3mm BIG BORE pistons

cjwell

cjwell

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I think I am going to have some +3 mm pistons made. Available for purchase with gaskets (head/base), head bolts and exhaust gasket. I am trying to source a couple used cylinders now so I can have them bored/plated to size on the shelf. If I cant, you guys will be responsible for having your cylinder bore/plated to size with the new piston. Plus 3mm makes it a 399cc. Gasket configuration will be 13.0:1 compression for street guys on stock cams and pump fuel. Stock is 12.6:1. It will also require my intermediate sized injector. For guys that have my kit items already thinner gaskets can be supplied for 14.0:1 compression install. Let me know what you think and if you have any interest in one.
 
J

John390

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while I won't be doing anything like this for a little while at least, I really applaud people keeping things going on this platform. Kudos to you.
 
Tom

Tom

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Chad, is there a difference in cylinders between the generations of our bikes? I vaguely remember reading somewhere about Austrian made cylinders being an upgrade. Also, are you able to source the new heads with the coolant flow modification? I would like for you to build a cylinder head for my 2017 rc390, and would prefer that it be done on the revised head.



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I had my Tyga header "White lightning" coated for added protection against radiant heat soak around the exhaust side of the motor. I think having the extra surface area around the head-gasket from the coolant block would help aid in preventing a blown head gasket.


I plan on having an estimate from Ferrea for a set of titanium valves in the near future (I just need to source an example of an intake and exhaust from the 2017 head) Would it be possible to go 1mm oversize on the valves with your overbore kit?

I already did a preliminary estimate of shipping the bike to you guys a few weeks ago (roughly $260 to $320) so your plans of a big bore kit has me even more determined to have some work done by you guys.
 
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Tom

Tom

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That is the Tyga header for fitting the '15-'16 exhaust systems to the '17 + models. Swaintech stated the welds on the header appear to be very well made, and they do not anticipate any issues with the increase of heat retention within the header. The total cost for coating was $40 and there was a two week turnaround time with the shipping included. I've used this coating many times before on other vehicles, it's a very effective product.
 
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Tom

Tom

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Rode the bike to work today on the yosh dual carbon using the timing values from the map you supplied me. All I can say is wow! I have a feeling you just help me create a two-wheeled speeding ticket machine. I'm sure with some custom tuning for the larger injector's fuel trims I would notice even more.

Chad, you need to come out with this big bore kit. People have been asking for this kit since the bike came out. Big bore kits are a major request for all small displacement bikes... I guess people like light bikes that can make big power.

If you can eek out 60 hp on these bikes, you would be in 600cc territory with a few light weight mods.
 
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Tom

Tom

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Reading over Chad's thread on his high compression engine kit, it looks like we probably wouldn't see this kit for about a year if he decides to produce it. =(

BTW, Chad, would it not be easier to just sleeve the cylinder rather than plate it? I would assume an iron sleeve would also dissipate heat better, and increase reliability.
 
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Tom

Tom

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Is there still a lot to be done as far as designing the cams, or should this be pretty much the same hardware you already have from the high comp kits? Trying to get a baseline on how much longer I have to impatiently wait lol.

The bike looks and sounds great with the Yoshi Dual CF, but it sucks getting picked on by cars that can blow me away on the highways.
 
cjwell

cjwell

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Tom said:
Is there still a lot to be done as far as designing the cams, or should this be pretty much the same hardware you already have from the high comp kits? Trying to get a baseline on how much longer I have to impatiently wait lol.

The bike looks and sounds great with the Yoshi Dual CF, but it sucks getting picked on by cars that can blow me away on the highways.
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Just doing the piston mainly. It will work with all my older kit stuff. No extra new stuff.
 
Tom

Tom

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Any ballpark figures on the price? I'm trying to figure out how many marriage points this will set me back.
 
Tom

Tom

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Any updates on the progress? I keep getting fatter, so I need something to make up for the loss in power/weight ratio.
 
streetfighter

streetfighter

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Any availability date on the big bore kit? Really hope that I can install the kit before the race season ends ...


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Tom

Tom

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LoL streetfighter is just as stoked as I am to get one of these builds. I'm curious to see the gains vs the high comp. standard bore kit. I know it's not going to be astronomical (there's only about a 10 hp and ft-lbs of torque difference between the ninja 300 and 400), but I still would enjoy having a gain in torque for the gearing I have.
 
Tom

Tom

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I think a lot of people are really excited about this, and the fact that Chad has finally decided to put his expertise behind such a project.

I think with a 43T sprocket and a high comp build, you would already be able to hit 120+. I have a feeling that this kit would produce roughly 2 to 3 more horsepower than his factory size bore kits. Of course this would all depend on the final compression ration on the end product.

What IÂ’m really curious about is the difference in redlines between the two kits. I imagine the extra surface area would equate to more friction on non-combustion down strokes.

The Yamaha forums have a lot of info on engine builds and it seems like they seem agree on the benefits of going to a single ring piston design. It drastically increases the life of the cylinder walls and allows for higher rpm redlines.

They even upgrade titanium valves to steel units due to the longer life and better heat dissipation on single piston motors. A lot of what I originally thought would make for a higher performing, high revving motor is completely backwards when it comes to thumpers. This is exactly why IÂ’m glad Chad is the one designing this kit. Anyone can piece together some custom built components but only some one with a lot of experience can do it right.
 
streetfighter

streetfighter

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Tom said:
LoL streetfighter is just as stoked as I am to get one of these builds. I'm curious to see the gains vs the high comp. standard bore kit. I know it's not going to be astronomical (there's only about a 10 hp and ft-lbs of torque difference between the ninja 300 and 400), but I still would enjoy having a gain in torque for the gearing I have.
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Yes. I am checking in every month to see if there is any update :)

It’s already half way through the race season. I have feeling this is becoming to look like a winter project if it happens at all



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