Prototype RZ250/350 YPVS HEAD

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lil_cons
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Prototype RZ250/350 YPVS HEAD

#1 Post by lil_cons » Mon Oct 09, 2017 1:59 am

Hi,

I thought some of you may be interested in a a head that I designed myself as a prototype for my Yammagamma Race bike.

This design is interchangeable between RZ250 and RZ350 Engines requiring only a change of domes, it has been made to utilize the Factory Head Studs/Nuts, rear Water outlet, Factory Temp sensor, and factory Thermo housing, it also has the depth to accommodate for the 55 Deg Thermo.

So far this design will only suit up to a 66mm Bore, but could possibly be adapted to other applications.

These are early days, but I am planning on developing/refining this head to a point that it could potentially be put into small volume production (or possibly one off orders, if so, custom Domes could be supplied).

There are issues that I will be addressing once I have it on the bike and running such as Baffling to improve flow Direction and heat Dissipation Calculations.

I will also be working on head profiles and Combustion chamber Volume Specific to my 250 and 350 Race bike.
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lil_cons
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Re: Prototype RZ250/350 YPVS HEAD

#2 Post by lil_cons » Mon Oct 09, 2017 2:02 am

Extra Pictures.
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JonW
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Re: Prototype RZ250/350 YPVS HEAD

#3 Post by JonW » Mon Oct 09, 2017 2:10 am

Looks good and great to see a local doing something like this! I may well be interested in one of these for a 250 setup if you do decide to make them to put in my new 251LC project, please do keep us posted.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

lil_cons
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Location: Tasmania

Re: Prototype RZ250/350 YPVS HEAD

#4 Post by lil_cons » Mon Oct 09, 2017 2:26 am

JonW wrote:Looks good and great to see a local doing something like this! I may well be interested in one of these for a 250 setup if you do decide to make them to put in my new 251LC project, please do keep us posted.
Hi Jon,

I just had a read of your 251LC Project.

Looks great, I know the developing the 250 is seen as flogging a dead horse, but I have built my bike to fit into a local Lites race class, It also easily hangs with a 350LC race bike on the straights with very few mods.

I'll develop this head somewhat, make sure it works as its intended, improve upon it, then if you are interested could I interest you in an Early stage/functioning prototype at a little over cost if I can prove its reliability? At a later stage in Development of course.

Also, I could imagine my 10.5cc Domes would be too small for a street application?, but if it came to it, I'd be happy to supply a Custom set to your specs.

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JonW
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Re: Prototype RZ250/350 YPVS HEAD

#5 Post by JonW » Mon Oct 09, 2017 3:16 am

That would be wonderful, no one is doing anything for the lil 250s and Id love to help out with feeding back my thoughts etc Drop me a PM if you want to chat some more :)

Oh and the 51L domes might well be a good start for the street version, they are shaped like the later 350 and we could measure those and go from there. the 51L is basically where Yamaha put all their work for the RZ in 250 form, after that they got more excited about the TZR I suspect.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

hondaror
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Re: Prototype RZ250/350 YPVS HEAD

#6 Post by hondaror » Wed Oct 11, 2017 12:40 am

Great work on the head. I'm a machinist. Very interested in your development.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

Headcoats
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Re: Prototype RZ250/350 YPVS HEAD

#7 Post by Headcoats » Sun Oct 15, 2017 7:37 am

Looks the business

Will it take standard head bolts and will they need a copper washer under them ?
Cryin' In The Beer Of A Drunk Man

graham heise
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Re: Prototype RZ250/350 YPVS HEAD

#8 Post by graham heise » Fri Oct 20, 2017 10:43 pm

good work mate. I would be interested in one of your heads for an rz350. keep us posted on your progress.
yamaha fanatic.

lil_cons
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Re: Prototype RZ250/350 YPVS HEAD

#9 Post by lil_cons » Sun Oct 22, 2017 9:34 pm

Headcoats wrote:Looks the business

Will it take standard head bolts and will they need a copper washer under them ?
It sure does mate.
graham heise wrote:good work mate. I would be interested in one of your heads for an rz350. keep us posted on your progress.
Thanks Graham,

The Sale able end product may be a while off yet due to funds and the head is yet to be to be proven. I can't see any faults in it yet, but improvements will be made and the design will be improved upon.

I am aiming to keep the head very affordable also, I'm not a business, I'm just a bloke with an interest in developing some parts for my own bike and Ideally I'd like to make a small sum of money to put back into Racing and RZ/RD projects.

JonW wrote:That would be wonderful, no one is doing anything for the lil 250s and Id love to help out with feeding back my thoughts etc Drop me a PM if you want to chat some more :)

Oh and the 51L domes might well be a good start for the street version, they are shaped like the later 350 and we could measure those and go from there. the 51L is basically where Yamaha put all their work for the RZ in 250 form, after that they got more excited about the TZR I suspect.
I have a 51l head here, it shouldn't be too hard to base it off that, they seem to have much wider and tighter squish than the 29l.

I think you are right, I was looking at some 51l Barrels the other day, I'd really like set.

I'd be happy to supply you with a head when they are a bit further along Jon, it would be great to have another bike up and running for R&D Purposes as well as general feed back.
250 engine on the Dyno as soon as it goes back together so I will be able to get an indication of performance and its cooling abilities and we'll go from there.


Some updates on the appearance of the head in the attached Pics.
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JonW
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Re: Prototype RZ250/350 YPVS HEAD

#10 Post by JonW » Mon Oct 23, 2017 2:13 am

Superb! Loving this... Why is it that this stuff gets me so excited, CAD porn... LOL!
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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Smoker
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Re: Prototype RZ250/350 YPVS HEAD

#11 Post by Smoker » Mon Oct 23, 2017 4:26 am

Excellent project.

What type of machinery is required to cut a CAD head like this?

lil_cons
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Location: Tasmania

Re: Prototype RZ250/350 YPVS HEAD

#12 Post by lil_cons » Wed Oct 25, 2017 8:35 pm

Smoker wrote:Excellent project.

What type of machinery is required to cut a CAD head like this?
As far as I know the Machine shop that I get to do it use a 5 Axis Mill with an Automatic tool changer and they use Electrical Discharge Machining (Spark Erosion) for the Embossed YPVS on the sides.

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kenny
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Re: Prototype RZ250/350 YPVS HEAD

#13 Post by kenny » Thu Oct 26, 2017 8:41 am

On the inserts you need to get some water as close to the spark plug as possible helps cool the plug more and avoid any detonation issues on a tuned engine with programmable ignition.
I would be interested in a head with no squish etc in the domes so I can machine my own chamber. Also would look better in my opinion with the corners and edges rounded off and the top looking like the OEM head.
Nice job with the prototype though mate.

lil_cons
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Re: Prototype RZ250/350 YPVS HEAD

#14 Post by lil_cons » Thu Oct 26, 2017 7:03 pm

kenny wrote:On the inserts you need to get some water as close to the spark plug as possible helps cool the plug more and avoid any detonation issues on a tuned engine with programmable ignition.
I would be interested in a head with no squish etc in the domes so I can machine my own chamber. Also would look better in my opinion with the corners and edges rounded off and the top looking like the OEM head.
Nice job with the prototype though mate.
Cheers Kenny.

I had originally based the Inserts outer appearance on an old TZ250 Insert, that's an easy fix though.

I had thought that people may be interested in the OEM look, I added some Fillets to the Model in the attached pics (Let me know what you think), if these were one off orders, I'd be happy to Manufacture them with or with out Fillets.

Also a Blank insert would be no hassle at all, you would just need to give me an idea of the measurement of the Deck to Plug height to make sure you can utilize your own Combustion chamber dimensions, unless you wanted that blank too?.

Also, my proto inserts have an OD of 75mm at the moment (Due to keeping the insert recess between the Stud holes.), which doesn't leave a whole lot of room for an O'ring Groove, this is something I will work on though.
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JanBros
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Re: Prototype RZ250/350 YPVS HEAD

#15 Post by JanBros » Thu Oct 26, 2017 7:51 pm

done this myself for a KR1S.
not much proto-typing/testing needed. I had 5 people who immedialy wanted to buy one, so we decided to make 1 that I would test. Which was good because he spark plug's where a bit too close to the waterpipe (on top for each cylinder) on my design. all the rest worked straight away. If I would design a head for the RD, I'd force the water first through the cylinder (block te water in the head, just leave a tiny opening for bleeding) and than let it go to the head again via the front of the cylinder)

make sure that the inserts stick out a tiny bit compared to the head surface (I used 0.05mm)
I only provided blank inserts , so many different engines with too many people wanting too many different designs/specifications. instead of 30 euro for a blank insert, it would cost a whole lot more. also made the spark plug side way to long, so the lath could get a decent grip on the insert. when the chamber is cut in, simply reduce the "spark-plug-end" to the needed length.
I kept the outside design to a minimum as to make the time on the mill shorter and lower costs but afterwards the maker said it wouldn't make much difference in price .
if it runs, you can race it !

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