rear pegs) I went with 1/4" and the front pegs with 3/8" but could be wrong, been a while since I did a pair. Also a small blob of weld on the carrier where the peg hits makes them sit straight, nothing worse than pegs hanging crooked IMO.
Post by: Cb750r on January 30, 2024, 02:29:44 PM
Not a bad tip about the shrink wrap, done similar on the brake return spring but never considered it for those springs.
Zinc plating turned out really dull, you sure it took?
I've done a few of these now and found the holes for the pin had started to elongate, this allows the peg to rattle and ends up making it worse. Due to no doubt Honda not greasing them from the factory and of course we never think to grease them until it's too late.
Same for the tunnel the pin runs through on the peg, I ended up going slightly bigger on the pin size and replacing them with stainless steel pins, washers and split pins.
I think for the 6mm pins (rear pegs) I went with 1/4" and the front pegs with 3/8" but could be wrong, been a while since I did a pair. Also a small blob of weld on the carrier where the peg hits makes them sit straight, nothing worse than pegs hanging crooked IMO.
Between the powder coat and the zinc its a fairly snug fit but if they get loose i may turn some new ones on the lathe.
As for the zinc it has definitely ‘taken’ its for sure not a professional job, but theres good layer of material on the parts i did. Heres a photo of s bunch of the parts i did. I had not yet buffed all of them. You can see the little hinge pin for the seat and the footpeg plates had been buffed up a bit. Also can see the brake reservoir bracket failed to take the plating in some spots.
Post by: SumpMagnet on January 30, 2024, 06:30:44 PM
I have got myself a bright zinc plating kit and plan to have a go when it gets a bit warmer, so if I can get that sort of coating I will be pleased enough.
Post by: Oddjob on January 30, 2024, 07:04:02 PM
Post by: Laverdaroo on January 31, 2024, 01:39:37 AM
shiney as the enclosed…..
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Post by: Laverdaroo on January 31, 2024, 01:40:52 AM
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Post by: Oddjob on January 31, 2024, 05:57:55 AM
As for the missing spots, because of the aeration and the bubbles, if you position a part so that air can become trapped underneath you’ll find the plating doesn’t stick to those parts as the fluid is held away from the metal by the air bubble.
Post by: Cb750r on January 31, 2024, 03:30:16 PM
I don’t have a tank heater and I’m working in a cool space so that could be part of the problem.
I tried plating that piece 3 times. Blasting it cleaning it each time, I also changed the orientation of the part several times.
This is a new process for me, shiny result would be nicer than a galvanized look but it’s not critical.
Laverdaroo it looks like you actually do some plating would be flat to get some more info on your setup. It’s been interesting getting the ball rolling with some plating and if I could achieve better results with some changes to my setup I’m all ears.
Post by: Laverdaroo on January 31, 2024, 03:41:39 PM
What power source are you using, do you have a controllable bench supply allowing you to change the voltage if required? If not, that could be another reason why your bits come out dull but in all honesty it could be anything in your set up that’s not playing how it should. There’s just a few rules to follow but once it clicks it’s very satisfying and you can save heaps of money.
Drop me a pm if you need some help mate. Not sure where aboots
you are in Canada but I’m in the states at the min so happy to chat but it would have to be through wattsapp or similar
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Post by: Cb750r on January 31, 2024, 03:58:13 PM
I’d recommend you get some aquarium heaters, one for your plating solution, one for your pasivate solution also….
Cheers appreciate the info I’ve sent you a direct message. Now that I’ve tipped my toes in the waters I’m more inclined to get some proper solutions.
Post by: Oddjob on January 31, 2024, 04:50:22 PM
Post by: Cb750r on January 31, 2024, 09:34:35 PM
We can’t buy chromate solutions in Canada, and I doubt I can get those chemicals shipped from the UK.
Pretty much the only kits are from Caswell and they’re expensive. $205 vs your Gateros $67 for the same sized kit.
Post by: Cb750r on February 02, 2024, 04:54:59 AM
These are old Boge shocks. I’m not certain how long they will stay on the bike. I have ideas in the wings for another potential swing arm.
Post by: Laverdaroo on February 02, 2024, 05:39:52 AM
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Post by: Oddjob on February 02, 2024, 10:31:18 AM
Calming down now, they look really nice, and the collars are really well made. Well done.
Post by: K2-K6 on February 02, 2024, 10:54:16 AM
I've not tried BOGE dampers on a bike but they have very good reputation and capability in car products.
Post by: Cb750r on February 02, 2024, 03:24:18 PM
I thought nice machining work on the collars too.
I've not tried BOGE dampers on a bike but they have very good reputation and capability in car products.
These have worked well for me, but were looking pretty ratty. I have an aluminum swing arm from a zrx1100 I need to finish modifying to fit which takes shocks that are eyelet not clevis mount so cleaning these up was a good little side project while I’m waiting for parts. And the machining of the collars was a good challenge to my very rudimentary ability on a lathe and mill. I got to do a bit of drafting and geometry to figure out the spacing of the preload ramps. The paint and the shock oil was in my shop already and it didn’t cost me anything for the powder coat. So it was a low cost refurb or buy new shocks I may replace in a year or so…
Post by: Cb750r on February 02, 2024, 03:38:20 PM
They look well, subtle colours and not the obligatory chrome finish
Cheers. This refurb was more a test if I could make those preload collars as one broke when I was adjusting the collar. These will look good, long enough for me to get my bike back together and get the swing arm swap sorted or shelved.
Post by: Skoti on February 02, 2024, 05:01:26 PM
The problem with repainting shocks is that not matter how careful you are it's never strong enough to withstand the adjusting process, the paint on the top of the lugs gets rubbed off as soon as you move the collars, then sometimes just the collar moving can rub the paint off underneath it, the springs can touch the body when they compress and that rubs paint off, they look great until you use them. Makes me mad as hell, all that work, all that time and they look worse than they did before within a few months, not to mention scratching the paint with the spring compressors, Jesus my blood pressure is going up just thinking about it.
Calming down now, they look really nice, and the collars are really well made. Well done.
Black plastic tubing of the type used to keep golf clubs from rattling together, fitted perfectly over the body of my Commando rear shocks.
Prevents the springs from damaging the paint.
If your shockers adjust with a C spanner, then just lag it with a bit of cardboard before preloading the springs.
Hope that helps.
Skoti
Post by: Cb750r on February 02, 2024, 05:20:04 PM
Black plastic tubing of the type used to keep golf clubs from rattling together, fitted perfectly over the body of my Commando rear shocks.
Prevents the springs from damaging the paint.
If your shockers adjust with a C spanner, then just lag it with a bit of cardboard before preloading the springs.
Hope that helps.
Skoti
Great tip cheers, I have some paint protection film in the garage in my haste to see how good things looked assembled I forgot I was going to apply to the shock bodies. I think I will give that a shot first. Yes I have a pin or C spanner for the preload. I actually filed and sanded its edge a bit to help prevent marring. I doubt I’ll change the preload from where it is though as it’s where I had it set before!
Post by: Cb750r on February 02, 2024, 06:40:53 PM
The problem with repainting shocks is that not matter how careful you are it's never strong enough to withstand the adjusting process, the paint on the top of the lugs gets rubbed off as soon as you move the collars, then sometimes just the collar moving can rub the paint off underneath it, the springs can touch the body when they compress and that rubs paint off, they look great until you use them. Makes me mad as hell, all that work, all that time and they look worse than they did before within a few months, not to mention scratching the paint with the spring compressors, Jesus my blood pressure is going up just thinking about it.
Calming down now, they look really nice, and the collars are really well made. Well done.
I appreciate that your standards for finish are a lot higher than mine.
I have spent several thousands of dollars on the things that matter to me on this project:
Race ported head, new valves new valve seats and HD springs
Custom cam, adjustable cam sprocket
Big bore high compression pistons, cylinder boring HD studs
Carillo rods,
“New” engine cases/better transmission, HD primary chains, cam chain, all new cam and primary tensioners, new engine bearings, new hardware etc….
Next expenses:
New RS34 carbs
New Stainless Hindle exhaust
I’m content and more importantly, ENJOYING the process of what I’m doing with the refurbishment of the aesthetic parts of my bike! So if you have something critical to say, how about you reserve it to your bikes, and I will do the same regarding your project(s)
Cheers
Grant.
Post by: Oddjob on February 02, 2024, 08:09:34 PM
I’ll refrain from trying to help in future.
Post by: Cb750r on February 02, 2024, 08:53:12 PM
How you got critical from my post I have no idea. It was meant to show how annoying it was to do all that work only to find it looking so bad within a short time.
I’ll refrain from trying to help in future.
Come on man, you crapped on my zinc plating and you wrote a paragraph explaining “how my work will look worse than it did before…”
What good does writing a paragraph on shortfalls and pointlessness of someone’s completed project “help”?
If I’m posting information or work that is unsafe or saying that this is how things should be done, I’m all ears to constructive criticism or feedback. But telling someone whose spend time and effort (and money, but not in this case) that their work is pointless is pretty poor form and does little to create a sense of community.
I didn’t seek advice on how to do something I was sharing the result of my efforts. You have no bloody idea how the springs had already started to corrode or how the paint was scuffed or the shock collars were stripped and broken. Or the fact that this was a stop gap measure and an exercise in learning some processes on my mill and lathe. Or that sometimes enjoyment is in the process more than the outcome.
Post by: Oddjob on February 02, 2024, 09:30:56 PM
As for the damper post, it was a comment on my experience on a using rattle can finish on damper bodies, more of a rant on how frustrating it is to see so much work turn out to be so disappointing. Maybe that helps someone helps to avoid the same mistake. But hey if you’re so sensitive that any comments not amounting to a pat in the back is unwelcome then that’s fine. I’ve said I won’t post anymore, even if at some point in the future you really do need some help or advise.
Post by: Cb750r on February 02, 2024, 11:44:03 PM
Crapped all over? I commented that it looked like it maybe hadn’t taken, you hadn’t explained you were using a home brew kit and the results were very different to the results we get in the Uk with better kits. You’d prefer not knowing? Fine.
As for the damper post, it was a comment on my experience on a using rattle can finish on damper bodies, more of a rant on how frustrating it is to see so much work turn out to be so disappointing. Maybe that helps someone helps to avoid the same mistake. But hey if you’re so sensitive that any comments not amounting to a pat in the back is unwelcome then that’s fine. I’ve said I won’t post anymore, even if at some point in the future you really do need some help or advise.
Well it doesn’t sound like I’m getting my point across so I will wish you well on your projects. I hope it comes out to your satisfaction.
I hope for the well being of others or myself if there’s anything I or any one else shares that’s unsafe or dangerous practice that regardless of our opinions it’s commented on.
Best of luck,
Grant.
Post by: SteveD CB500K0 on February 03, 2024, 07:49:40 AM
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Post by: Moorey on February 03, 2024, 09:36:22 AM
just over 12mnths ago he flounced threatening to leave the forum but came back stating he would come back but be hardly posting. I bet he must
have done well over 1000 posts since.
I have been doing the CBX550 over winter and its nearly finished but he and his attitude is the reason I rarely post now and there will be no pics of
the CBX on this forum.
I know for a fact others that no longer bother with this forum for the same reason.
Post by: McCabe-Thiele (Ted) on February 03, 2024, 10:50:05 AM
I'm a grown man not a Snowflake so I accept his comments as they are based on solid experience of the 500 models. There is not a bad bone in his body imho when he posts replies.
I have PM'd him many times when I have had issues on my 500 build progresses receiving positive helpful replies fully explaining any ancillary questions I ask.
I for one did not want Ken to leave when he was having issues I am very grateful that he listened to other members and stayed.
This sohc forum is a fantastic site made up of a very diverse & experienced members we should allow for any individual idiosyncrasis.
Post by: Moorey on February 03, 2024, 02:14:29 PM
In defence of Ken yes sometimes he might be a little direct if he sees things that are not correct but at least he goes on to say why. He does not say stuff like "I've never had that problem" and offer no solution.
I'm a grown man not a Snowflake so I accept his comments as they are based on solid experience of the 500 models. There is not a bad bone in his body imho when he posts replies.
I have PM'd him many times when I have had issues on my 500 build progresses receiving positive helpful replies fully explaining any ancillary questions I ask.
I for one did not want Ken to leave when he was having issues I am very grateful that he listened to other members and stayed.
This sohc forum is a fantastic site made up of a very diverse & experienced members we should allow for any individual idiosyncrasis.
Would you care to expand on the "I'm a grown man not a snowflake "
Post by: McCabe-Thiele (Ted) on February 03, 2024, 03:56:48 PM
In defence of Ken yes sometimes he might be a little direct if he sees things that are not correct but at least he goes on to say why. He does not say stuff like "I've never had that problem" and offer no solution.
I'm a grown man not a Snowflake so I accept his comments as they are based on solid experience of the 500 models. There is not a bad bone in his body imho when he posts replies.
I have PM'd him many times when I have had issues on my 500 build progresses receiving positive helpful replies fully explaining any ancillary questions I ask.
I for one did not want Ken to leave when he was having issues I am very grateful that he listened to other members and stayed.
This sohc forum is a fantastic site made up of a very diverse & experienced members we should allow for any individual idiosyncrasis.
Would you care to expand on the "I'm a grown man not a snowflake "
I was speaking for me "I'm a grown man" 6ft 1 in tall, 76 years of age, Snowflake I understand is the modern term for folk who easily take offence.
I am pretty thick skinned having worked for 27 years in Policing dealing with difficult people in stressful situations often at the worst end of humanity. I later worked for 5 years in the customer complaints section of a Mercedes Dealership collecting vehicles that fell well short perfection. The impact of my working life has moved me well away from easily being offended to being probably unusually tolerant or even stoic.
If I received what I perceived as unfair comments about my bike I would try to understand the view given, I might answer back seeking clarification or evidence. I might end up respectfully agreeing to disagree. At the end of the day were often seeking advice - one does not have to accept or take it.
Post by: Cb750r on February 03, 2024, 04:50:23 PM
Ive been on motorcycle forums for a long time, I also work in automotive parts sales, so i have fairly thick skin.
People join these forums for many reasons, most of us joined up because we needed help or parts or something like that.
Most of us stick around for the sense of community, getting to see other like minded individuals doing similar work. Get ideas or inspiration for their bikes.
Ive had Personal messages of support from other members who feel the same way, and some comments to that effect above. I am not glad for this, Im just saying im obviously not the only one who doesnt welcome how he is providing his feedback. On the other hand i had another member assure me Oddjob means well, but is very VERY detail oriented.
When it comes to critical component like brakes, or engine assembly things are pretty cut and dry, but when it comes to asethetics, theres such a huge range of personal opinion, satisfaction in the process, personal ability and cost.
To have people jump on your build thread and be critical of your efforts without offering solutions DOES NOT HELP, its AFTER THE FACT.
In regards to these shocks im hoping to get 1 or 2 seasons out of them, not another decade. They looked thrashed when i took them off the bike, and the broken preload collar was a really fun challenge to my minimal machining skills. The collars turned out well enough that it made the rest of the shocks look even worse so i gave the shocks a lick of paint… i have a good friend who powdercoated my shock springs, frame and lots of bits and pieces for free. Does that sound like a waste of time to you?? If so, i dont need your input you’re not my kind of person.
Do i care about concours restorations? no but i respect them for their skill and attention to period correct detail.
Do i like the modern brat bike plank seat look? No but good for them they’re out there wrenching and riding. Its not their fault i broke my hip and need a comfy seat!
Do i care about drag racers? Man bikes are for corners but those guys know how to make horsepower so i listen when they talk engines.
Built not Bought guys? Dude good on you if you can do it all, I know i cant and I'm glad to pay for nice results when the process is beyond me.
My point? There is a myriad of reasons to ride and wrench on these bikes, lets do our best to help people when they as or if it appears they might be doing unsafe or costly they dont realize, let offer solutions, lets acknowledge we have different visions, skillsets, piggy banks.
Is that too Snowflake of me?
Post by: ozzybud on February 04, 2024, 03:40:37 AM
Lets keep this fun. like the fun i have in my shop when i am trying to improve these classics and keep them on the road
Now lets get back to your project and great posts about YOUR progress.
Ozzybud
Post by: Cb750r on February 04, 2024, 05:19:40 AM
My stator cover had some damage to it. I used a really great product from Devcon it’s an aluminum epoxy putty that is very hard and can be filed and even drilled and tapped. However it didn’t like the powder coat process much and I had to sand spot glaze and paint over the spot where the filler was used.
Post by: McCabe-Thiele (Ted) on February 04, 2024, 09:29:45 AM
Did you use ordinary Cellulose rattle can paint or something special like Acrylic?
Post by: Cb750r on February 04, 2024, 09:51:11 AM
There have been previous discussions about potential problems applying paint over powder coating good to read that it can be done.
Did you use ordinary Cellulose rattle can paint or something special like Acrylic?
It was suggested by my friend who did the powder coating, when the flaw showed up after the attempt to powder coat it. I used an Acrylic Enamel engine paint.
If it doesn’t hold up it’s a simple matter to strip it of and start from scratch.
Post by: SumpMagnet on February 04, 2024, 07:20:23 PM
Post by: Cb750r on February 04, 2024, 07:43:53 PM
That Devcon putty looks like good stuff. Then I checked hte price for it and ...ouch. In the UK its roughly £100 for a 500g tub. they don;t seem to make it in a smaller size.
Yes its pretty specialized but it was cheaper here. Id gladly swap prices for what you folks can get electroplating kits for!
I originally purchased it to repair my k5 cases that were damaged some time in the past, i had a weeping oil leak near the final drive because the case halves didnt seal properly. I had damaged the ‘repair’ over the years trying to tighten down that area as seen, i made the repair, drilled and tapped and helicoiled that area but, a parts bike with an f2 engine came up for sale locally and i shelved that project for a later date and have been using the ‘new’ f2 engine as the base of my rebuild.
Post by: Bryanj on February 04, 2024, 10:47:27 PM
Shocks, you are spending a fortune on the engine to increase power and torque but skimping on the parts to make it stay on the road, false economy in my humble opinion.
As to Ken being rude i disagree, he has made comments using his knowledge on the information at the time, e.g. the first plating post made did not say it was home brew and it did not look go for paid for or a "kit" finish but acceptable for home brew
Post by: Cb750r on February 05, 2024, 06:39:40 AM
Devcon is the bees knees of metal fillers and comes in different grades for different metals, used it in merchant navy, yes expensive but can be worth it for repairs on expensive bits,
Shocks, you are spending a fortune on the engine to increase power and torque but skimping on the parts to make it stay on the road, false economy in my humble opinion.
As to Ken being rude i disagree, he has made comments using his knowledge on the information at the time, e.g. the first plating post made did not say it was home brew and it did not look go for paid for or a "kit" finish but acceptable for home brew
I have plans of using all my leftovers and finishing that engine build some day to see if i made a functional repair.
Interesting take on the shocks, as I'm usually the one advising others on suspension! However these shocks were a noticeable upgrade to the stock units. Also I did just service them. I flushed them out and put fresh oil in them, they don't leak, so unless i move up to adjustable ikons, ohlins, etc i don't really see the point. I do fork services for all my bikes and a few friends as well, Except for nitrogen equiped shocks im pretty comfortable with suspension work.
I do a couple track days a year and own some modern very capable bikes, while i am eagerly looking forward to having fun on my old Cb750, it sure isn't the bike i will be dragging a knee on!
As for your last bit, ok thanks for your perspective, Ken like many of us has a lot of knowledge and experience. It seems like some of our friction may have been a case of message not received due to method of delivery.
Post by: Bryanj on February 05, 2024, 08:53:22 AM
Somebody once told me that england and america(i will take a bit of leeway and put canada in with us) are two countries separated by the same language so misinterpretation is rife and can be distressing, there are a lot of geriatric old farts like myself and ken on this forum and several of us have worked for main honda dealers with between us probably centuries of experience but we are here to try and remember, and pass on, the pitfalls we have bothseenad done ourselves, good luck with the build
Post by: Cb750r on February 06, 2024, 04:55:47 PM
Post by: Cb750r on February 06, 2024, 11:24:43 PM
I was suspicious of it when I dry fitted the piston without rings and it seemed looser than any other fresh piston I’ve installed. Im working on a solution, but I’m pretty frustrated and not sure how much luck I will have at getting the shop that ruined my cylinders to cough up a refund.
Post by: McCabe-Thiele (Ted) on February 07, 2024, 01:01:52 AM
Post by: Cb750r on February 07, 2024, 01:32:27 AM
That's dreadful - they need to sort some replacement liners and do it correctly.
Thanks,
It’s a crappy deal, I work in the automotive parts wholesale industry and the machine shop I had do the work is also my customer which is going to make this resolution quite tough to manage.
I might have a back up cylinder lined up to get machined, just working out details.
Post by: Bryanj on February 07, 2024, 03:17:32 AM
Clearance for Honda pistons is 1 thou, i dont know about the special kits.
I just had problems with a 550 block so i willdo the extra for nothing and pay for machining i cant do, a reputable machinist should repair for free
Post by: Cb750r on February 11, 2024, 11:38:24 PM
So I undertook the task of making them less floppy, by making a Delrin washer that’s thicker so in the upright position it’s snug. I also made Delrin bungs for the end of the peg so when in the “down” position the Delrin plug butts up against the bracket at 90 degrees. The added benefit is that the Delrin should be a lot more gentle on the brackets paint so folding them up and down won’t be sanding the powder coat down.
Post by: SteveD CB500K0 on February 12, 2024, 06:30:42 AM
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Post by: Cb750r on February 12, 2024, 06:40:54 AM
Had to Google that…
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Same material a lot of modern bikes frame sliders or similar bike protection is made out of. It’s a very easy to machine plastic. I think non trademark name is Acetal plastic.
Ive made a variety of sliders and rear stand bobbins, bushings spacers step washers etc with the material.
Post by: Cb750r on February 14, 2024, 05:32:24 AM
I got sick of this and purchased my own dial bore gauge and measured all 4 cylinders. And my machinist is right the very top of all the bores are on target… but sadly that’s as good as the story gets.
All cylinders are barrelled. All of them are the most narrow at the top of the bore and tighten up a bit right at the bottom. Unfortunately that leaves them at the most wide at points where piston velocity and side thrust are at the peaks if I’m not mistaken.
While I’m not a machinist I did my best to take accurate measurements and can see how easy it would be half a thousandth out. However I can consistently repeat measuring the inconsistency in the final bore.
I think these cylinders will make a great decoration and will have to get another set machined by a motorsports specialist. I’ve attached my measurements below. Note I re measured #1 it does barrel as large as 0035, but comes back down to 0030. Have it written down that 0035 was at bottom but it’s not.
Post by: Johnny4428 on February 14, 2024, 07:53:36 AM
Post by: McCabe-Thiele (Ted) on February 14, 2024, 08:38:26 AM
Bryanj will know.
Post by: K2-K6 on February 14, 2024, 10:49:11 AM
Usually associated with feed rate in general machining, the tool has to be buried into the material it's cutting, with a wedge shape of the base material being sheared out of its structure as the tool is forced through it in removal.
If the entrance feed was cautious to preserve face of bore, speeded up through mid part, then slowed for exit, this could produce a barrel effect. Basically with higher feed it has more aggressive cut width on each revolution, with the tool being "pulled" further into the wall as it travels with that difference in feed. Its a bit like stripping wallpaper, when you get too much angle on the blade and it's goes "oink~twang" taking a neat little triangle of your plaster with it :)
You'll get it on a lathe too, with a longer tool extension being a little flexible if reaching a long way in. On that you try to offset that little wedge of removed material by grinding a back rake on top of tool face to minimise that wedge in size, the angle of attack effectively.
Drill bits in lathe headstock do it too, you have to go at it really slowly to stop the drill nose "walking" around in a circle if biting too hard, especially as it's likely there's imbalance across the drill cut blades from one side to another.
It shouldn't happen obviously from a good machine shop, often you'll see experienced machinists going about something in a certain way that may look odd, but experience in that process gives them ways to mitigate shortcomings in process.
Post by: Bryanj on February 14, 2024, 01:57:36 PM
Post by: Cb750r on February 14, 2024, 03:12:44 PM
From what I understand this is likely to bad honing setup/ technique. Either way these sleeves are toast as 65mm is max bore on stock sleeves.
I may try these on a cheap set of 65mm pistons in these if I build up all my leftover engine parts into a second engine some day. But these cylinders sure aren’t going together with all the expensive bits I’ve assembled for this build.
Post by: royhall on February 14, 2024, 05:03:07 PM
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Post by: Nurse Julie on February 14, 2024, 05:08:32 PM
At 0.0025" that's almost old British bike spec where they use a lollypop stick to measure the clearance 😂😂😂
Post by: Cb750r on February 14, 2024, 05:34:44 PM
Also according to the measurements required which is .5” up the skirt this is closer to. .0020 measurd conventionally at the base of the skirt
. I’m not really debating the spec set out by the piston manufacturer. I am more concerned about the lack of workmanship and my Un usable cylinders.
Post by: Bryanj on February 14, 2024, 06:05:29 PM
Post by: royhall on February 14, 2024, 06:11:05 PM
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Post by: Bryanj on February 14, 2024, 07:29:41 PM
Post by: K2-K6 on February 14, 2024, 08:13:15 PM
You can see, just within their own range of alloy, that 2618 expands at + 15% over the alternative, let alone the stuff we are referencing and of cast higher silicone content Honda OEM parts....these effectively expanding more or less a match with the cylinder construction.
They'll get to the same clearance once warmed up though.
Post by: Cb750r on February 27, 2024, 05:54:27 AM
I have a balanced alternator also on the way. APE will be sending their clutch kit back with the crank which “should” bring an end to the list of purchases for the engine internals.
I have a set of ZX14 forks and triple clamps. I had previously purchased for another bike (Zrx1100) I’ve been eyeing up for duty on the front of the CB… I’m in the process of turning a new stem on the lathe, will see how things progress. I’m not in a rush to make that swap but I’m in a bit of a holding pattern at the moment so spent some time on the lathe.
Post by: Laverda Dave on February 27, 2024, 08:26:28 AM
For us on here ordinarily accustomed to std Honda pistons and their metallurgy https://www.jepistons.com/je-auto-blog/2618-vs-4032-piston-material-differences/ gives good appreciation of that supplier and the alloy specified as used here.
You can see, just within their own range of alloy, that 2618 expands at + 15% over the alternative, let alone the stuff we are referencing and of cast higher silicone content Honda OEM parts....these effectively expanding more or less a match with the cylinder construction.
They'll get to the same clearance once warmed up though.
Thanks for posting this Nigel, that was an education for me. The pistons used by Morgo in their Triumph 750 conversion kits are forged. Unfortunately the person who originally built my engine decided to swap them out for Hepolite cast pistons but kept the compression really high. When I stripped the engine down after just 320 miles those cast pistons were oval!
Post by: McCabe-Thiele (Ted) on February 27, 2024, 09:17:45 AM
As a student back in the mid 1960's I bought a set of mint looking (used for one race) Hepolite Forged Racing Pistons for my first humble 850cc Mini at the bargain price of £25.00.
At the time I was a student living in Bradford so visited the Hepworth & Grandage Factory Trade Counter who supplied me with a complete set of new rings. They also sold me a special set of Champion Spark Plugs for the highly tuned engine. I came out of the shop substantially poorer.
Looking back putting a used piston in my 45k mile Mini is not something I would do today. They had cut away skirts with the oil control ring being just under the Gudgeon Pin if my old memory serves me right.
Post by: Cb750r on March 07, 2024, 02:54:40 PM
Recovering from Covid, progress in the shop and life was slowed to a crawl for a bit there. Glad to make a little forward progress…
Post by: Cb750r on March 23, 2024, 02:38:51 PM
Post by: SteveD CB500K0 on March 23, 2024, 05:35:52 PM
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Post by: McCabe-Thiele (Ted) on March 23, 2024, 05:49:19 PM
"gourmand de punition"
Post by: Cb750r on March 23, 2024, 08:07:13 PM
Is there a Canadian version of the phrase “ glutton for punishment “ ?
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Dad has expressed interest (has eyes on my 750), so hopefully we can make one of these his!
Plus I kinda know these F2s pretty well. I might as well continue working on restoring some to running condition!
Post by: K2-K6 on March 23, 2024, 08:16:00 PM
Never owned one, but look after a friend's that he's owned from new.
Guess the cost it less than the original models now ? They are an important end of line from the original "superbike" four cylinder engine architecture too.
Quite a few friends owned and ran them when new.
Post by: Cb750r on March 24, 2024, 12:02:08 AM
For me as a 46yr old, and these being pretty much the same age it’s fun. Plus these being the precursor to all of the inline 4 Supersport and superbikes of the 80’s and 90’s has always made me a fan of the 750F where as the older K1-6 are more “retro” in my eyes.
Post by: Cb750r on March 25, 2024, 07:51:09 PM
Can’t wait to have this lightened and balanced beauty back inside the engine! Have a balanced stator rotor to install on the end which should make this one smoooth 836cc when put back together!
Hopefully all of my bearing clearances measure out well, and I can proceed with final assembly.