Adding AC to KA24DE Swap Bracket Design

[Datsunworks]

I'm picking up on this where 620_Brian left off on this post:

https://ratsun.net/topic/74907-620-ka24de-swap-underway-pics-pics-pics/page/3/

So much so that I now own his truck:).

 

The problem is that all of the larger Sanden compressors hit the steering box. Brian made good progress by purchasing a SD7B10 which is a smaller version and that is where I'm picking it up from. It was obvious that the compressor would need to be rigid mounted and tensioned with an idler like the factory mount. The first thing I did was pull the needed data points from the factory bracket.

 

 

Mostly the block bolt pattern and the relationship of the idler slot face to those bolts to establish the belt position.

 

I then measured the compressor and it's mounting points and started the design process. I like to get to the CNC mill as soon as possible when reverse engineering/designing because ultimately that is where the rubber meets the road for me. It's a game of make a piece, test fit, get more data, rinse and repeat.  Here is the final model that I derived from all the test fitting:

 

 

 

 

I like to make my test pieces bolt together so that I can easily make modifications. Here is the final test piece. Partially used Ticonderoga for scale:)

 

 

 

The material is Type 1 PVC. I use it a lot for this kind of work. I think this was the third iteration of the original bracket. I started out with .5" plate but that was a non starter since it put the compressor too close to the box. I switched to .25".  I had to make the rectangular cutout to clear cast lettering in the block.

 

And here it is installed.

 

 

The belt lines up great.   There is about .625" clearance between the compressor and the box. The engine torque direction should improve that gap so that's always nice:) You can just fit the compressor into place from the bottom.

 

 

 

 

I have no plans on producing these but will happily hand over the final STEP file for anyone that wants to take the ball and run with it. You would need to make the design work for your method of production but the critical data is there.

 

 

I'm going to use a steel .25" plate with some welded gusseting and the rest will be aluminum and steel pieces that are bolt on kind of like what you see. Since I'm only doing one I want to make it as modifiable as possible. 

 

 

 

 

 

 

 

 

 

 

 

 

 

[]2eDeYe]

Excellent. 
I like the pvc plate for prototyping. Easy to work and bolt together. 

[Datsunworks]

Behold the $2500.00 AC bracket. 😀

 

 

Yes that is what I would have charged someone to get to this point. And this is what I do for a living. $125.00 an hour adds up pretty quickly.

 

 

AC compressor fits great.

 

 

 

I'm concerned by the amount of unsupported weight I have hanging below the 4 mount points where the idler mounts. I added the flat bar reinforcements to hopefully mitigate it. If it starts howling I suppose I could hammer a 2X4 in between the plate and oil pan. 😂

 

 

All in all I'm happy with how it turned out.  Hopefully it will work as designed when I get it plumbed up.

[Stoffregen Motorsports]

Nice work.

[Datsunworks]

Thanks. 

 

I did a clay test with multiple hard pulls and it looks like it is really close to hitting the box. I'll have to see how it goes. I didn't notice a rattle but then again under hard pulls there is enough chaos going on that It may not be an issue. Path of least resistance at this point will be a torque strap. This isn't my forever motor so how much time do I really want to put into it.  I thought I could get by without AC for a bit but in Florida these days it seems like you need it 365/24/7.

 

Ideally I would have made a quick pattern and had one of the foundries I work with cast it in iron but that was a hill too high right now time wise. For others, committing to laser cutting and a more traditional welded design would get this to where it needs to be.