Enduro 360 H7 cylinder with Cappra 414 piston

[jurado]

I am re-building my Enduro 360 H7 and will install a cappra 414 piston in the engine. This was quite often done here in Spain in the 80s for cross country racing. 

Both, the original Enduro 360 H7 (83.4 mm) and the cappra 414 piston (88 mm) have the same length, so no need to adjust the cylinder position.



Cylinder has been bored to fit a brand new cappra 414 piston. See below, piston still with its label stating the price back in the early 80s (15800 pesetas = 95 euros).



This is the already bored cylinder. Cylinder-piston clearance has been set to 0.07 mm, with piston diameter taken at its skirt. I will also install new “L-shape” rigs.









Cylinder head need some minor bore some 2 mm on the border of the compression chamber, so that the border of the wider piston (88 mm piston), does not touch the cylinder head when at TDC.



Rest of engine will remain so, since stroke will be as per original (64 mm), resultant engine size will be:

(3.1416 / 4) x 8.8 x 8.8 x 6.4 = 390 cc

Regards
Jurado

[cappra]

Did you have to cut the cases where the sleeve sits down?

[TooFastTim]

Bloody hell Jurado, some "bits" have flown around in there at sometime.

[jurado]

The cylinder and its sleeve are the originals for the Enduro 360 H7 engine, so I did not have to cut anything. Sleeve has just been bored to fit the 414 piston (88 mm when compared with the 83.4 mm for the 360 engine). Resultant sleeve thickness is still ok (reduced from 4.4 mm to some 2.2 mm).

Regards.

[jurado]

The 360 h7 with cappra 414 piston is finished. Here are some pictures:

-   new pipe, tailor-made
-   original silencer Tecnomoto, cut some 10 cm
-   New Keihin 39 pwk
-   New disk brake


























Here is a link with the sound of the engine.

http://www.youtube.com/watch?v=h56tN8zVFkM


The only missing thing is a longer speed indicator cable. I need to get a longer cable from wheel to indicator. I´ll get a new cable.




Regards

[TeeBone]

Great job, Jurado...who makes the pipe?

[firko]

Really nice bike Jurado. Is it hard to start with that short arse kicker?

[jurado]

The pipe was made by an “artist” here in Spain. I have not seen anyone better.

The Cappra 414 has the same kick-starter lever. What I do is to do 2-3 small kicks, not strong enough to get spark, but sufficient to get mixture to the crank and cylinder. Then an almightily kick. It kick-starts with just one.

[mx250]

Sooooooo, what's the verdict - worth the effort? What does it go like?

[Montynut]

My current VB360 race bike (Ex Ross Nimmo bike) has a 0.25mm OS 414 piston installed and has been running perfectly for years. I did find that it needed a new piston earlier this year when I found a very small crack radiating from the boost port in the rear of the piston although that piston had done three seasons of VMX. The engine revs very freely with the 414 piston as the bore : stroke ratio is even larger than standard.

From my experience it is a great converstion which has proven reliable and given that it has only been recently that you could buy Cappra 360 pistons again (Italikit) it was the only alternative. I am currently building a H6 engine for a VE Cappra chassis to use for Dirt Track next year.

Detonation can be a problem if the compression ratio is not corrected

[jurado]

I have upgraded my Enduro 360 h7 engine with a new 414 piston, new pipe, reduced the weight of the Rotor and new Keihin 39 pwk carb. I have also included a ported cylinder for better response.

Result is that a significantly improved response in the whole power band, but getting some clutch slipping from 4th gear onwards. I did not change the old clutch yet.

I need now to change the clutch plates and I will also put a new set of springs, hoping to get rid of the clutch slipping.

As far as I know, there were different spring models differentiated by colours. The green ones were for Cappra 414/360 and, I believe, were stronger than the ones for 360 h7 Enduro.

Am I right?. Does anyone know where I could get a new set of these green ones?

Regards,

[cappra]

I no longer have any of the green springs in stock. Maybe shim the stock springs?
Newfren has new clutch plates (F1424AC) but I have never tried them. Still searching
for new springs. I am also getting slippage with the 414 and this is with the green springs
and the 15 plate clutch. 66M uses the 16 plate clutch and enduro springs.

[jurado]

Standard 360 h7 clutch springs are available, and dimensions are:

34.00 mm high
12.60 mm wide
2.30 mm thick

The springs for cappra 360/414 are, as far as I have been told, stronger, and thus are the ones I would like to fit in my 360 h7 if possible. At least in Spain these springs stalled in the cappras had a green colour.

I have found a supplier in e-bay USA that is selling cappra 360 clutch springs. I asked him the dimensions are these are:

26.70 mm high
12.70 mm wide
2.80mm thick

They are thicker and thus seem to be rather stronger than the standards for 360 h7. They are also shorter. What I do not know is whether they would be suitable for the 360 h7. Any views?

Does anyone have the spring dimensions for a cappra 414?

[cappra]

In looking at the parts book, the 360 and the 414 use the enduro springs (6763.027)
The VB 250 uses the 5363.02701 springs (green colour) and oddly the VE 250 uses the
6763.027 enduro springs with the 5363.023 clutch pak (15 plates) I was using the earlier
VR clutch assembly (15 plates, green springs) on the 414, but it is now starting to slip.
I have not tried the stock 414 clutch (16 plates) with the green springs, so I'm not sure
how it would work on the 360 H7. I would imagine that the clutch lever pull would be
little harder with the green springs.