Power/engine questions

[mike97760]

We're pretty new at all of this and so far all we've had are Raptors and kt100 engines. We've seen a lot of stuff being run and I'm really curious about how all these different engines compare to each other. Could anybody make a stab at rating the various engines power-wise, from the wankels down through the suburus? Another thing I don't understand is the differences in the Animals, how a modified engine compares to a box-stock engine and whatever comes between the two. Could someone rate them or make comparisons? Thanks!

[mike97760]

oh come on, you guys are always talking about your engines! how much power are they putting out and how do they compare with others?

[wilywin9]

Good luck on this one. The thing with this club is there are people all over the board on this topic (motors). 2 stroke -vs- 4 stroke!!! And you know how it is with racers? Esspecially competative racers....one person says there motor makes 50hp and the next guy will say theres makes 60 then the 3rd person comes in with 61. And Joe Schmo bought such and such motor from some guy back east and it made 62hp. It never ends!!! LOL! Its that way in all forms of racing! But anyways good luck on this one. How fast you want to go just depends on how much money you want to spend i guess!

#9

[chuck62]

Dont know much about the 2 smokes but I take a stab at the 4 cycle. 5 hp/flathead/Rapter you just don't see em. Mayme JR1 class but most are running the animal. Animal OHV in box stock form 7-8 hp. Blueprinted stock w/ 002 cam / decked head & block /billet rod /alky carb will pull 11-13 hp. Lim. Mod w/ all the goodies will pull 18- 26 depending on the builder and the dyno. Opem class Animal can be 300 plus cc. Big blocks/strokers/big valve billet heads the skys the limmit. Full opem Animal can be 35-50 hp.
Speed cost how fast do you want to go
#62

[darrinf63]

My last KT-100 was Decent compared to others, but not the best one I ever had. It made 20.8 on a Dyno that was known to be optomistic with an RLV A2 Pipe. I suspect it would have made under 19 on a dyno calibrated to SAE standards. I've seen numers on 100 CC opens from 24 on gas to 33 on alcohol.

[spaldingracing]

Here are what i have seen as "honest" numbers:

Yamaha: 17-19hp
open yamaha: 21-30ish hp
Other piston port (JICA or similar): 20-25hp
100cc reed: 25-30hp
100cc rotary: 28-34hp
116 open: 30-40hp
125 and up..... let the BS roll....but a good open should be in the 45ish hp range

These ball park numbers are for a quality blueprinted motor, properly built with a modern pipe. Also with honest dyno calibration, and without manipulating the dyno pull for big numbers.

[darrinf63]

Over the years I was a customer of 3 local builders. All are are good guys and good builders. One commented several times This moter makes x hp. Take it across town and it would probably make y hp. His point was that he felt that the other guy's dyno made better numbers than his. The third builder's dyno made better numbers yet. The problem is once a builder advertises a 24 hp KT-100, others need to follow suit. This leads us to a lot of optomistic dynos

[mike97760]

thanks everyone for the info. i was looking along the lines of re-powering and have really been curious, i'd like to test drive all of them.

[wilywin9]

LOL....Hey Jeff on your h.p. scale there down at the bottom 125cc an up 45ish.......your absolutely right and the funny thing is i have heard people claim 60 on the sudams. I will stick to Elmers theory...." It makes enuff horsepower to kick your as_! " LOL

#9

[TaTeR DiggER]

are you sure it wasn't 52 and 68

[Kartiac]

Coming from the cage kart ranks, there is a lot of disagreement on the output of a Honda CR500. I was hearing 80 hp in stock form, and as much as 100 hp in fully-massaged form. I also know a guy with a dyno who builds his own engines and swears 65 hp max from these on the dyno at the drive wheels. Who knows? The trick is still putting it all to the ground and having enough torque to pull out of the corners, which doesn't mean doo-doo if you can't get through the corners.

Motocross Action Mag claims 55hp stock, so maybe the 100hp mark is a fantasy, but the guys in Norcal have been working on these for years. Ooooh, maybe there is a monster motor out there!

Nick

[mike97760]

thanks everyone this is pretty interesting. does a 4 stroke have an advantage (all hp things being equal) on a dry slick track? or vice-versa?

[dixracing3]

nope............ a driver that can utilize what the engine will give him-her is the key .......but the 4/ 's are way better now, and they have the bottom end grunt advantage.......depends on track size........pick yer poison.......did you see what dave h. did in the bk2?....underpowered h/p wise but mass torque earned him a podium....imo

[bcoates54]

Well here we go again everyone has an opion and it turned into 2 vs 4 stroke didnt look like that was what he was askin to me. But looks like spalding hit the numbers close on two strokes and chuck hit the four strokes but my question is what do you want to know the hp numbers for? I ask this because unless your going to race open outdoors hp like #9 said is for the most part obsolete. In the last two years I have seen stock yammis win a couple opens to Claims of 60hp sudams win but its all means nothin in the wood, the track is gonna allow the hp that can be used. So i guess what I am saying is are you plannin on somethin that more info would help us answer better or is it simply just wonderin what they make?