Datsun 510 Plans

[GasSavers_Gollum]

Hi, I'm new but let me get straight to the point.

I'm a car nut. Through and through I'm a garage engineering hot rodder. I drive a 280Z that's getting about 20mpg and with a new EFI upgrade (megasquirt) later this year it should be getting around 30mpg. Still not great I know, but it ain't bad considering how fast it is.


But I've got an itch. I can't fit my guitar gear in the Z due to the narrow hips at the shock towers, and I only plan to make it faster, decreasing gas mileage. I also drive A LOT! Well, maybe not a ton compared to some here, but I drive at least 20k miles a year, if not more like 25k+.

I'd considered getting a Metro, or a CRX HF as a daily driver, but I just can't get past the looks of the metro, and I've owned a CRX and they're a pain to lift a 60+ pound object into considering the high rear setup, and tail gate that doesn't open far enough from the factory.

I also kinda wanted something else that would be presmog, so that I didn't have to worry so much about the legal police getting on my case about modifications that "might" cause emissions. I like cars to run clean and not smell, but I also don't like having to keep things OBD I, OBD II, stock ignition, etc.

I'm very familiar with Datsun/Nissan engines and smacked myself on the head saying "DUH!", why not the Datsun 510?

Stock weight is around 2250 pounds, and can easily reach the 2000 pound barrier, and even with the stock carb'ed engine 30-35mpg is expected from an engine that's running right. It comes in a wagon variant at the sacrifice of giving up IRS for a solid rear axle. I know the IRS diffs from nissan very well and having an IRS car would make gear selection easy.

So I'm thinking that with a 2 door varient I can plan on putting a large guitar cabinet in the passanger seat area via the door, or open up the truck to rear seat area and weld in a frame to add rigidity that I removed by doing so. I'll probably lexan the rear and corner glass, leaving the OEM glass in the sides and front obviously.

The engine has been a real tricky topic though. Granted I've only been trying to plan this out for about 5 days, but this is the real roadblock. I'm doing this to SAVE money, not SPEND money to get impressive MPG figures. It's better to get 30mph for free than spend $10,000 getting 60mpg. It just takes too much time to recoupe costs.

So I'm thinking if I stick with the stock engine and add EFI I should be able to get around 40-45mpg, but with a KA24DE, KA24E, or SR20DE I shuold be able to reach 50mpg.

I'm a pretty spirited driver, so the RWD setup of this car should suit my liking well. I'll be able to live with a relatively low HP/weight ratio without gouging my eyes out. A car can obviously be fun without being fast, but the economy of a metro doesn't exactly get my blood rushing.

So why am I posting this here?

I'm not exactly tied down to this car idea, so other suggestions are welcome and appreciated.

I'd also like to hear other people's experience with their setups. Was it better to run higher compression and add more fuel, or lower compression to run leaner? How much has water injection improved MPG when tuned right? Stuff like that.

[FritzR]

Go for it Datsun 510s are indestructable. I think if you could find a 5 speed that would fit 40+ MPG would be no problem on the highway. I had a '73 wagon and it would go high 30s on trips no problem. It loved 82 octane mexican Nova grade fuel. I took that $100 car to Cabo San Lucas every year for 8 years, 1400 miles each way, and it never stranded me.

I think you might still be able to get aero body kits for the sedans as they were the original "ricers" or "the poor man's bmw"

[theholycow]

I don't think it's necessary to invest so much money and effort in weight reduction. Basic economical driving habits make simple weight reduction pretty ineffective unless it's accompanied by a smaller engine or taller gears.

I'm not familiar with the Datsun 510, but would the IRS be aerodynamically better than the solid axle? I know it would in a truck, but in a car I imagine the solid axle is tucked up anyway...

[Philip1]

I love Datsuns especially the 510. I see no problem shooting for 40 or even 50 mpg. weighing in under 2200 lbs stock and stripped they can get down to 17-or even 16oo lbs. I am currently trying to purchase a 510 and I plan to do some crazy things to it.

power:
CA16DE (1.6 liter dohc I4 110hp)
Trans:
Ca20 5 speed (1985-88 200sx)
Differential:
R200 open diff 3.36:1 (1975 280z)
wheels:
light weight aluminum 14-15 inch with LRR tires
performance:
1975 280zx brakes front and rear, large sway bars, 2 inch exhaust
Aerodynamics:
reduced ride height, rear window deflector, front and rear under trays, air dam
Comfort:
Integra seats
entertainment:
head and 2 system as light as possible

I see this as an easy 40-50 mpg setup

[R.I.D.E.]

A good engine would be the L20B truck motor. All of the prop shafts use the same input splines, if memory serves me right.

The original tranny was a "monkey motion" linkage, you want to get rid of that and use a pickup truck tranny. I think you need a long tail shaft.

The original 510 diff was a R160. If mileage is your object you might want to consider the early 240 R180 diff with 3.36 ratio. Combine that with a 5speed tranny and the higher .75 overdrive 5th (versus the .825) and you would have a very nice tall final drive ratio combined with a very strong low end torque motor.

Check out the BRE 510 racers of the era for some mods. Lowering is simple, just cut the stock springs and you make them stiffer, but dont use a torch.

A guy nmamed Turbo Tom Wyatt used to build some unreal 510s capable of blowing away 427 Cobras on Road Atlanta. he was running over 20 PSI boost, and doing sub 10 second 1/4 mile runs in the late seventies or early eighties.

The worst accident of my life was in a 510, but it wasn't the cars fault.

A mighty nice setup would be the current version pickup truck engine and tranny (4cyl) if you wanted to go the high tech route.

Use the L20B with flattop (late 280Z) pictons for higher comopression especially if you are using fuel injection. If you use side draft carburetion use only the Cannon manifold made in Australia. It feeds one barrel into cylinders 1&3, with the other connected to 2&4. If not you will never get it to run properly. Another good setup would be a single Mikuni SU type carb.

You dont need 4 valves per cylinder for economy, the old wedge head Datsun engines were good. My 76 Z had an 82 bottom end, under a 76 280 head, with the .75 overdrive tranny and a 3.54 rear end from the 76 280Z. The 76 was one of my favorites because the Federal car had no catalyst, no EGR valve, and no air injection. The fuel injection was all that was necessary to get the emissions in spec for that year, however California ws different.

regards
gary

[GasSavers_Gollum]

Hey, I found some datsun heads!

Originally Posted by theholycow

I don't think it's necessary to invest so much money and effort in weight reduction. Basic economical driving habits make simple weight reduction pretty ineffective unless it's accompanied by a smaller engine or taller gears.

I'm not familiar with the Datsun 510, but would the IRS be aerodynamically better than the solid axle? I know it would in a truck, but in a car I imagine the solid axle is tucked up anyway...

1st off, I understand driving habbits are a huge part of gas mileage. I've never had a problem meeting or exceeding EPA ratings on most vehicles when I want to. And fact of the matter is, I'd rather build a car that CAN get 60mpg, then have fun and get 50mpg still, than drive a car able to get 40mpg and scqueeze 50mpg out of it driving like a grandma. It's hard to go less than 70mph here in the bay area without people breathing down your neck, and I can't say I blame them. We have beautiful twisty roads and sometimes I can't resist the urge to have a little bit of fun.

I also don't plan on investing much money on weight reduction, just lots of time!

2nd thing, smaller engines don't get better gas mileage. As far as an engine is concerned, gas mileage is about HP per CFM. The more HP it can make for a given air volume, the more power it's going to make under super lean conditions and keep a maintained speed. Some engines can run very lean, yes, but if they don't make power in those conditions then you'll end up using more throttle to keep the car at your desired speed. I know guys with LS2 powered Z cars that get 30mpg with 450+HP naturally aspirated. Not bad considering the stock 2.8 liter struggles to get past 30mpg, even with modern EFI. It's all about how much power that engine is putting out with very small amounts of air and fuel.

3rd thing. You're right, a solid rear axle is generally more aerodynamic as it doesn't dip down on the sides and is rounded in nature. You can also easily desing a pan to deflect air more softly around the axle. BUT! I plan on removing as much air from under the car as possible. Lower the car an inch or so, add a low air dam, low side skirts and the air under the car will be almost nonexistant compared to stock. This will negate most gain seen from solid axle vs IRS.


I'm not trying to be an A$$ or anything. Just showing you that I've already put lots of thought into this kind of stuff and I'm not exactly stupid.

Originally Posted by philip1

I love Datsuns especially the 510. I see no problem shooting for 40 or even 50 mpg. weighing in under 2200 lbs stock and stripped they can get down to 17-or even 16oo lbs. I am currently trying to purchase a 510 and I plan to do some crazy things to it.

power:
CA16DE (1.6 liter dohc I4 110hp)
Trans:
Ca20 5 speed (1985-88 200sx)
Differential:
R200 open diff 3.36:1 (1975 280z)
wheels:
light weight aluminum 14-15 inch with LRR tires
performance:
1975 280zx brakes front and rear, large sway bars, 2 inch exhaust
Aerodynamics:
reduced ride height, rear window deflector, front and rear under trays, air dam
Comfort:
Integra seats
entertainment:
head and 2 system as light as possible

I see this as an easy 40-50 mpg setup

Sounds SWEET! But why the R200? Plan on putting extremely stick tires on it? From what I've seen the R180 would take the beating just fine from that CA18DE. Now, the CA18DET might be a different story. Remember, what kills driveline parts is torque, and the shock loads it can produce.

I'm starting to think I should be shooting for 60mpg for this project of mine.

Originally Posted by R.I.D.E.

A good engine would be the L20B truck motor. All of the prop shafts use the same input splines, if memory serves me right.

The original tranny was a "monkey motion" linkage, you want to get rid of that and use a pickup truck tranny. I think you need a long tail shaft.

The original 510 diff was a R160. If mileage is your object you might want to consider the early 240 R180 diff with 3.36 ratio. Combine that with a 5speed tranny and the higher .75 overdrive 5th (versus the .825) and you would have a very nice tall final drive ratio combined with a very strong low end torque motor.

Check out the BRE 510 racers of the era for some mods. Lowering is simple, just cut the stock springs and you make them stiffer, but dont use a torch.

A guy nmamed Turbo Tom Wyatt used to build some unreal 510s capable of blowing away 427 Cobras on Road Atlanta. he was running over 20 PSI boost, and doing sub 10 second 1/4 mile runs in the late seventies or early eighties.

The worst accident of my life was in a 510, but it wasn't the cars fault.

A mighty nice setup would be the current version pickup truck engine and tranny (4cyl) if you wanted to go the high tech route.

Use the L20B with flattop (late 280Z) pictons for higher comopression especially if you are using fuel injection. If you use side draft carburetion use only the Cannon manifold made in Australia. It feeds one barrel into cylinders 1&3, with the other connected to 2&4. If not you will never get it to run properly. Another good setup would be a single Mikuni SU type carb.

You dont need 4 valves per cylinder for economy, the old wedge head Datsun engines were good. My 76 Z had an 82 bottom end, under a 76 280 head, with the .75 overdrive tranny and a 3.54 rear end from the 76 280Z. The 76 was one of my favorites because the Federal car had no catalyst, no EGR valve, and no air injection. The fuel injection was all that was necessary to get the emissions in spec for that year, however California ws different.

regards
gary

Yea, I know a ton about the 6 cylinder L engines, but not a ton about the 4 cylinder varients. If I could reach 9:1 compression or higher with good amounts of quench I might just go with the L20B like you were saying. They're cheap, and were a factory option so they'll drop right in. For the tranny I'll probably get a 81'-83' 280ZX 5 speed. They have the lowest 5th gear availible I think, and a VERY nice spread on ratios. Probably the nicest tranny nissan made for these engines I think. I've owned 4 280ZX cars and it's amazing how one of those trannies shifts when it's in proper shape. Extremely light for how durable it is too! I know guys putting 400hp and over 500 torque through them. As long as 1/4 mile runs aren't done with slicks they usually take the beating ok.

And regarding BRE, well I had the honor to meet Pete Brock earlier this year. Amazing guy no doubt. I'll definately be turning my head to what they did on the 510 though. I've always been more interested in the Z cars they built.


And the 3.36 R180 would be a good option, and I've considered it. What I'd really like to do, is find a LSD R160 and rebuild it with a taller ratio, closer to the 3.36 R180. The trouble is I don't know what ratios the R160 was availible in. Luckly they're extremely common in subaru cars, so I just need to figure out what ratios they've had with the R160.


I'm honestly surprised to find so many people that know so much about the 510. This is refreshing hope that I can get some help around here with the project when the time comes.

[theholycow]

Based on your responses, it appears that I've entirely failed to communicate clearly. I'll try again.

Originally Posted by Gollum

1st off, I understand driving habbits are a huge part of gas mileage. [...]scqueeze 50mpg out of it driving like a grandma. It's hard to go less than 70mph

I do not advocate driving like a grandma or using low highway speeds, though I know many others here do. I accelerate anywhere from mild to brisk normally; on a daily basis I have to go balls-to-the-wall once or twice on some difficult road entries; and I rarely go less than 70 on the highway myself.

My point wasn't about driving habits, it was about weight reduction's effect on fuel economy. My observations have led me to believe that the only condition in which fuel economy is improved by simple weight reduction (without making other changes) is when someone drives like a complete jerk with absolutely no consideration for economy or reason at all -- low gear wide open high RPM from red light to red light, throwing all that energy away by accelerating right up until it's time to shove the brake pedal into the floor.

If you're doing basic reasonable driving, weight reduction probably won't help unless you can do a LOT of it (say, 50% or more). People talk about weight reduction a lot but I rarely (though not never) see anyone talking about worthwhile results. If you accelerate however you like but try to cruise through lights, coast or DFCO up to stops, and carry your existing speed through turns (translation: have fun flying around curves), you're not going to see statistically significant improvement from a 10% weight reduction.

I also don't plan on investing much money on weight reduction, just lots of time!

Well, by all means, have fun...it'll probably be fun to do.

2nd thing, smaller engines don't get better gas mileage.

That was a simplification, obviously not necessary for you. If you require a certain amount of acceleration, removing weight means you can sacrifice some power for economy, which is usually an easy way to increase economy (though it's not always necessary).

3rd thing. You're right, a solid rear axle is generally more aerodynamic as it doesn't dip down on the sides and is rounded in nature.

Actually, I thought maybe IRS is better, envisioning the huge axle with a big differential under the rear of my truck, with lots of frontal area, vs. an IRS with its reduced frontal area. However, I don't know much about car axles.

[R.I.D.E.]

This car still looks the same today.

regards
gary

[GasSavers_Gollum]

Originally Posted by theholycow

Based on your responses, it appears that I've entirely failed to communicate clearly. I'll try again.



I do not advocate driving like a grandma or using low highway speeds, though I know many others here do. I accelerate anywhere from mild to brisk normally; on a daily basis I have to go balls-to-the-wall once or twice on some difficult road entries; and I rarely go less than 70 on the highway myself.

My point wasn't about driving habits, it was about weight reduction's effect on fuel economy. My observations have led me to believe that the only condition in which fuel economy is improved by simple weight reduction (without making other changes) is when someone drives like a complete jerk with absolutely no consideration for economy or reason at all -- low gear wide open high RPM from red light to red light, throwing all that energy away by accelerating right up until it's time to shove the brake pedal into the floor.

If you're doing basic reasonable driving, weight reduction probably won't help unless you can do a LOT of it (say, 50% or more). People talk about weight reduction a lot but I rarely (though not never) see anyone talking about worthwhile results. If you accelerate however you like but try to cruise through lights, coast or DFCO up to stops, and carry your existing speed through turns (translation: have fun flying around curves), you're not going to see statistically significant improvement from a 10% weight reduction.



Well, by all means, have fun...it'll probably be fun to do.



That was a simplification, obviously not necessary for you. If you require a certain amount of acceleration, removing weight means you can sacrifice some power for economy, which is usually an easy way to increase economy (though it's not always necessary).



Actually, I thought maybe IRS is better, envisioning the huge axle with a big differential under the rear of my truck, with lots of frontal area, vs. an IRS with its reduced frontal area. However, I don't know much about car axles.

Well, I'm not going to say you're wrong, I'll just try to be one that will try to give you some worthwhile data. Everything about driving a car hinges upon converting gasoline into usable energy (torque). If you have less weight you need less power, thus less gasoline, to move the same load in the same amount of time.

I have a feeling why many might see little difference is that it's hard to change your pedal habbits to keep the same accelleration and speed rates as before weight reduction. Once you remove 300 pounds from a car it's amazing how different if feels, and it's hard not to take advantage of it.

But again, we'll just wait and see. I'll probably try to do all my weight reduction for a motor swap, so I can try to calculate how much each item helped.

Oh, and I try my best to improve gas mileage by never braking in the corners.

Today though I've got other things on my mind. I just drove my FREE 280ZX to work for the first time in 5 months. It took that long to get the title transfered. The last 280ZX I had wasn't running right and got about 22mpg, others get around 28 mpg. I'm going to see what I can do to try to get 35mpg out of it. She's going to be a good stepping stone to getting the 510 project rolling. 20mpg in the 75' is killing my spare cash.

Originally Posted by R.I.D.E.

This car still looks the same today.

regards
gary

82'-83' Turbo wheels. Does it have anything else from that particular car? Engine perhaps?

[Philip1]

I have had a few datsuns (40+) and built a few fast ones but what I've learned is a light car with an efficient engine will get great milage. I had a '69 wagon L20 bored to 2.1L 219 head dual SU carburetors (sss setup) and a late L20 exhaust mani flowing to 2.25 in exhaust it made an easy 150+hp and got 32mpg at illegal speeds. I have found the DOHC engines make better power at the same displacement so a 1.6 probably will give the best milage compared to going for cubes after all John morton won the 2.5 series with just a 1.6