62t 61x reverse engineering/billet machining

BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
Hello all,

I am new to yamaha, i have multiple kawis including a 440, 550sx, 650sx, and sxr800. I have convinced the company i work for to 3d scan and machine from billet a jet ski engine (castings only) for a trade show this september. I chose the 701 because i want a super jet and never really got around to buying one, either way the 701 has the best current aftermarket and People seem to rave about ite. I did just a touch of research and found that the 62t cases coupled with the 61x jug seems to be the most desired for the stock 701cc setup in a superjet. So i ordered 62t cases and a 61x jug and head from ebay. Today we got the jug in and scanned it to an STL file. We are currently working on modeling the solid and i was wondering if i selected the best castings and what changes you may recommend to the castings i have selected. Thanks in advance for any info.
 
550kid171

550kid171

Location
UT
I may not be the best to touch on this subject but there are already a few companys making billet cases and cylinders for big cc stroker yamaha based motors. The stock style non Powervalve yamaha (61x or 62T) cylinders have become obsolete for this demographic as all of the people spending big money on a billet motor build are going for a powervalve cylinder from a well known motor builder to make the most bottom end power.
 
BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
I
550kid171 said:
I may not be the best to touch on this subject but there are already a few companys making billet cases and cylinders for big cc stroker yamaha based motors. The stock style non Powervalve yamaha (61x or 62T) cylinders have become obsolete for this demographic as all of the people spending big money on a billet motor build are going for a powervalve cylinder from a well known motor builder to make the most bottom end power.
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i understand that. I an not going for big power. I am machining this for a CNC machine tool trade show. I plan to use my demo parts instead of throw them away. I qm not trying to sell anyone anything or start a company... simply what changes would you make?
 
S

Storbeck

Location
Minnesota
You could search around for the common porting that is done on stock cylinders and cases and basically replicate that, also could take a look at the basic things that the billet cylinders are doing differently than stock. You probably don't want to do something as complex as adding an exhaust valve, but you might be able to cheat the transfer ports a little bigger or maybe use big bore sleeves if you want to do something a little more involved. It's all a matter of how far you are willing to do some of your own design vs just copying what is there.

http://www.x-h2o.com/index.php?threads/home-porting.1540/

Pretty good overview of what people do to stock cylinders at the "stuff average joe knows about" level.

Anything beyond that and people start getting a little tight with their hard earned tricks and secrets.
 
S

Storbeck

Location
Minnesota
Also just occured to me the stock cylinders are notorious for cracking on the intake size where they bolt to the case. That's why everybody uses girdled heads. If you just replicate the stock cylinder in billet the material is probably enough of an upgrade to make it a moot point, but you might as well add a little more beef there since it's easy.
 
BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
Storbeck said:
You could search around for the common porting that is done on stock cylinders and cases and basically replicate that, also could take a look at the basic things that the billet cylinders are doing differently than stock. You probably don't want to do something as complex as adding an exhaust valve, but you might be able to cheat the transfer ports ale more involved. It's all a matter of how far you are willing to do some of your own design vs just copying what is there.

http://www.x-h2o.com/index.php?threads/home-porting.1540/

Pretty good overview of what people do to stock cylinders at the "stuff average joe knows about" level.

Anything beyond that and people start getting a little tight with their hard earned tricks and secrets.
Click to expand...
Thank you
Storbeck said:
Also just occured to me the stock cylinders are notorious for cracking on the intake size where they bolt to the case. That's why everybody uses girdled heads. If you just replicate the stock cylinder in billet the material is probably enough of an upgrade to make it a moot point, but you might as well add a little more beef there since it's easy.
Click to expand...
thanks! This is exactly the input i am looking for.
Storbeck said:
Also just occured to me the stock cylinders are notorious for cracking on the intake size where they bolt to the case. That's why everybody uses girdled heads. If you just replicate the stock cylinder in billet the material is probably enough of an upgrade to make it a moot point, but you might as well add a little more beef there since it's easy.
Click to expand...
also let me know about clearance issue areas were aftermarket may interfere, if you know of any.
Storbeck said:
Also just occured to me the stock cylinders are notorious for cracking on the intake size where they bolt to the case. That's why everybody uses girdled heads. If you just replicate the stock cylinder in billet the material is probably enough of an upgrade to make it a moot point, but you might as well add a little more beef there since it's easy.
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te4250 said:
What’s the chances you want to share those stls? Lol
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pretty reasonable, maybe
 
BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
Storbeck said:
Also just occured to me the stock cylinders are notorious for cracking on the intake size where they bolt to the case. That's why everybody uses girdled heads. If you just replicate the stock cylinder in billet the material is probably enough of an upgrade to make it a moot point, but you might as well add a little more beef there since it's easy.
Click to expand...
are you talking about here (see pic)
 

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S

Storbeck

Location
Minnesota
If you look at later Yamaha 760 64x cylinders they added gussets, and that whole area is a little bit thicker walled and beefier. Aftermarket billet cylinders usually make the "mounting flange" much thicker.

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Quinc

Quinc

Buy a Superjet
Location
California
You might try calling ET if you have any questions on the cnc process.
http://www.x-h2o.com/index.php?threads/et-sj-billet-bigbores.120675/

For making improvements you could add more clearance for big bore cylinder/sleeves like the 850 sleeves that blowsion sells. And add clearance to the cases for a stroker crank.

If you want to make some side money, scan and build some factory pipe bpipe manifolds and headpipes. :)
 
BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
Quinc said:
You might try calling ET if you have any questions on the cnc process.
http://www.x-h2o.com/index.php?threads/et-sj-billet-bigbores.120675/

For making improvements you could add more clearance for big bore cylinder/sleeves like the 850 sleeves that blowsion sells. And add clearance to the cases for a stroker crank.

If you want to make some side money, scan and build some factory pipe bpipe manifolds and headpipes. :)
Click to expand...
Thanks for the idea on the manifold/ headpipe, we will see how this motor turns out. I am not too worried about the CNC process, i work for a CNC machine tool Manufacturer and train people on programming for a living! Thanks for the link though, that dude makes some nice motors!
 
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BallsJohnsonDance

BallsJohnsonDance

Location
Midwest
8d0b7a8a2ba3f2505bcc120ed8ada247.jpg

62t cases getting scanned tomorrow


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