B210 A13 with 728 round port cylinder head...

[74 B210]

EGR is all stock. 

[datzenmike]

12 minutes ago, 74 B210 said:

Will check the EGR system. I went to a colder plug no change.  timing is at 5. pings under light throttle, not med throttle.

going with supreme gas on monday. hopefully better runs.

 

Try pulling the vacuum advance off the distributor. It adds advance in proportion to engine load. Light throttle more heavy throttle less. Doesn't mean something is wrong perhaps the distributor base timing is too advanced?

 

Whats the stock timing?

 

As to the EGR it may all be there but still not working.

 

Perhaps the 728 head has increased the compression ratio? in which case all you can do is reduce the timing till it stops or try higher octane gas.

[Stoffregen Motorsports]

1 hour ago, 74 B210 said:

Will check the EGR system. I went to a colder plug no change.  timing is at 5. pings under light throttle, not med throttle.

going with supreme gas on monday. hopefully better runs.

Ping under light throttle tells me that the vacuum advance is pulling in more timing than the engine needs at light throttle.

 

I go back to my distributor re-curve advice. It's quick and inexpensive to have someone do for you. Or you can tinker with it by yourself.

Try adding a stiffer spring to one side of the distributor cam. You can use the generic domestic V8 springs sold by Summit or Jegs, etc.

You could even try putting a vacuum restrictor in the hose, to limit the amount of vacuum to the distributor.

[74 B210]

Hi guys I put 91 gas in the car ran good, pulled the rear end apart to verify the ring gear and guess what it was a 37:10 3.70 gear nice. all that work for nothing.... 

still not getting the mpg I want cant think of any more ideas.... the engine combo does have higher compression put colder plugs in. my lower engine short block is stock.  The FU engine nissan built used a A14 engine with dished pistons and closed compression head 728. by swapping my open stock A13 head for a closed 728 round port. I have reduced the compression chamber size, thus causing the pinging. but with the 728 round port that supposed to swirl the gases for better mpg, no effect. even with 91 octane which made the pinging to stop.. and the EGR system is working.  other options to increase engine output for more mpg. car was aligned today. tech said it was fine no adjustment needed. My other option in the future is too install my A15 engine with stock H95 swirl port head and see what she can do, then try my 990 head on it. the A15 does have dished pistons so the compression is lower a bit...as per datzen mike I tracked the spedo tripodometer and gps says it is off at 50 miles by 1.25 miles.  so that is good to know.  and for any 74 b210 coupe owners my fuel tank capacity is 11.500 to the filler neck cap.   

[datzenmike]

You can easily get a 10% mileage increase by changing your driving habits. Just realize that every time you accelerate up to speed you've invested gas to do so. So stepping on the brakes for any reason is throwing this away as you have to get back up to speed after. Anticipate stops up ahead and slow down slowly anticipating that the light will turn green and traffic will get moving ahead of you. Leave more space between you and who you are following so you can slow and speed up gradually. Try to keep vehicle moving and avoid stops. Accelerate slowly. Biggest gas saver is go the speed limit and maybe a few MPH over so people don't get pissed off. It takes a lot of practice to do this well. Drive in the right lane. Second biggest gas saver is never be in a hurry.

 

If you drive on the highway primarily an over drive 5 speed can help with mileage by reducing cruise RPMs. Waste of time if all you do is commute in town. 

 

Check tire air pressures every month and adjust seasonally. Higher is much safer than too low. Hard tires roll easier.

 

Empty the trunk out. Every unnecessary pound needs gas to accelerate up to speed.

 

Keep a log of mileage and gas used. Notice when gas mileage changes up or down, figure out why and adjust.

 

 

[74 B210]

I would drive 55MPH on the freeway but I think I would get shot in the Bay Area.  their speed demons here. 

[74 B210]

would a port mismatch cause a significant lose in mpg??? on the intake.

 

[datzenmike]

Not at all. This is something that by itself gains you very little but when combined with several other little things adds up to a free and noticeable increase in efficiency and power, mostly power. I found the exercise very pleasant as you are physically correcting small defects and you had a part in this. You 'know' that it is better for your time spent on it.

 

Port matching and cleaning up the bowl area below the valve seats, is free, never wears out or needs replacement or tuning.  

[Stoffregen Motorsports]

Port matching the exhaust does almost nothing. Datsun engines in general have large enough exhaust ports from stock.

[74 B210]

what about the intake port, would a mismatch there, cause loss of mpg and noticeable power?  

[74 B210]

hey mike if I go to a smaller tire would it improve my mpgs?

 

[KELMO]

Smaller tires would make your engine rev higher. I have 2 1200's (the model that evolved into the B210), one with 12" tires and one with 14" tires.

It takes a lot more RPM's to move the 12" tires down the road.

[datzenmike]

12 hours ago, 74 B210 said:

what about the intake port, would a mismatch there, cause loss of mpg and noticeable power?  

 

Answered here...

 

23 hours ago, datzenmike said:

Not at all. This is something that by itself gains you very little but when combined with several other little things adds up to a free and noticeable increase in efficiency and power, mostly power. I found the exercise very pleasant as you are physically correcting small defects and you had a part in this. You 'know' that it is better for your time spent on it.

 

Port matching and cleaning up the bowl area below the valve seats, is free, never wears out or needs replacement or tuning.  

 

 

8 hours ago, 74 B210 said:

hey mike if I go to a smaller tire would it improve my mpgs?

 

 

As stated your engine would have to turn faster at the same speed with a smaller tire. So generally, no won't help. A larger diameter tire would be best for mileage but it causes other problems like sluggish pull away performance and your speedometer /odometer will read higher and farther than you are actually going making working out the actual mileage very difficult.

[Stoffregen Motorsports]

15 hours ago, 74 B210 said:

what about the intake port, would a mismatch there, cause loss of mpg and noticeable power?  

No

[Stoffregen Motorsports]

Just curious why you're bent on maximizing your MPG. Is this a pet project or are you really trying to save money?

[datzenmike]

The best mileage B-210 was the GX with the dogleg 63A 5 speed with overdrive.

[74 B210]

why was the 63 trans better for mpg??  it is my project and I want to prove it can be done on a daily driver.

[74 B210]

I thought the 60 series is better for weight and same gearing?

[74 B210]

Also were can I get another spedo gear to align my spedo so its not so far off. it reads higher than what 
I am driving with stock tires. the gps says 62 at 70mph on the spedo...?

[datzenmike]

 

4 hours ago, datzenmike said:

The best mileage B-210 was the GX with the dogleg 63A 5 speed with overdrive.

 

 The stock 4 speed in 4th gear sends one turn of the engine to one turn off the driveshaft. The overdrive 5 speed reduces engine RPMs about 15%.

 

 

 

On 11/1/2022 at 11:52 PM, 74 B210 said:

Hi guys I put 91 gas in the car ran good, pulled the rear end apart to verify the ring gear and guess what it was a 37:10 3.70 gear nice. all that work for nothing.... 

 

Well I did say that.

 

On 10/16/2022 at 5:59 AM, datzenmike said:

Your H-145 is 3.889. If the H-150 is from any automatic B-210 it's the same. Manual B-210s were 3.70 from '76 onward.

 

 

19 minutes ago, 74 B210 said:

Also were can I get another spedo gear to align my spedo so its not so far off. it reads higher than what 
I am driving with stock tires. the gps says 62 at 70mph on the spedo...?

 

That would indicate a speedometer error of about 11.5%?

 

On 11/1/2022 at 11:52 PM, 74 B210 said:

 I tracked the spedo tripodometer and gps says it is off at 50 miles by 1.25 miles.

 

This would indicate that the error is only 2.5% or 2.5 miles per 100 miles.

 

So your odometer is pretty close to correct so the tire and transmission gearing is also correct. Your speedometer is out to lunch. Ignore or replace the speedometer and use the odometer for calculating gas mileage.

[74 B210]

thanks mike

 

[74 B210]

I was just looking at the gearing on a 63 series and a 60 series and the gearing is very close off by .04 and lower in 5th gear for the 60 series. and 20 pounds lighter.

[datzenmike]

Yes indeed the later 210 60 series 5 speeds will work just fine and are both higher OD and probably easier to find than the 63A.

 

The 63A* has a 14.65 OD

The 60 series L* is 15.4% OD '79

The 60 series A is 17.9% OD '80-

 

* Dogleg shift pattern with reverse above first.

 

R  2  4

------

1  3  5

[74 B210]

dang Mike u almost scaried me, I was like I have to switch trans. I do have a 63 in storage, never used it. 

cause I want the best one for mileage. So I have the 60A on my car now. to bad nissan never made a 6 speed. bolt on!

I quess the next thing is weight reduction, I have a euro front bumper to try on and lose 40 pounds of the front...

[datzenmike]

Keep in mind that you can't OD forever, the engine power wouldn't support it. Same with a 3.364 differential, there are limits. 60A is fine, keep the 3.70. Make the engine as efficient as you can, run narrow profile tires and maximize the air pressure to the safest upper limit.

 

The B-210 Honey Bee was a stripped down car. I mean they stripped everything out of it.

 

 

• No Wheel covers (dogdish caps fitted)
• No “honeycomb” wheel covers
• No Spare tire cover
• No Trunk mat
• No Cigarette lighter (blind plug fitted)
• No Speedometer trip meter
• No Rear window defogger switch (blind plug fitted)
  • 1976 Honey Bee has the defogger
• No Carpet (only Mat)
  • California models included carpet
• No Arm rest (pull handle is fitted)
• No Door trim moulding
• No Rear side moulding
• No Rear seat ashtray
• No Wiper blade high-speed fin (uses basic type from 620 truck)
• No Door lamp switch for assistant side
• No Console box
• No Non-glare glass
• No Chrome moulding for windshield
• No Chrome moulding for rear window