240z su's on a l18??

[jonesy510]

so a friend of mine is given me a set of stock 240z su's for free and also a mani that i can use to bolt the su's onto my l18 and i was wondering would this b to much carb for my motor if i got them re-jetted?? the l18 has a peanut head flat top pistons and also a cam out of and l20.. i was thinking maybe with a bigger cam i would b able to use them?? or should i just not bother running them..

[datzenmike]

I think it's a great idea. The SU is a constant velocity carb and will only open up as much as the engine can handle. You will need to monkey with the needles and jet sizes. I think Jason on here has SUs in his car see what size he is running as a base start.

[jonesy510]

well i have seen some people runnin 45's on webers and mikunis so i thought mayb that would b a good start.. as for the cam shud i try to find a bigger cam or run the l20 cam thats in it.

 

"i know nothing about cam specs or duration or anything of that so any help would b greatly appreciated"

 

datzenmike idk jason or jason name on ratsun so cud u give it to me so i could shoot him a pm??

[zerow]

I have toyed with the idea for my L20B, but I still think that's a lot of Air/Fuel for a 4 cylinder.

 

Here is some good reading that supports my opinion: http://www.jetlink.net/~okayfine/su/zsus.html

 

Not saying it won't work, but I still think it's a lot for the 'Little L'.

[jonesy510]

ya thats wat i was thinking but hey sense i got them for free i figured i should try it out thanx for the link i will have to check that out when i get back from work

[Jason]

The L16 and L18 SSS's from Japan ran a 38mm SU. The 46mm SU's on a stockish L18 should work fine, a little rich, but, you could lean them out if need be. I run my 38mm's dry on long, hard pulls on my L20b with a Shadbolt 445 cam.

 

No jets in these guys, just one big honking needle up the middle and as Mike says, constant velocity. The 38's that I run are OK for milage and give decent torque at low to mid range revs, but, crap out at higher revs if it's sustained for any great duration. The 46's should help with that part though ... Try it out and let me know. I've got a pair of 46's waiting on my manifold to be machined for my new LZ22. (Thanks Mike!)

[jonesy510]

thanx jason!! il try it out i think they gotta b rebuilt first haha

[jonesy510]

so i put the su's on my car but i have to run a throttle cables so i can use them. im plannin to go to the jyard to c if i wat i can come up with for cables. anybody have any pointers of wat i need to b able to pull this off?? is there a different direction that i should go with running these su's?

[benzo]

try contacting steve epperly at Z therapy as he does or knows of this mod. I personally think and have a strong feeling the Z su's in your current motor state will be too much carburetor. If you had a bigger displacement motor I would use them.

[DISLEXICDIME]

z su's work on 2.0 and above

[hughdogz]

I second talking to Steve.

 

I'm no SU expert, but it may be possible to use needles and jet nozzles off a roadster, or other 4-cyl L motor in the Z SU's

[jonesy510]

alright well i will try them out how they r now an c wat happnes

[jonesy510]

so this past weekend i put the su's on and tried to think of a way to link them by shortening the linkage that came on the manifold but ran into problems with that idea ... i was wondering if anybody else has any ideas on how i can have the su's open together??

 

i was thinking of just welding a tab to connect the to su's so the open simultaneously but do i need to b able to have adjustment between the two carbs???

[Pacific coast Datsun]

Jonesy- ill go down & take a pic of how my throttle cable loks on my 620. Im running flat top SU's as well.

[Pacific coast Datsun]

Ok here ya go. I used a part [painted aqua] off some roadster carbs i have. had to cut apart & weld back together but it works. The black bracket i made & bolts to the exhaust manifold & then used another piece to keep the black bracket from flexing. True Ratsun low tech. crafsmanship at work :D

[jonesy510]

thanx pacific ill try to run my throttle cable that way but i forgot to mention that i have the round top su's an they open the opposite way.. :( but i can use still some of the ideas u should me. and u know the lil piece that the aqua thing is linked to... the one with the balls at each side of it?? i had to shoten mine and its still to long to connect the two su's... can i just wel a peice of metal right there to connect them??

[Pacific coast Datsun]

Ill bet you can just run the cable from the oposite side & get results. & do what i do...stare at the part till you figure out what will work..:D

[jonesy510]

haha ok..i think i have an idea for the throttle cable that will work. just not the point were the two carbs connect.. well connected and still have adjustment..