Author Topic: Engine "handicaps"  (Read 17485 times)

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Offline Jack Gifford

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Engine "handicaps"
« on: June 26, 2017, 01:51:55 AM »
SCTA rules in 1950 included specific "handicaps" for various engine configurations- OHV siamesed ports, OHV individual ports, OHC, DOHC, etc. Included was a 10% handicap for two-stroke engines- it makes sense to me to differentiate them by some amount. At what point did 2-strokes and 4-strokes get "homologated" in the rules?
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Offline RichFox

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Re: Engine "handicaps"
« Reply #1 on: June 26, 2017, 09:27:46 AM »
As I remember AMA ran the motorcycle classes at that time and used their classes. When SCTA/BNI took over the biked, they went with classes more like the car classes. I think you can still run AMA rules at the BMST event.

Offline Jack Gifford

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Re: Engine "handicaps"
« Reply #2 on: June 27, 2017, 01:50:29 AM »
Sorry- I should have clarified that I wasn't asking about motorcycles; just about engine types in landspeed vehicles.
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Offline jacksoni

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Re: Engine "handicaps"
« Reply #3 on: June 27, 2017, 07:54:21 AM »
I have a gap in my rulebook collection but the specific wording allowing 2 stroke was not present in 2003 but was in 2005 editions. So Was added either in 2004 or 2005. Prior to then, the wording said "Otto" cycle. DOHC "racing engines not based on a regular production block" were advanced 1 engine displacement class until the late '80's. (88 or 89 I think). Until '91 blown gas and fuel engines were advanced 2 engine displacement classes. (streamliners excepted in both of the above differences). Also in '92 (maybe 91) gas and fuel classes were specifically split as were blown and unblown. (made a lot of open class records).  Before then there were specific gas and fuel classes for some categories and not all classes had both as they do today (few exceptions such as production etc)

Dan may chip in with more info or precise dates as mine may be + or - a year.
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Offline jacksoni

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Re: Engine "handicaps"
« Reply #4 on: June 27, 2017, 08:02:12 AM »
I do not recall seeing the 10%handicap rule for 2 strokes but may have missed that somewhere. And you are correct, changes for Vintage engines/ports etc started showing up as well (X, XO XOO classes etc). I can try to check dates if you want but someone with Vintage engine experience/interest may be better able to sort that out.
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Offline RichFox

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Re: Engine "handicaps"
« Reply #5 on: June 27, 2017, 08:55:09 AM »
I do remember before there were supercharged classes, that supercharged engines were advanced two classes. And before twin cam four valve engines were common, they were advanced one class. I don't remember the other exceptions that you mention. When I started running my Turbo GMC, Blown stock head engines ran in the same class as 12 port GMC engines and flatheads with Ardun heads. XX class. There was a 12 port, a blown flathead, and an Ardun running together with me. I am not sure, but I think it was 81 or 82 when the flat head Fords cried enough to get their own safe space. Some years later the blown classes split my GMC out of XX and into XO/B. So. In the vintage engine classes, specifically XO and XXO number of ports still counts. I don't remember it ever being an issue in the rest of the car classes.  
« Last Edit: June 27, 2017, 05:44:51 PM by RichFox »

Offline Jack Gifford

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Re: Engine "handicaps"
« Reply #6 on: June 28, 2017, 01:24:29 AM »
... the specific wording allowing 2 stroke was not present in 2003 but was in 2005 editions. So Was added either in 2004 or 2005. Prior to then, the wording said "Otto" cycle...
This present ruling- allowing 2-stroke engines- is what prompted me to start this discussion [thanks for all the responses!]. It seems strange to me that more records aren't held by 2-stroke powered machines. Yeah, larger engines (class F and up) might be challenging. But for less than three-liter, it seems logical that a 2-stroke would have a huge advantage in potential power. :?
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Offline dw230

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Re: Engine "handicaps"
« Reply #7 on: June 28, 2017, 11:23:27 AM »
Maybe the lack of records is due to the fact that no one runs a <3 liter two stroke engine.

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Offline RichFox

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Re: Engine "handicaps"
« Reply #8 on: June 28, 2017, 01:35:39 PM »
 I don't see any classes or records for two stroke engines in the current rule book. I will say that Jack Costella called recently to talk about thye four cylinder two stroke McCulloch Drone engine he had and was hooking to some chain drive chassis.

Offline manta22

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Re: Engine "handicaps"
« Reply #9 on: June 28, 2017, 07:32:46 PM »
Rich;

At one time I had three or four of those McCulloch drone engines. They are nice little engines- 72 lbs and 72 BHP in stock trim. It had a hand adjustable-mixture single-barrel carburetor (wide open, no throttle) and a fixed advance magneto. Inside, it ran ball & roller bearings on the crank mains and rods. The disadvantage is that the crank is very light since it was designed to drive a "flexible" load (propeller) not a drive train.

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline RichFox

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Re: Engine "handicaps"
« Reply #10 on: June 28, 2017, 08:32:04 PM »
And not made to run very long. The signal battalion that I was in flew them occasionally as targets.I never got to do anything cool like that.Jack was discussing an Electro Motive crank trigger ignition and some kind of mechanical fuel injection. I should go over there and see whats up.
« Last Edit: June 28, 2017, 08:35:53 PM by RichFox »

Offline Seldom Seen Slim

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Re: Engine "handicaps"
« Reply #11 on: June 29, 2017, 06:26:10 AM »
Mike in S A posted this on FB:

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Offline panic

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Re: Engine "handicaps"
« Reply #12 on: June 29, 2017, 08:47:21 AM »
Speedy Babbs had an Indian 841 with a drone engine about 50 years ago, opposed boxer - yes?

Offline RichFox

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Re: Engine "handicaps"
« Reply #13 on: June 29, 2017, 09:30:02 AM »
Yes opposed four cylinder. Fires the front two cylinders at the same time. 180 degrees later fires the rear two.

Offline manta22

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Re: Engine "handicaps"
« Reply #14 on: June 29, 2017, 09:32:56 AM »
Yes, a 4-cylinder opposed configuration. Although they weren't designed for "longevity", they were well made, even had hard chromed aluminum cylinders.

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ