Preparing For Honda K24a3/AST5 6spd Conversion

lookforjoe

True Classic
Worked further on the AC support brackets. Decided it was easier to raise the whole thing 1/2" and keep the breather assembly than deal with modding the intake further. Ears will be cut off, like Rodgers.



Made a cardboard template for the outer bracket. I used an old Volvo ancillary bracket & cut it up to make the outer support.





Once I had that situated, I welded the two together, then setup the anchorage on the intake.



Intake bracket will be properly reinforced.



 
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kmead

Old enough to know better
As there is actually no need for your quadrant on the side perhaps consider filling it in and adding material across the area to stabilize this tang sticking up.

D18D30B3-3B95-41BA-8DD0-A501F2C08E5B.png
It could be filled in even more than I show here

Or even going for more stability by adding a return across the center in addition going to the open hole on the intake

AD3BF551-DC62-40A3-98CF-BE57A1714521.png

I assume this will be the general form of intake manifold bracing?

39FE8FF7-7414-41A4-A3C2-7453C3EE0682.png
 
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lookforjoe

True Classic
As there is actually no need for your quadrant on the side perhaps consider filling it in and adding material across the area to stabilize this tang sticking up.

View attachment 20343
It could be filled in even more than I show here

Or even going for more stability by adding a return across the center in addition going to the open hole on the intake

View attachment 20342

I assume this will be the general form of intake manifold bracing?

View attachment 20344
Hey Karl

That forward (Volvo) section had a circular cutout - I was contemplating adding to that space - I have to at least make the inboard side reinforced to get rid of the cavity from the adjuster. The intake brace won't be as quite as elaborate as your excellent mock up, but will taper out into the runner since it cannot go beyond vertical on the inboard side..
 

lookforjoe

True Classic
Got a little more done on the AC mounting.

Support plate. May need to tidy up that bottom arc, now that the top side is streamlined...



added a contoured shoulder to the inner backside - to fill the slot & so that some of the load is transferred off the mounting bolt



compressor spacing still looks OK



Figured out the belt length - I had ordered the 1500 length based on Rodgers, but for me it's gonna be around 1625. I had a Volvo 1743 belt, so I ran that, pulled the adjuster about 1/2 back, squeezed the belt to take up the slack & measured that, about 110mm.



Also making a manifold support - using the stock bracket & extending it upward




this piece will be welded to the manifold



7176 adaptor fittings came in the mail also



have to figure out what the radius on #10 180º fitting will be, to route the suction side back to the PS where I will be installing the accumulator.
 

lookforjoe

True Classic
Decided to add an idler between the AC and the alt, to improve the alt pulley coverage a touch.

Idler I settled on is the same as used for the tensioner. May have to order a differnet belt again. I'l check the 1625 when it arrives, but it might be too short now.





had my local machine shop turn me a 1" OD spacer, 45mm to shoulder, 17mm OD step 12mm depth. Threaded at each end, I'll weld it to the ancillary bracket.



 
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lookforjoe

True Classic
New set of issues to resolve. Transaxle is obviously completely different than earlier version. Here I’ll have to either chop up and rework the MWB bracket or fabricate an adaptor that locates on the two holes seen in second pic.





No locators at all here. Not sure how I’ll address this one.



 

lookforjoe

True Classic
My concern is really with two mounts not fitting, I'm going to have to be really careful about drivetrain pitch/angle/position relative to the chassis. I think my only realistic option is to weld bosses to my bellhousing to align with the MWB mount, since that would be a fixed reference point with the other three mounts set in place.

These are the MWB reference pics:

left forward mount - no such mount points. Not sure about frame clearance in that area - I don't believe there is room to bring a beefy bracket up & over to the block boss as in Karls' sketch.






Crop from Rodger's pic that shows the bosses



Large boss on trans that I don't have (top left):


I'll have to make a sturdy bracket attached to the two M12 vertical bosses in my previous pic (below). This is a nuisance, but not really troubling.

 
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kmead

Old enough to know better
Pardon my interrupting. Karl, what software did you use to draw the brackets.
Autodesk Sketchbook with an Apple Pencil on my iPad.


Using his pic I then add a layer (or more) to draw on. Sorry these were rushed so not well rendered by me. My instructors would not be pleased.
 

kmead

Old enough to know better
4859189E-FEA1-48F0-A079-12E124A93B57.png


Perhaps a bracket like this?
Sorry it doesn’t show it tucked under the bump, it was intended to do so I was lazy and didn’t make a version of the image that did that. The tab for the big fastener on the trans would be welded on the vertical edge to the body of the bracket. There likely isn’t room for a bend there due to the size of the fastener head and the inside radius.

A cardboard mock-up would allow you to learn a lot.
F7414484-8855-4685-939C-EBAC2075BAC1.png 8FBC7738-9D3D-4EC7-AF70-2B789CCA3C10.png
 
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lookforjoe

True Classic
Thanks Karl

I typically use cardboard box flaps to cut up & tape together to figure out bracketry.

The problem here is that I need two locating tabs to secure the bracket, and a surface mount as pictured won't allow the (MWB bracket) bolt to pass through unless I drill a hole in the bellhousing. I'll have to assemble the subframe under the motor & figure it out later in the week, after I take care of homework I have hanging.

View attachment 20791

Perhaps a bracket like this?
Sorry it doesn’t show it tucked under the bump, it was intended to do so I was lazy and didn’t make a version of the image that did that. The tab for the big fastener on the trans would be welded on the vertical edge to the body of the bracket. There likely isn’t room for a bend there due to the size of the fastener head and the inside radius.

A cardboard mock-up would allow you to learn a lot.
View attachment 20789 View attachment 20790
 

kmead

Old enough to know better
Thanks Karl

I typically use cardboard box flaps to cut up & tape together to figure out bracketry.

The problem here is that I need two locating tabs to secure the bracket, and a surface mount as pictured won't allow the (MWB bracket) bolt to pass through unless I drill a hole in the bellhousing. I'll have to assemble the subframe under the motor & figure it out later in the week, after I take care of homework I have hanging.
I was referencing I was thinking the MWB mount would need to be shallowed up to allow for the threaded boss added to the flat face of the bracket. I missed the lower bolt entirely, shows the focus bias I sometimes suffer :)

Perhaps re think the MWB bracket entirely to make something that goes all what way down to the rubber mount and gets rid of these intermediaries. It should be one bracket that goes from the engine/transmission to the rubber mount on the subframe.

Hmmm.
 

lookforjoe

True Classic
I was referencing I was thinking the MWB mount would need to be shallowed up to allow for the threaded boss added to the flat face of the bracket. I missed the lower bolt entirely, shows the focus bias I sometimes suffer :)

Perhaps re think the MWB bracket entirely to make something that goes all what way down to the rubber mount and gets rid of these intermediaries. It should be one bracket that goes from the engine/transmission to the rubber mount on the subframe.

Hmmm.
The problem that arises then is material. It needs to be same/similar gauge to the heavy square stock - using bent flat stock would be iffy, perhaps 1/4" would be OK. Problem becomes that no supplier near me carries that gauge/dimension square stock, so this can get very expensive very quickly. If I can't easily come up with an adaptor I'll just go with welded bosses on the bellhousing.
 
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