Suzuki Gs850 EFI Conversion

[rjteeter]

I started an EFI conversion for my 850 a bit over a year ago. I started with 1999 Suzuki GSXR750 injected throttle bodies and home brew, cnc cut adapter manifolds to adapt them to the GS850 head (protos cut from wood). Almost exactly a year later (with no activity) I redesigned and re-cut the proto manifolds. I ordered most of the expensive hardware (fuel pump, plumbing, blank fuel rail stock, fuel pump and filters, Megasquirt).








Dummy fuel rail has been machined, spacing confirmed and new injector and FPR o-rings in hand.

[storm 64]

Looks great. I'm looking forward to seeing how it all comes together. 👍

[rjteeter]

Adding more photos and splitting original post.

I've been stumbling a bunch as the spacing needed for the 850 head doesn't give enough room between the outer throttle bodies but finally settled on a design/modification to make it work. I've designed two butterfly shafts, one for each outer pair of throttle bodies apposed to four separate shafts.

[posplayr]

looks like a great kit. This is something you might actually be able to sell in some moderate quantities. Can you adapt easily for either 1000 8V or 1100 16v?

[rjteeter]

looks like a great kit. This is something you might actually be able to sell in some moderate quantities. Can you adapt easily for either 1000 8V or 1100 16v?

Adaptions should be easy. I just need to get measurements off the heads. But at over 4 hours of mill time in wood it is a bit time consuming to cut he manifolds. Cutting in aluminum could almost double mill time. I am working on a third design though which I hope will cut down on mill time.

[93Bandit]

Adaptions should be easy. I just need to get measurements off the heads. But at over 4 hours of mill time in wood it is a bit time consuming to cut he manifolds. Cutting in aluminum could almost double mill time. I am working on a third design though which I hope will cut down on mill time.

I'm sure you could charge enough to make it worth the time. Of course, any improvements in design that will reduce production time is always a good idea.

I know I would be interested in a manifold set if you get this to work and decide to manufacture them someday, depending on price of course.

[Wingsconsin]

Can the manifolds be 3D printed ?
I wonder if there is a company somewhere that could do it reasonably...

[rjteeter]

I'm sure you could charge enough to make it worth the time. Of course, any improvements in design that will reduce production time is always a good idea.

I know I would be interested in a manifold set if you get this to work and decide to manufacture them someday, depending on price of course.

You have a bit of contradiction here, I think. Although I got a good financial start with 2 motorcycles for $300 USD, this project is not being done because it's a cheap solution, and in comparison to other options; it's not. I bought the bikes because they were cheap and the acquisition was fairly leisurely. The conversion is because I dislike carbs, I like the possibilities, reliability and advancement of EFI, and because EFI adds a level of show off/eccentrics to my otherwise bland and overweight motorcycle. Also I have an addiction to old clunky vehicles but again, I like them to run well, reliably and if I can make it pop when I let off the throttle then I'm sold.

Can the manifolds be 3D printed ?
I wonder if there is a company somewhere that could do it reasonably...

I'm sure they could. I have been considering a 3d printer for some time. I don't think manufacturing, either 3d printed nor subtractive machining would be cheap or affordable to me let alone you. Once I have a complete system I might try to toss out a few kits here and there.

[93Bandit]

You have a bit of contradiction here, I think. Although I got a good financial start with 2 motorcycles for $300 USD, this project is not being done because it's a cheap solution, and in comparison to other options; it's not. I bought the bikes because they were cheap and the acquisition was fairly leisurely. The conversion is because I dislike carbs, I like the possibilities, reliability and advancement of EFI, and because EFI adds a level of show off/eccentrics to my otherwise bland and overweight motorcycle. Also I have an addiction to old clunky vehicles but again, I like them to run well, reliably and if I can make it pop when I let off the throttle then I'm sold.

Most people here understand that an EFI conversion wouldn't be economical, as most components will need to be adapted or made from scratch. So it is reasonable to assume the price for an entire kit, or just the custom parts would come at a cost greater than rebuilding the carburetors. However, like you said yourself, you want the reliability and smooth operation of EFI, and I think many here would like the same, they just don't have the resources to blaze the trail. But if someone like yourself does all the hard work and comes out with a manifold, for example, that could be used to adapt an existing EFI system, then many would probably be willing to shell out the cash for the custom manifold, even if it is somewhat expensive.

My point was, if it costs you $30 in materials and ~4 hours of mill time, and you charged $40/hour, that would make the total for the manifold $190. To some that might be too expensive, but considering replacement OEM rubber carb intakes are $31 each and you need 4 in total which is $124, it'd only cost $66 more to purchase these manifolds. Yes, all the other EFI components would have to be purchased, but if you're doing this conversion you understand it won't be "cheap." That's my take on it.

[GSX1100 dreamn]

Here is that thread I mentioned before,

https://www.thegsresources.com/_forum/showthread.php?255966-quot-Black-Sheep-quot-81-GS550L-EFI-conversion

Cheers Andrew.

[mmattockx]

But at over 4 hours of mill time in wood it is a bit time consuming to cut he manifolds. Cutting in aluminum could almost double mill time.

I'm sure you could charge enough to make it worth the time.

I doubt he can. At even a bargain CNC rate of $50/hr those manifolds are going to cost $400+ if OP puts no value on his time for all the design and development work.


Mark

[posplayr]

I doubt he can. At even a bargain CNC rate of $50/hr those manifolds are going to cost $400+ if OP puts no value on his time for all the design and development work.


Mark

I have been watching some videos that do sand castings. That would probably be a lot cheaper. Not as high tech as CNC from billet.

https://www.youtube.com/watch?v=XlRK_SMWX7Y

CNCed Lost wax casting might be more economically feasible option.

https://www.youtube.com/watch?v=HVgPM1ojyLw

[rjteeter]

Here is that thread I mentioned before,

https://www.thegsresources.com/_forum/showthread.php?255966-quot-Black-Sheep-quot-81-GS550L-EFI-conversion

Cheers Andrew.

I did read it but I think he didn't make it too far.

I doubt he can. At even a bargain CNC rate of $50/hr those manifolds are going to cost $400+ if OP puts no value on his time for all the design and development work.


Mark

I'll see what I can do to keep the price low but the last manifold design would have been around 7 hours of mill time on my little mill. I have a third, redesigned version that I'm hoping will lower the mill time along with increase adaptability to other projects.

I have been watching some videos that do sand castings. That would probably be a lot cheaper. Not as high tech as CNC from billet.

https://www.youtube.com/watch?v=XlRK_SMWX7Y

CNCed Lost wax casting might be more economically feasible option.

https://www.youtube.com/watch?v=HVgPM1ojyLw

If I were to go another direction it would probably be 3d printing. I like the machining aspect and don't need another hobby, lol.

_________________________

I’ve re-designed the manifolds/adapters. The goal is to separate the runners from the mounting plate to allow for quicker, more accurate and cleaner machining as well as increase adaptability to other projects. I've spent the last week trying to find a Cam solution in my current resource bag that will allow me to do this. I had to revert back to an old CAM solution and setup an old computer to accomodate this solution. I think as of today I am back on the track to progress and hopefully can get my new manifold prototype out this week as well as the new butterfly linkage and possibly the final product fuel rail.

[GSX1100 dreamn]

I noticed on my donor 1250 Bandit it has straight and offset bolt on intake rubbers.
I haven't measured the screw spacing yet, they fit 36mm throttle bodies.
Just an idea for design or possible fitting

Cheers Andrew.

[mmattockx]

I'll see what I can do to keep the price low but the last manifold design would have been around 7 hours of mill time on my little mill.

Don't think I was dumping on you, I wasn't. But I am familiar with solid modeling and CNC work and I realize that machines don't run for free and costs add up quickly. It is just a fact of life and cannot be avoided.


Mark