U20 engine 150hp stock ?????

[sssr20det510]

so i was told and read that some of the datsun u20 engines came stock with 150hp, thats more than a ka comes with stock so whats the story i couldnt find any pics of this engine???

[datzenmike]

The 150 might be net hp for a time when motors were rated that way. The KA may be RWHP????

[greybeard]

IIRC the 150HP was a dealer installed option for the 2000 roadster, replaced the SU carbs with dual sidedraft mikunis and a hotter cam.

 

but you have to remember that was old school HP, measured at the flywheel with no accesories (alt, waterpump etc.) and the KA is new HP, measured with the alt. and all the pumps, full ehxaust etc.

also the Roadster had no smog standards to meet, and much higher octaine fuel available.

 

 

so it's like compairing apples to oranges.

[sssr20det510]

what does that mean "net at the time" ka is rated at the flywheel i believe

[greybeard]

net was HP at the flywheel with no acessories

 

new standard is SAE, HP at flywheel with the acessories and exhaust

[ggzilla]

No auto manufacturer rates engine rwhp -- it is always flywheel HP (either net or gross). The newest SAE "net" specification about 15 years ago caused a lot of manufacturers to change their ratings once again.

[Jason]

The "150hp" U20 came as a factory/dealer deal. You needed the high lift cam and bits as well as the dual 44mm Solex's etc ... It was probably measured at the crank with no accessories attached as was normal for the time. I've got that setup it's pretty fast, but, not as fast as an LZ22 with the same cam/carb setup in a 510 sedan for example ...

 

Edited December 5, 2009 by Jason

[sssr20det510]

oh, still dont sound to bad, l20b is rated at 96hp

[benzo]

side note beautiful roadster Jason.

[Jason]

Thanks Benzo, wish I could've drove her this year, but, the engine has bad bearings and I haven't quite got all the parts for the rebuild yet. I'll get there ....

[MikeRL411]

IIRC the 150HP was a dealer installed option for the 2000 roadster, replaced the SU carbs with dual sidedraft mikunis and a hotter cam.

 

For what it's worth, I can give you the part numbers for all items required for this "150 HP" conversion, straight from the NISMO catalogue. Slight chance of getting them at this late date. I have heard of some builds with "blue print" of the engine that tested as high as 165 HP, but not sure just how long these engines lasted. To quote a mechanic who worked the Datsun USA race team, "It's amazing just what you can do to an engine when it only has to last an hour and a half."

[bytor]

The "150hp" U20 came as a factory/dealer deal. You needed the high lift cam and bits as well as the dual 44mm Solex's etc ... It was probably measured at the crank with no accessories attached as was normal for the time. I've got that setup it's pretty fast, but, not as fast as an LZ22 with the same cam/carb setup in a 510 sedan for example ...

 

 

Sweet car, Jason. Here's mine.

 

 

Yours is the first I've seen the same color as mine. I need to get a set of stock wheels though. When I was prepping it for a track day, I put smaller tires on it, probably a little smaller than yours, to lower the overall effective gearing and gain some contact patch, and noticed the wire-basket wheels on it are HEAVY!

 

Do you know if the U-20 is at all rare these days? I believe it was also their truck engine, so perhaps not very rare. Still, I've considered taking out the U-20 and storing it and, what the heck, while I'm at it and do occasionally use it at track days, see what else I can stuff under the bonnet that's less valuable but more powerful. I was initially thinking about building an L20B for it, since I have a lot of experience with that one, but in snooping around the net for a posi diff for it (or, dare I hope, a posi IRS rear that fits right under it?) I ran across a lot of references to later and larger motors being bolt-in replacements for the U20.

 

Thoughts?

 

Introductory post about mine, followed by several others, including pics: http://cars.talkzilla.com/boards/read_msg.aspx?message_id=830

[FoxyRoadster]

The solex roadsters had 150 the u20 with SU carbs had 135

[shifty]

The U20 was only used in the roadster and I would consider it fairly rare. The only direct bolt in replacements are the R16 from the 1600 roadster and the H-series used in the Nissan Urvan and Nissan forklifts. The H-series are basically the same as the R-series - simple pushrod engines, but also came as a 2-liter.

 

L-series engines are much taller and the frame will need some modification to fit under the hood.

[bytor]

The U20 was only used in the roadster and I would consider it fairly rare. The only direct bolt in replacements are the R16 from the 1600 roadster and the H-series used in the Nissan Urvan and Nissan forklifts. The H-series are basically the same as the R-series - simple pushrod engines, but also came as a 2-liter.

 

L-series engines are much taller and the frame will need some modification to fit under the hood.

 

Hmmm... I'll have to look for that L20B reference I'd seen earlier. It made it seem a bolt-in. Of course, I'm unwilling to modify the frame, and if the U20 is as rare as it sounds, I'll either need to treat it more gently (hard to do -- it's so fun getting wild on the track with it!) or take the performance hit, if necessary, of an engine it wouldn't be devestating to destroy.

 

I have a question that likely isn't directly relevant to this thread, but as the operator of a couple of message boards myself, I don't like creating new threads for too granular of subjects so I'll just ask here.

 

http://cars.talkzilla.com/boards/read_msg.aspx?message_id=23115

 

Mine is certainly an omelet since it's a 1600 with all the appropriate pieces from a 2000. But note the frame rail and the font.

 

Can anyone confirm whether that's the font Datsun used for stamping VINs on frames? And whether they dented the frame rail like this in the stamping process?

 

In a way, too bad it's an omelet as it appears to be way up the list of last ones built (within last 2000 of them, so maybe within last few hundred still operational?), but if it wasn't a mutt, I couldn't stand to have the fun with it I do. And if you see all the verbiage I've written about the car on my site, you'll see how much I adore it especially when seriously driving the wheels off of it.

[Jason]

Sweet car, Jason. Here's mine.

 

 

Yours is the first I've seen the same color as mine. I need to get a set of stock wheels though. When I was prepping it for a track day, I put smaller tires on it, probably a little smaller than yours, to lower the overall effective gearing and gain some contact patch, and noticed the wire-basket wheels on it are HEAVY!

 

Do you know if the U-20 is at all rare these days? I believe it was also their truck engine, so perhaps not very rare. Still, I've considered taking out the U-20 and storing it and, what the heck, while I'm at it and do occasionally use it at track days, see what else I can stuff under the bonnet that's less valuable but more powerful. I was initially thinking about building an L20B for it, since I have a lot of experience with that one, but in snooping around the net for a posi diff for it (or, dare I hope, a posi IRS rear that fits right under it?) I ran across a lot of references to later and larger motors being bolt-in replacements for the U20.

 

Thoughts?

 

 

Introductory post about mine, followed by several others, including pics: http://cars.talkzilla.com/boards/read_msg.aspx?message_id=830

 

Hi Bytor, the U20 can be considered passing rare these days, and no, I don't believe the truck/forklift engine is the same, that one is a H20 OHV engine much like the R16. The hardest bits for the U20 are the timing sets, the 2 chains, gears and guides. I now have most of a new set, bloody expensive too it was and hopefully I'll get back into that direction next year. That's a nice looking roadster from the bits I can see not being squished by the shovel and tracks :blink:! The L motors have some fitment problems which I haven't fully investigated as yet, however, KA and SR motor swaps have become common place into the roadsters. With the LSD diff for it, I really haven't looked at much in terms of performance for her so I've no thoughts other than the Nissan LSD H190 which are expensive and rarish too and for which parts are now NLA. I'd consider a KA swap myself, but, I'm rebuilding my U20 first.

[shifty]

Bytor, I can't really tell what the VIN is from the picture. The dents do look suspicious. If the dash VIN and the firewall VIN are 1600 - that's probably what it is. Which grille is on he car?

 

Quick way to tell what year your car could be is the side markers and the taillight configuration. If you have rectangular side markers, it's probably a '70 and close to the end of the production run. The reflectors on the rear were also moved from above the taillights to inboard of the bottom taillight on the '70 cars.

 

You should check out http://www.311s.org - lots of info, tech wiki and discussion board - all about roadsters!

[ppeters914]

...no, I don't believe the truck/forklift engine is the same, that one is a H20 OHV engine much like the R16. .

Just want to clarify the H20 is a pushrod motor -NOT- OHC like the U20, L-series, etc.

[dimedriver]

This guy runs in my autocross group. http://www.steve510.com/coppermine/displayimage.php?album=181&pos=86 He claims close to the 200hp. I have not seen his dyno sheet, but he runs leaded 110 octane gas and its one of the fastest cars in the run group. He also has the Detroit locker. I think the head work was done by Rebello. The U20's can build plenty of power. I would get the head built up before doing a SR or KA swap.

 

-Dime

[murderwagon]

oh, still dont sound to bad, l20b is rated at 96hp

my 70 51 wagon with a l16 in it is rated at 96hp how is the l20 rated the same?