Reducing displacement of a stock engine

[Manas]

Wanted to know if any team had tried with cuting down the displacement of a greater than 610 cc engine (e.g. a 800 cc three cylinder) to suit the FSAE regulations . . ??

Or is the idea not acceptable with the judges at the first place?

I think the concept is worth a try . . . what say ? and the rules don't Prohibit this . (or Do they??)...// for the F-Stu event //

this holds a very vast scope of application of ideas and some large scale tweaking around. . .

And what can be the possible ways of reducing the displacement ? . . . Applying gaskets in cylinders leads to excessive increase of CR...
What about shutting down the middle cylinder (blocking it out)?

All brickbats are more than welcome . .

[adrial]

You could install steel sleeves to reduce the bore...leave you with a torque monster.

I would have to wonder if it is worth the extra weight though.

[GTmule]

You could also offset grind the crankshaft to decrease the stroke. The weigh, though....I'd imagine it'd be better to bore up a smaller engine to suit.

[rjwoods77]

Thats alot to reduce. You are going to comprimise something major in order to get it down under 610cc. cant sleeve it down because you will shroud the valves which is a bad idea. So then that leaves de-stroking and you would end up with really think crank journals. Save yourself the trouble and find something closer to the max or under for that matter.

[VFR750R]

Starting with something like a NT650 Hawk or SV650 might be a real good idea. Those engines are small, light, and leave lots of room either side for packaging, although they might be a touch long. In either case, sleaving would be very realistic as long as pistons could be sourced. Valve shrouding might not be an issue and machining the sleaves for clearance isn't new if they are. Smaller valves and new seats would also be a viable option considering the reduced flow rate due to the restrictor. A GSX-R600 with a 750 crank and then sleaved would give you higher thermo efficiency and more material in the block for forced induction applicationshttp://fsae.com/groupee_common/emoticons/icon_smile.gif as well as leaving total displacement at 610cc. This is really spliting hairs but if you've got a blown up GSX-R...why not.

[drivetrainUW-Platt]

how the heck do the judges check for displacement??? if your running a different crank or sleves its gona be tough to prove without showing them dimensions

[Patrick W. Crane]

i imagine they just tell you to take off the head.

[Z]

TDC - pour oil in the spark plug hole - BDC - top up with oil - then you clean up...

Or use a "borescope" (?)...

[Chris Clarke]

See SAE Rule #3.5.1.2

They have a tool that they can use to measure the displacement through the spark plug hole with an accuracy of 1%. The rule also states that: "The organizer will measure or tear down a substantial number of engines to confirm conformance to the rules."

[Denny Trimble]

Yup, they check certain cars after endurance. The tool fits through a spark plug hole, is about a foot long, and requires the engine be turned over slowly (push the car in top gear). It helps if you don't have to remove the engine to do this...

I don't know how they come up with the list of cars to check, maybe it's random. They didn't check us last year after we got 3rd on time.

[Manas]

http://fsae.com/groupee_common/emoticons/icon_biggrin.gif thanks guys .

yeah . . i was kinda aware of the input is to output ratio for the effort. . . but, just that the spares for an sbk engine are soo hard to fetch here. . .(read as impossible to fetch . . with importing as the only alternative) http://fsae.com/groupee_common/emoticons/icon_frown.gif

and the closest to 600 cc with sufficient bhp (with a respectable availability of spares) was the 800cc engine . . . and the most powerful // capitaL M capital P // 500cc produces a track churning 25 bhp http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[VFR750R]

They checked us in 2003 with a borescope and dial indicator. I had never checked our displacement myself, but they got 608cc when we have untouched nikisil bores and stock crank. They said normally if it's that close they pull the head and measure with a bore guage, but they'd do us the favor this time and let it slide. I was heated up but I would have been even more so if they made us take the head off. I didn't have another head gasket so we would of had to swap engines...which would have, I'm sure, ringed some bell somewhere to check that engine too.

Yes, easy access to the sparkplugs holes is convienient. We had to take out our firewall and seat so they could get to the sparkplug holes with their equipment. By the way, they checked it during tech before we even started the car in michigan. I havn't seen them check anyone after competition.

[Charlie]

We were checked last year during competition, I think it was after endurance, but there's a small chance it was after autocross (it's all a blur http://fsae.com/groupee_common/emoticons/icon_wink.gif )

Don't remember what they found but we should have been around 596cc anyway, so I doubt it was close.

[BryanP]

That is the concept with our engine. We have a Yamaha YzF 660 engine.( Yamaha Raptor) Resleeve it with a Grizzly sleeve and piston and you have 595 cc. Not very expensive either. There are photos of our engine on the high school sae car page. Unfortunately we can't compete. Rats!!!!
Good luck. I would love to see someone try it.
Bryan
Originally posted by Manas:
Wanted to know if any team had tried with cuting down the displacement of a greater than 610 cc engine (e.g. a 800 cc three cylinder) to suit the FSAE regulations . . ??

Or is the idea not acceptable with the judges at the first place?

I think the concept is worth a try . . . what say ? and the rules don't Prohibit this . (or Do they??)...// for the F-Stu event //

this holds a very vast scope of application of ideas and some large scale tweaking around. . .

And what can be the possible ways of reducing the displacement ? . . . Applying gaskets in cylinders leads to excessive increase of CR...
What about shutting down the middle cylinder (blocking it out)?

All brickbats are more than welcome . .