Honda-SOHC

SOHC.co.uk Forums => Project Board => Topic started by: haynes66 on February 26, 2018, 07:44:53 PM

Title: 500-4 scrapheap challenge
Post by: haynes66 on February 26, 2018, 07:44:53 PM: dont know if this is going anywhere, but i'll give it a shot. back in 2015 i bought the remains of a 500-4 for £90. it was just up the road and the seller even dropped it at my house!

(https://i.imgur.com/3TTKuFJ.jpg)

it came with a full set of original pipes which i sold for £60 so it's effectively cost me 30 quid. everything was seized solid and the frame was rusted through in some areas but i thought it would be a fun school project as i work as a site manager at a residential behavioural school. some of the kids are keen to learn about mechanics so they started to help me dismantle it. however, it really was too bad to work on, the kids rounding off or snapping the many rusted in bolts and screws, so i put it in the boiler house and gave them a worn out superdream which was mouldering behind my shed. this has proved to be a much better choice as they are enjoying taking it apart.
so i'm attempting to strip the engine in my dinner breaks but it may well end up as scrap if it doesnt work out. i hacksawed the frame away but the long mounting bolts are proving something of a challenge. i suspect they may have to be drilled out >:(
Title: Re: 500-4 scrapheap challenge
Post by: Trigger on February 27, 2018, 07:50:35 AM: Cover it in snow foam, a quick wash down and that will be ready to go ;D
The only way is drill ;)
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on February 27, 2018, 04:43:46 PM: i like a bit of patina ;D
Title: Re: 500-4 scrapheap challenge
Post by: Trigger on February 27, 2018, 09:39:46 PM: I can't work it out, is it a K0 or K1 ? Must be a few hard to find parts on her ?
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on February 27, 2018, 10:10:43 PM: i believe it's a k1, according to someone on here. i may not get very far with it, but i wouldnt bin it. there would certainly be quite a few salvageable bits on it even if it's not worth rebuilding.
Title: Re: 500-4 scrapheap challenge
Post by: AshimotoK0 on February 28, 2018, 09:37:52 AM: Quote from: Trigger on February 27, 2018, 09:39:46 PM
I can't work it out, is it a K0 or K1 ? Must be a few hard to find parts on her ?

If the seat is original ..reckon it's a K1.. the rear drum alone would be worth 30 quid if liner isn't cracked.
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on February 28, 2018, 07:11:48 PM: someone on here has already had the front hub, but for some reason refused the rim, spokes and perfectly reasonable tyre...
Title: Re: 500-4 scrapheap challenge
Post by: taysidedragon on March 01, 2018, 12:16:23 AM: Quote from: haynes66 on February 28, 2018, 07:11:48 PM
someone on here has already had the front hub, but for some reason refused the rim, spokes and perfectly reasonable tyre...
Fussy huh? ;)
Title: Re: 500-4 scrapheap challenge
Post by: Green1 on March 01, 2018, 09:50:03 AM: I will have the inner tubes if they still have some Japanese air left. ;)
Title: Re: 500-4 scrapheap challenge
Post by: matthewmosse on March 01, 2018, 12:42:50 PM: That can be saved. My favourite 500/4 had extensive frame rot, I've had to 're fabricate virtually all the rear sub frame and bits of the loop. Some of it two times over as I have given it a decades worth of winter riding and rot does seem to spread if you miss a bit.
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on March 01, 2018, 04:05:10 PM: the frame has been disposed of as it was really bad on the offside. i wish i'd taken a photo of it. the area around the battery box/side panel had rusted away completely, probably as that was the side that got rained on the most. i've had a panther frame re-fabricated many years ago but this was too far gone. it didnt have a log book either. i do have a superdream frame which could work!! a CB500N would get the purists gnashing their teeth! seriously though, i have a big enough task stripping the engine. the only other salvageable parts were the wheel hubs, forks and rusty swingarm
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on March 30, 2018, 02:27:09 PM: so, i posted the above post about a cb500n in jest. but the idea kept going round and round in my head until i thought i'd sit the 250 frame on top of the engine to see where the sprocket position was, and to be honest, it wasnt far off.after further butchering of the frame it sort of almost lines up, so at this stage it's a possibility. the only thing that will scupper the whole thing is front wheel clearance as it's a fair bit further forward than the 250 motor.

(https://i.imgur.com/HOxHqIx.jpg)

it's a bit of a squeeze and there is no room for an airbox but it could be an interesting project. so why am i even doing this when i already have a couple of 750's on the go? well, my wife and i have had a turbulent couple of years but things are a lot more settled now. however, i still have a lot of thinking time in my work which doesnt help, so i'm spending 30 minutes of my lunch hour to do a little work on the project every day. so instead of dwelling on negative thoughts about the past, i'm focusing on the next hurdle/bracket/bodge that needs doing next. i call it the 'clutter principle' where i fill my thoughts with relevant stuff instead of what i tend to dwell on. anyway, it works for me!! also, i think this project has some comedy value to it and will certainly confuse a few bikers if it ever sees the light of day. the idea at this stage is to build it up to a rolling stage and more or less establish where everything will fit and so on, welding brackets where needed as i go along. and even if it doesnt all work, it will be therapeutic for me over the next year or so.
some people might get a little annoyed that i appear to be butchering two 'classics' to make this thing but the 500-4 cost me very little and the engine is potentially scrap and the superdream was about to be chucked in a skip. if the engine is salvageable and i did get this thing on the road, i suspect that a few years down the line the motor would be returned to a 500 frame and the superdream bits thrown away, so no great loss there!
Title: Re: 500-4 scrapheap challenge
Post by: mike the bike on March 30, 2018, 03:04:00 PM: Could be worse - a CB550 frame with a Superdream engine
Title: Re: 500-4 scrapheap challenge
Post by: Colonial-Clive (yindi) on March 30, 2018, 03:12:36 PM: Keep us updated I like the oddball ideas that work. And it looks like that just might make it.
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on March 30, 2018, 05:10:13 PM: i've thrown everything together just to get an idea of front end clearance and it's not looking too good.

(https://i.imgur.com/RgKBPO5.jpg)

(https://i.imgur.com/1ujHB7G.jpg)

in the second pic i'm holding the ruler fairly horizontal and it is 5" from the filter bolt to the tyre. can anyone with a 500 take a quick measurement from the same points please?
Title: Re: 500-4 scrapheap challenge
Post by: Nurse Julie on March 30, 2018, 05:49:13 PM: Just measured CB500, ruler in same place is 5 inches. Slightly difficult to measure as this bike has front mudguard on.
Title: Re: 500-4 scrapheap challenge
Post by: Colonial-Clive (yindi) on March 30, 2018, 07:15:50 PM: Hi, from front bolt to tyre is 6", from no 2&3 pipes 5" so you should have enough room, or you could rake the neck a tad.. ;)
Title: Re: 500-4 scrapheap challenge
Post by: matthewmosse on March 30, 2018, 08:44:54 PM: I like what you are doing, I have a cb125 twin engine and Ns125r frame that are a similar idea, the frame had previous really dodgy welding on the monoshock mounting, given it was known to be tuned to accelerate like a banshee and do 110mph there was no way I wanted to put it back to standard format, so I got a replacement frame and v5c and intend the ns125r to become a ns125f, no big deal, cheap learner machine, might be fun. The old ns125r frame will be strengthened and twin shocked and get superdream wheels that failed to get sold at 99p on eBay. The rest of the running gear will be stuff that came in job lots or was given by various mates clearing garage space. Kids and getting laid off have slowed progress on bikes to a virtual halt as starting up in self employment and the stresses on a marriage that career rollercoasters and kids bring do not leave a lot of shed time, but one day the project will come back to the front, like you, I find it good to head out to the shed and solve the problems involved in a 'custom' project to clear my head, though there are a few such projects in my shed, mini dumpers made from industrial grass cutters also fill that role and look to potentially earn a few pennies, plus damn handy things for my handy man jobs, save a lot of pushing wheelbarrows.
Looks like you are hopefully about there on clearance. Weight wise my first 550 came in a job lot with several cb250s, I remember the engines were close or weight and width when I loaded them in the van. Might make a fun bike. If the clearance is too tight a tad more rake to the frame with careful welding, slab yokes to kick things foreward or leading link forks might make it both more interesting and involving and more unique. Equally a smaller diameter wheel and longer forks might increase clearance. ( trail bike forks?.)
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on March 30, 2018, 10:15:12 PM: thank you all for your input. i put another spare set of forks on which have no springs in, so the thing sits at full travel and it looks like it might be ok. i will be looking out for a 400n front end as the forks are a tad thicker and has twin discs but that is down the line a bit yet. new engine mountings are next on the agenda and i'm still unsure about downtubes. i was thinking i would need to run tubes under the engine but having seen a few racing 400s, the frame seems to be stable enough to use the engine as a stressed member. i'll need some professional advice on that one, i think.
Title: Re: 500-4 scrapheap challenge
Post by: Bryanj on March 30, 2018, 10:26:18 PM: lots of bikes used the engine as a stressed member and it was not unknown to build a "Trifield" a 500 triumph twin in an enfield 250 frame using dural plates
Title: Re: 500-4 scrapheap challenge
Post by: SteveD CB500K0 on March 31, 2018, 07:20:53 AM: I all the years I’ve been running this site, I believe that this is the first “transplant” that has been attempted!

Good luck and keep the posts coming

Steve

Sent from my iPhone using Tapatalk
Title: Re: 500-4 scrapheap challenge
Post by: matthewmosse on March 31, 2018, 08:50:31 PM: I think the cb250n used the engine as a stresed member didn't it? So my guess is it would handle the modest power increase as it's fairly smoothly delivered. That said bending up a set of removable cradle tubes might be worthwhile - I think the 650 used such a device, not sure if I'm right on that, bought a job lot of 650 stuff and one bit looks like it would have done that job.
Best fortnights work I had was work expirience placement at metal malarkey engineering, one project we were doing was fitting a Cr500 motor tuned to over 90 bhp into a Cagiva mito 125 shoehorned in so as to look as close to standard as possible.
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on April 23, 2018, 05:31:24 PM: i've cut the frame about and cut some engine plates etc which is the easy bit but now the hard work begins. the cover on top of the engine was the first to be removed but two of the long bolts have snapped already so i think it's going to be a long slow slog at an attempted strip using heat, diesel and a little brute force. i'll post any updates as/if things progress.
Title: Re: 500-4 scrapheap challenge
Post by: matthewmosse on April 23, 2018, 09:18:08 PM: Paint it in old engine oil, being slightly acidic and very oily it really helps with freeing off old engines, especially mixed with a bit of carb cleaner and wd40. I used such a mix on a cb550 engine that was so corroded the clutch casing had dissolved, amazingly the top end was mint, especially things like camshaft and cam journals which whilst caked in oily mud cleaned up lovely.
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on April 23, 2018, 09:46:08 PM: thanks, i'll try that
Title: Re: 500-4 scrapheap challenge
Post by: haynes66 on May 14, 2018, 10:56:55 PM: i've been attempting to strip the motor but it's infuriatingly slow as nothing much is budging. the round cover has been removed but two screws have snapped. thankfully, most of the cam cover bolts and screws are loose but i will have to drill out a couple. to give myself a break, i've been cutting and filing engine plates which has been therapeutic. the first pic shows the piece removed from the frame.

(https://i.imgur.com/6iqGxG8.jpg)

i had some 5mm plate machine folded to give the frame some strength before tackling the engine plate

(https://i.imgur.com/oovz05B.jpg)

then i spent a while cutting and filing the engine plate itself. this is bolted on at this point to make sure of the sprocket location. i slotted the bolt holes to get the engine height in the correct spot.

(https://i.imgur.com/CXnzlsJ.jpg)

sat the frame on top to see where everything fits and it looks ok. the pod filter is an ebay cheapie to check for clearance. the next stage will be welding the rear plate in place and maybe think about downtubes although i dont want to spend any more money at this point in case the engine is scrap.
(https://i.imgur.com/8j3iDDw.jpg)

(https://i.imgur.com/AQC6Mf0.jpg)