L18 / L24 SU's interchangeable?

[72dat]

I've come across some cheap SU carbs from an L24 and was wondering what it would take to put them on my L18? Any tips or advice?

[Skib]

there differant, Iv seen them made to work tho.

 

if there flat tops dont bother, there paper weights

[benzo]

they are different as the 510 used 38mm su's and the Z used 46mm su's. you should contact steve epperly at Z therapy as he is supposed to be god when it comes to SU's. would the Z su's run a l18 sure but probably not good unless the motor has some mods that warrant using a big intake system

[72dat]

ok thanks. The L18 isnt built yet but its going into my 1200 so it'll have some good muscle anyway.

[jonesy510]

im running the round top z SU's on my l18 and i enjoy them. some things to remember :

 

the 38mm su's open up a different way then the 46mm z SU's. wat i mean by this is if the opening for the air to enter is facing u, the z SU's levers twist towards the front of the SU "away from the intake manifold" but the 38mm turn the opposite way "towards the intake manifold"

 

 

The round top z SU's also sit closer together on the intake then the 38mm SU's. so u have to find a way to link both SU's together so they open simultaneously but are able to be adjusted separately.

 

an then u have to figure out a way to connect the SU's to ur pedal but thats easy because vatozone "autozone" carries a universal throttle cable kit just have to grind down a small portion of the pedal ill take pix later today of my setup so u can have some visuals and... and everyone loves pictures :) haha

[zerow]

im running the round top z SU's on my l18 and i enjoy them. some things to remember :

 

the 38mm su's open up a different way then the 46mm z SU's. wat i mean by this is if the opening for the air to enter is facing u, the z SU's levers twist towards the front of the SU "away from the intake manifold" but the 38mm turn the opposite way "towards the intake manifold"

 

 

The round top z SU's also sit closer together on the intake then the 38mm SU's. so u have to find a way to link both SU's together so they open simultaneously but are able to be adjusted separately.

 

an then u have to figure out a way to connect the SU's to ur pedal but thats easy because vatozone "autozone" carries a universal throttle cable kit just have to grind down a small portion of the pedal ill take pix later today of my setup so u can have some visuals and... and everyone loves pictures :) haha

 

You are correct, and one other piece of trivia: The 46mm Z Car carbs have four bolts instead of the two on a 38mm 4 cylinder L-Series manifold for mounting to the manifold. You will need new phenolic spacers between the carb and the manifold to be "hogged out" to allow for a good transition between the carbs and the intake. Otherwise, you will not get the full potential of the 46mm carbs. Many writeups on it, I would like to try it one day, but until then I love my 38mm carbs.

 

Here's some more reading for you: http://www.jetlink.net/~okayfine/su/zsus.html

 

Good Luck. I've seen them run, a little harder to adjust for a 4 banger, but if you're building for fast, why not go for it?

[jonesy510]

haha thanks zerow i forgot to mention the 4 bolt and two bolt thing... im just using the four bolt spacers because i couldnt bore out the two bolt spacers do u think im losing a lot of performance?? i couldnt find any write-ups so i just kinda tried stuff out... but then again i didnt look to hard cause i really wanted to use the SU's i got. i mean i traded a cannon intake and i got 2 46mm SU's that are in damn good shape, the intake thats really clean and even the linkage stuff i ended up shortening too so i was a happy camper :D. im kinda thinking of playing with the needle size and all that stuff but i heard there is 200 some odd different combinations that may work but maybe later down the road. oo i forgot to take pictures when i was in the garage... ill go do that now for u

[jonesy510]

ok so here are some pix of my set up...

 

 

 

two round top 46 mm Su's umm im runnin a throttle cable cause to me it was the easiest way. to link them to the pedal.. i had to bend some metal and drill a hole in it so the cable would be pulled straight to open the SU's and it just bolts to the SU's place for the air cleaner... i wanna run trumpets so i gotta do some adjusting so i can put them on..

 

 

 

i welded the tab to one of the SU's and as the tab is pulled it opens up both SU's u can also c the linkage i shortened a lot in order to connect the SU's together. its the the linkage used for the Z's i just basically cut out the entire middle section and welded it together. i also had to add a small piece of metal to the right side of the linkage so i could have a lil bit more adjustment between the two SU's

 

 

here is just another pic just incase u want a different view of things... the heat shield to me looked out of place to me for some reason so i found a big spring attached it to the opposite SU and one of the brake lines that run to the back of the car..

[zerow]

im just using the four bolt spacers because i couldnt bore out the two bolt spacers do u think im losing a lot of performance??

You're not losing performance at the spacers, if you're running the 46mm spacers. I can imagine the vacuum leak/ lean condition that you are going to inevitably encounter at the manifold side of the spacer down the road as the gasket slowly withers away because the mating surfaces are different shapes. Did you hog out the manifold? I would take material from something easier to work with (the phenolic material)versus the metal of the manifold. You will transition from the 46mm-ish at the carb down to the 38mm of the intake within the 13mm +/- of the spacer material. Taking it from the manifold can be done, but you will never run 38mm carbs on it again.

[jonesy510]

well i cant run 38mm anymore really anyways and i never had plans to run them in the beginning actually i was gunna run mikuni side drafts but i got all this stuff for free pretty much so i cant complain :)

[banzai510(hainz)]

Jonesy

 

You going to Plug that PCV valve or you have a hose to go to crankcase?

[jonesy510]

im gunna plug it i do believe the lil linkage gets in the way but i haven't really looked at running a hose to the crankcase

 

what would b better to run it to the crankcase or to just plug it?

[zerow]

im gunna plug it i do believe the lil linkage gets in the way but i haven't really looked at running a hose to the crankcase

 

what would b better to run it to the crankcase or to just plug it?

Run a hose to the crankcase. The engine likes it, and the manifold was designed to evenly distribute the gases for efficient burn.