Datsun Roadster Forum-311s.org

I can't remember the name of the show, but its on Discovery Channel? 2 Teams got to modify 2 240z's for a drag race with the winning team getting both cars.

During the flashback sequence they cut in old footage of the Z's racing and right behind the were a couple of Roadsters. Had to be about 1970 or 1971. Even mentioned the BRE team.

Cool stuff.

I watched the first part of the show (Full Throttle) when it was on a week or so ago. I didn't like the brothers when they were on that one show before, and I still don't like them.

Anyway, they said that the L24 was descended from the 1600 cc engine in the roadster. Ha! Maybe the U20, but I doubt very much an overhead cammer is related very closely to a pushrod engine.

Be that as it may, since I have no interest in drag racing, I didn't watch the rest of the show. <snort>

p.s. Drag racing is for fast cars. Autocross is for fast drivers.

The U20 is indeed a descendant of the R16 and the G15. If you read Phil Brook's book, you will get the scoop.

The L24 is a decendant of the L16 engine that was in the original 510's.

Lou Smaldino
66-2600
67-2000
65-1500

The L24, L26, L28, came from the L20B, 18, 16, all of wich came from the U20 that was developed from the R16 (the reason so many of the parts are interchangeable between the two.) In effect all the 510s, Zs and later Nissan sports cars owe their exsistance to the roadster.

Will

Unless I am mistaken, the L series motors were not descendents of the G,R,U, and H motors. They were a fresh design.

Sid,
Essentially you are right. However they took much of what they learned with the U20 and improved upon it in some ways, took steps back in others. There is a book out that is called How to Modify your Nissan OHC engine. It deals with the L series engines, however much of it is already done on the U20. The head design especially. The shapes of the ports are already for the most part what the book recomends to machine the L series to. The combustion chambers are close to what they recomend as well. The bottom end is a heavier duty version (U20) of the L series as well. They did away with the jackshaft (formerly the cam on the R series) and simplified the timing chain setup. So yes it is a new design, but they took lots of notes from the U20. Besides, it was the first Nissan OHC engine, and for a long time it was the most powerfull engine Nissan had. (L24 was 150, L26 was a little less, and the DOHC of the KGP10 Skyline was 150 as well. If I'm off please correct me.)

Will

Will

From what I have heard/seen/been lied to about...

The L16 was a simplified version of the dual overhead cam engine that was licensed (or was it simply copied) from Lotus (possibly some other, but something like that).

Then, of course the L24, and all other following L's are a tweak of the L16.

To say that the L series is a derivation of the U20 is a bit silly as they were launched in the same model year. OK, 67.5 versus 68 but to think that something learned from a U20 made it into a full scale production launch a half year later...Of course the same designers were at work on both engines, so there are similarities, but the OHC and jackshaft engines really are different.

I bet spriso (or a friend of) knows the real history...TR

TR,
I hadn't heard that before. You learn something new all the time. I could see the Lotus connection. Good trivia.

Will

i went and saw the incredables last night there was one in the high way


steve

I owned a 260z for a while. The hp ratings slung about are incorrect. The L24 in the 240z was rated 150hp (SAE), the L26 in the 260z 162hp (SAE), and the 280z a bit higher than that. The flattop carbs were horrible, but the 260z was not rated lower than the 240z.

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At some point the ratings went from SAE to NET, but I believe that was after the 280Z. The 74.5 260Z I had (280z style heavier body) said 162hp on the VIN plate. I don't have the car or pictures to prove it, but I'm pretty sure (and a quick perusal through Google found a few - but not many - sites that agree) the 260z was stamped 162hp and the 280z was stamped 170hp.

After finding a LOT of sites that say the 260z was rated lower than the 240z, I finally found what I was looking for - a 260z ID plate. This is (almost) what mine looked like.

http://www.classiczcars.com/photopost/s ... photo=5303

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Yeah, it's possible that mine was a non-US model or what they called a "Federal" model. I'm not sure what the differences were to bump the horsepower. I know the VIN plate I linked to is a RHD 2+2, whereas I had a LHD 2-seater (RLS30). Mine also had 240z carbs, a 5-speed transmission, and a header, but all were added by a previous owner.