John's JDM Honda K24A 818R Rebuild

[Hobby Racer]

I've lowered the engine./trans about as low as I dare. Lowering it this much causes a slight upward angle on the drive axles. Not ideal, but in the acceptable range I think. Pushing the engine/trans back as far as I have also requires me to relocate one of the rear wish bone links that rubs the CV joint boot.

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[Hobby Racer]

I got started on the motor mounts and really like the way they are coming together. I designed the mounts in CAD and had them made out of 3/16" plate steel. I used SendCutSend again and they did a great job. I could have made the brackets myself but I didn't have the right material on hand and for the cost it didn't seem worth my time. The laser cut brackets fit perfectly.

Here are the brackets as they came from SendCutSend, followed by versions after some needed welding. And finally painted, from this angle you can see that the intake side needed two different length standoffs as no two bolt holes on that side of the block, in the area I wanted my motor mounts, are on the same plane.

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Next I had to secure the engine/trans in space so I could get real measurement between the frame and the motor mounts. I used multiple straps pulling against one another in all three planes of movement. This allowed me to adjust the precise position of things to get the engine centered in the engine bay, the angle of tilt (approx 15 degrees), and transmission angle relative to the ground set right.

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Everything is only tacked in place for now. After I get the transmission mounts and frame bracing in place I will final weld all the pieces.

[Hobby Racer]

I finished the custom throttle body adapter that was needed to join the larger throttle body from my Subaru EZ36 motor to the Honda intake manifold.

In the first picture you can see the 4 countersunk holes that fasten the adapter to the intake manifold and the 4 tapped holes that the throttle body bolts too. In the second picture you can see the taper that transitions smoothly from the smaller inner diameter of the throttle body to the larger inner diameter of the intake manifold.



This small piece was complex enough that I needed to design it in CAD first to be sure everything would come together correctly. I'm embarrassed to say I made MANY prototypes before I got everything to fit up right. I started off using a 3D printer but found that the tolerances were too loose so I moved on to making them out of MDF board on my milling machine.

Here are some of the prototypes and test pieces.
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Here are some more pics of the setup in the lathe cutting that smooth taper. It was such an odd shaped part I had to bolt it to a square board to mount it up in my 4 jaw chuck. Finally some close ups of the finished part.

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[FFRWRX]

Very nice work. Sometimes I find that when I skip the prototyping stage (because in my head it is going to come out perfect without doing that) I end up scrapping the part and starting again....and again....and again. I learn slowly.

Rick

[Rob T]

Very Nice. One advantage of bolting the odd shaped piece to the board in the 4-jaw was that you could cut the taper just past the end of the piece into the wood without hitting the 4 jaw. Genius.

[Hobby Racer]

I had a marathon day of welding. I finish welded the motor mounts, made the transmission mounts, made a small cross brace and finally welded everything into place! I might add some cross bracing if I can find a spot that it will fit.

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[Hobby Racer]

With the engine and transmission sitting on the finished mounts, you can see everything is a really tight fit. Here are a bunch of pics from various angles.

Next I need to add back some cross bracing to the rear firewall.

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[Jetfuel]

I really hope that you’re rewarded for your hard work in your quest for speed and reliability.

Jet

[Hobby Racer]

One of my goals for this rebuild was "minimal frame modifications". Well I failed on that one.

I added some diagonal triangulation and tied off the suspension mounting points at the lower section of the firewall.

[Hobby Racer]

When you combine the additional length of an inline 4 cylinder engine, the transmission adapter and the longer Subaru 6 speed; you find the CV joints exit the transmission and do not have enough room to clear the rear most lower lateral link connection point. I had to move the inside connection point closer to the back. It is easier to understand looking at the picture. You can see where I cut off the original and pushed it back as far as possible, eliminating the spacers in the process.





Here are both sides welded in place.

[Mark Eaton]

Is that 6 spd transmission the same width as the 5 spd? Im just wondering if it will affect the length that the CV axle needs to be? After all the issues I'm having trying to find a replacement CV joint for my 818 I am very tuned into this issue!

[Hobby Racer]

Is that 6 spd transmission the same width as the 5 spd? Im just wondering if it will affect the length that the CV axle needs to be? After all the issues I'm having trying to find a replacement CV joint for my 818 I am very tuned into this issue!

The 6 speed is wider, taller, longer and heavier than the 5 speed. It does not effect the axles though. The FFR design has plenty of room for lateral movement and slight variations in transmission width and placement. I used the FFR axles in both my original 5 speed and this 6 speed.

[Hobby Racer]

After some well spent time with the die grinder, the intake manifold is now port matched to the cylinder head. It really makes the cheap knock off manifold very nice.

[Hobby Racer]

I know it looks like I'm going backwards, but it really is forward progress.

In order to run a baffled wet sump oil pan you have to change the oil pump from the stock K24 to the stock K20 version. Those do not have balance shafts that get in the way of the pan baffles. Plus they are lighter, allow the engine to rev higher and provide a more stable oil supply. But to do it you need to remove the front timing chain and all the bits associated with it.

[Dave 53]

Watching your progress with interest. On the one hand, you're making it look easy. On the other hand, I've given up any fantasy of doing it myself.

[Hobby Racer]

Power-train goes back in for final fitments tomorrow!

Now tell me that red valve cover isn't worth at least 15hp! It does look a lot nicer now.



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[cob427sc]

Does look sharp! Love following your buildup.

[Hobby Racer]

Finishing up, connecting oil, cooling, exhaust, wiring etc... Fabricated the new rear tower bracing. Because the motor is right up against the rear firewall and slanted 15 degrees the supports are asymmetrical and do not meet in the center of the firewall.

I'm very pleased with how the packaging is falling into place.

Hoping for first start in April.


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[Hobby Racer]

I'm looking at the transmission cable routing and I am having a difficult time finding a good way to do it. With the engine tight against the firewall it limits my options. I'm even considering running them under the car starting at the gas tank and coming up under the transmission.

Any ideas are welcome!

[Ajzride]

Do something similar to Art and put mechanical linkage in the cockpit that moves the cables to the far edge of the cabin and then route your cables back along the fender well.

[Hobby Racer]

Do something similar to Art and put mechanical linkage in the cockpit that moves the cables to the far edge of the cabin and then route your cables back along the fender well.

I thought about that for a bit, but with the stock fuel tank there is not enough room to run the rods and linkages. I would need to swap to a different tank like Art did, and if I do that I could just customize the tank to run the cable under it.

Wait a minute, maybe I'll look at putting a pass through port in the tank.

[Ajzride]

I raise my tank 1" and went under it.

[Hobby Racer]

I raise my tank 1" and went under it.

Ok, I like that idea. What did you use under the tank to raise it up?

[Ajzride]

Ok, I like that idea. What did you use under the tank to raise it up?

1" square tube, just like the frame.

[Hobby Racer]

1" square tube, just like the frame.

Any pics?

[Ajzride]

Not great ones. You can kind of see where I boxed the frame so I could go through it here:

https://thefactoryfiveforum.com/show...l=1#post388714

I'll try to get some more tomorrow out in the garage.

[Hobby Racer]

Not great ones. You can kind of see where I boxed the frame so I could go through it here:

https://thefactoryfiveforum.com/show...l=1#post388714

I'll try to get some more tomorrow out in the garage.

No need, I get the idea from the post. I'm going to mock up something this weekend and see how I like it. Thanks!

[Ajzride]

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[Hobby Racer]

I see your also using a different tank. I'm still using the FFR steel tank and I don't think you can raise it much before it contacts the aluminum removable firewall panel.

I think I'm just going to bore a hole through the tank in the location I need and weld in a tube. This will give me a nice pass thru to run the cables and reverse lockout cable.

[autostang]

I see your also using a different tank. I'm still using the FFR steel tank and I don't think you can raise it much before it contacts the aluminum removable firewall panel.

I think I'm just going to bore a hole through the tank in the location I need and weld in a tube. This will give me a nice pass thru to run the cables and reverse lockout cable.

I put a tunnel through my gas tank this winter for shift rods and it worked out pretty well....do wish my welding skills were better, but it got there in the end. It makes for a nice direct path to the back of the car! I put a pivot point in just behind the firewall, then transitioned to short 3ft cables under the engine. It seems to shift well, but I haven't actually gotten the car back on the road yet to test.
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[Hobby Racer]

I cut the pass thru holes today. The compound angles needed to get the 2" pipe to pass through cleanly started to make my head hurt so I modeled it up in CAD and just asked the computer for the angles.

Tomorrow, hopefully I will have time to cut the tube ends flush with the tank and weld it all up.

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[Ajzride]

A fuel tank strapped to a milling machine makes me feel inadequate.

[Rob T]

Two things...1) I guess you got all of the explosive vapor out of the fuel tank (I'm glad) 2) The answer to the question is "because I can". I am constantly amazed by your ingenuity and resourcefulness when it comes to solving complex problems with precision. It is inspiring.

[Hobby Racer]

I finished welding the pass through tube in the fuel tank. The routing came out very good. I fabricated a new mounting point at the rear for securing the cables. Now the engine and transmission can be removed from the car without disturbing the cables.

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[Hobby Racer]

Only thing left to do is the wiring and the fuel system.

I routed everything on the outside of the cabin this time instead of using the center console.

[Ajzride]

Which ECU are you running? First post just said "existing standalone".

[Hobby Racer]

Which ECU are you running? First post just said "existing standalone".

I'm running a MegaSquirt MS3Pro ECU.

[cob427sc]

Looking great. Can't wait to hear it run and see how it performs versus the subie engine.

[Sgt.Gator]

Incredible work!

[q4stix]

Great work, I'm glad to see you make all the progress you have even with the earlier EJ setbacks