4 stroke vs. 2 stroke

[Jack Gifford]

Speaking only about special-construction classes- am i missing something in the SCTA rules that differentiates 2-strokes from 4-strokes? For instance, could a 3 liter 2-stroke engine run in an F class car?

[trimmers]

No, you're not missing anything.  Nothing in the rules differentiates between 2-stroke and 4-stroke engines,  Yes, a 3-liter 2-stroke would run in class "F".
Catzilla 2 ran at Speedweek this year as a G/FS, powered by two separate 1000-CC Arctic Cat 2-stroke engines. 

Jeff in Boise

[jacksoni]

Rulebook 2.A Engines: " Any internal combustion engine using either a two-stroke or four- stroke Otto cycle.......May run in any category except Vintage... See 2.A.1
Only streamliners and unlimited diesel trucks may use more than one engine.

[Milwaukee Midget]

Tom Donney runs two-stroke SAAB motors in MGT.

[Seldom Seen Slim]

ECTA rules did differentiate between 4-stroke and 2 -stroke when I ran there in Maxton.  I don't have a current rulebook for them.  As I recall they ran in different classes (vs. same class with a break to one or the other).

[Stan Back]

But was that a motorcycle rule?

[Seldom Seen Slim]

Well, yes, now that you mention it.  I wonder if there was something about 2- and 4-strokes for cars. . .

[jacksoni]

last ECTA book I have is 2014 so not sure now, but they have generally followed SCTA rules pretty closely and do in this case (in 2014).

[Jack Gifford]

Thanks for the info. I'm surprised that two-strokes aren't exploited more in N/A land speed racing.

[jacksoni]

There are a couple 

[panic]

If you go back far enough, 2 strokes were given a displacement advantage in NHRA.

[Stan Back]

And now (if I'm not mistaken) NHRA gives Harleys a huge displacement advantage to keep their kind winning the Pro Stock (Harley) events.

. . . and then there are Pro Stock Mustangs with Chevy engines in them.

[trimmers]

Harleys?  What's that?  All I've heard them called this year is "V-Twins".  I suspect H-D pulled the sponsorship plug, so now they won't say their name, even though that's what they're running!   Of course, the Suzuki's are competitive, though.

Jeff in Boise

[Stan Back]

"Of course, the Suzuki's are competitive, though." . . . hauling a lot more weight per cu. in.

[Rex Schimmer]

I love two strokes and Jack's engine is a real jewel! The amount of thought and engineering that went into it is staggering and it is a record holder now. His previous engine was a 4 cylinder (I don't remember the make) that he adapted an Indy 4 valve, DOHC head to, also an impressive effort.

If you want to see the ultimate two stroke it was the Crecy built by Rolls Royce in the late 40s. It was a 1700+ cu. inch V12, two stroke with rotary sleeve valves and made about 50% more power than the Merlin or Griffon 4 strokes. It was so loud that the first time it was run on a dyno it cracked the dyno cell walls!! Look it up on YouTube.

Rex