inline 4 cylinder 2 stroke engine?

[Gil Gallad]

after MUCH googling etc, i cannot find an instance of a modern inline 4 cylinder 2 stroke engine - well not for a bike anyway. apart from mr millyard's welded together crankcases to make his multi's, i'm stumped. i'd love to build a 500cc engine using the gt250's as my base. the crank would be fairly easy, but the crankcases are such a weird shape, getting 2 of them side by side looks virtually impossible. converting an inline 4 cylinder 4 stroke to 2 stroke looks just as difficult. any thoughts/ideas would be welcome. apart from don't do it :D
cheers, gil.

[m in sc]

theres been quite a few rds done , especially in the uk. as far as a gt250 motor? hm.  I mean, -maybe- you could get a set of GT750 cases and add 1 cyl, then use t500 barrels.  just a thought.

[rodneya]

Mattoon Machine make triple and 4 cyl cases.
I think they only have a Facebook and ebay store

[Gil Gallad]

thanks for that both of you  8)
any chance of a link to the yamaha inline 4 cylinder? would be most appreciated.
wonder if any of those crankcases are for 2 strokes? hard to tell from the photo  ;D
cheers, gil.

[m in sc]

they are, all pretty much banshee based.

looks like the websites broen but the FB page is up

https://www.facebook.com/mattoonmachine/


4790 NE Henery Creek Rd
Dayton, Oregon 97114

(503) 864-8083

[Dvsrd]

Maybe not what the OP is looking for, but I saw a TZ 500 triple on Phillip Island in 2011. Apparently,  some British or Aussie engineer/racer added a third cylinder to a TZ250/350. He had made an extra crankcase section, and bolted it onto the original cases on the ignition side. And obviously built a custom crankshaft. Pretty neat, actually.
The obvious, easy solution for the OP would be a Yamaha V-max 4 snowmobile engine, at 750 cc. And some kind of HD primary/clutch/gearbox setup. Or maybe a custom racing gearbox for a Norton?

[Gil Gallad]

i think the chances of getting  a Yamaha V-max 4 snowmobile engine here in england are nil. i think i'd have more chance of allen millyard knocking on my door and offering to work for me  8) thanks anyway. i'll keep my eyes peeled, you never know, something might crop up  ;D
cheers, gil.
p.s. wtf is an op? old pensioner? old person? 

[Dvsrd]

OP=Original Poster, i.e Yourself 😊
You may be right that snowmobiles are scarce in the UK, but rather plentiful in Finland, Sweden and Norway.
Not to mention Canada and US. So it should be possible to find one, if you really want to.
Also, Arctic Cat had a 1000 cc triple, made by Suzuki, which was more powerful than the Yam 750-4. Even later 800 cc Ski-Doo/ Rotax twins were really powerful , and much lighter.

[Striker1423]

I shot them a message out of curiousity. Would be interesting if they could fab up an RD case. Albeit would not be cheap at all.

[RD7]

Have you looked at GT380 or 550 cases? Less complication than the watercooled 750.

[AAAltered]

I saw a 4 cylinder 60's Yamaha at Mid Ohio some years back.  It looked like a YM1 type bike.  I have pictures somewhere but can't find them right now...

[Evans Ward]

It's been done several times with the Kawasaki H2 750 by adding an additional cylinder.

[Dvsrd]

I shot them a message out of curiousity. Would be interesting if they could fab up an RD case. Albeit would not be cheap at all.

I think I saw someone making TZ750 crankcases, maybe some company in Italy. Would be stupid expensive I guess. Anyway, AC RD as well as LC top ends should be possible to use on a TZ750 case. So a 500/700/750/800 four should be possible, if someone with deep enough pockets should want one :)

[m in sc]

the tz 750 cases are about 6k for bare cases last i checked.

btw tz500 is a 4 cyl, not a 3.

most 4 cyl home brewed cases are added to the sprocket side BTW, then the sprocket is carried over with a jackshaft.

[pdxjim]

TZ250/350 with an extra cylinder grafted on was actually a pretty common mod before the 500/750 came out.