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You're my boy, Blue '71 521 - KSwap

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I tracked down a second NA Miata 5 speed - this one has the shifter, speed sensor, and I got the clutch / flywheel / clutch plate which leaves me needing a K24 starter and KMiata flywheel, kmiata...ect ect lol

new tranny got a simple greening and pressure wash 


then we swapped out the trannys and bro snagged a stock RSX header from a coworker so we can see if it was going to work, had to be modified or if we have to go full custom


Then we shoved the truck off his trailer and wheeled her over


Anyone else going to try this, it's easier if you take the hood off first - we wanted to see how close it would be before hand and it turns out you have to put it in at a pretty extreme angle if you don't wanna cut the front upper support. We also jacked the cab up in the back a little to help.


and away she goes


she fits reallllllllllllllly well, like I am super impressed -




here you can see where the stock mounts are on the frame and where some custom ones will have to go on the driver side / intake side of the engine. 


here is roughly how much space is goign to be left in the back, you are going to have to modify your stock collant neck or get an aftermarket one - i am ordering the K24a2 upper coolant neck from kmiata tonight with the 1.25" barbed hose fitting for the radiator and no sensor ports


how much room is left in the front without having to modify the front frame


then we shimmed the engine a bit and tossed the hood on to see if it would clear


and she's good!


she misses the main supports for the hood as she sits 'level' and has 1/4" clearance. we are goign to be able to get a good half an inch or more though as the truck cab is still sitting directly on the frame. I am ordering the spacer kit tonight as well and we are moving forward on mounts for the engine and plotting out the trans tunnel / roll cage next. 

Edited by BrothersGarage
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11 hours ago, banzai510(hainz) said:

Dig the be and bike

Bro has a nice collection of his own, that's his first ever bike (he's got like 3-4 more lol) Super beetle on the left we are doing a Subaru Legacy engine swap into, and the white one was our grandfathers that my bro first turned a wrench on. 

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Bro has been working without me! Crazy bastard is as excited to be finally working on something as I am and he pulled the engine himself to test fit the mounts.

Spacers for the back on the driver side:


mocked in place


from above

and he made the parts to attach to the factory mounts:


Amazon came with the new cab mounts and rear tranny mount arrived:

and Fedex dropped off the KMiata K24a2 upper coolant neck arrived today as well,



Once this is done it which puts us at basically being able to finish mounts and move onto figuring out intake and exhaust.

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Bro busted so much ass today it's not even funny. Went over today and he told me he got bored last night and finished up the engine mount plate on the drives side


followed by out the passenger plate and started measuring out the length of the spacers needed


With those done it was on to mounting and mock-up


closer picture on passenger side:


then out came the grinder and Bro chopped out the old tranny brace the previous owner put in to hold their swap / got everything mocked into 'final' placement

We then cut out the old tranny brace the previous owner put in and mocked up the placement of the tranny in the tunnel


And out comes the welder


Bro started with the more difficult passenger side:


and with them tacked in place out came the CAD


and braced on the back side


then over to the driver side


closer picture - note they are not joined in the bottom against the block


With everything tacked into place we pulled everything again, and Bro got into the nitty gritty work




in adding in more bracing 


half way though:



Close up of those spacers from earlier


and then driver



While Bro bushed some more ass, I ran out and met a guy to pick up a RBC intake manifold &K-Tuned gaskets:


And NOT to my surprise Bro had already finished both mounts, bolted them to the engine and resunk the engine into the truck in 45ish minutes!! So we slapped the new intake manifold on just to see what it looks like with the engine sitting on it's own mounts for the first time!



That will have to get chopped a bit and have the intake side flipped, plus we still have to do the tranny mount, and then mount the bed to the frame, but even now with the cab sitting on the frame everything fits and we will only GAIN space in doing so. 


Edited by BrothersGarage
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Met up with the guy that I bought the 2nd Miata tranny and got a stock drive shaft today. 


Look at this sad shit LOL the custom drive shaft will either replace it all the way up @ the front - but I am thinking that I may just have a connecting piece made so that if I blow one of these up then I can just swap them out - and have a custom like 13" pr 14"  piece made here:



and connect back up with the stock back end for now - until we go 'stage 2' with this shit 😄

Here is a better picture of the tranny brace that the other guy put together that Bro had to chop out. At least with this he can get the bolt hold measurements up before he remakes it to work with the K24


New body spacers added to the 620 frame. Looks like the cab from the 521 bolts directly up in the back, but the front is off just a little bit. Here's some pics of the spaces installed,


This is how far we are going to have to move only the front spacers before the bolts just drop though:


but this is now how much space we have between the Kseries and the stock hood - no worries WHAT so ever:


Since people on Instagram have been asking, here are pictures of the stock oil pan from the font so you can see where the lowest point will be without having to build full custom suspension:




And once we had it jacked up so Bro can tinker with the brace on the back of the oil pant needs to be slightly grinded just in case of torque. :



and a better picture of the drivers side intake loosely bolted in / firewall clearance / drivers side mount before powder-coating



Currently looking for a eBay dual core aluminum radiator / will bring over the stock 720 steering shit to just check clearance (we will be using 2013 Toyota Prius parts to build a custom electronic power steering and upgrading the front brakes)  / KSeries starter / 

Fenders on to check placement of wheels on the frame and this blue bitch is starting to look like a truck 


Edited by BrothersGarage
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2 hours ago, Charlie69 said:

On Wayno's 520/521 720 chassis swaps and my 66 20 720 chassis swap we lined up the front mounts and modified middle and rear cab mounts.  Looking good keep at it.

We chose to slide it forward for an almost perfect line up with the dead center of the wheel wells / fenders, and as you can tell from the hack job on the front - we are already going to have to chop a little off to mount the stock 521 bumper on the front anywho, and with the new radiator coming and what needs to be done in the front to the frame we will just tackle it all at the same time. 

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Going though my old honda parts we can repurpose this engine torque dapener (not that it's going to be crazy but why not)


Taking a step backward - Bro is going to tackle chopping up the stock manifold first to see if that works  so we put half of it back on the truck:


while he took the other part to work and started chopping




[i have more pics but goddamn email is being fussy]

and this is where the tranny lines up in the cab - may have to go with a shifter extension 😄


Edited by BrothersGarage
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So as we are diving into this K24 - there was a bit of rust in the 1st cylinder so I contacted the seller we got the engine from and they asked us to do a leak down test. 90% loss so the engine is coming back out and they are swapping us out just gotta put it back to the way we got it - after chopping into the stock manifold today. LOL so when they come to swap engines I will just swap the stock manifolds and send the junk engine out with the new manifold and keep the old modified one. 

Bro absolutely killing it with the fab on random stuff like the new trans cross base:




Engine is back out, all the KMiata parts are off of it now, and it is waiting for pickup - also have the new radiator on the way and even more parts from KMiata on the way that were ordered today. 

Edited by BrothersGarage
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Engine place showed up - K24 #2 


time to strip crap off that isn't needed


most parts and mounts back on


radiator showed up today, as did some intake parts that we can get to later. close up of engine mounts for those on instagram that wanted to see them





passenger top:



face of the passenger mount


tranny will go back on tomorrow, we will resink the engine and continue with fab on Saturday so more picture to come then. More parts should arrive on Monday as well. ❤️ have a good weekend. 

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Updates: So I bought a 14" riverside hose reel for $20 yesterday:

Got up early and Bro and I headed to the "junk yard" to pick a part some Kseries engines for stuff foe Old Blue here. Found a TSX


And got the power steering pump + pulley from it, as well as the starter, and the gas pedal:



there was also a CRV that had stock Return fuel line that we got as well



that i pulled apart while Bro grabbed parts:



This is the junkyard haul for $60


Back at bros house = the CRV with return line got attached as well as the chopped stock intake - and if you look below the TSX starter:



then we had to bolt up the Miata tranny, and mark out where we had to cut for the stock K24 starter:



Bro busts out the portaband:


And gets fucking funky with it:


Followed by his grinder - rounding the edges and  leftover-parts :


close-up for those that are following on Insta:


there will be a cover made and welded to go back over this but for now we wanna make sure everything fits and she will starts


and all bolted together:


Then we took 15 min and dropped her back in the 521:


Bro then bolted in the new tranny support he built: 



and took the front cross member and ground it down:




dropped some lines on it for support:



let that fucker cool:



painted it and put in place before we take everything a part and send it to powder coat:


spacing on the new stock oil pan is better than the previous one:



Now that we are fuckin' FINALLY back to where we started, Bro took some aluminium and put it against the stock intake the he chopped:



and we marked where it landed on the plate:


and laid it out for him to take to work and waterjet / grind out:



We are basically suck here till he can go into work on Monday because his entire shop is shut down for the stupid Mexican Beer Virus , but because his tranny adapter arrived on Thursday we started drilling out his pot welds on the Super beetle to start mock up on the Subaru engine swap:



And that was 10 hours of work so after Bro tinkered a bit more on his bug we called it a night. 


Edited by BrothersGarage
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11 hours ago, mrbigtanker said:

We’re are you guys going to run the water lines under the pan or down the tunnel. I did a rotary swap in my 65 notchback years ago. Ran down the tunnel but what a pain. 

Haven't decided yet but I don't think we will run anything down under the pan with the mods we are looking at doing with the steering rack. 

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13 hours ago, BrothersGarage said:

Haven't decided yet but I don't think we will run anything down under the pan with the mods we are looking at doing with the steering rack. 

Yeah because every speed bump is going to be looking at you funny.

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On 3/15/2020 at 11:54 PM, 4perrev said:

Very nice build with this one.  You guys are doing awesome work and fabrication.

Thank you! Bro has a serius knack for this stuff!

Mail call today. KMiata trans plat block off + heater port adapter + FREE STICKERS (love that shit, thank you!)


and I got a Titanium Kill Switch key from Lonely Driver for ole blue when she's ready:



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  • BrothersGarage changed the title to You're my boy, Blue '71 521 - KSwap

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