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SRX 900


TALKED TO PAT ABOUT A MONTH AGO, AND THE NEW CYLINDERS DID NOT MAKE AS MUCH POWER AS HE HOPED SO HE SCRAPED THE IDEA.
BUT IF YOU STROKED THE CRANK, THATS WHERE YOU WOULD MAKE MORE POWER.
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Sleep disorders advice
 
Thanks for the information.
I have heard that the Hauck big bore top gun kit (780) for SRX and add stroking the crank would be awesome 900, do You know something about this?
 
the problem with stroking the engine using a stock cylinder is that the port timing gets screwed up with the stroking, and its hard to correct it with out using aftermarket cylinders. i have spent an enormous amount of time developing my 780 big bore engines, i make a stg two 780 that makes 170 hp in trail form, 176 hp in race form. (my dyno is very conservative) the sled looks 100 percent externally stock. i will guarantee you my 780 kit kicks #*$&@, or your money back. jeff
 
HSP, I can verify that this kit does kick- #$%&* . ;)! I loved beating up on 800+ and 900+ sleds last summer. The only sled I had trouble with is a fully setup HTG Polaris. (Who know what that thing was... I know it was at least a 900)

Here is a link of me running: http://www.sohonetworkx.com/

Click on the: 'Buster696 in launch mode with the CPR 780 big bore' and 'Hilton Drags with Sled rammed into Truck, Buster696, Tony 3:16, Paul's Viper, a Black Bender turbo, A REV with bottle, just a bunch of stuff'

This will show me with the White helmet, white t-shirt, and black vest... I ran a doo 800 w/NOS and some AC-900's, another sled that gave me trouble but did not make the video is a 1??? Thunder Cat that I ran. When we finished I was on his rear flap...

Go with the CPR Kit… It works… Period!
--Buster696--
 
jeff's 780 is awsom kit, and stone reliable. pat's stroker kit is new and i never tryed it. on race motors strokeing it makes the most power but on a srx the 780 is the way to go. i would stick with jeff.
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Cuautitl?n assembly
 
stroking the crank would make for some very wild and not necessarily trailable/good time area curves. stroking cranks is nothing new tho, there's lots of places that will do it, but from what I understand 72mm is the biggest crank that will fit in the SRX cases. but from my measurements, that means that the ports need to be more or less open till the bottom of the skirt, which is possible, but the 2-stroke guru's question the validity of it.

to put it in blunt terms... there's never been an overly successfull race engine that was designed with open ports in mind.

it's my personal theory that the rings create a secondary high/low pressure wave inside the port, creating higher pressures on the inside "wall" of the port (which is now a piston and more importantly, ring. which obstructs flow since the pressure difference between the pressurized crankcase and depressurizing cylinder is less than it would be otherwise.

if jeff or anyone else wants to jump in on that go for it, but don't feel obligated, 2-smokes are my passion.
 
stroking works great on alot of engines, if the cylinder casting will support it, some will, srx and viper won't. raw unmachined aftermarket castings work well for this because you are starting with a clean sheet of paper to design your engine with. it gets more technicial from there, you just need a good base to start with, or your wasting your time. jeff
 
ya I agree with you jeff, in order to stroke an SRX/Viper motor, you SHOULD be going with aftermaket barrels, but aslong as you're going aftermarket barrels, you can go more or less any bore you want (start running out of center to center distance at about 76mm I believe, if you did it that way you could go with a longer stroke, but at some point you have to ask yourself why you're going to this much effort to use stock cases (since that's the only stock part of the engine remaining now)
 
no stroke price cylinders that i have built at a 82mm bore have made 232 hp, its not what i would call great, but it will beat the hell out of my 780 race kit, it also costs around 8000.00 to have me do one with my pipes, so in the end result, power is power no matter how yo get it. a stroked version with reconfigured cylinders will make more yet, but why not just get a rx-1 and put a turbo on it and have up to 400 hp for the same money. jeff
 
ya 4-stroke turbo's are a good way to do it to, I think that with a 1140cc motor should have more than 232hp on tap if it's set-up right tho man, hell the GP racers where making almost that on 500cc's all a matter of rpm's I guess... making a 2-stroke engine is an artform, 4-strokes are much simpler to extract that last 5hp out of. you can turbocharge the 2-stroke as easily as you can the 4-stroke tho, just the ground hasn't been broken as clearly as it has been by the hot rodders and rice burners with the 4-strokes.

I'd like to experiment with oval bore 2-stroke cylinders in the future to, perhaps over the next couple years I'll have the opportunity to try that out, it's never been done to my knowledge, and I unfortunatly think it's much better suited to a V-block set-up than it is to an inline cylinder layout. it's all just a matter of running the math if you have access to CNC mills I guess. working port timing and expansion chamber design on forced induction 2-strokes becomes bloody complex awfull fast tho.
 


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