N360 on dyno, DOHC head

Jfbrink · **Posted:** Thu Dec 30, 2010 10:08 pm

Hi, all,

Has anyone found any more details on this v-max head setup? Even the Japanese sites have very little info. One does refer to the engine as "hand carved" (thanks, google translate), which I think supports Carrotsnax's theory that the cylinder portion of the engine is custom made to match the 360 below and the v-max above.

I more-or-less have the resources and the skills to machine such a thing, but what I'm not sure of is how much I would gain over my stock n600 sohc. Any thoughts on the actual benefits of this sort of upgrade?

Jesse.

vwdmc16 · **Posted:** Mon Jan 03, 2011 2:32 pm

AHHHH! sucess! i finally found the website that clearly breaks down how to install a yamaha v max dohc head on the N600 engine. now be forewarned its in jibberish but has good pics.

basically they remove the stock top end and and re drill the holes for the stud pattern in the upper crankcase and install a custom barrel set up with the 600 liners, then bolt the yamaha head on that

http://66.163.168.225/babelfish/transla ... fdohc1.htm

also some dyno results:

http://66.163.168.225/babelfish/transla ... ivent8.htm

http://66.163.168.225/babelfish/transla ... ivent6.htm

Some more race details on another DOHC car, with some great restoration reapir photos
http://66.163.168.225/babelfish/transla ... 2fn360.htm

Jfbrink · **Posted:** Mon Jan 03, 2011 11:23 pm

Ah, the DOHC information, straight from the source. Well done!

It almost makes sense, although I'm baffled by the talk of an added 5th gear. To augment VWDMC16's summary, below are better translations of the two summaries on the page itself (one at the beginning and one at the end):

"In the beginning tried to make N600 engine a DOHC engine including a missing 5th gear. Then it's said that it's good for nothing, and I'm going to put 600 cranks in 5th gear of GS.

● N600 crank is changed to type 180-degree.
● A stroke is long, so about 20 mm of cylinder is raised.
● Because a N600 primary is used, so a driven sprocket became big and a chain also became thick.
● A cover in a driven place was reformed newly including a spacer in the left crank side cover case.
● A tensioner is also manufactured newly.
● A cylinder also manufactured
● The sentence muffler which became expensive newly.
● It's cold for winter, so a duct is also manufactured."

And, later...

"DOHC-N (5th gear of ZGS + VMAX)

Engine details, first version
-Under the lower back 5th gear of ZGS
-The N600 crank is changed to 180 degree crank-type.
-Primary drive sprocket 21 T -> 16T (N and made of Z) is changed.
-Upper case Stat bolt installation hole drilling Full tiger for type Ⅰ (digital Susumu Sumi made in DYNA) Take a crank.
-New pickup magnet embedded in crank pulley (N and made of Z)
-New crank housing made for starter motor
-Piston (VMAX) 12.6mm ID piston pin made; A piston 1mm offset.
-Head (VMAX)
-An FCR35mm carburetor with pace/pitch changed
-New one-off muffler (stainless steel) Only EKIPAI.

Results: A tensioner damaged-> reinforcement. A piston pin damaged.

Engine details, second version
Reinforcement piston pin It's made newly 10.2mm of inside diameter.
The crank condition lot part 1 mm was set off and an offset of a piston was lost. I make a mistake in pin height and put a shim of 1.5mm under the cylinder."

Honestly, most of the rest of the text on the page is a semi-imaginary dialogue between "Mr. I" and "The Chairman" in which they bicker about whether the build can be done. At least there are lots of photos. I believe that there is almost enough information now to do this, if the doer has a good sense of how to build an engine.

VWDMC16, I thought you gave up on this in May, but does this mean that it is still on your mind? Are you moving forward or just curious?

Jesse.

vwdmc16 · **Posted:** Tue Jan 04, 2011 1:45 am

The way it talks about the 5th gear from the GS is strange, now there were a few trim levels you could buy a z600 in :

Z (ACT)
Z PRO
Z TS
z GT
and the GS

I believe the GS model was the full loaded one maybe with 5th gear, also ive read that it had better brakes some how

Here is some brochures i have, can anyone read these?

as for your question, while yes im still very curious about the history and rare facts of these cars in not planning to perform large modifications on my Z anymore

Camshaft · **Posted:** Tue Jan 04, 2011 10:48 am

vwdmc16 wrote:

I believe the GS model was the full loaded one maybe with 5th gear, also ive read that it had better brakes some how

Yup. And don't forget the twin carbs for a fire-breathing, tire-frying 36HP!

rasta N · **Posted:** Tue Jan 04, 2011 12:42 pm

so the GS came with the duel carbs? if so would that bolt up to the n600 head?

vwdmc16 · **Posted:** Tue Jan 04, 2011 2:18 pm

The upper head section must be different, with a wider port , maybe seperate runners for each valve.

I was under the impression that only the Hawaiian export models had the twin carbs, not sure why they need 2 over others.

and adding another carb to get 4 more hp?

anyone read the brochure?

Camshaft · **Posted:** Tue Jan 04, 2011 4:17 pm

Erm, the top spec JDM 360s had the twin carbies AFAIK. Concerning US cars, I do believe only the Hawaiian Z360s/Z600s had factory twin carbs.

rasta N · **Posted:** Fri Jan 07, 2011 4:16 pm

I have also seen a pic of a 72 z600 gss. It looks like a twin carb to on the early motors with a orange air box I can't really tell its a small pic but the outher s might be a type o. Ill post up the pic later today.

rasta N · **Posted:** Sun Jan 09, 2011 6:28 pm

heres the pic

Team_Dandism · **Posted:** Wed Jan 12, 2011 11:20 am

The car with the orange air box is a later GTL ie liquid water cooled car. Most if not all the carbs I've seen for sale in japan have been twins on a different intake manifold than euro or us cars.

I didn't think any 600's had twins only the 360's. The did sell the N600E in japan but that has the same Keihin carbs as the euro spec 45 bhp versions.

It'd be cool to see someone from the english speaking world do this vmax swap on a 600cc car to see what effect it has.

As an aside where can I get the rear number plate light shown on that green car. I'm trying to restore mine to more of a Japanese spec.

Robb · **Posted:** Thu Jan 13, 2011 5:33 pm

79cord · **Posted:** Thu Jan 13, 2011 6:18 pm

Yes as said the last car is one of the later Honda Life based Watercooled Honda Z360 that replaced the Z360 air-cooled (with a signifigantly revised front structure & engine/transmission layout: 80mm longer wheelbase -same length).

The 600 engine would be VERY rare in Japan since they didn't fit in the regular 360cc Kei-car tax category so some of their sites talk of importing these engines or complete cars from the US. with American spec. cars sometimes appearing for sale there.

So the Z GSS with a 5-speed g/box, twin carbs & 'Upgraded brakes' mentioned would have been a 360cc car with significant engine/transmission differences possibly making the fitment of those parts into a 600 bottom end difficult.
The Standard Z600 disc brakes would have been an upgrade since most Z360 only came with drum brakes all round. I'm not even sure if disc brakes were offered on the later watercooled Z360life cars since I guess they would mostly have been developed for the export oriented Z600

N360 on dyno, DOHC head

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