I don't know what I'm doing: Modern drivetrain into a 40-year-old Honda

So over the past couple years, I've been very slowly pulling pieces off a junkyard '83 Civic hatchback:

As it sits now, it's a bare shell with a windshield, engine, trans, and a few bits of suspension:

The goal for this car is to shoehorn a modern drivetrain in there -- I've been thinking from a Fit, but open to suggestions. Nothing too nice though, since, as noted in the title, I don't know what I'm doing and will certainly berkeley it up somehow. Also this is meant to be a fun, grocery-getter go kart, so ~100 HP from an L15A is plenty.

For now, I've been knocking back smaller areas of rust with a grinder and Rustoleum primer. The car is actually more solid than I expected, but the floorpan seams all around are almost rusted through:

What's the best way to weld this back up? Should I cut the floorpan out completely? In sections? And how do you get rid of that sticky seam sealer glue that runs around the border of everything?

There are several ways you can fix that, if you cut out the entire floor, then you have to make everything fit again.  Looks like just the floor edges need repair, I think I would cut out a 1/2 to 3/4 inch wide opening about a foot long, get some strip steel inch wide.  Repair about a foot length at a time, would have overlap seem on each edge of the patch strip.  Doing a fairly small section at a time, the seat mounts and everything will still line up and fit later.

There are so many solid powerplant options from the Honda catalogue.  Even the pedestrian non-vtec b18 is 142hp.  I'd do a bunch of junkyard measurements and go from there.  Seems like a ton of ~200hp factory setups that have great aftermarket support.  I'd swap in literally everything from a good runner.  Love the idea as there are not enough of these being hotrodded!

I would go with the most common VTEC swap that you can find. You do not want to be re-inventing any of the engine management or engineering any swap components if you can avoid it. Take advantage of what works and is documented.

Go for the most power you can find in a stock package. Chances are if you don't, you will spend time and $$$ trying to increase power after the car is on the road. Overkill is just about perfect. OEM power will always be cheaper and more reliable than home-brewed.

As to the rust in the seams, I would wire wheel the rust and fix only where there is actual holes in the floor. The rest I would slather with POR and seam sealer and call it a day.

I could not possibly support this more than I do now. 
 

Thank you for taking this on  and keep up the good work. 

A d series should be plenty for that chassi. And rarely anybody builds them. So they usually go for next to nothing

This is awesome. Cool old car, updated powertrain to make it more fun AND easier to live with. Win/win.

You think you don't know what you're doing now, but you'll be getting better at it the whole time.

Regarding the seam sealer, I wonder if the get-it-very-cold trick as espoused by GRM for sound deadening would help.

I learned how to drive in my mom's 4 speed 1981 Civic. Similar to this but door mounted mirrors and round headlights.

Looking forward to see where this goes!

Loving this!  I had a  79 Accord, basically same layout slightly larger.  These were like 65hp or something and under 2000lb, so even the 125hp B engine would be pretty sporty.

Also liking the 9000 towering over the Civic!

@TED_fiestaHP: Thanks for the advice! Sounds like a good method for getting the edges of the floorpan patched up.

NOHOME said:

I would go with the most common VTEC swap that you can find. You do not want to be re-inventing any of the engine management or engineering any swap components if you can avoid it.

100% agreed. It's going to be hard enough for me to swap over the engine, trans, suspension and brakes; I'm not going to try to fabricate anything beyond what's required to interface new OEM power to the old chassis.

@Woody & @Jesse Ransom: Thanks! I did use the get-it-very-cold trick for removing sound deadening, which was night and day compared to trying to chisel it off at room temperature.

@Slippery: Really cool, thanks for digging up that picture! Hearing stories like that is half the fun of these cars -- I found a pin under the driver's seat when I was pulling the interior out of the Civic:

Turns out it's from a karaoke bar in my hometown that shut down when I was still a kid. I've since talked with a few people who remember it, and it's started some fun conversations.

@XLR99: You're right, it wouldn't take much to make this thing feel quick. And good eye for the Saab! That's my daily, a '93 CSE with a 5-speed.

I vote for a D16Z6, only because I know they fit. A B16 would be cool also but a bit wider head. But then with the B you get the aux axle & have equal length axles for reduced torque steer. There were a couple D's with the aux axles but then no vtec. The D16Z6 barely fits in my '76. Having the brake booster on the right on the 1st gen allows clearance for the intake. Your 2nd gen is on the left. Might need to get creative to get it to fit. 
Also start gathering parts to upgrade the braking. You can adapt newer larger discs, MC & booster. You can also build a nice rear disc setup using jy 1st & 2nd gen Prelude parts & a rear  4th & 5th gen Civic hub.  The key is finding the rear caliper plate from the 1st gen Prelude, which bolts to the spindle after all the drum parts are removed. I have another set somewhere. I built about 20 kits & sold them online many years ago. Mine stops as well as it goes. 
I did all of the above mentioned on my '76.

@mdshaw: Thanks for the info! I've seen your '76 around here and it's definitely inspiration for me.

Man the D-series is such a tight fit there! The 2nd gen wheelbase is a couple inches wider, so I'm hoping that translates to a bit more room in the engine bay.

Removed the last of the front suspension, brakes, and steering yesterday.

So, the chassis is currently 10" off the ground. I have the headroom to lift it up to 42", but how should I do that (and how to keep it lifted)? Do people leave high-lift jacks like these under there? Fabricate some sort of frame? What's the best (budget-friendly) way?

Spending $1500 on a rotisserie for a $200 car feels... indulgent.

I've heard that people build rotisseries out of a pair of engine stands... You should be able to build a stout wooden table (search for Locost project chassis build tables?). Please, please do not try to work under it on jacks; that's a recipe for wearing the car, and even a little one like this void of guts is still heavier than you want to bench press for your life with a bunch of broken bones from the landing.

You need to figure out what bits you need access to while you have it raised so your solution gives you that access while solidly supporting the car.

I need to figure out a similar thing for a similarly small car, and am trying to figure out whether to put an MDF top on a table I built from 2x6s for building garage doors on and then use blocks to support the body where I can get at it, or whether to build a rotisserie type thing. It's a classic Mini-based car, so there's a lot of documentation, and I understand that there are pass-throughs to more or less mount the car on a length of tube, so I get an easy option that I suspect you don't have (but it's worth taking a step back and looking at your car with that sort of clean-sheet answers there are to "how do I securely support this car in the air; what mounting points are nice and solid, and what parts do I not want to block off while supporting it?"

Also, check CL and FB for used rotisseries, and keep in mind you can sell one when you're done with it. It's not always going to be a $200 car, tools are good investments, and if it makes the project easier, faster, safer, and more fun, you'll get a better result.

@Jesse Ransom Thanks for the tips and info. I definitely won't be working under anything supported by jacks. And valid point -- this won't always be a $200 car. Hopefully.

I think I'm going to grab 4 of these adjustable stands from Lowe's. That would make use of all the available headroom I have for $400.

The question remains how to lift it up that high in the first place. Possibly a pair of farm jacks and some lumber?

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For lifting, I guess you could use cribbing to build it up to height.  The shell itself is pretty light, I'd be more concerned about getting the newly assembled car down. 

Maybe set up a CL/FB search for a mid-rise lift?  I found a Bendpak for 600 a few years ago.  It does have limitations, mainly access in the middle, but also allows you to adjust the height as needed.  It also can be used for your other vehicles, unless you do like me and park it under a stalled project car, then pile a bunch of crap in front of it.

I had the misfortune of spending much of yesterday under my daughter's 2011 civic -the pics of mdshaw's awesome Civic reminded me that at some point Honda swapped rotation - the originals and my EK Civic (98) had engine on the left, newer ones including my RSX are on the right.  I'm assuming using EK or earlier like he did as the donor would 'somewhat' simplify things. 

I love that we have enough skilled people that you can drop in and say 'I'd like to engine swap an early Civic' and somebody else is already driving one!

Also, speaking of 9000s - I found a box of 9k parts last weekend.  I'll shoot you a PM once I take a look at what is in there. 

If an L fits a D will, if a D fits a B will, if a B fits... well I wont lie to you Honda Legos kinda stops after that but step away from the L it's just going to be a problem. A 140ish hp D16 can be constructed from the junkyard and machine shop for about $1000, brand new swap harness on Ebay $300, a well used S300 gets you the last piece of the puzzle for another $500. 

@XLR99: That's a great idea, I don't think I've seen a mid-rise scissor lift like that. Looks like they're upwards of $2k new, but I'll keep an eye out for a used one.

And as for the 9000 parts, I'm definitely interested. Especially if you're in Medina; my family is there so that's where I'll be for Thanksgiving anyway.

Wow, talk about small world!! 

D16Z6 or D16Y8 for simplicity and cost.

solfly said:

D16Z6 or D16Y8 for simplicity and cost.

This is very likely the best answer. But I'm kind of hoping to find a whole front-end donor and swap everything over: engine, trans, brakes and suspension. Which made me think Honda Fit, because it would be pretty easy to find one at Copart that had been rear-ended.

Great project

More stuff came off the car this week:

Rear suspension and brake stuff, exhaust shielding, wheel arch trim, various skid plates and the shift lever. And 2 more jack stands went in, because every time I'm under the car now I keep thinking of @Jesse Ransom's words -- bench press for your life -- and it's put the fear of gravity in me.

Also, I've been going over the options for getting more access to the bottom side of the chassis: jack stand cribs, farm jacks with offroad stands, some kind of wood frame... and I keep coming back to a rotisserie. @Jesse also pointed out that some people make them out of a pair of engine stands; I found this one on Imgur:

Full disclosure: I've never welded before in my life (see title of this thread), but welding bar stock and angle iron seems like what people start with anyway. Is it totally daft to try and make such a rotisserie myself?

We had a '78 and '80 back in the day when I was a kid.   I was taught stick shift on these.  great to see you picked this body type.  I came across one of these in a yard 2 years ago.  If I can think of where, and if its still there, I'll pass it on.

Good Luck!

greasemonkeyreborne_5x1gs said:

We had a '78 and '80 back in the day when I was a kid.   I was taught stick shift on these.  great to see you picked this body type.  I came across one of these in a yard 2 years ago.  If I can think of where, and if its still there, I'll pass it on.

 

Good Luck!

Awesome, and please do! It's really tough to find parts for these.

There's one guy (Panhandle Automotive on eBay) who has a bunch of oddball cars (Mitsubishi Precis, Hyundai Excel, ZX2 Escort, Nissan Stanza, Audi 5000, Dodge Daytona, etc.), including a couple 2nd gen Civics on his lot. I've reached out a couple times but he won't go pull parts other than what he already has listed.

Kind of makes me want to take a roadtrip to Amarillo.