Hi all

I'm hoping that someone can tell me the answer to this:

Would 435cc pistons and barrels fit a 2CV6 engine? Are they shorter?

I always thought that the barrels were the same as 2CV6 and just had thicker walls. But would they even fit?

If you kept the 2CV6 crank what size engine do you end up with?

Cheers

Matt

http://www.scooterhelp.com/tuning/defs.ccs.html.


I hope the above takes you to a page that explains how to work out CC and includes a calculator..

515cc as long as the crank clears the bottom of the barrels they have relief cut outs for the 70mm throw crank not sure if the 435s do.

68.5 dia bore so : (bore/2 sqd )3.14 x70 - crank throw x2 two cylinders gives a huge number because its in cubic mm so take the first 3 digits ( well it has to be greater than 435 and less than 602).

every days a school day

Matt,
because the 435cc engine has a much shorter stroke, the 'head to head' measurement is considerably less than on a 602.

All approximate, but should give you an idea.
435 barrel, lower spigot OD 78mm, crankcase opening to top of barrel 77mm.
602 barrel, lower spigot OD 82mm, crankcase opening to top of barrel 99mm.

I think the appropriate advice is "You're on a hiding to nothing with that plan, m'dear".

Ken

ah!

Oh arse! That's quite a lot shorter.

Are the 435 and 602 crankcases different also then? What about the cylinder heads? Are they also different?

Too many differences to list?

Ken

425 (4 stud), M4 and M28 barrels are interchangeable - at least, those are the ones I've compared. I know 435s have shorter barrels.

However, you can't really put M28 pistons in an M4 because of the head shape which results in weirdo compression ratios, so goodness knows what it would do to a 425.

Cylinder heads:

You can fit M4 heads to an M28 to create a hybrid, a number of M4 owners have done that given the rarity of M4 parts, thus preserving the exhaust/carb/linkages of the M4 negating the need to change pedal boxes.

I guess you could therefore also fit M28 heads to an M4.... although I don't know why you would.

Given the barrels are the same. I guess you could do M28 heads/barrels/425 lump.... but why bother molesting engines. A well used and maintained 425 will do 60mph and Hetty has no issues with 65 so I must admit other than the 'its possible so lets have a go' attraction, I'm not sure why people bother.

Sam

I basically want a 435cc engine and possibly gear box for an experiment. I've never seen a 435 up close so I have no idea how different it is.

Anyone got one? lol