Quick photo comparison of Mean Streak pistons 1500vs.1600

Mechaniac · 11-10-2022, 06:08 PM

The original 1500 mean streak had many higher output engine parts. I'm putting them together with the 1600 crank, rods, and jugs. I just wanted to share the difference in the piston dish. The 1500MS (9.0/1) is almost a flat-top while the 1600's have more dish to maintain 9.0/1 along with the longer stroke. The standard 98-00 Vulcan 1500 was 8.6/1.

Using the flat-top piston in the 1600 should yield about 9.5/1.

recumbentbob · 11-12-2022, 05:39 AM

Interesting

andyvh1959 · 11-14-2022, 10:19 AM

I agree on the many Mean Streak engine parts. I already have the MS heads/valves/cams/throttle body to on my VN1600 engine build. But if the 1500 MS and the 1600 Classic have the same rated comp ratio at 9.0:1, how does using the MS pistons raise the comp ratio to 9.5:1 in the 1600? Is the gain in comp ratio just a factor of the piston pin to piston deck height difference, if it is different?

Mechaniac · 11-18-2022, 10:43 PM

Hey Andy, the difference is right there in the pics. The 1500 and 1600 have the same bore size but different strokes as you know. The crank is changed to have 2.5mm longer throw on the 1600 than 1500. The connecting rod was shortened the same amount, all other things equal including deck height, the longer throw will pull the piston down an extra 5mm overall. So the charge is larger on the 1600 because the piston travels further with the same heads, ports, valves, and camshafts. The dished piston has more void at TDC than the flat-top. That void equals less squeeze of the charge than the flat-top that compresses the charge tighter.

Since the rod is shortened the same amount of the crank extension you end up with the piston in the same exact spot at TDC (+2.5mm stroke -2.5mm rod length = 0). But at BDC you have -2.5mm stroke down and -2.5mm rod length = 5mm further down. That's how they did it and maintained the same spot at deck height.

Difference is in piston void and longer stroke. Longer stroke compresses more volume into the same spot. Dished piston maintains the same compression as the lower displacement engine in the same spot. Flat piston compresses it into a smaller space on either engine.

andyvh1959 · 11-22-2022, 04:17 PM

Yes, I know all that and understand it. So yes, because the piston travels further it has greater swept volume in the bore, more swept volume for the same bore size creates a larger air/fuel charge in the combustion chamber. That is, assuming the intake system from the air box through the throttle body to the valves and head can effectively flow more air/fuel mass charge for a given RPM. Larger charge in the combustion chamber means more power if it all can be effectively burned to create more power. But I don't agree on the Mean Streak pistons raising the compression ratio. The Mean Streak 1500, Mean Streak 1600 and Classic/Nomad 1600 all specify the compression ratio as 9:1. If the 1500 Mean Streak pistons did indeed produce a higher comp ratio why hasn't Kawasaki advertised or specified it that way? If the 1500 Mean Streak piston alone would raise the comp ratio in a 1600 Classic or Nomad a lot of people would have jumped on that easy upgrade long ago.

The VN1700, with the same bore size as the 1500 and 1600, specs the comp ratio as 9.5:1. And the pistons for the 1700 look much different on top than those for the 1500 and 1600. The VN1700 pistons are actually more flat than dished, maybe more like a recessed flat top. Also the VN1700 pistons feature valve clearance notches that are not on the VN1500 or VN1600 pistons. That's why I am hoping to find the 1700 pistons can be fitted to the 1600 con-rods to bump the comp ratio up on the 1600.

RACNRAY · 12-21-2022, 04:32 PM

SWEPT cylinder volume PLUS total combustion chamber volume divided by said c/c volume equals static compression ratio.

Bare in mind that total combustion chamber volume includes the combustion chamber itself, head gasket thickness and whatever shape of piston top design. The 1500 has a slightly dished design (they are not flat tops),whereas the 1600 pistons have a deeper thus more volumous piston top design. BOTH of these pistons are referred to as REVERSE DOME, as a dome infers a higher piston top than the actual piston height.

Now by increasing bore diameter and/or stroke increases swept volume. IF the total combustion chamber volume remains the same, the static compression INCREASES, thus the need with 1600 pistons to have that deeper reverse dome to bring the compression down to 9-1.

Arbitrary non real world nmbrs NOT related to anything other than the math. Nmbrs are swept, c/c volume minus c/c volume equals static compression all in cc.

500 + 50 =550 div by 50 = 11-1 c.r.

Increase swept volume by any/method(s) but keep c/c volume the same.

600+50 =650 div by 50=13-1 c.r.

Now in the case of the 1600, increasing swept volume(5MM LONGER STROKE) and maintaining c/c volume would theoretically (and as @Mechaniac correctly stated) 9.5-1.

The total c/c volume would have to be INCREASED by about 4.5cc to bring the c/ratio down to 9-1, thus the deeper more volumous reverse dome on the 1600 piston.

RACNRAY

mick56 · 12-22-2022, 11:25 AM

Quote:

Originally Posted by RACNRAY

SWEPT cylinder volume PLUS total combustion chamber volume divided by said c/c volume equals static compression ratio.

Bare in mind that total combustion chamber volume includes the combustion chamber itself, head gasket thickness and whatever shape of piston top design. The 1500 has a slightly dished design (they are not flat tops),whereas the 1600 pistons have a deeper thus more volumous piston top design. BOTH of these pistons are referred to as REVERSE DOME, as a dome infers a higher piston top than the actual piston height.

Now by increasing bore diameter and/or stroke increases swept volume. IF the total combustion chamber volume remains the same, the static compression INCREASES, thus the need with 1600 pistons to have that deeper reverse dome to bring the compression down to 9-1.

Arbitrary non real world nmbrs NOT related to anything other than the math. Nmbrs are swept, c/c volume minus c/c volume equals static compression all in cc.

500 + 50 =550 div by 50 = 11-1 c.r.

Increase swept volume by any/method(s) but keep c/c volume the same.

600+50 =650 div by 50=13-1 c.r.

Now in the case of the 1600, increasing swept volume(5MM LONGER STROKE) and maintaining c/c volume would theoretically (and as @Mechaniac correctly stated) 9.5-1.

The total c/c volume would have to be INCREASED by about 4.5cc to bring the c/ratio down to 9-1, thus the deeper more volumous reverse dome on the 1600 piston.

RACNRAY

What is all this going to achieve ?

RACNRAY · 12-23-2022, 01:09 PM

1500 Mean Streak pistons installed in a 1600 will bump the c.r. .5 point from 9-1 to 9.5-1.

mick56 · 12-24-2022, 03:45 AM

Quote:

Originally Posted by RACNRAY

1500 Mean Streak pistons installed in a 1600 will bump the c.r. .5 point from 9-1 to 9.5-1.

Well i'll be damned. Excuse me, whlle i have a jig around the lounge

andyvh1959 · 01-01-2023, 05:13 PM

Okay. I just checked piston part numbers on Ron Ayers, and there is a different part number for the 1600 Classic vs the Mean Streak piston part number. But yet, the online specs for both engines show the same comp ratio.

By your description the MS pistons in the same bore produce a higher comp ratio. What am I missing?

Mechaniac · 01-04-2023, 02:07 PM

You're missing that many of the online specs published show the wrong compression ratio for one of the bikes. I've found some in the past that listed the Classic as 8.75/1. Since they are in fact lower compression pistons compared to the other. I think that is correct. The only alternative is that the Classic is 9.5/1 and the Meanstreak is higher. My owners manual for the 1600 states premium octane fuel is required but I think that is a carry over from the 1500 manual as it runs exactly the same on regular with the dish piston and longer stroke.

I didn't save all the sites I referenced when planning the build so I haven't posted a link to the site(s) that I think had the correct ratios listed.

There are some articles about the 1500 Mean Streak when it first came out that seem more accurate than mega specs sites.

Vernon

Mechaniac · 01-04-2023, 02:10 PM

Quote:

Originally Posted by mick56

What is all this going to achieve ?

Cheap thrills when I engage in a contest of speed with Mr. $$$$$$ on his Harley bagger.

Vernon

andyvh1959 · 01-05-2023, 11:01 PM

Not trying to argue, just trying to learn more about the 1600. I just looked up the engine specs in the Kawasaki factory manual for both the Classic and the Mean Streak, and both are listed as 9.0:1 compression ratio. I cerntainly understand that online publications can be anything but right. Yet the factory manual lists them as the same comp ratio.

I just want to learn more.

And yes, more comp ratio generally means more fun with the happy grip. Can even mean better fuel mieage. My BMW R1200RT, flat twin, air/oil cooled specs a comp ratio of 12:1, creates 120hp at the crank, and routinely get 48mpg in general riding. Now, it makes that power and torque spinning a lot more revs than my VN1600 Classic. But the 1600 makes a lot more torque at lower revs than my BMW,

Mechaniac · 01-08-2023, 10:39 AM

Andy are you referring to the factory manual engine specs for the 1600 or the 1500?

When they went to the 1600 they all got the same engine, identical pistons. Only the paint on the outside was different AFAIK. The new 1600 made similar power but more torque than the two year 1500 MS that actually had the higher compression pistons than any of the others. The 2 year run 1500 pistons will fit in the others and that's what I am working on as an improvement over the standard 1600. The camshafts were quite different on the 1500 MS as well as the engine control module. All to utilize higher compression and make more power.

I don't take it as an argument, I take it as a misunderstanding to figure out.

Mechaniac · 01-08-2023, 11:07 AM

120 HP at the crank is pretty good for a 1200cc engine and I am saying that as a BMW enthusiast with two of them in the fleet, E60 535i's. Is that improved by performance tuning or factory? What is the RPM range of that one? My Honda Magna v4 is a 700 but it has less torque and a ton more top end power up to 10,000 RRM than the Mean Streak. It's about a 80HP engine stock.

11-12-2022, 05:39 AM	#2
recumbentbob Sr. Member Join Date: Mar 2009 Location: Newburgh IN Posts: 3,404	Interesting __________________ VBA #01084 "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed."
	1

11-14-2022, 10:19 AM	#3
andyvh1959 Advanced Member Join Date: Dec 2017 Location: Green Bay WI Posts: 759	I agree on the many Mean Streak engine parts. I already have the MS heads/valves/cams/throttle body to on my VN1600 engine build. But if the 1500 MS and the 1600 Classic have the same rated comp ratio at 9.0:1, how does using the MS pistons raise the comp ratio to 9.5:1 in the 1600? Is the gain in comp ratio just a factor of the piston pin to piston deck height difference, if it is different? __________________ My $1200 Vulcan, to start from.
	1

12-21-2022, 04:32 PM	#6
RACNRAY Sr. Member Join Date: Sep 2011 Location: SOUTH FLORIDA Posts: 1,210	SWEPT cylinder volume PLUS total combustion chamber volume divided by said c/c volume equals static compression ratio. Bare in mind that total combustion chamber volume includes the combustion chamber itself, head gasket thickness and whatever shape of piston top design. The 1500 has a slightly dished design (they are not flat tops),whereas the 1600 pistons have a deeper thus more volumous piston top design. BOTH of these pistons are referred to as REVERSE DOME, as a dome infers a higher piston top than the actual piston height. Now by increasing bore diameter and/or stroke increases swept volume. IF the total combustion chamber volume remains the same, the static compression INCREASES, thus the need with 1600 pistons to have that deeper reverse dome to bring the compression down to 9-1. Arbitrary non real world nmbrs NOT related to anything other than the math. Nmbrs are swept, c/c volume minus c/c volume equals static compression all in cc. 500 + 50 =550 div by 50 = 11-1 c.r. Increase swept volume by any/method(s) but keep c/c volume the same. 600+50 =650 div by 50=13-1 c.r. Now in the case of the 1600, increasing swept volume(5MM LONGER STROKE) and maintaining c/c volume would theoretically (and as @Mechaniac correctly stated) 9.5-1. The total c/c volume would have to be INCREASED by about 4.5cc to bring the c/ratio down to 9-1, thus the deeper more volumous reverse dome on the 1600 piston. RACNRAY __________________ "TRUE HAPPINESS IS IN THE HEART, NOT IN THE OUTSIDE FIXES" WITH OVER 46 YEARS AS A MOTORCYCLE TECHNICIAN/HI-PO SHOP OWNER I AM A PURVEYOR OF FACT NOT FICTION! "WE LIVE OUR LIVES IN CHAINS NEVER KNOWING WE HAD THE KEY" Last edited by RACNRAY; 12-21-2022 at 04:35 PM.
	0

12-23-2022, 01:09 PM	#8
RACNRAY Sr. Member Join Date: Sep 2011 Location: SOUTH FLORIDA Posts: 1,210	1500 Mean Streak pistons installed in a 1600 will bump the c.r. .5 point from 9-1 to 9.5-1. __________________ "TRUE HAPPINESS IS IN THE HEART, NOT IN THE OUTSIDE FIXES" WITH OVER 46 YEARS AS A MOTORCYCLE TECHNICIAN/HI-PO SHOP OWNER I AM A PURVEYOR OF FACT NOT FICTION! "WE LIVE OUR LIVES IN CHAINS NEVER KNOWING WE HAD THE KEY"
	0

01-01-2023, 05:13 PM	#10
andyvh1959 Advanced Member Join Date: Dec 2017 Location: Green Bay WI Posts: 759	Okay. I just checked piston part numbers on Ron Ayers, and there is a different part number for the 1600 Classic vs the Mean Streak piston part number. But yet, the online specs for both engines show the same comp ratio. By your description the MS pistons in the same bore produce a higher comp ratio. What am I missing? __________________ My $1200 Vulcan, to start from.
	0

11-18-2022, 10:43 PM	#4
Mechaniac Member Join Date: May 2022 Location: Magnolia, Texas Posts: 81	Hey Andy, the difference is right there in the pics. The 1500 and 1600 have the same bore size but different strokes as you know. The crank is changed to have 2.5mm longer throw on the 1600 than 1500. The connecting rod was shortened the same amount, all other things equal including deck height, the longer throw will pull the piston down an extra 5mm overall. So the charge is larger on the 1600 because the piston travels further with the same heads, ports, valves, and camshafts. The dished piston has more void at TDC than the flat-top. That void equals less squeeze of the charge than the flat-top that compresses the charge tighter. Since the rod is shortened the same amount of the crank extension you end up with the piston in the same exact spot at TDC (+2.5mm stroke -2.5mm rod length = 0). But at BDC you have -2.5mm stroke down and -2.5mm rod length = 5mm further down. That's how they did it and maintained the same spot at deck height. Difference is in piston void and longer stroke. Longer stroke compresses more volume into the same spot. Dished piston maintains the same compression as the lower displacement engine in the same spot. Flat piston compresses it into a smaller space on either engine.
	1

01-04-2023, 02:07 PM	#11
Mechaniac Member Join Date: May 2022 Location: Magnolia, Texas Posts: 81	You're missing that many of the online specs published show the wrong compression ratio for one of the bikes. I've found some in the past that listed the Classic as 8.75/1. Since they are in fact lower compression pistons compared to the other. I think that is correct. The only alternative is that the Classic is 9.5/1 and the Meanstreak is higher. My owners manual for the 1600 states premium octane fuel is required but I think that is a carry over from the 1500 manual as it runs exactly the same on regular with the dish piston and longer stroke. I didn't save all the sites I referenced when planning the build so I haven't posted a link to the site(s) that I think had the correct ratios listed. There are some articles about the 1500 Mean Streak when it first came out that seem more accurate than mega specs sites. Vernon
	0

01-05-2023, 11:01 PM	#13
andyvh1959 Advanced Member Join Date: Dec 2017 Location: Green Bay WI Posts: 759	Not trying to argue, just trying to learn more about the 1600. I just looked up the engine specs in the Kawasaki factory manual for both the Classic and the Mean Streak, and both are listed as 9.0:1 compression ratio. I cerntainly understand that online publications can be anything but right. Yet the factory manual lists them as the same comp ratio. I just want to learn more. And yes, more comp ratio generally means more fun with the happy grip. Can even mean better fuel mieage. My BMW R1200RT, flat twin, air/oil cooled specs a comp ratio of 12:1, creates 120hp at the crank, and routinely get 48mpg in general riding. Now, it makes that power and torque spinning a lot more revs than my VN1600 Classic. But the 1600 makes a lot more torque at lower revs than my BMW, __________________ My $1200 Vulcan, to start from.
	0

01-08-2023, 10:39 AM	#14
Mechaniac Member Join Date: May 2022 Location: Magnolia, Texas Posts: 81	Andy are you referring to the factory manual engine specs for the 1600 or the 1500? When they went to the 1600 they all got the same engine, identical pistons. Only the paint on the outside was different AFAIK. The new 1600 made similar power but more torque than the two year 1500 MS that actually had the higher compression pistons than any of the others. The 2 year run 1500 pistons will fit in the others and that's what I am working on as an improvement over the standard 1600. The camshafts were quite different on the 1500 MS as well as the engine control module. All to utilize higher compression and make more power. I don't take it as an argument, I take it as a misunderstanding to figure out.
	0

01-08-2023, 11:07 AM	#15
Mechaniac Member Join Date: May 2022 Location: Magnolia, Texas Posts: 81	120 HP at the crank is pretty good for a 1200cc engine and I am saying that as a BMW enthusiast with two of them in the fleet, E60 535i's. Is that improved by performance tuning or factory? What is the RPM range of that one? My Honda Magna v4 is a 700 but it has less torque and a ton more top end power up to 10,000 RRM than the Mean Streak. It's about a 80HP engine stock.
	0