Individual / single heads from another Yamaha

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Vinpg
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Re: Individual / single heads from another Yamaha

#46 Post by Vinpg » Wed Dec 27, 2017 1:16 pm

When the water is funneled in the rear and it can go straight to the exit it won't make much difference, it's like the first cool heads the water went in and right out letting the water bake in the cylinders, I get the gasket cut outs but I think it takes the path of least resistance

jeff10
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Re: Individual / single heads from another Yamaha

#47 Post by jeff10 » Fri Dec 29, 2017 8:25 am

Cheap fix if you have figured out how to get the coolant exiting the barrels ... use a lower head & matching head gasket .
I don't recommend it , but I've raced with this setup .
The cylinder-head stud holes are too large to allow the head ( s ) to be centered accurately over the bores even if per chance the combustion chambers were located correctly . They're not .
One head per cylinder gentlemen .... ??

jeff10
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Re: Individual / single heads from another Yamaha

#48 Post by jeff10 » Fri Dec 29, 2017 8:47 am

Almost forgot .
When I stripped out the MK 1 horror with the Yamaha approved " wobble the head around till it feels centered bullshit " ( Stan Stevens still does this ) what did I find ????
Piston to head contact around one third of the piston ... and wait for it ..... detonation directly opposite .
Most of you guys are smart enough to work that one out .
I hope this helps .

Vinpg
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Re: Individual / single heads from another Yamaha

#49 Post by Vinpg » Thu Jan 25, 2018 6:18 pm

I've got 10 sets of heads done, O-rings copper washers new acorn nuts and stk domes.

Vinpg
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Re: Individual / single heads from another Yamaha

#50 Post by Vinpg » Fri Jan 26, 2018 8:10 pm

All the parts are up on my site
Driveline Performance Racing the cranks will be there when they arrive

David de Botton
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Re: Individual / single heads from another Yamaha

#51 Post by David de Botton » Fri Jan 26, 2018 10:24 pm

YZ heads have an oring. Ease of servicing. No gasket issues

RC45
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Re: Individual / single heads from another Yamaha

#52 Post by RC45 » Sat Jan 27, 2018 3:39 am

What is the weight of the billet heads compared to the stock RZ heads?

Hopefully not heavier.
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Vinpg
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Re: Individual / single heads from another Yamaha

#53 Post by Vinpg » Sat Jan 27, 2018 11:45 am

They are almost a lb. heavier, machined a ton out of them but they still weigh more

RC45
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Re: Individual / single heads from another Yamaha

#54 Post by RC45 » Sun Jan 28, 2018 2:35 am

Ouch - and half that weight is added up high.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
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TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
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tacky1
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Re: Individual / single heads from another Yamaha

#55 Post by tacky1 » Sun Jan 28, 2018 12:47 pm

I don't think that Little extra weight will make much difference to a 500, They are not known for their light weight, These things weight more than a modern 100cc bike... :smt003
1985 RZv500
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RC45
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Re: Individual / single heads from another Yamaha

#56 Post by RC45 » Sun Jan 28, 2018 3:25 pm

tacky1 wrote:I don't think that Little extra weight will make much difference to a 500, They are not known for their light weight, These things weight more than a modern 100cc bike... :smt003
I am currently at 360lb fueled up, and still have about 20lb to go - every extra pound added is robbing what little HP it makes :)
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

Vinpg
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Re: Individual / single heads from another Yamaha

#57 Post by Vinpg » Sun Jan 28, 2018 8:59 pm

Oh I forgot you get to lose the metal gaskets

silverstrom
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Re: Individual / single heads from another Yamaha

#58 Post by silverstrom » Mon Jan 29, 2018 12:45 am

RC45 wrote:
tacky1 wrote:I don't think that Little extra weight will make much difference to a 500, They are not known for their light weight, These things weight more than a modern 100cc bike... :smt003
I am currently at 360lb fueled up, and still have about 20lb to go - every extra pound added is robbing what little HP it makes :)
Would the potential power gained by using the new heads with your chosen domes (ccs) offset the weight gain?

Having said that, is there any benefit to using individual heads compared to re-profiled and milled stock heads? O-ringing the stock heads isn't rocket science if you want to lose the gasket, but that would factor into the amount, if any, that would be milled, with only so much being possible before detonation becomes a concern. If more power and losing weight is the end goal, then re-profiled/modified stock heads with o-rings would be the answer. It would also be cheaper.
Last edited by silverstrom on Mon Jan 29, 2018 12:51 am, edited 1 time in total.

Vinpg
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Re: Individual / single heads from another Yamaha

#59 Post by Vinpg » Mon Jan 29, 2018 12:51 am

Absolutely, if you could tell us how far your piston is below deck what you are looking for in compression, we can change squish band width there's a lot to work with just supply the valuable info

RC45
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Re: Individual / single heads from another Yamaha

#60 Post by RC45 » Mon Jan 29, 2018 1:51 am

I still have the ex-Gus/Vito barreled by way of Mark Brown 7xxcc monster motor for my ultimate power build. One day LOL.

I figure if any RZ500 should be dressed up to look like the 1983 Daytona bikes then it needs this motor.
Last edited by RC45 on Mon Jan 29, 2018 4:26 am, edited 1 time in total.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

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