GS450H Adapter Plate
GS450H Adapter Plate
Just thought Id share I've been working on this today and 3d printed it and test fit it and it fits like a charm. I will be making this for my build and will have either bolts or a center hole for welding the flywheel on, depending if I go steel or aluminum. As I will use it as a mounting point for the transmission and other items if deemed needed.
What was I doing?
- TheSilverBuick
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Re: GS450H Adapter Plate
You must have a large format printer for something that size?
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Re: GS450H Adapter Plate
No I just sliced it by .01mm then glue back together after print
What was I doing?
- TheSilverBuick
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Re: GS450H Adapter Plate
Why not just water jet it out of plate steel or aluminum?
Need to learn. Starting from the basics.
Re: GS450H Adapter Plate
I needed a test fit first - now I will get it laser cutTheSilverBuick wrote: ↑Mon Dec 14, 2020 6:13 pm Why not just water jet it out of plate steel or aluminum?
What was I doing?
Re: GS450H Adapter Plate
Hy Gigas
Nice looking adapter plate,
I just realist that I mad a minor mistake on the Drawing of the bolt plattern i posted in this forum.
One hole diameter was not corect.
Nice looking adapter plate,
I just realist that I mad a minor mistake on the Drawing of the bolt plattern i posted in this forum.
One hole diameter was not corect.
- ggeter
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Re: GS450H Adapter Plate
Can you make the 3D file available? I'd be interested in getting one cut for my project.
Houston, Texas, USA
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
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Re: GS450H Adapter Plate
Attaching some files that might also help. Drawn up from the dimensions above and fits 100%. Includes mounting holes in lower corners.
- PacEmaker
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Re: GS450H Adapter Plate
Thanks for the dxf file!
Geoff
Is this smoke trying to tell me something ...
Is this smoke trying to tell me something ...

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Re: GS450H Adapter Plate
Yes, cut out of the flywheel and cleaned up on the lathe. Bit of approx 63mm OD 8mm wall off the shelf mechanical tube then.
- Gregski
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Re: GS450H Adapter Plate
thanks for this, I just had mine cut, cost me $300 at my local mom and pop place, anyway first I am totally appreciative so these are just a couple of observations, I aint complaining
the bottom two holes could be larger in diameter to match those of the bell housing
also I noticed that you missed two holes for more tension pins, I found that these 3/8ths tension pins from my local hardware store work great for precise plate mounting, so there are two holes currently and I thought at least three would be more better, anyway I will add pics later to show which ones I am talking about, here's some pics for now
here's a funny video for a laff
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
- Gregski
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Re: GS450H Adapter Plate
once again I am very thankful for this design, and the goal of the video below is just to provide some hands on real world application feedback
I wish there were at least three tension pin holes in this plate to allow for more of a triangulation when mounting it, currently it only supports two pins as explained in the video. The two red Xs in the pic below show where the other two holes should be drilled.
I wish there were at least three tension pin holes in this plate to allow for more of a triangulation when mounting it, currently it only supports two pins as explained in the video. The two red Xs in the pic below show where the other two holes should be drilled.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: GS450H Adapter Plate
How well does the plate align?
Tension pins are not great for concentricity / alignment as they will spring a bit off center.
Are there factory alignment collars or pins in the transmission usually? The challenge is if you make the plate for a very exact fit the machining costs go up a bunch and your other machined parts and tolerances have to be exact. If you're a bit off or as the tolerances add up and shift things it can load up the input shaft bearing.
Leaving it a bit loose let's you jiggle it centered as you tighten it down.
Tension pins are not great for concentricity / alignment as they will spring a bit off center.
Are there factory alignment collars or pins in the transmission usually? The challenge is if you make the plate for a very exact fit the machining costs go up a bunch and your other machined parts and tolerances have to be exact. If you're a bit off or as the tolerances add up and shift things it can load up the input shaft bearing.
Leaving it a bit loose let's you jiggle it centered as you tighten it down.
- Gregski
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Re: GS450H Adapter Plate
ah good point(s) and yes I agree, some holes had to be enlarged a smidgeon like the very bottom two, it's all in the excruciating boring video above, and I plan on using the tension pins to align and drill all the holes in the fly wheel pressure plate ninja star to lock the input shaft, then mount the plate without the tension pinsjrbe wrote: ↑Sat Dec 07, 2024 4:31 pm How well does the plate align?
Tension pins are not great for concentricity / alignment as they will spring a bit off center.
Are there factory alignment collars or pins in the transmission usually? The challenge is if you make the plate for a very exact fit the machining costs go up a bunch and your other machined parts and tolerances have to be exact. If you're a bit off or as the tolerances add up and shift things it can load up the input shaft bearing.
Leaving it a bit loose let's you jiggle it centered as you tighten it down.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: GS450H Adapter Plate
I'm guessing op might not be interested in updating this.
Greg, If you get me what the hole sizes need to be i can update the DXF.
Doesn't the ninja star need a spacer? I could draw up a bent sheet metal spacer that could get welded in or could do a bolt in version. Ît should simplify this a lot. Can you get dimensions of all this stuff?
Any other mounting holes needed to help make this more universal?
I'll make a pdf drawing that gets printed out to 100% scale to give a printable drill template to help guide your hi tech tooling.
- Gregski
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Re: GS450H Adapter Plate
thanks I will try to get you those measurements, and what would really be helpful is having these 4 holes to mount the Ninja star via bolts since I don't think many folks like me will be welding this especially since I plan on using a 1/2 aluminum plate, Artur did this on his Jaquar and has been driving the car for about 4 years now, I actually plan on using eight M10 bolts to hold my star down, 4 in the stock OEM closer to center holes that are already there, and 4 on the outside which we need to enlarge ie drill outjrbe wrote: ↑Sat Dec 07, 2024 7:55 pm I'm guessing op might not be interested in updating this.
Greg, If you get me what the hole sizes need to be i can update the DXF.
Doesn't the ninja star need a spacer? I could draw up a bent sheet metal spacer that could get welded in or could do a bolt in version. Ît should simplify this a lot. Can you get dimensions of all this stuff?
Any other mounting holes needed to help make this more universal?
I'll make a pdf drawing that gets printed out to 100% scale to give a printable drill template to help guide your hi tech tooling.
"I don't need to understand how it works, I just need to understand how to make it work!" ~ EV Greg
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Re: GS450H Adapter Plate
In my understanding, the dowel pins should be smooth and solid. They should be all but press fit. Zero wobble or flex. Factory specs for a normal transmission is 0.004" I think.
I thought I "learned" that two of the dowel pins "always" have a line between them that intersects the exact center of the shaft, and the half way point between them is the exact center location of the shaft. I saw one template diagram like that and I was blown away. That makes so much sense. They're already so precisely aligned, might as well double down on that precision and use that to find the center shaft. I figured I was kinda dumb to have never noticed that before, and presumed all dowel pins have locations selected for those two purposes.
Then I see your template and... nevermind. None of those 4 even intersect the shaft.
...
Is the GS450H transmission like most other transmissions, that lack a bearing for the shaft and instead are centered by a pilot bearing in the engine? Or is it centered through a bearing that's part of the transmission? The latter would certainly be more convenient.
What I'm getting at is, do you actually have to precisely align the shaft and the splines, or, in this case is it already aligned for you and you just need a diaper over top of it to prevent fluid from blowing out the sides?
I thought I "learned" that two of the dowel pins "always" have a line between them that intersects the exact center of the shaft, and the half way point between them is the exact center location of the shaft. I saw one template diagram like that and I was blown away. That makes so much sense. They're already so precisely aligned, might as well double down on that precision and use that to find the center shaft. I figured I was kinda dumb to have never noticed that before, and presumed all dowel pins have locations selected for those two purposes.
Then I see your template and... nevermind. None of those 4 even intersect the shaft.
...
Is the GS450H transmission like most other transmissions, that lack a bearing for the shaft and instead are centered by a pilot bearing in the engine? Or is it centered through a bearing that's part of the transmission? The latter would certainly be more convenient.
What I'm getting at is, do you actually have to precisely align the shaft and the splines, or, in this case is it already aligned for you and you just need a diaper over top of it to prevent fluid from blowing out the sides?
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Re: GS450H Adapter Plate
With an ice, usually there are 2 bearings in the transmission and a pilot bearing or bushing in the crank or flywheel. They need to be all in line or will load the bearings until they wear or get destroyed.
So yes, they normally need to be aligned well.
Doing this mod eliminates the need for the pilot bushing / bearing. Since the shaft isn't turning it might not be very sensitive to being a bit bound up, depends if it loads up something else that rides on it. But it's not a lot of effort to help it float when tightening the locking plate up.
Some older engines may have used dowel pins in line to the crank. With cad and CNC it's a lot easier to align things sort of arbitrarily.
There should be a seal in the transmission on the shaft. No diaper required.
So yes, they normally need to be aligned well.
Doing this mod eliminates the need for the pilot bushing / bearing. Since the shaft isn't turning it might not be very sensitive to being a bit bound up, depends if it loads up something else that rides on it. But it's not a lot of effort to help it float when tightening the locking plate up.
Some older engines may have used dowel pins in line to the crank. With cad and CNC it's a lot easier to align things sort of arbitrarily.
There should be a seal in the transmission on the shaft. No diaper required.