fuel question

[herculesinwyoming]

what year did datsun go unleaded in the U.S?

[ggzilla]

1970. Although you couldn't actually but unleaded until some years later, the engines were ready for it.

[DanielC]

Are the trucks different? I have parts for four 521 trucks, the latest build date is 4/70, and it does not have a narroe "unleaded neck for the gas filler.

 

I think every L-head I have ever had worked on had to have the softer bronze intake valve seats sunk into the head and new seats put in.

[datsunaholic]

I have over 300,000 miles on several L-heads. They use unleaded just fine. In fact the last Nissan engines sold in the US that didn't have hardened exhaust seats were the 1969 J13 heads. J13 heads are cast iron and there are no valve seat "inserts" but the seats are ground directly into the heads, just like old American heads.

 

All L series and A series engines, being Aluminum, had seat inserts. It's the exhaust seats that needed to be hardened.

 

Nissan did not REQUIRE Unleaded fuel (except in California) until 1980. That's when they added catalytic converters. In California, cats were required in 1974 or 75, so Unleaded was required there. But the engines themselves were no different internally as far as valve seats in the L-series. However, even before Catalytic converters were installed, Nissan was recommending No-lead or Low-Lead fuel.

[Dat Lurka]

Leads good yo

Burn it up

seals shit yo

[Royal Sierra]

I always run 110 fuel in mine..its expensive but does great

[Laecaon]

Rea

I always run 110 fuel in mine..its expensive but does great

 

Really? If it doesnt ping at 92 its a waste...

 

I remember a car&driver article where they took 2 civics (I forget which ones, eg?) and ran a whole tank of regular and super. Somehow the regular actually got better mileage and more power (if by a hair). Ultimately they showed, its very vehicle dependent.

[Dat Lurka]

Fuel is funny.

 

My scooter was made to burn regular. I got better mileage with mid grade. But premium from this place up in the hills that offered ethanol free premium gave me another 5-8 mpg.

[herculesinwyoming]

i was just asking because my 76 datsun 620 is running average 135 psi compression i figure the valves are worn. Good thing i have mr raiders freshend engine to swap in.

[wayno]

I run regular in everything I own except the 67 roadster and the mini, they get premium.

All my L heads get hardened seats, otherwise they sink into the head and I run out of ajustment, my machine shop guy says it's because I have my foot into it to far, but that's the way I drive. :P

[Dat Lurka]

Are there other ways to drive a datsun?

 

Throttle closed

Throttle opened

[DanielC]

With a modern computer controlled engine, you run the fuel it was designed for, for best economy.

 

Our Datsun engines are not computer controlled, the timing is where you set it.

Fuel Octane rating, engine compression, and timing are all related to each other. So is weather. So is the altitude you are driving at.

 

Theoretically, you want maximum pressure from the burning gasses in the combustion chamber to happen about 15 degrees ATDC (After Top Dead Center)

 

Premium gasoline actually burns slower than regular fuel. Increasing compression makes the fuel burn faster. So, with a high compression engine, you use a slower burning fuel, and the faster burn from the high compression cancels every thing out.

 

You can also take a Datsun L engine that runs on regular, advance the timing slightly, and to avoid knock, run premium instead. You will slightly gain power, or economy, but you will probably not gain enough economy to make it cheaper to run the engine advanced, with premium.

 

As far as ethanol is concerned, it does increase the octane rating when added to gas. But it does not have the same "energy density" as gasoline. You can get more power from running ethanol, but you will burn a lot more of it.

[Dat Lurka]

[ggzilla]

running average 135 psi compression i figure the valves are worn

If you get 135 psi, it is guaranteed that valve seal is very good. With valve not sealing slightly you won't get that much compression.

 

135 psi on a calibrated gauge means the rings are worn. Or if the gauge is uncalibrated, they could be perfect if the gauge is reading incorrectly low.

[herculesinwyoming]

thanks for the info

[Ben280]

I always run 110 fuel in mine..its expensive but does great

 

Where do you get 110? Pumped or do you have to get cans?