Yet another engine swap decision thread

[mattanonymous]

I hate to be "that guy", but I need some advice for which motor to swap into my 1970 1600.

I originally planned on doing a KA swap because I remember the motors being dirt cheap a few years ago (especially the KA24E) and I erroneously heard they'd just drop in. Neither is true, so I'm back to the drawing board.

I'm going to be doing as much of the work myself as possible. I know everyone loves the SR motors, but how much of that is hype and the novelty of the motor having to be imported? Are they really that much better than the KA or CA motors? I'm inclined to go with an NA SR20DE despite all the effort just because there are so many people who have done it and a decent amount of documentation and the parts are available from spriso (although $355 for 2 motor mounts seems pricey unless I'm missing something).

Requirements:
- Powerful enough to put me back in my seat (is ~150hp enough? it sounds like going turbo really complicates the swap)
- Reliable
- Easy to swap. Minimal custom components, frame and body modifications. I don't want the process to be so long that the excitement wears off halfway through.
- Good availability of parts
- Cheaper is better obviously

Thanks,
Matt

[spriso]

Hi Matt,

The SR20DE swap is extensively documented, and we offer conversion parts to make your life much easier. We have been swapping SR20-series engines into roadster chassis for nearly 20-years now, and all the common road blocks or pain points have been documented and engineered solutions have been made.

I'm sorry that you find the prices for our motor mounts too expensive--- they are laser cut and TIG welded and the design has been proven for many years. With the rental of our engine placement JIG, it will get the engine in the correct location in the engine compartment with the correct tilt, etc. This R&D work has worked for many, many customers for many years. I have not raised my prices on conversion parts for nearly 4-years despite cost increases on the motor mount isolators from Nissan...

We also offer technical assistance with your conversion, so if you do get stuck, just give us a call or send us an e-mail and I will likely be able to help you with a solution.

Yes, the NA SR20DE has enough power to be fun-- both my SR20 powered roadsters are NA powered, and they never fail to put a smile on my face each time we take them out on the road.

NA SR20DE engine sets can be found for $1000-1500 all day on eBay, and will get you a good engine with lots of life left in it. Parts are easy to source, and really, other than tune up parts (which you can get at the local dealer), you really should not need to touch the engine at all.

Please don't hesitate to ask if you have any further questions-- the SR conversion is outstanding for a roadster-- you drop weight, the car steers and stops better, and the engine will rev for days-- they are an absolute hoot to drive!

Michael

[AC77]

I don't think that's expensive for motor mounts for a modern motor. I'm pretty sure I spent more than that on the mounts I needed for my mustang when dropping in a newer engine and switching over to power rack and pinion steering.

[fj20spl311]

I am a swapper and I love SR20 conversions, but they would not be my first thought given your criteria:

Requirements:
- Powerful enough to put me back in my seat (is ~150hp enough? it sounds like going turbo really complicates the swap)
- Reliable
- Easy to swap. Minimal custom components, frame and body modifications.
- Good availability of parts
- Cheaper is better obviously

I don't know your skill level, BUT
My first thought would be a duel SU/Solex/Weber/SK....KA24E or DE. KAs can be done without having to modify the frame.
You will need to fabricate the manifold, flanges are available, also Motor mounts, but there are pictures for ideas

If you want EFI, that might not add much in cost to either motor, but it does require a lot more skill and custom fabrication.

[2mAn]

Check this out.

https://bringatrailer.com/listing/1966- ... oadster-3/

No major hacking involved

[fj20spl311]

BTW, If I were doing another swap it would be a SR20DE.
It can go very quickly once you decide to have the frame modified.
Order the mounts and jig.
Get a couple of friends to get the body off.
Cut and weld the frame and mounts.
Put the body back on.

You could even do it without disturbing the dirt......LOL

[Alvin]

I hate to be "that guy", but I need some advice for which motor to swap into my 1970 1600.
We like "that guy"!
I originally planned on doing a KA swap because I remember the motors being dirt cheap a few years ago (especially the KA24E) and I erroneously heard they'd just drop in. Neither is true, so I'm back to the drawing board.
There isn't a single non-factory engine that will just "drop-in" to your roadster. Adaptation is required at some point wheter it be wiring, drivetrain mounts, cooling, etc.

I know everyone loves the SR motors, but how much of that is hype and the novelty of the motor having to be imported?
I don't think anyone in their right mind would find importing an engine to be novel, nor increase the desirability. Wouldn't it be annoying, if anything??

Are they really that much better than the KA or CA motors?
No. All of those Nissan engines are great and have different characteristics the internet can help you decide between.

I'm inclined to go with an NA SR20DE despite all the effort just because there are so many people who have done it and a decent amount of documentation and the parts are available from spriso (although $355 for 2 motor mounts seems pricey unless I'm missing something).
If you think this is pricey, why are you considering an engine swap? What is your proposed budget for the engine swap? We could help you with a realistic estimate.

Requirements:
- Powerful enough to put me back in my seat (is ~150hp enough? it sounds like going turbo really complicates the swap)
Only you can answer this. Some people think 150hp is enough. Some don't.
- Reliable
A common misconception is that an engine swap magically increases "reliability". Pick your desired engine, and make it reliable.
- Easy to swap. Minimal custom components, frame and body modifications. I don't want the process to be so long that the excitement wears off halfway through.
I'd recommend a KA, CA, Zetec, BP (miata as 2mAn suggested) as they require less fabrication and are documented
- Good availability of parts
- Cheaper is better obviously
"cheaper" than what? An R16 or U20? Give us a little more info on your power goals and budget. For example, you can build a 200hp U20 for $8-9k and it will drop right into your roadster.

Thanks,
Matt

[AidanDawn2000]

I'm sure SR20s are great engines but i'm personally not into cutting up the limited number of roadster frames out there. Also from my brief time behind the wheel of one, it seemed to me that they are very sleepy under 5k. That being said, Spriso and others have done beautiful swaps that look factory and outperform stock in pretty much every area.

[JT68]

Agree, the NA-SR is a nice engine but it won't embarrass a healthy Solex_U. As Aidan says they have a nice top end, but don't pull any harder in normal RPM's. (Torque output similar).

An NA-KAde does have the edge in a straight line race since there is a noticeable increase in torque. The KAde will cruise effortlessly in most any gear, very nice in general.

The original requirements described above conflict in my opinion....none of the NA combinations will really pin your ears back... but they are all great driving combinations....quick, but not insanely fast.

Swaps to build an insanely fast roadster are not easy and do involve serious hacks to the chassis and engine compartment. If you are trying to win street races against super cars, you will need significantly more power, so a SRdet, KAdet, VQ,VG etc are in order. None of these swaps are easy but will make all the power and torque you could ever want. Someone here was working on a 2Jz which is a great engine, but certainly no drop in.

[AidanDawn2000]

Swaps to build an insanely fast roadster are not easy and do involve serious hacks to the chassis and engine compartment. If you are trying to win street races against super cars, you will need significantly more power, so a SRdet, KAdet, VQ,VG etc are in order. None of these swaps are easy but will make all the power and torque you could ever want. Someone here was working on a 2Jz which is a great engine, but certainly no drop in.

Makes me wonder...Is there a clear winner for highest horsepower roadster as of now? And if so whats the number? I thought I heard someone cracked 350 but don't remember exactly the setup or who it was.

[RCMike]

Makes me wonder...Is there a clear winner for highest horsepower roadster as of now? And if so whats the number? I thought I heard someone cracked 350 but don't remember exactly the setup or who it was.

The Australians like to use crank horsepower numbers, so given a very conservative 15% driveline loss, Jon's low boost 341 wheel HP makes it right around 400 crankshaft..

And he has finally gotten used to the power. He was hinting he might be ready to turn it up to where it was built to go.. Spinning it up from 12 psi to 20+ could be interesting..lol

[dynaguy]

http://www.311s.org/phpBB3/viewtopic.php?f=27&t=17915


Hi Matt,

I've been through the process of an sr20de swap. Owned a '69 2000. Owned a '97 Miata. Driven Ted's sr20det cars. Have a roadster buddy with a 67.5 2000 race-prepped Solex 185hp sweet machine.

I purchased (stole) my sr20 car as a completely disassembled unfinished project. The guy had the sr20 motor/trans and 90% of body work done and many new parts on hand when things got a little sideways with his wife. I think an ultimatum was issued. Needless to say, I got into my project "very" reasonably. the car was located close to Spriso so I had the frame delivered to Michael and had them do the mods and purchased all of his swap parts. THIS WAS THE BEST INVESTMENT I MADE IN MY PROJECT. Sorry for the caps, but for ease of install and unlimited support, it was money well spent.

Cooling system, air intake system, fuel system, wiring (I used Wiring Specialties for engine harness), brakes, rear end, etc. costs can add up fast.

As far as comparison, it depends on what you want to do with your car. My wife and I take day trips and plan on touring in the future. We have many twisty roads in our area and enjoy "spirited" touring. I like that the sr20 is rather mild mannered in daily use. But when it comes on at higher revs, you cannot wipe the grin off my face. The engine loves to rev and sounds good doing it!

My '69 2000 was a SU car, basically stock. A very fun drive. The sr20 would easily walk away from it. I would still have it if I had not purchased this car. I was made a 'Godfather' offer and reluctantly parted ways.

The Miata was uninspiring, engine did not have the soul of either my U20 or sr20. My opinion is if you want a Miata, buy a Miata.

Comparing the sr20de with the sr20det. After driving Ted's cars, I told my wife that I was not mature enough, (even at AARP age), for that kind of performance. The power was smooth and plentiful.

My buddies' 67.5 2000 is a beast. His driving skill easily surpass me, but I can keep up with him in most cases if he is feeling generous.

These are my experiences and opinions. Hope you decide what works best for you. The process of a swap can be challenging, but the support is here on the forum.

Good luck with your project!

Pat

[mattanonymous]

You guys are the absolute best! I love this forum!

Mike (spriso), I meant no disrespect when I mentioned the price motor mounts. In thinking about it further, 2 custom, hand-welded mounts that have an OEM-like feel and reliability would go for about that. I hope you'll forgive me as I'm new to custom/restoration car stuff.

I've got some homework to do. I didn't realize more swap options than the SR, CA, and KA were documented. Hadn't even heard of the Zetec.

[spriso]

Matt wrote:

Mike (spriso), I meant no disrespect when I mentioned the price motor mounts. In thinking about it further, 2 custom, hand-welded mounts that have an OEM-like feel and reliability would go for about that. I hope you'll forgive me as I'm new to custom/restoration car stuff.

No problem at all-- I have felt that our prices are very reasonable and I can assure you, no one is getting rich doing this kind of stuff.

We are here to support what we feel is the best engine swap solution to the roadster chassis-- with normally aspirated engine options from 140hp (S13 SR20DE) to the more common 160-165hp S14 and S15 SR20DE engines.... if you really want to go crazy find the 200hp normally aspirated S15 Autech version for a really fun ride. Turbo SR20DETs start around 205hp (S13) and it just goes up from there.

What I guess that you should keep in mind is the SR platform is very flexible, with extensive parts support and a wide variety of engine HP options depending on which version you choose-- the big win is the weight savings over many of the other engine options, and a rev-happy platform that just begs you to press the loud pedal even harder!

If you don't want to re-invent the wheel and engineer solutions to fitment issues (which there are always issues), then we have a solution for you...

Michael

[Gregs672000]

Love all the discussion. Might I suggest you consider the listed U20 for Sale? A well done U20 is a wonderful, reliable, easily adaptable engine made for your car. Do a bit of head port work, carbs (many options there), a reasonable cam properly timed, improved ignition and you'll have a car that will be balanced, fun, powerful enough make you smile and pass when you want.