1974 Honda CL360 barn find

ridesolo said:
Hmmm, dat's kinna cool. (the 1 into 2 above)
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It is tempting. But I can imagine it would take a lot of trial and error to get it to run right (assuming you pick the right carb size to begin with.

Speaking of size, 2x the area of a 28mm circle is 40mm. However, even though the volume of air would be the same, the vacuum signal would be different because of the alternating intake pulses. This is why I was thinkin the TM36-68 might be the right size. However, this carb is generally run on larger displacement (500cc plus). Like I said, a bit of a guess.

Mikuni manifold with carb.jpg
 
I collect cheap VMs from swap meets and Ebay, or buy bodies from either place. I have tackle boxes full of the various parts. Combine parts on hand with whatever is missing from Niche or Jets R US usually gets me a good VM built and tuned for under $100. If I'm going single VM, I'd probably put a 34 on it. I think the 36 would be too big. I put 28s on my 360s with stock bore and 32s on the 385. I run a single 38 on my 79 XR500 (bored 530) engine. Twin 34s on CB750s. If PJ chimes in, he'll tell you he doesn't like the VM on this bike.
 
For the sake of posterity, here are the cam specs for Megacycle compared to the OEM Honda 360 cam as measured by Megacycle: (https://www.megacyclecams.com/):

1702502561217.png


Valve to piston clearance on the Megacycle cam is:
Intake - .043
Exhaust - .047

Cost for regrind on your cam is $500.

They intend to have the factory cam specs in their catalog, but they are way behind on updating their catalog.

Barbara was very chatty and helpful. A couple other recommendations from her:

1. In any motorcycle, run only Motul or Valvoline VR1 oil, but only use the Valvoline on dry clutch bikes.
2. Honda 360 rockers are notorious for being worn through. They will clean them up and re-plate the wear surface for $100/rocker.
3. If you need a 360 cam she thought there were a few in the shop that could be reworked.
 
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Web cams can do custom grinds for less than mega cycle. When i had a custom cam ground a several years ago it was $150 cheaper
 
Untame said:
It is tempting. But I can imagine it would take a lot of trial and error to get it to run right (assuming you pick the right carb size to begin with.

Speaking of size, 2x the area of a 28mm circle is 40mm. However, even though the volume of air would be the same, the vacuum signal would be different because of the alternating intake pulses. This is why I was thinkin the TM36-68 might be the right size. However, this carb is generally run on larger displacement (500cc plus). Like I said, a bit of a guess.

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I have a pair of VM34s you can have. They are pretty much all there, but I know they came off a snowmobile so the jetting will be all wrong. You can have them if you want them.
 
The stock 360 engine was detuned by Honda to make it more enjoyable to ride. The result was 34hp @9000 rpm. The previous Honda model the CB350 was rated at 36 hp @10,500 rpm. The one advantage of the 360 engine over the 350 is the full horsepower comes on at the earlier rpm. My Ninja 250 produced 38.5 horsepower stock and with a simple tune and a better exhaust it pulled 48 on the dyno at Daytona last month. So how much HP are you trying to get out of your 360? Speed costs money, how fast can you afford to go? You can have the fastest Honda 360 in town and still get beat by modern 250. If the engine needs boring, it makes a little bit of sense to use overbore it. A single carb will never flow as well as a dual carb setup. If your stock carbs are in decent shape do the PJ mods. If they are not rebuildable, then look for alternatives. I'm not trying to dissuade you from building a hot motor as we've all done it. But you need to get realistic about how you are going to use the bike and how much money you want to dump into it.
 

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ex119x said:
I have a pair of VM34s you can have. They are pretty much all there, but I know they came off a snowmobile so the jetting will be all wrong. You can have them if you want them.
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I appreciate the offer, but I'm not going to go the 2-1 route. Probably do a pair of VM30s (kit from Speed Moto).
 
Rider52 said:
The stock 360 engine was detuned by Honda to make it more enjoyable to ride. The result was 34hp @9000 rpm. The previous Honda model the CB350 was rated at 36 hp @10,500 rpm. The one advantage of the 360 engine over the 350 is the full horsepower comes on at the earlier rpm. My Ninja 250 produced 38.5 horsepower stock and with a simple tune and a better exhaust it pulled 48 on the dyno at Daytona last month. So how much HP are you trying to get out of your 360? Speed costs money, how fast can you afford to go? You can have the fastest Honda 360 in town and still get beat by modern 250. If the engine needs boring, it makes a little bit of sense to use overbore it. A single carb will never flow as well as a dual carb setup. If your stock carbs are in decent shape do the PJ mods. If they are not rebuildable, then look for alternatives. I'm not trying to dissuade you from building a hot motor as we've all done it. But you need to get realistic about how you are going to use the bike and how much money you want to dump into it.
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It's an engineering exercise. And something about being a red-headed stepchild makes me love 360s. I've never done a cam swap on a 360, but I've done everything else. 110 mph is plenty for this frame and that's achievable with a stock motor and PJs carb mod. The GS piston is worth the trouble, imo.
 
irk miller said:
It's an engineering exercise. And something about being a red-headed stepchild makes me love 360s. I've never done a cam swap on a 360, but I've done everything else. 110 mph is plenty for this frame and that's achievable with a stock motor and PJs carb mod. The GS piston is worth the trouble, imo.
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Hearing you say this makes me want to be the one to try the Megacycle cam. Should pair well with GS850 pistons, a Mikuni VM30 kit, and freeflow mufflers.

There is something about just knowing your machine is a little extra special on the inside.
 
If you are going with a built engine, I'd make sure to pick up a spare bike to use for parts as this is going to be a never ending project.
 
ex119x said:
If you are going with a built engine, I'd make sure to pick up a spare bike to use for parts as this is going to be a never ending project.
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I'd be slightly careful about that. I'm not 100% sure but I think there MAY have been some differences between the engines on the '74s and those the '75-on. When I got mine it came w/ most of another engine and it looked like there were slight differences between it and my '75. I checked the numbers and it was a '74. Probably PJ or Irk can confirm this or confirm that I'm fulla' beans.
 
My friend was over for dinner and mentioned his dad used to have a CB360. He sent me this last night, and I thought you guys would enjoy this. I think his dad was nuts!

received_1446775295873434.jpeg
 
Holy cow! What an intrepid guy. Times have certainly changed. These days the woke set would probably try to run him off the road for killing Bambi and not being Vegan, and if he had a rifle rather than a bow he probably would be pulled over by Sheriffs Deputies, Highway Patrol, ATF, and Homeland Security!
 
I'll eat Humble Pie if I'm wrong, but isn't the CB360 a 180 degree crank engine? If so, through personal experience and then reading up on it later, single-carb set-ups on 180 degree twins don't work too well due to both cylinders pulling one right after the other? Again- my apologies if this is in error.
 
irk miller said:
I collect cheap VMs from swap meets and Ebay, or buy bodies from either place. I have tackle boxes full of the various parts. Combine parts on hand with whatever is missing from Niche or Jets R US usually gets me a good VM built and tuned for under $100. If I'm going single VM, I'd probably put a 34 on it. I think the 36 would be too big. I put 28s on my 360s with stock bore and 32s on the 385. I run a single 38 on my 79 XR500 (bored 530) engine. Twin 34s on CB750s. If PJ chimes in, he'll tell you he doesn't like the VM on this bike.
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It isn't that I don't like VM's on 360's just that I haven't spent enough time with them to get carburation right for most.
The ones sold as 'set up' don't have correct emulsion tubes or slides as they are 'too expensive' for re-sellers to swap out (around $100+ for parts, haven't seen guy making custom emulsion tubes @$48.00 + shipping on eBay for several years)
I have a modified set off early Suzuki (piston port)
I made new emulsion tubes for (then broke mini mill controller board) that work very well of my XS650~800 even if they are a bit small. I haven't made any since then as new mill/drill doesn't spin fast enough for 0.80mm drill bits.
I fitted Yamaha RD 400 to my CJ'400' as they are set up for a 'four stroke' motor (due to reed valves giving different signal compared to piston port)
Even with 26mm VM the CJ was good for about 120mph.
360 is a 180 crank so there are two firing impulses very close together then a lag before it happens again.
Personally, I wouldn't even entertain the idea of single carb on one, original CV is fine and can be modified for K&N or Uni filters (cheap pods are restrictive over 5~6,000rpm).
Oh, there is a build on here with 378 conversion and I think half race cam (?) Guy's in California and said '360' was better than CB900 on canyon roads. I forget name but bike was BOTM a few years ago, pale blue/green maybe?

That's a great story about deer hunting on a CB360, wouldn't have imagined doing that even in the 70's. :cool:
 
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Holy Smokes, I am surprised I didn't see your buddy's dad on the road. 1975, I am a freshman at UW-LaCrosse. Deer season is around Thanksgiving and I am going to meet my brothers at our usual deer hunting spot near Necedah, about 75 miles away, so I get up at 5 am and load up my 1975 Honda CB400F and head out in the cold. I am so frozen by the time I get to camp it takes me until afternoon to thaw out enough to go hunting. I am so glad I didn't get a deer that year, cause I couldn't imagine hauling it back on the bike. When a bike is your only form of transportation, you do what you gotta do.
 
Got a set of used GS850 Pistons. Now to break down the motor and have the cylinders bored.

20240315_150408.jpg
 
New rings are in the mail. PJ has my Keihin CV carbs. So some progress taking place again.
 
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