The Place

I hope this is the right section. What year did IOM standardize on the 600cc motor?

I'll guess until BigTim and Geoff Bell come back with the right answer about 93?
There was a period when 600s were in as well as 350s.. I was on a 350 in 92 at the TT but on a 600 in 1990 on a 600 in the UK but we weren't included in F2 here at that time with all clubs, with some we were still in the open class.

The last year of "Open Sidecars" was 1989 at the TT. An F2 class was run alongside the Open Class from 1984 until 1989.

The TT became solely F2 in 1990, and most outfits ran the TZ350 twin cylinder motor, (one or two ran other variations such as the Ringhini and Armstrong), although there were a few 600 outfits used in that year. 1000cc twin cylinder fourstrokes were also allowed in until 1993, most notably used by Vince Winstanley (BMW) and Neil Smith (Ducati). In 1991, a few more 600 outfits appeared, a number in long tubular chassis, although from the start of the 1992 season onwards, l.w.b. outfits were not allowed in the F2 class.

The 600's became more prominent, both in terms of gaining results and popularity throughout the mid to late 90's; although a handful of teams continued to use the 350 two stroke.

For the last few years, the regs have stipulated the use solely of "501 - 600cc, 4 stroke, 4 cylinder, Production based" motors. I am unsure when the exact year that the rule was brought in that only option was to use a 600cc motor, but I would guess that it was at least five years ago, possibly longer.

thanks! You guys are the best!

one more dumb question - did anyone race water-cooled motors in the late '80s? If so which ones, size, etc.

TZ's were water cooled

edit - tim's about to post a list

steve-e wrote:edit - tim's about to post a list

Tim must have reached for another pint instead!

I saw him online and didn't think he'd miss the chance

There's probably someone better informed than me to comment on this, but by my reckoning the following were used which were water cooled. Most, if not all two stroke motors - that's twin (350) and four cylinder (500, 700, 750) TZ Yamahas, the Suzuki GT750 (Kettle), and other 350's, such as the Armstrong and Ringhini (although I seem to remember the Ringhini was used in the early 90's by one or two, so maybe not the 80's as such). I don't know the dates on G.P. motors (Krausers etc), but they were, as far as I know, four cylinder water cooled two strokes. There may still have been one or two Konig's (500, 680, 750) on the club scene, but not at the TT by the late 80's.

In terms of fourstrokes, by the late 80's, there were still a few of the old air cooled twins about in the F2 class. The open class had quite a number of air cooled fourstroke engined outfits from the early part of the decade, such as the Kawasaki Z1000, Suzuki GS1000 and even one or two Honda CBX1000 (six cylinder). Later in the decade, some liquid cooled fourstrokes appeared, mainly the early Suzuki GSXR1100 (from the "Slabside" road bike), and the Kawasaki GPZ900 motors. The fourstrokes tended to be / (often) rumoured to be bored out to much bigger sizes than the manufacturers specification, the capacity limit for most events being 1300cc.

The Kawasaki GPX600R was water cooled, and first used in a Formula Two sidecar in September 1989 at Scarborough.

By no means an exhaustive list, and I apologise for any inaccuracies, but hopefully it's a start.

Hi

Also remember seeing water cooled 500 hi-tac Suzuki, IMP, Saab, MG miget and a Fiat engined outfits all in the early 70's.

John

If Ian started driving in 1990, then dad must've been driving still at the end of the 80's and he definitely had ZX-10 and GPz900R (he wanted me to get one on the road, so much more sensible than the T140 I was after, that's dad for you )

thanks guys! I definitely live on the wrong continent.