Top speed on your STOCK engine

[harlow426@msn.com]

I don't know the absolute top speed possible in a "stock" 720 but a good z-22 z-24 will do 55mph in second b-4 shifting(5sp). If u pull the peg @ 85mph on an 82 speedo I can stuff it all the way to the H in MPH(leaving 4th gear/into 5th). Something internal keeps the needle from going farther. Headwinds and crosswinds really impact speed on a 720. If it had a tach I suppose I could get an accurate top speed # but I am sure my 82 would do every bit of 105.....maybe 110 on a good patch of asphalt. Good luck even getting close to those #'s if u have an L20b powered 720...like my new 80KC.

I love to grab 3rd approaching corners and eat-up the "tuner" cars on the road.....Audi a6/BMW M3 drivers' eyeballs get huge in the rear view mirror when u catch-em exiting the tight stuff(often while pulling a trailer). I'm sure they are thinking "where the hell did he come from!"...."didn't I just pass him a mile or 2 back?" :thumbup:

please note above data aquired w/ weber and 2 1/8" ex w/o cat, 235-60-15 tires and engine in perfect state of tune

[bryant2482]

ive hit an easy 90 in 5th at about 3600 rpms. thats with 205/50/15 size tires, a properly calabrated speedo and 3.55 diff gears

[foxfan1992]

Fastest I've done in my little truck is 90mph on level-ground. Downhill I've taken it to 95mph before I decided I was going too fast and slowed down. (It was a high-mountain freeway, only reason I did that speed is because there was little traffic and had to catch up to my travel-mates in a Honda Fit).

 

Truck is equipped with original Z24 engine and automatic transmission - and stock carb.

[Cpl620]

90mph with an L18 in a 620 gets pretty sketchy.....

[DaveZilla]

Mine's not completely stock, it's a 4x4 with a Holley 32/36 carb (same as Weber 32/36), headpipe back exhaust system, aluminum flywheel, electric fans, cam advanced to #3 position, 3" body lift and running 32" tires.

it can cruise at 80 pretty easily and tops off at around 90. Fastest I've seen it hit on the gps was 89 on a long stretch of straight flat highway before I had to slow down. 

With the body lift and the taller tires, the wind resistance really starts to add up once you get it over 70 or so, but it's geared so it's right close to it's torque peak hitting 2800 rpm just under 80 in 5th, to get it above 80 you have to be in 4th tho, then it'll slowly accelerate to about 90 if you got enough highway and the balls to take it that fast.

 

I swapped out the carb too quickly after buying mine (the fuel solenoids were toast and I found a really good deal on a Holley 5200 series carb, which came out cheaper than replacing the fuel solenoids) so I have no idea what it would have done bone stock, but it was really struggling to do over 75 with just the carb swap but getting the jetting right helped a bit. Advancing the cam to the #3 position made a noticable difference in power, but it also falls off about 500 rpm sooner. I also swapped out my flat weber adapter for this one http://www.amazon.com/gp/product/B000CQ47RE/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1 , it fits but needs the holes on the base elongated just a bit to fit the 720 manifold, this helped just enough to be noticable as well with a little bit better bottom end torque and some decent midrange. The aluminum flywheel and electric fans don't add power, but it does make a noticeable difference in 4th gear acceleration since there's less drag on the engine as well as less need to downshift on hills or passing. All these little mods add up so it runs really strong between 70 and 80 on the freeway, being a 4x4 with a body lift and oversize tires, that's about as fast as any sane person would want to go in this... it Will go faster, but not recommended...

[datzenmike]

ive hit an easy 90 in 5th at about 3600 rpms. thats with 205/50/15 size tires, a properly calabrated speedo and 3.55 diff gears

 

Try it in 4th. You would go faster.

 

 

90 mph stock '74 710 slight up hill grade. Oh yeah... for those that think autos are lame... it was an automatic.

[hellcatfa]

Just this morning my 720 topped out at an even 80. Thats on downward sloping flats, with a ladder rack and toolbox.

[heywier427]

go nismo go!!!

 

IMG_0292%5B1%5D by heywier427, on Flickr

 

the backyardian!

 

hasn't been washed in 10 years :)

 

IMG_0380%5B1%5D by heywier427, on Flickr

 

could probably hit 110 with a fresh wax!

[Dguy210]

In my younger and dumber days, 127mph. In a B210. With an A13 and 4 spd.  Rebuilt stock engine, stock carb, matchbox dist.

 

 

This was on a very straight, very long road, with no on-ramps, and no other traffic, that I knew very well. In hindsight, it was a pretty stupid thing to do.

[Ranman72]

on a fun run with a lady on my ass ( so close I couldnt see her head lights ) I got a little tired of that after giving her several hints to back off, 

I hit the gas to the floor was still pulling hard when I let off 

I never looked at the speedo but the GPS clocked 110  on flat ground 

but it is not stock 

 

in a more stock 510 but completely new everything inside L16  down hill hit 130   Yes I was alot younger and Dumber but it was on the freeway 

the same motor on flat ground passing 6 cars at once I hit 125 

[720buck]

5 mph.  tops.

[hosestop@msn.com]

3.90s gears and stock sr20det 100 in 3rd ,often I always wonder if maybe would do 140 or more ,again stock with 7psi maybe when I get a matched set of 16s on there with a good fresh balance job ,then there's the low flying brick thing !

[hosestop@msn.com]

Oh sorry, it's a 510, not 720.

[Beastlikethat1]

122MPH in my 1978 280z 5spd around 5K (had more room too). 90ish mph in 1977 620 pickup with L20B 5spd. Now putting a Z24 with L16 head and double Mikunis so will see if it is any better!

[datzenmike]

Try a U67 head. The stock L16 head had small valves and ports and you are going to try to pass 50% more air through them? Not to mention the 10.36 compression. It will run.... but would run better with an L20B head.

[Tinman]

Not sure if I ever posted this before, but I did get to 105 on the speedo on a long..... VERY LONG run through the Mojave desert.  I almost ran out of planet, but it did get up there....

The first 85mph were easy.  But then....

 

Oh yeah, 85 Standard cab, standard bed, 2wd 5speed with a camper shell.  Maybe the shell gave it some aerodynamics.

[Daryl]

Going down to Bakersfield from SF on the I-5. 79 620 stock everything, 100+/- with an autotragic. No idea on rPMS but sure was loud.

[captain720]

85mph in my 4wd 720 going downhill in neutral. It felt like I was gonna die with the way the truck was screaming and dancing and shacking.

[8m0untainman8]

In my 76 620 with a stock l20b plus a weber, and new head gasket, ive gone 68- 70mph, consistently for 15 minutes, no hesitation. I dont like holding my rpms higher than like 3000- 3200. Rpms were barely above that.

[KELMO]

For the first 5 years of the Mutli State Datsun Classic I drove the grey 1200 coupe. First year bone stock, original carb, 4 speed trans, and 12" wheels/tires, engine was running about 4000-4500 rpm's and if I was lucky I may have hit 55mph.  For the last couple years that I took the grey 1200 upgraded to a Weber carb and 14" wheels/tires, roughly same rpm's but possibly 60-65 mph. NOT a fast car at all.  Last year we took the green car....on a trailer so, yeah, that car is slow also.

[distributorguy]

620 with L20b.  Still 2 liter displacement, no boost.  Not stock however.  .600" lift cam, 300+ duration, dual Weber DCOE 50's.  110.7 on the Bonneville slat flats with tons of wheel spin at 8100 rpm in 4th gear.  The tach indicated the truck should have been going 151 if we could hook up.  Going for 130 next year.  

 

In an earlier life, 145+ in an Eagle Talon AWD turbo.  The needle went past the gauge at 140 and out of sight at 145+.  

[8m0untainman8]

620 with L20b. Still 2 liter displacement, no boost. Not stock however. .600" lift cam, 300+ duration, dual Weber DCOE 50's. 110.7 on the Bonneville slat flats with tons of wheel spin at 8100 rpm in 4th gear. The tach indicated the truck should have been going 151 if we could hook up. Going for 130 next year.

 

In an earlier life, 145+ in an Eagle Talon AWD turbo. The needle went past the gauge at 140 and out of sight at 145+.

So on an average day with a stock 620 with l20b how far can someone push the rpms regularly? The red line is at 4k on my rpm gauge, i replaced gasket, and put arp head studs in. I bought the studs because they were tested for way higher psi. Can a safely rev higher than 4k on a stock l20b?

[Knugcab]

60 mph on flat ground, hit 75 once down a very steep hill though that was scary :P

1985 4x4 diesel.

[datsunaholic]

So on an average day with a stock 620 with l20b how far can someone push the rpms regularly? The red line is at 4k on my rpm gauge, i replaced gasket, and put arp head studs in. I bought the studs because they were tested for way higher psi. Can a safely rev higher than 4k on a stock l20b?

 

A stock L20Bs rated max HP is at 5600 RPM.  4K isn't even pushing it.  You can, assuming the parts are all in good order, take it safely occasionally over 7K.  But there's a pretty good falloff after 6k on a stock engine.

[datsunaholic]

Oh, and now that I have a 720 4X4 I've had it at 70 several times, but with the dryrotted tires and the amount of shaking I keep it around the speed limit.  It's the first Datsun I've had that I absolutely have to downshift on significant hills.  Pushing too much air with those big tires, and carrying a 200lb air compressor in the back isn't helping.