Welcome to the Yamaha Star Bolt Motorcycle Forum

Why join our motorcycle community?

  • Membership is free and easy
  • Get technical support and information for your Yamaha Star Bolt motorcycle or search for information before buying
  • Use the member map to find riders near you
  • Participate in our monthly virtual bike show (or at least vote)
  • Get rid of these annoying boxes asking you to register  ;D

More importantly, make new friends!!

Author Topic: Wiseco 10.5:1 pistons for Bolt  (Read 1444 times)

0 Members and 1 Guest are viewing this topic.

Offline Doug

  • Newbie
  • *
  • Posts: 5
Wiseco 10.5:1 pistons for Bolt
« on: November 18, 2021, 09:54:06 am »
I find the Wiseco high compression pistons interesting for a performance gain.
However, as a professional engine builder I know this modification will require complete ignition remapping of the stock ECU.
To my knowledge, that option is not currently available.
Another area of concern is quench. I'd want .030"



Offline Sattes

  • Jr. Member
  • **
  • Posts: 76
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #1 on: November 19, 2021, 05:08:50 am »
Ivans performance I believe has a tune for the hi comp pistons.  Don't quote me but that is one of the questions they ask on their application.  I am interested in these as well.  I just feel they would be better suited for a custom cam.  I don't know how well they would perform with a stock cam. I would hate to just accelerate to 80 real fast then fall flat. These pistons would be great for a top end cam. I think it is terrible our bikes don't have engine performance mods.

Offline Sattes

  • Jr. Member
  • **
  • Posts: 76
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #2 on: November 19, 2021, 05:16:01 am »
I find the Wiseco high compression pistons interesting for a performance gain.
However, as a professional engine builder I know this modification will require complete ignition remapping of the stock ECU.
To my knowledge, that option is not currently available.
Another area of concern is quench. I'd want .030"

What is the quench on a stock XVS950? 

  • Advertisement

Offline Doug

  • Newbie
  • *
  • Posts: 5
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #3 on: November 19, 2021, 09:28:01 am »
I don't know what the quench is on the stock engine.
I'd want .030" if I built one. Fortunately I own a machine shop and could modify cylinders or heads. Cometic will also water cut gaskets and that may be an option.
As for cams, I'd be interested in knowing stock cam intake closing time. The stock engine rolls over quite easily and I doubt cams would be required.

Offline srinath

  • Hero Member
  • *****
  • Posts: 912
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #4 on: November 19, 2021, 11:30:43 pm »
Well I can tell where you are on the right track and where you might not be - machine shop or not - well depends on how much you're willing to "machine" I guess.

So 9.0 to 10.5 will get you more torque especially if you combine it with the right cams. And while you can get much of the gains with just the cam, yea higher compression will get you more on top of just the cams. Yea you need springs that will be able to compress more etc but really its not a huge extra step.

OK more compression = more torque down low. Obtainable. OK fine, but how does that translate to the real world.

This bike has a crap ton of torque down low. Especially since its hauling me and nothing else, its just plenty, thank you. And I am running a stock bike with just a sawed off and slip on fitted stock ECU, FI, intake etc etc.

Now the part where its deficient maybe - no IMHO its 110+ top speed is plenty for me - but anyone seeking more power will want more revs and higher top speed (my guess).

Here the bolt fails miserably. Higher power is all about rpm. More torque but with heavier components will barely result in extra power because as rpm climbs instead of power climbing you start hitting the limits of stuff like valve lift and piston weight etc. peak power is all about RPM. RPM is all about air flow. You cant get it to flow more with that intake manifold that makes a 120 degree turn next to your left knee. So machine work - the best bet is to machine heads that pull in air straighter. Rear cyl from in front of your left knee, and front cyl from behind your right knee. Yea basically a set of identical heads just turned around 180 degrees. Ofcourse 2 separate injectors, air filters etc. But intake air goes in from outside to inside straight as a ruler. Anyway, let me know how the 10.5 compression pistons works for you.
Cool.
Srinath.

Offline Doug

  • Newbie
  • *
  • Posts: 5
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #5 on: November 20, 2021, 08:40:29 am »
This is my company www.head-quarters.com.
I'm 71 years old and have 50 years of experience designing performance engine combinations.
All Harley-Davidson, but the same rules apply to all brands.
A compression increase will produce more power from bottom to top of the RPM range *if* the tune is proper.
I don't think the Bolt is a motorcycle owners will spend thousands of dollars on for performance upgrades. (there may be a few exceptions)
 

Offline cjscr

  • Newbie
  • *
  • Posts: 11
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #6 on: November 20, 2021, 10:12:19 am »
did you see the turbo bolt project on youtube? looked like the didn't care if the blew it up.

would an oil cooler be needed on a 10.5:1 engine?

Offline DrM

  • Hero Member
  • *****
  • Posts: 548
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #7 on: November 20, 2021, 10:15:58 am »
I can't see spending a lot of money on an air-cooled engine unless I had a specific use for it, such as put it in an airplane.  Not that I haven't done it before.  I did bore out a '73 Yamaha TX 650 to 750, and dropped in some Wiseco heads and such.  It was a lot of fun building it, and I did get the finished bike up to 120 mph going downhill with the wind at my back, but only about 90 going uphill against the wind.  So it was a short-lived thrill.   If you have the dough and like rebuilding, I'd say go for it.  But for the ordinary rider, probably better to buy a liquid-cooled bike rather than the Bolt.

Offline lunkhead

  • Hero Member
  • *****
  • Posts: 1673
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #8 on: November 20, 2021, 02:21:25 pm »
I have the Wiseco pistons (not installed) and posted the valve specs on this site last year for future reference. The stock cams are symmetrical with 5 degrees of advance for more low end torque. My plan was to just slot the sprocket to take out the advance and run premium gas if I ever install them. I already have Ivan's flash so the rev limit is raised enough. Unfortunately, the long restrictive intake tracts aren't good for anything but low revs without forced induction. I now have a 2017 Triumph 900 twin that is a better candidate for increasing HP. The only thing it needs is a decat that I have and a cam that I'm trying to get shipped from England. If I come across a cheap used Bolt, I'll change the pistons but my current Bolt runs too good to mess with.
C-SPƎC

Offline SCRBen

  • Jr. Member
  • **
  • Posts: 50
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #9 on: November 20, 2021, 06:15:07 pm »
This is my company www.head-quarters.com.
I'm 71 years old and have 50 years of experience designing performance engine combinations.
All Harley-Davidson, but the same rules apply to all brands.
A compression increase will produce more power from bottom to top of the RPM range *if* the tune is proper.
I don't think the Bolt is a motorcycle owners will spend thousands of dollars on for performance upgrades. (there may be a few exceptions)

I had Boz at Powerglides install me some Wyrd Brothers cams a few years ago in my old 96” Dyna - really woke that bike up!! Nice to make your acquaintance  :D
Keep us in the loop if you decide to proceed with any Bolt-based upgrades.

I have the Wiseco pistons (not installed) and posted the valve specs on this site last year for future reference. The stock cams are symmetrical with 5 degrees of advance for more low end torque. My plan was to just slot the sprocket to take out the advance and run premium gas if I ever install them. I already have Ivan's flash so the rev limit is raised enough. Unfortunately, the long restrictive intake tracts aren't good for anything but low revs without forced induction. I now have a 2017 Triumph 900 twin that is a better candidate for increasing HP. The only thing it needs is a decat that I have and a cam that I'm trying to get shipped from England. If I come across a cheap used Bolt, I'll change the pistons but my current Bolt runs too good to mess with.

What cams are you trying to get shipped from over here, @lunkhead?

Ben

Offline lunkhead

  • Hero Member
  • *****
  • Posts: 1673
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #10 on: November 20, 2021, 09:16:30 pm »
I emailed TEC USA and they said I had to email George Milborne directly. Seems they ship everywhere but the US on their online ordering form. Here's the link:

https://www.tecbikeparts.com/product/camshaft-de-restrict-900cc-early-type-street-twin-street-cup-t100-water-cooled/
C-SPƎC

Offline SCRBen

  • Jr. Member
  • **
  • Posts: 50
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #11 on: November 21, 2021, 01:52:08 am »
I emailed TEC USA and they said I had to email George Milborne directly. Seems they ship everywhere but the US on their online ordering form. Here's the link:

https://www.tecbikeparts.com/product/camshaft-de-restrict-900cc-early-type-street-twin-street-cup-t100-water-cooled/

Aah yeah, TEC Bike Parts…..well known over here. Let us know if you think it would help having someone in the U.K. reach out to them 👍

Ben

Offline Sattes

  • Jr. Member
  • **
  • Posts: 76
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #12 on: November 21, 2021, 03:06:46 am »
I'm working on a stock intake manifold for research purposes.  I am going to cut the underside out in a rectangle shape between the the intake runners and remove the wall separating the runners.  Creating a large void in the manifold.  I might fill in the dog leg runner on the outside and remove material on the inside to get more of a straighter runner.  My thinking is, I'd  open up the manifold and the dog leg side might get a straighter flow to the cylinder allowing faster movement of air to that cylinder possibly adding more air flow to the cylinder.  Kind of like a box intake manifold on a fox body from the late 70's to 90,s.  That is what I am working on and I will post my opinion down the road.  Hell if anybody has done this and it wasn't beneficial let me know.  I really don't want to waste an afternoon.

Offline Doug

  • Newbie
  • *
  • Posts: 5
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #13 on: November 21, 2021, 08:16:20 am »
Ben, nice to see you here. I still talk to Boz regularly. He has a new Indian Challenger now and likes it. I still have a Victory Magnum and a few Harleys.

Offline srinath

  • Hero Member
  • *****
  • Posts: 912
Re: Wiseco 10.5:1 pistons for Bolt
« Reply #14 on: November 22, 2021, 07:43:09 am »
I'm working on a stock intake manifold for research purposes.  I am going to cut the underside out in a rectangle shape between the the intake runners and remove the wall separating the runners.  Creating a large void in the manifold.  I might fill in the dog leg runner on the outside and remove material on the inside to get more of a straighter runner.  My thinking is, I'd  open up the manifold and the dog leg side might get a straighter flow to the cylinder allowing faster movement of air to that cylinder possibly adding more air flow to the cylinder.  Kind of like a box intake manifold on a fox body from the late 70's to 90,s.  That is what I am working on and I will post my opinion down the road.  Hell if anybody has done this and it wasn't beneficial let me know.  I really don't want to waste an afternoon.

I've not done this nor even taken it apart in that aspect. But IMHO if we had throttle by wire and a no rack design, which actually with a fly by wire we can always "derack" it we can put 2 throttlwe bodies on 2 short intakes as a straight shot into each intake port.
Cool.
Srinath.