trickedcarbine Posted August 14, 2014 Report Share Posted August 14, 2014 I literally just googled about 30 different profiles between KTM, yamaha, kawasaki, Honda, etc. Lots of different stuff out there. When I'm not so tired I'll post a bunch with different questions to keep this going. This could get to be a decent thread. Quote Link to comment Share on other sites More sharing options...
registered user Posted August 14, 2014 Report Share Posted August 14, 2014 i dont even wanna see a cr250 head. heard the newer ones have a intentional converging band. i havent verified it but more than one person has said it. ive seen a few different jap and older ktm head and they mostly used the standard hemi style from what ive seen. maybe there was some variation along the way that i havent seen Quote Link to comment Share on other sites More sharing options...
registered user Posted August 14, 2014 Report Share Posted August 14, 2014 check it out. bet this dumb fucker didnt notice a thing and kept on ridin '14 and '15 are using this one. dont really care for it. just kind of rolls into the bowl with no real squish band. supposedly they lost a couple hp from previous years Quote Link to comment Share on other sites More sharing options...
Atomic Monkey Posted August 14, 2014 Author Report Share Posted August 14, 2014 Should take a look at outboard motors on boats. That's the first thing I thought of when I read "bathtub style". The chambers are oblong craters with the funkiest looking pistons. Quote Link to comment Share on other sites More sharing options...
Atomic Monkey Posted August 14, 2014 Author Report Share Posted August 14, 2014 I did talk to Lane from Driveline last night. He's going to be cutting the domes, and had some great advice on the setup I'm working with. He also gave me some background on the pistons... I've got to say I'm happy to be dealing with him! Quote Link to comment Share on other sites More sharing options...
Pastrykiller Posted August 14, 2014 Report Share Posted August 14, 2014 So what your saying is that his pistons are completely different than wise or any other readily available? If that's the case, what is the piston crown shaped like and how far in/out of the hole is it? Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted August 14, 2014 Report Share Posted August 14, 2014 So what your saying is that his pistons are completely different than wise or any other readily available? If that's the case, what is the piston crown shaped like and how far in/out of the hole is it?There is a thread on the new Weisco/driveline piston. It's an awesome read with no results! Get your popcorn . Quote Link to comment Share on other sites More sharing options...
Pastrykiller Posted August 14, 2014 Report Share Posted August 14, 2014 Ahhhhh I just read it. Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted August 14, 2014 Report Share Posted August 14, 2014 It is a wiseco piston and it has the same piston crown as 513 series piston. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted August 14, 2014 Report Share Posted August 14, 2014 Are you guys selling a lot of them yet BHP? Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted August 14, 2014 Report Share Posted August 14, 2014 (edited) Few questions for guys who are really doing a lot of the machine work. Last night I must of googled 2,000 images of different domes for different machines and styles of motor. There seems to be common shapes and profiles but it makes me wonder a few things. Toridial or turbo swirling, gimmick right? What is convergant angle and what is the theory behind why guys keep trying it if it's supposed to be shit? On a motor with zero changes other then squish band width, how would it respond to a narrow band vs a wide band? Registered user posted two photos I looked at last night and one just seems to be a smooth rollover from the band to the dome area it self. How does that compare to something with a very pronounced edge that drops in to the dome valley? I'm assuming there are velocity issues with this. Does the shape of the dome valley really play much role? Like a wide shallow dome vs a narrow deep dome area? I've got more and again maybe I'll post photos to get fellas chatting. Edited August 14, 2014 by trickedcarbine Quote Link to comment Share on other sites More sharing options...
Bennett131 Posted August 14, 2014 Report Share Posted August 14, 2014 This thread is interestin. I like it. Quote Link to comment Share on other sites More sharing options...
Atomic Monkey Posted August 14, 2014 Author Report Share Posted August 14, 2014 Here's some details about the pistons that was shared with me: They were built for the 4mil L/R of course... utilizing the stock dome profile, a pin location that is 1mm higher than a 795 piston, the rings are also relocated lower to keep them at a stockish depth in the cylinder in relation to the deck, and relocated windows to reduce the stress on the skirt that a modified window 795 or blaster piston would see. He said the mods to the 795 and blaster windows are commonplace in his line of work. The real advantages I see is for the guy who can only budget for a stroker crank and pistons. He can run with a thicker base gasket, and everything else stock... no more spacer plates. I was told that the ideal way to run is with a thinner base gasket, get the porting done, and have the head cut. To that point, the piston was developed to eliminate some of the intrusion created when having a stock head cut for piston pop-up, 1mm vs. 2mm. Quote Link to comment Share on other sites More sharing options...
registered user Posted August 15, 2014 Report Share Posted August 15, 2014 wasnt turbo swirling on the head just snake oil like turboswirl crankshaft ? im not aware of anyone intentionally cutting a converging angle. well except honda from what i hear Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted August 15, 2014 Report Share Posted August 15, 2014 wasnt turbo swirling on the head just snake oil like turboswirl crankshaft ? im not aware of anyone intentionally cutting a converging angle. well except honda from what i hear as far as the dome, gimmick as far as I'm concerned. But on cranks, well..... I've seen it work VERY well on a few sleds. Larry @ Doc Fang Engineering has proven some motors to actually benefit the turbo vane while it actually hurt some others. Quote Link to comment Share on other sites More sharing options...
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