Project K2xPine - Sunbeam Alpine K-Series Swap

Howdy folks, the name is Rob. I'm a long-time GRM and Classic Motorsports reader, going back to my childhood in the mid-90s. I split my time these days between being a PhD student, a husband, and working on the car(s).

In the past, I've had a 2010 Mazdaspeed 3 (campaigned in D-Stock, then DSP, and track days); 1993 Mustang LX (drag car), 1991 Honda Accord 5-speed (H-stock beater!).

In our stable these days, we have my wife's driver a '11 Mazda2 Sport 5-speed, Michelin rubber and Corksport suspension bits underneath it. My daily driver/parts hauler, a '07 Toyota FJ Cruiser (4wd, but mostly stock). And the project/money pit/Broken British Car (I know that's redundant), my 1963 Sunbeam Alpine Series 3.

A bit of history on this car. My father bought it ~2002/2003 and drove it for a number of years. The car was 'restored' at some point in the probably the 1980s. Which meant, it was painted (fairly well), the interior was redone with naughyde, and the stock 1592cc engine was replaced with a later model 1725 with twin Zeniths on top. My dad drove and worked on the car off and on, but somewhere around 2008-2009, the brakes ended up locking up. He rolled it into the garage and it sat. While he and my mother proceeded to restore a couple of old houses, enjoy time with the grand kids, etc. Dad always wanted to do an engine swap, because of the fickle nature of the Rootes engine and the difficulty in reliably getting parts. Unfortunately, he passed away late last year after a few years of fighting bone cancer. Shortly after he was diagnosed, he decided I should have the car and gave it to me. Our last conversation was about what color to paint the car.

Unfortunately, circumstances (see "PhD Student" above) prevented me from really taking possession of the car and working on it then. It was located at my parent's house until July of this year, when I was able to lease a small garage here in Chicago (proper urban Chicago, not the 'burbs). And thus began a long journey of moving a car, parts, tools, a 1000+ miles from Texas to Chicago.

This is a FULL build - consisting of replacing the entire drivetrain from the 1725cc engine that made <90hp when new, with a Honda K24A2, a Getrag 260 (out of an E30), a Winter's Quick-Change rear end, custom suspension setup, rewiring the car stem-to-stern, body work, paint, etc. Because of a budget and a general DIY attitude (my father was a contractor for 60-years), I'll be teaching myself some new skills (like TIG welding) and relearning old ones (like block sanding...). And trying to do as much as possible in my little garage.

The ultimate goal is to have a driver, autocross, time trial, and HPDE car. I would love to someday drive One Lap of America (drive, not 'win'). I'm not a 'car show' guy...I like driving and love time trails and auto-x.

Here is the garage. It's 10x20' with 13.5' ceilings...

Lights help tremendously (so does a dehumidifier in Chicago summer). The lights were 60 bucks on Amazon.

I towed the car up on a UHaul hauler and it's British...So it came across all British on the trip up. You can't see it well here, but the front tire on the trailer is flat. Fortunately, the Toyota towing the British car was very Toyota. Despite having nearly 175k miles on it, no problems towing the car and trailer at 60-65mph, even averaged a nice 15mpg doing it.

Pro-Am Tip #1: UHaul 'Box' is a relatively inexpensive way to move a lot of stuff with minimal effort. It's like a POD in practice (i.e., a container you fill and then they ship and warehouse). However, unlike a POD, you can actually go to UHaul and pick up one of these mounted on a trailer and save cash picking it up and delivering it back to UHaul. It took about 10-days for my tools and car parts, loaded in the 'Box' to arrive in Chicago. Less than a couple of hours with the help of my wife to unload it all into my garage.

Pro-Am Tip #2: The 27-gallon black/yellow lid totes from Lowes/Home Depot are $10-15/each and can hold A LOT of parts. The 40-gallon ones (in the back of this photo) can contain an entire set of jackstands, a floor jack, and a Sunbeam Alpine transmission. Just don't try to lift them when that loaded...

Car, tools, some parts are here in my garage, time to get started! Step one! Remove the old drivetrain...Wait no step 1...remove the hood...by myself...and it hinges forward (because it's cool, but also, that's kind of a pain to remove...)

A little block and some paracord...

Et voila! It's off...

I started pulling bits out after that...but how am I going to get the engine out? I should get a hoist...I could rent one...but I mean...I could buy one. I'd love one that folds up super compact. The Black Widow Hoist does...but 500 bucks?! Not budget friendly. But an open box deal from Discount-Ramps and I can drive to Milwaukee and pick it up for $175? Done.

Hoist here, stuff clear, time to pull the engine. You know, that front bumper might be in the way, I should pull it off and put it aside...Wait..what's this?

NOOOOO...not hidden bondo?! (My dad never had the bumpers off this car, nor ever painted it, this bondo was present when he bought the car). Oh god...more bondo?!

Shop hound Edsel Ford (that is his actual name...) is not impressed...

MUST KNOW...what's the metal underneath?! How much rust am I fixing? Oh thank goodness...it was just someone lazy who didn't want to do body work...Everything (here) is solid. Leaving only a few spots in the floors that need to be patched.

Whew...time to get back to pulling the engine and gearbox. 355 pounds without generator/intake/exhaust (I weighed those pieces separately and add them back in for 393 pounds total).

___

And that was where I was and the next bit of this should be sheet metal work and welding. Except...late last week, I found a Getrag 260 on eBay and drove to Indianapolis to pick it up. You can't buy a transmission for your engine swap and not see if it's going to fit, right? Right.

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260 compared to Rootes 4-speed. I'll have to get a longer driveshaft...that's sort of odd for an engine/trans swap.

Okay...so from here to the radiator support, I have 23" clear...and a K24 is 21" long.

But I probably have a bit more space, because this boss here is hitting the side of the tunnel. Once I grind it down, I think it's going to set back about another inch and a half. Where it will probably line up perfectly with the old cross-member mounting holes.

Even the shifter is going to work out, since the Getrag uses the same type of shifter that a ZF from an E30/36/46/etc uses. I'll probably opt for a chassis mount shifter and fab my own double-shear type linkage.

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And that brings us up to date from effectively 8/15/2020 to 11/29/2020 -

Obviously, things are just ramping up. I'm trying to stay focused on one aspect of the project at a time and see it through to completion (for instance step 1 - get the old engine and gearbox out). And importantly, not buy (too many) parts that aren't absolutely needed at this stage. The G260 was such a good deal ($350), that I snagged it. Knowing how hard it is to find a good G260 these days.

I'm now on Step 2: Sheet metal. Repair and prep. 

Then we'll be on to Step 3: Fabricate mounts and align everything for the swap.

Between now and Step 3 - I have to defend my dissertation and find a post-doc - so it won't be happening as fast as I'd hope. But things are rolling!

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Thanks for reading!

Cool project.  Sorry to hear about your dad but sounds like he passed the car gene onto you.

I love the idea of the modern engine in the classic car. Especially this combo. Definitely keeping tabs on your progress. 

Very cool. 

Look forward to seeing the suspension mods and possibly picking up ideas for my Alpine. Curious why you decided to run a quick change? Seems like it would be a bit overkill and heavy.

I'm actually planning to go with a 7" Winter's quick change. So, quite a bit smaller than your traditional hot rod. The whys are fairly simple: 1) It's much easier to get the right width (as you know the Alpine is very narrow). 2) The 7" Winters QC runs 2.5" Baby Grand National rear hubs, which come in the 4x4.25" bolt spacing the Alpine has*. 3) Quick change gearing ratio swaps for being able to drive to the track or autocross event and pick my gearing. I used to do pit work for my Uncle when he ran circle track and learned some of the tricks to rapidly change the gears. The gear spacing in the Getrag is a little wide (for instance 3.83 1st; 2.20 2nd...). Given the 8500 RPM limit the K24 will be spinning at...being able to tune final drive will help quite a bit. 4) The 7" with Magnesium Housing and steel tubes will come in about 10 pounds lighter than a narrowed 8.8 or 9" Those are the basic reasons for a Quick-Change. Now...to further explain my rationale... ____ *I'm keeping the silly bolt pattern, because I'm planning to keep the Sunbeam front spindles and use Wilwood front hubs with their Tiger/Alpine front brake upgrade. I called Wilwood about whether or not I could get 4x4.5 front hubs made for in the Alpine/Tiger format. They said, "Yes. But it will be a custom engineering charge. It starts at $5,000." And that was the end of that conversation. After looking it all over, with thoughts of using Mutt spindles/hubs/etc, I don't think the juice is worth the squeeze. The main purpose with my suspension setup, will be to have fully adjustable upper A-arms, for caster/camber setup without needing to shim. I'll probably drill the Sunbeam spindles to accept a Mutt balljoint for simplicity, but I'm not planning to dramatically alter the whole setup. Going with adjustable A-arms up top and tubular down low, will give me weight reduction and an easy way to mount coil-overs. I also wasn't keen on mucking with the steering. I've driven the Alpine enough, to know the steering is actually pretty nice overall. I couldn't find a compelling reason to switch to a rack, when the way the steering is now, it's up out of the way and doesn't create oil-pan clearance issues. With the K-Series swap, the exhaust header moves from the driver's side (LHD), under the carbs, to the passenger side. Thus there should be ample clearance for the pitman arm. There is a guy over on the Sunbeam forums (SAOCA) that has worked out a way to adapt the electric power steering setup from late-model GMs to work with the Alpine column. I am considering this addition, because it would make in-town driving better (and I wouldn't be opposed to a smaller diameter steering wheel...). And there ya go...way more answer than you probably wanted!

This will be a really great car when completed. K swap all the things!!

Yes, watching this one for sure! 

In reply to RevolverRob :

Thanks for the detailed answer. Didn't realize there was a smaller quick change - was thinking of the big sprint car style one. Sounds like a good plan, look forward to seeing it come together.

It sounds like you have a solid plan. I'll be following along!

Awesome, and welcome from another chicagoland grmer!

Let me know if you ever need a hand with something.

This is exciting! I love tiny cars with revvy motors.

Watching and learning! I really like the idea of modern drivetrains in LBCs, and I keep looking at my Elan and wondering....

Crawled under the car today to strip back some of the original undercoating and get a good look at the rust.

I knew going in that the area between the inner door sill and the floor pan (I think called the 'Under Door Panel' by the Brits...but apparently cameras and/or diagrams with labels haven't been invented over there yet...) on both sides of the car was rotten and will require a new piece to be fabbed. Fortunately, it's basically a 4x8" rectangle. Then I knew that each of the rear floor pans has some soft spots in them and would need to be patched as well.

Of course that was what I could see. I got under there with a 3" wirebrush chucked in my drill and got after it...and found quite a few more spots...

Some orientation for folks - you're laying under the car, head towards the front, feet towards the towards the rear. This is the passenger side (right hand side - this is a LHD car).  This is the area I believe called the 'Under Door Panel'. There is still a lot of grain here that is undercoating and I haven't hit the edge of the sills with the brush yet (that's all surface though, I have hammered around there with a screwdriver and ballpeen and the rockers/sills/doors/fenders are all solid.

Moving farther inboard

And farther inboard and towards the rear of the car

None of that is good, obviously, but that last little section, where the yellow circle is, was a new spot I was unaware of. Worse, on the other side of that frame rail is another hole, which leads me to question what the metal above the frame rail looks like. The did not spot weld this spot, but rather seam welded it and the weld is a wee bit mushy on this side.

I started this post with the plan of basically asking, "Repair or replace?" - But at this point, I think I'm going to have to stop and rip the interior out of the car and take a really good look from the top side. I suspect the driver's side isn't quite as bad, but isn't (much) better. But with the amount of work I'm already finding here, plus having to spend a lot of time under the car stripping undercoat. I'm learning firmly towards 'replace'.

Of course the kicker...floor pans seem to be difficult to source in the US. So...order them from the UK for around 500 bucks, or go to Eastwood (which is local to me...) and buy a bead roller and order up plenty of 16-gauge steel and roll my own? This is (mostly) a rhetorical question.

In reply to RevolverRob :

The larger the panel you replace the less welding you do, and the less warpage you need to accommodate. thus replace is the answer, even for just a small area.

Got the carpet and underlayment out and started checking around with RevolverRob's Love Tester (2-pound Engineer's Hammer) and probe (janky flathead screwdriver). As is usual with rust there is good news and bad news.
 

Good news? Most of the front passenger floorboard is very solid. Only a patch will be needed. 

Bad news: The whole rear pan is toast and so are the seat supports.
 

Which brings a whole new challenge the rear pan is 2"  lower than the front pan This results in a seat that is tilted way too far back for most people of average height including my wife and I (I'm 5'6" my wife is 5'3"). I had intended already to build some spacers to tilt the seat backs up a smidge and then also intended to raise the seats up around an inch. Because as it is, the door top is level with my neck when I drive. It limits vision when driving and comfort as well. Also the mounts are a little far back (driver's side). My slider is all the way forward and it's not a great pedal reach. 

So now is a good time to build a new set of mounts. But maybe it's a good time to simply reengineer the floor a bit. I could flatten the floor and make it level. But this creates a new problem. The frame rails here are ~2" lower than in the front, such that I'd need spacers to fill the gaps or extend the frame rail (not crazy about this idea). 

Seems like the better idea is to copy the drop in the floor, and then build a big box that bridges the gap and serves as my seat mounting area? 

I guess I better start looking for some seats I can use long-term. That was a "way down the road" plan. But I'll want seats to do my mockups with. 
 

Forgot the pic of the seat mount. Boxed end looked a little suspect after probing. So I hit it, once, with the Love Tester and this was the result. I'm sure that would have held together in a crash...

Make sure you fit with the top up, and getting in and out easily. Not something that everyone thinks through. Same with the windows up.

Yes, i know its a convertible. But EVERYONE gets caught in the rain at some point. And the top is a nice sunshade. 

As far as seats,  look at early 90s na miata seats. They have the Sierra auto tops covers available in black for ~$100. Im running the tan version in my nb miata on the seats with a little foam tweaking and am very happy. 

In reply to Dusterbd13-michael (Forum Supporter) :

Solid point! I may not run the softtop and instead go hardtop for track/auto-x (required if I do any Rallycross). When cruising I can always leave the hard top at home and just keep a 'Bimini' in the boot if I'm stuck in the rain. But I don't want to smash my head on a hard top on the track. Which also means sitting the seat, top up, with my helmet on. 
 

I'll check out the NA seats.
 

This is also a good time for me to stop and figure out how I'm going to deal with the 6-point rollbar I want to install. Mrs.RR mandated safety upgrades and I concurred. Since the car will be street driven a lot I didn't want a full cage with bars to smash my non-helmeted head on. But since the last time I got hit was a T-Bone - front bars that extend forward and offer some side impact support would be nice. 

My office smells awesome. I normally like to wait to buy parts as I need them not when "they're a good deal". But in this case, the deal was too good. 60-sq feet if Horween Treated Essex (chrome stuffed horsehide) in a ~2-3 ounce weight. Makes it much lighter and thinner than cowhide and horsehide has much better weather resistance too. 

While I haven't decided if I'm going to carpet the car yet, I knew I wanted some luxury in it. This is destined to become door panels, console cover, if I plan it out I can probably do the dash pad in it as well. With enough left over to give swatches to the upholstery shop for seat covers. 
 

Ooh, horsehide! One of my favorite leathers because it will patina and develop so much character. I hope you're willing to embrace that character, because I know it's not for everyone. 

On the floor: I'd suggest replacing the floor sections in kind, and then adding height to the seat mounts. It's easy to adjust height on a seat, but a lot harder to add it back to the floor plan when you find out it was a bad idea to remove that low floor. 

This is such a cool project!
 

If NA Miata seats aren't a good fit for style reasons, there's also a Miata seat with a separate headrest (only in the '95 M edition here, but available in NB Miatas overseas so you may be able to find them in the UK relatively cheaply). Porsche 914 seats are also a good fit for small cars - a friend of mine just got this set recovered to go into his Midget

Mezzanine said:

Ooh, horsehide! One of my favorite leathers because it will patina and develop so much character. I hope you're willing to embrace that character, because I know it's not for everyone. 

On the floor: I'd suggest replacing the floor sections in kind, and then adding height to the seat mounts. It's easy to adjust height on a seat, but a lot harder to add it back to the floor plan when you find out it was a bad idea to remove that low floor. 

The best part of horsehide is the patina! I have half a dozen gun holsters and a couple of pairs of boots made of horsehide. I honestly always prefer it for leather, because horsehide is an end-of-life product. As cheesy as it may be to some, I like knowing that the animal wasn't killed to make my interior or shoes. Instead this hide was recycled from an animal that reached the end of its natural life. 
 

On the floors, yes I have decided to copy the original floor style and then build a separate box to mount the risers to. Once I get the seat height right, I can weld the box in. Bonus, it'll add an additional little torque box area along the frame rail. 

Those 914 seats are quite nice! I love that style overall and I do think it would be a good fit, style wise, for the car. 
 

Folks have probably already seen it - but if not - GTS Classic Seats - they're awesome - but maybe not GRM Budget friendly - https://classiccarseats.com/

Another consideration for seat height is the clearance from top of helmet to height of roll bar/cage (the broomstick test). Check with your sanctioning body.

paddygarcia said:

Another consideration for seat height is the clearance from top of helmet to height of roll bar/cage (the broomstick test). Check with your sanctioning body.

Excellent advice! 
 

I have the original buckets for the car. I'll bolt them in, put the hard top on and sit down. I'll get the wife to measure head clearance and also how high I sit with the helmet on. That will give me the ability to estimate clearance. 

It occurred to me that if I need height clearance, I could drop the seat mounts into the lower part of the floor. The steering column in the Alpine telescopes nearly 3". And I had previously thought of using a floor mounted pedal box to move the pedals farther back for more clearance between me and the column anyways. 
 

At which point my car would be like the Alpine that Arnold tears the seat out of in Commando...