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pdp8

Cr engine weight questions

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So, thinking about a swap in my 1200.  Not that I don't enjoy the A12 motor but I'd love this car to lose some weight and since I need to find a manual transmission anyway...

Seems like the CR series motors are sort of spiritual grandchildren of the A motors and Al block to boot so I thought I'd have a look.

If I use a CR12 I can feel OK about the 1200 badge on the boot lid, question is, what does a CR12 series weigh?  Also,  does a CR10 or CR14 weigh more or less?

 

Obviously, since I'm in the states the availability of CR motors is poor so I'm willing to consider other options but I don't have the heart to put anything Honda or Toyota in there, perhaps something from Smart or Ford but Nissan motors get first look.

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Ah, just Google stuff:

CR10 ~110KG

CR12,CR14, ~120KG

Odd, since that's a lot heavier that An A12 or A14 despite that Al block...

Perhaps it's something like an all-up weight with gearbox or all the engine control stuff, in any case it seems to not make a lot of sense.

Anybody out there with first-hand A12 vs CR1x experience?

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Isn't it a FWD engine? What about a RWD transmission? Also it doesn't make much more power than an A14 or A15. A series will literally 'drop in'.

 

Why not build an L20B (120 Kg) and a 71B truck or car 5 speed? About 93 hp stock but lots of add on things.

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If I just wanted a little more power I'd go ahead and drop in an A14 or even just do mods on the A12 (87Kg) and it easily could come to that. 

I was looking for modest performance gains, lower emissions, and a way to capitalize on one of the car's outstanding attributes, it's light weight. 

It did seem like an engine of similar displacement but using an Al block and other modern attributes (timing belt rather than chain, direct drive distributor, no pushrods, plastic intake manifold, tube steel exhaust manifold, etc.) *should* be lighter

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pdp8, note I'm not poo-pooing the idea but here are some things to think about.

 

What people forget is that the aluminum blocks need to be thicker than cast iron to give similar strength so they aren't as light as one would think.

 

Twin cam motors are by their very design heavier; you need all of the supporting structure for the camshafts, the extra weight of the additional camshaft itself plus the additional 8 valves. The A-series complete head is something ridiculous like 15lbs complete versus a typical twin cam motor at 40lbs.

 

The complete  motor in my race car is 185lbs (this is complete including clutch, flywheel and starter) the A series box weighs 38lbs. Combined that's 15lbs lighter than a Hayabusa motor. 1600-2000cc twin cam motors vary between 290lbs and 350lbs, additionally most of the transmissions for these motors weigh 80-100lbs. 

 

There is nothing wrong with wanting to bolt in a modern motor but you have to look at all the factors. CR12DEs being FWD may not have an easy way to bolt up a RWD transmission.  While CR12 makes 12 more horsepower than the A12 it makes the same horsepower as an A14/15.  For the cost of the CR motor you could source an A14 or A15, clean up the ports in the head, install a new exhaust system, mild cam,  weber 32/36 carb and thus increase the A series motor output by about 15-20hp. Couple that with a lower rear gear (3.9 to 4.11 ring and pinion) and a 5 speed transmission (5th gear overdrive) and that would make it much nicer to drive. Note there are fuel injection set ups for A-series engines (standard Nissan as well as fabricated ones detailed on 1200.com) The standard Nissan fuel injection for the A-series tends to be pricey for what it is.

 

The most common modern-ish swaps for 1200s are CA18 and SR20. The L series is an easy swap and given the fact no one wants an L16 you could probably get one stupid cheap. The L16 would make more power stock than either an A14/15 or CR12. If you don't care about keeping it Nissan I'd snag a Miata 1.6 as those have tons of support as well as a sweet gearbox, plus it's one of the lighter packages when it comes to twin cam engines.

 

Now with all that said if you want to install the CR12 motor just to be different than I say go for it.    

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47 minutes ago, Tom1200 said:

pdp8, note I'm not poo-pooing the idea but here are some things to think about.

 

What people forget is that the aluminum blocks need to be thicker than cast iron to give similar strength so they aren't as light as one would think.

 

 

 

I weigh engines for fun.  The SR aluminum block acording to my back is quite a bit lighter then any cast iron block I've lifted.  I should weigh those next.  Unless you have the same scale and weigh all the motors I don't trust any weights online.  Like those LS guys....  

 

We race with a team that runs a 240Z  this year they pulled the tripple carbs and went with megasquirt.  They lost 2 HP but on the track they shaved 2 seconds per lap!  Peak HP is just that.  just some thoughts. 

 

I would ditch the A in a second.  My truck has one.  I got a FJ to replace it :)  If I didn't have the FJ I would do a S14 SR20DE only 1500 bucks for the hole swap and they weigh the same as a L20. 

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As weighed on a bathroom scale the A12 block (with main caps) is 70lbs.

 

I've been doing a lot of research on weights as of late; If someone online has a picture of said assemble hanging from or sitting on a scale then I consider the weight as reliable.

 

One of the things that surprised me is how little the difference actually is in weight between a 5.0 ford with aluminum heads and turbo twin cam fours. In some cases it's as little as 20lbs, then when you factor in the gearbox weight the turbo motor and tranny combo weigh more than the V8 tranny combo.

 

People do indeed forget about the drivability of a motor and get hung up on peak power. On the carbs versus FI front; injection doesn't work any better than properly set up carbs but the difference is it works more often. I also race a F500 single seater; in the two stroke powered cars people routinely make jetting changes between sessions but if you have a significant change during a race (wind, temp, humidity) you're stuck. For the street there are significant weather changes day to day that will affect the car, it may drive fine but it certainty won't be at peak operating efficiency.  I've jetted my car for cooler months of the year (I only race from the fall through late spring) I don't change the jetting for the track days I do in May and September because A. the FCR cabs are very tolerant of changes and b. I'm lazy and c. I don't care that I may not getting the max out of the motor at a track day.

 

The A12 engine and gearbox combo is going to be the lightest thing you're likely to find, even the 1000cc bike motors weigh more, the main issue is power. My A15 made 99whp and it would be street-able. The current A12 is around 80whp (haven't dynoed it yet). The stock A12 is around 40whp so yes it's slow. there is also the issue if you need to rev them (even in stock trim) to get the power out of them. Putting in a 2.0 - 2.4 liter truck motor offers up a nice flat torque curve and that's hard to argue with, the extra weight in an already light car isn't likely to be an issue for 99% of the people driving it.

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On 5/27/2019 at 8:56 PM, pdp8 said:

If I just wanted a little more power I'd go ahead and drop in an A14 or even just do mods on the A12 (87Kg) and it easily could come to that. 

I was looking for modest performance gains, lower emissions, and a way to capitalize on one of the car's outstanding attributes, it's light weight. 

It did seem like an engine of similar displacement but using an Al block and other modern attributes (timing belt rather than chain, direct drive distributor, no pushrods, plastic intake manifold, tube steel exhaust manifold, etc.) *should* be lighter

 

14 hours ago, Tom1200 said:

pdp8, note I'm not poo-pooing the idea but here are some things to think about.

 

What people forget is that the aluminum blocks need to be thicker than cast iron to give similar strength so they aren't as light as one would think.

 

Twin cam motors are by their very design heavier; you need all of the supporting structure for the camshafts, the extra weight of the additional camshaft itself plus the additional 8 valves. The A-series complete head is something ridiculous like 15lbs complete versus a typical twin cam motor at 40lbs.

 

The complete  motor in my race car is 185lbs (this is complete including clutch, flywheel and starter) the A series box weighs 38lbs. Combined that's 15lbs lighter than a Hayabusa motor. 1600-2000cc twin cam motors vary between 290lbs and 350lbs, additionally most of the transmissions for these motors weigh 80-100lbs. 

 

There is nothing wrong with wanting to bolt in a modern motor but you have to look at all the factors. CR12DEs being FWD may not have an easy way to bolt up a RWD transmission.  While CR12 makes 12 more horsepower than the A12 it makes the same horsepower as an A14/15.  For the cost of the CR motor you could source an A14 or A15, clean up the ports in the head, install a new exhaust system, mild cam,  weber 32/36 carb and thus increase the A series motor output by about 15-20hp. Couple that with a lower rear gear (3.9 to 4.11 ring and pinion) and a 5 speed transmission (5th gear overdrive) and that would make it much nicer to drive. Note there are fuel injection set ups for A-series engines (standard Nissan as well as fabricated ones detailed on 1200.com) The standard Nissan fuel injection for the A-series tends to be pricey for what it is.

 

The most common modern-ish swaps for 1200s are CA18 and SR20. The L series is an easy swap and given the fact no one wants an L16 you could probably get one stupid cheap. The L16 would make more power stock than either an A14/15 or CR12. If you don't care about keeping it Nissan I'd snag a Miata 1.6 as those have tons of support as well as a sweet gearbox, plus it's one of the lighter packages when it comes to twin cam engines.

 

Now with all that said if you want to install the CR12 motor just to be different than I say go for it.    

 

My 2 cents:

I'd say go for a hot A14.

Had one back in the day in my 1200 coupe and it was more than enough power to be dangerous without a lot of other upgrades. Also, the swap is easy and the rest of your drivetrain will survive longer.

 

Things not to do: 

Decide to cram a KA into a 1200. Just don't do it. Trust me on this one.

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As the subject motor in this topic was light weight motor I should have mentioned the E series engines from the early 80s that are found in Pulsars and Sentras. The E15 is 22lbs lighter than the A-series. The E15 or E16 will bolt to the A-series bell housing, the E flywheel would need to have an A ring gear installed. Additionally the distributor on the E15 is sticking out the back of the cylinder head so the motor would need to run EDIS/crank trigger ignition.

 

The down side of the E15 is in North American trim it makes less power than the A14/15. There is the E15ET turbo motor from turbo that made 113hp that can easily make more with little effort. The naturally aspirated motors can be upgrade easily as well with the usual side draft carbs, header cam etc. 

 

I happen to know of a racer who is looking to sell of all of his E-series engines and parts (His car now uses a motorcycle engine). I haven't made an offer yet as I'm not sure which direction I'm going with my car long term. For the street the motors would likely need D-tuning as compression is 12-1 and the camshaft grind is pretty  roarty. The motors also use crank fire ignitions as well as dry sump, one might want to change the sump back to wet sump.

 

I've also got a couple of A15s in need of rebuilding that are free to anyone who wants them.

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I must admit to being a bit surprised and disappointed that the aluminum motors aren't lighter than a cast iron motor and also don't seen to make more power than they do.  Changing to a 16V crossflow head did pretty amazing things for the other motor series I spend time with, the 2.0 Saab engine.  I have a spare A14 but I think I'd rather keep the A12 and put a turbo on it, for the same weight increase I'd get a lot more torque and who dosen't smile after waiting for the snail to spool it finally makes full boost.

I appreciate that people are trying to help but the "X makes a lot more power than a A12" isn't what I need since just about anything makes more power than a stock A12.  I'm looking for reduced weight and increased efficiency, sure I'll make it more powerful but I want to make the rest of the car work better and with the work I did on my 210 I was impressed by how shaving 50lbs off the car made it feel.

 

OK, an E15 is lighter than an A, thanks very much for that.  Now we're getting somewhere.  I wonder if that's an A14/15 in which case it weighs about the same as an A12.  I'd rather have less weight but more power in the same weight is as least not going the wrong direction.   I imagined that I'd eventually go with a crank-fire setup though it wouldn't have hurt my feelings to be able to run a distributor while I got things settled a bit.

 

I'm not particularly attached to the A bolt pattern since the car currently has the dreaded slushbox and with all the Spridget folks driving the price of a 5-speed so high I imagine I'll be reconsidering my transmission anyway.  Of course if anybody has a 5-speed tranny for a reasonable price I'm willing to reconsider. 🙂

 

I'm a machinist with a CNC or four at my disposal so adapter plates and such aren't a problem.

 

I do still wonder what a CR12 really weighs, or rather what that weight includes.

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Per Datsun1200.com the E15/16 is 22lbs lighter than the A-series, the A14/15 is 12lbs heavier than the A12 so even if the E15 is  22lbs lighter than the A14 it would still be 10lbs lighter than an A12.

 

The fact that you have a auto in the car is a bonus as it has a large tranny tunnel and given the fact you can machine up your own adapter plate for a transmission you have a lot of options.

 

Here is a link to various 1200 component weights.

http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=70067&forum=1&post_id=490878

 

I would venture guess that the CR12 is pretty close to the A12 weight wise (maybe one of the Micra/March forums knows the exact weight), the aluminum block offsetting the extra weight of the DOHC head.

 

My 1171cc A12  with FCR carbs, GX head, cam and ports cleaned up made 73whp, while rather underwhelming it is 33 more than the are in stock trim. Getting another 20hp out of the motor isn't that difficult. I have a 63 series 5 speed I might let go of but that depends on what you consider cheap. I also have some Yamaha FZR1000 carbs that you could have for the price of shipping them to you. Honestly if you can do your own adapter plate I'd find a Miata 5 speed for $150 and make an adapter.

 

As for weight replacing the standard battery with a Group 51 battery from a Civic or a Miata battery will save 12lbs. A LiFoPo battery will take 25lbs off.  The stock 20lb flywheel (manual car) can be lightened to 14lbs (I also have an A14/15 14lb flywheel) so there is potentially 30lbs right there. I also thing going to a manual transmission would take at least 50-60lbs out of the car. The 71 series Jatco trans is reeeeally heavy, the tech section on 1200.com says it weighs 70KG more than the 1200 trans which would make it something like 190lbs but I don't know how accurate that figure is.

 

The one big advantage of the A-series is Nissan used it for 35 years (all the way until 2010) worldwide so basic parts availability is good. In theory you can shave 75-100lbs out of your car and add 20hp just by bolting on standard components.

 

I will admit I like the idea of doing something different than everyone else but it comes down to the amount of time one spends just to be different. In my case I can't machine parts and even if I could I'd rather pay for the parts and spend more time driving. As a machinist I suspect making and fitting the parts is a large part of why you play with cars.

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I wonder what the Miata gearbox is, oh wait... the internet!  Looks like 76-80lbs and, wow are they ever cheap!  I just weighed a 4-speed transmission I pulled off an A14 at 45Lbs so that is going the wrong direction in a big way.  I'll run the 4-speed unless I find something lighter or 5-speed I can afford.

I did just check the Micra forums and I suppose it's not a huge shock that Micra owners seem less technically savvy than the folks here, not a lot of detailed technical information to say the least.  I'll dig some more and see what comes out.

 

The battery is great advice of course.  I killed a couple very expensive lithium batteries due to aging electrical issues with my 210 so switched to a small AGM.  It's a lot cheaper, more robust, but still only weighs about 11Lbs.  Not only does it save you a lot of weight, it's weight that is really far forward and up high so I really felt it.  At the time my commute was up a winding mountain road and just changing from a big wet battery to the lithium made the brakes work better and saved me a lot of gear changes.

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Admittedly I don't know jack about any of this. Have you ever looked at jet ski motors? Don't even know if it is a viable option, but they appear pretty potent.

 

Yamaha GP1200 Non PV 135HP 144lbs
Yamaha SVHO 1.8L 260HP 261lbs
Seadoo 4tec SC 1.5L 215HP 218lbs

Kawasaki 15f 160HP 197lbs
Yamaha 1.8L NA 180HP 248lbs

Seadoo 787 110HP 87lbs
Seadoo 951 130HP 125lbs
Yamaha 701 80HP 80lbs
Yamaha 1100 triple 110HP 128lbs
Yamaha 1200 PV 155hp 217lbs
Kawasaki 1100 110HP 189lbs
Kawasaki 300HP 236lbs

Yamaha 800 twin 66e 131lbs
Kawasaki triple 900: without Ebox 146lbs with ebox 156.8
Kawasaki 750: 92lbs

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They would tend to work best at constant and high RPMs.

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Have to figure out a way to cool them as well.  I'm trying to not go too far outside the box, hence an interest in the CR engine since they at least have a touch of common heritage with the A-series motors.  I did consider the V4 Ford motor for just a moment, similar to a A-series in weight, capable of some power, and would look super cool under the hood.   So far the E15 sounds like the only winning swap and even then not by much.

I'll hope to get an honest weight for a CR1x motor someday but until then I guess I'll consider just doing a turbo/FI A12. 

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FYI there is a thread on 1200.com about doing budget EFI turbo set up.

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44 minutes ago, Tom1200 said:

FYI there is a thread on 1200.com about doing budget EFI turbo set up.

Thinking I'll skip over the electronic part, an old Bosch K-jetronic system needs ignition and starter power and nothing else electrical while fixing most of what I don't like about carburettors.  It's barely possible that one could build a lighter megasquirt setup and I'm sure one could come up with a better fuel-map but easy wins for me on this.  Should cost me under $200.

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