koleson Posted January 24, 2012 Report Share Posted January 24, 2012 I have dual su carbs and need and intake for a l20 for them Link to comment
ggzilla Posted January 25, 2012 Report Share Posted January 25, 2012 Datsun didn't make one, but won't the factory twin-carb L18 or L16 manifold fit the L20B? Or do you need that for an L20 (six-cylinder)? The 240Z setup will fit. Link to comment
Ratty260z Posted January 25, 2012 Report Share Posted January 25, 2012 The roadster 2000 dual SU intake manifold will work. You have to shorten the width off it slightly but it works. My buddy is running it on his L20b with the roadster carbs. Link to comment
merlin Posted January 25, 2012 Report Share Posted January 25, 2012 78 620... yes the SSS l16 or L18 SU mani will be fine... make sure you get the linkage.. i think you can still get them new from Nissan. been a few listed on here recently too. Link to comment
Sealik Posted January 25, 2012 Report Share Posted January 25, 2012 The roadster 2000 dual SU intake manifold will work. You have to shorten the width off it slightly but it works. My buddy is running it on his L20b with the roadster carbs. Just like an L6 mani...(sort of)...which is a little more common and sacrificial...so to speak 78 620... yes the SSS l16 or L18 SU mani will be fine... make sure you get the linkage.. i think you can still get them new from Nissan. been a few listed on here recently too. I'm not sure that linkage is still available....? Nissanparts.cc lists them.....but so are their lash pads etc... most are now MIA Delivered...is...was...about 40+ bucks...? Other than the linkage kit I have....I've seen none on Ratsun...just a couple of individual parts listed Link to comment
Jesse C. Posted January 26, 2012 Report Share Posted January 26, 2012 My friend Miguel has a K14 Big Port SU manifold that will work on the L20B. He wants $125 shipped. PM if interested. Link to comment
ggzilla Posted January 26, 2012 Report Share Posted January 26, 2012 Say Hi to Miguel for me. He sold me a GX twin carb setup. Link to comment
Jesse C. Posted January 27, 2012 Report Share Posted January 27, 2012 Say Hi to Miguel for me. He sold me a GX twin carb setup. I sure will! Link to comment
Ratty260z Posted January 27, 2012 Report Share Posted January 27, 2012 Here is a picture of the U20 intake on a L20b, You can see right about where the linkage ends on the manifold is where the PO welded it back together, Other then that he didn't modifiy it anymore then that, atleast that I can tell, He did have to grind offset "valley's" around the coolant holes in the intake because they have different spacing then on the Head of the L20b, (w58 on this particular car) But you could easily just plug the holes in the head and intake and not worry about it. The Previous owner was a Co-Owner of a Datsun shop back in the 80's and did a lot of work with Roadsters, Hence the Roadster 5 speed and the U20 intake and SU's. The ports in the U20 intake were also quite larger then the ports of the W58 head if I remember correctly, but with some porting it turned out fine, Or if you feel like it you could just weld up the U20 intake to make the ports smaller so less grinding on the head can be done, this L20b is pretty built though, Its got a old school norris cam, balanced to 6500rpm, overbored, head shaved, exhaust liners removed by the previous owner :( not the greatest left the radius pretty ragged around the valve but the motor revs to 7000rpm no problem and is pretty quick. Link to comment
Sealik Posted January 27, 2012 Report Share Posted January 27, 2012 Here is a picture of the U20 intake on a L20b, You can see right about where the linkage ends on the manifold is where the PO welded it back together, Other then that he didn't modifiy it anymore then that, atleast that I can tell, He did have to grind offset "valley's" around the coolant holes in the intake because they have different spacing then on the Head of the L20b, (w58 on this particular car) But you could easily just plug the holes in the head and intake and not worry about it. The Previous owner was a Co-Owner of a Datsun shop back in the 80's and did a lot of work with Roadsters, Hence the Roadster 5 speed and the U20 intake and SU's. I see he's 'flipped' the SUs...no doubt to fab up the new linkage???? Link to comment
Ratty260z Posted January 27, 2012 Report Share Posted January 27, 2012 I see he's 'flipped' the carbs...no doubt to fab up the new linkage???? Yeah I've noticed that as well, I think the reason he did it was to keep it cleaner for the Fuel line, since either way will work but having the float bowls right next to eachother makes it possible to run 1 hose to the float bowls. He may have swapped the throttle shafts and varying parts as well but I'm not 100% sure on that but it wouldn't be too difficult I just had the carbs apart as I was replacing the bushings for my buddy. Forgot to mention he used the U20 heat shield as well, cut down to fit the manifold, this way he can keep the throttle return springs and give it a cleaner look. Link to comment
Sealik Posted January 27, 2012 Report Share Posted January 27, 2012 Yeah I've noticed that as well, I think the reason he did it was to keep it cleaner for the Fuel line, since either way will work but having the float bowls right next to eachother makes it possible to run 1 hose to the float bowls. He may have swapped the throttle shafts and varying parts as well but I'm not 100% sure on that but it wouldn't be too difficult I just had the carbs apart as I was replacing the bushings for my buddy. Forgot to mention he used the U20 heat shield as well, cut down to fit the manifold, this way he can keep the throttle return springs and give it a cleaner look. Fuel lines would just need a tee..?.........nothing to invasive of course...aesthetics and all :P Bushings......which ones? Size of the intake ports? Link to comment
Ratty260z Posted January 27, 2012 Report Share Posted January 27, 2012 Fuel lines would just need a tee..?.........nothing to invasive of course...aesthetics and all :P Bushings......which ones? Size of the intake ports? I believe the Carbs are either 42mm or 46mm I can't remember for sure, We just went to ace hardware got some 3/8 bushings IIRC and we drilled out the throttle bodies pressed in the brass bushings, had to slightly drill out the bushings to get the throttle shafts to fit through and about $15 later, no more leaky throttle shafts, It would be easier on Z carbs because the Roadster carbs have really weird throttle shafts because Datsun was cheap back in the day but other wise it made a world of difference the car starts up very easy every time even when cold. Now that I think about the carbs should be 46mm since Roadster carbs were basically left over Series 1 240z carbs, just slightly different. They do run a little rich but that could be because of the cam, it lopes pretty good at about 1200rpm. Link to comment
Sealik Posted January 27, 2012 Report Share Posted January 27, 2012 I'd say 46s.........I meant the intake/head port size of the U20 IM........not the SUs themselves 38MM...give or take? Should do a 'how to' on those throttle shaft bearings......... Link to comment
Ratty260z Posted January 27, 2012 Report Share Posted January 27, 2012 I'd say 46s.........I meant the intake/head port size of the U20 IM........not the SUs themselves 38MM...give or take? Should do a 'how to' on those throttle shaft bearings......... I'm not sure on the U20 intake size, You could probably ask a Roadster guy, I forgot to measure it when I had the intake off a while ago. Maybe I will do a write up when I need to do them on my 260z. Link to comment
Sealik Posted January 27, 2012 Report Share Posted January 27, 2012 My friend Miguel has a K14 Big Port SU manifold that will work on the L20B. He wants $125 shipped. PM if interested. I'm not sure on the U20 intake size, You could probably ask a Roadster guy, I forgot to measure it when I had the intake off a while ago. Maybe I will do a write up when I need to do them on my 260z. Write ups are good.... :D Here is the big port K14....slight buff to get it to 38mm Link to comment
Ratty260z Posted January 27, 2012 Report Share Posted January 27, 2012 Write ups are good.... :D Here is the big port K14....slight buff to get it to 38mm The port on the intake on the right looks pretty close just by eyeballing it and from memory. Link to comment
ggzilla Posted January 27, 2012 Report Share Posted January 27, 2012 2000 Roadster used Hitachi HJG46W -- 46mm bore size. They came out 2 years years before the 240Z. 240Z used the same series carbs for 3 years after they stopped making roadsters. 260Z uses a different carb, the HBM46W. The 38mm Hitachis (1.5") are technically too small for a high-output 2-liter. Link to comment
Jesse C. Posted January 27, 2012 Report Share Posted January 27, 2012 $125 shipped. K14 SU intake manifold Link to comment
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