School me on carbs

[Hooligan]

Need some info......

 

Current setup - L20B, W58 head, Schneider 270-80F cam, Schneider retainers and valve springs, Matchbox, (5 speed coming soon). Right now it is currently running a Weber 32/36. Carb runs... just want a change, little more on the performance end of things.

 

Had bought - 220 intake with a pair of SUs. Gave up... SU's are a hodge podge of parts. Missing linkage, incorrect linkage, etc etc

 

Now... I am looking at buying new considering I don't want the truck down forever while I mess with a carb that I know nothing about. I had thoughts on a Weber DCOE. I have read that running a single DCOE causes cylinder 1 and 4 to run lean due to runner length. Now I may be wrong here.... but I am not sure I can run dual DCOEs and clear the booster setup in a 79' 620. 

 

What are some good options here? I have no desire to send the SUs to ZTherapy (just want to make that clear before its said). Looking to get away from those all together

[jvb5577]

I would try the 38/38 weber.  A lot of people like it.

[Hooligan]

I thought about that carb as well.....

[datzenmike]

The 38/38 is a six cylinder carb. It will work, but will only be at it's best when revved way up with lots of air going through it. You will enjoy a good 32/36 more.

[exit64]

OK, let's look at this from a different perspective.  What is the purpose of getting away from the 32/36?  You want performance and reliability, go to the next size up on the Weber, 38/38 I think.  You want cool factor, any of the dual carb set ups will achieve that.  You want simple and reliable, SU's all the way.  Get a set from Ztherapy and be done with it.  Yes I read your post.  Coming from the Roadster side of things, I can tell you for a fact that the ZT carbs are worth every penny.  Between that and a matchbox dizzy it solves 95% of the drama.  There are a ton of roadster guys up in your area that would more than likely help you get your set up sorted out.  I went down the DCOE road at one point and gave up on them.  Hard to get real dialed in.  Mikuni's seem to work better once they are set up correctly but are on the upper end of the dollar scale.  There is a guy in Portland that is the guru for those but it's hard to get on his build list.  His carbs work perfect when they are finished though.

Lots of choices but it all comes down to how much fiddling around you want to do.

[jvb5577]

The only thing I didn't like about the 32/36 is for power your foot had to be to the floor..  Other than that there was nothing wrong with it.  

[Hooligan]

OK, my 32/36 is working... not that greatest, needs a rebuild, but is very usable. I really thought about the ZTherapy route. They are a little on the pricey side but I am sure well worth it. The reason I looked the other way was the PO of my SUs mounted a pair of 4 bolt flange carbs on a 2 bolt manifold. When they did this they cut off the upper inside mounting hole on both carbs for linkage clearance. With those cut, not being able to use them for a trade in... now I have to add the core on the price which makes the that much more. 

 

I like the looks of the DCOE but with clearance issues I believe I would have, I am not sure how much of a fuel starvation issue I would have on the outer cylinders running just one.

[Hooligan]

Not having good cores puts the ZTherapy carbs at $780

[ggzilla]

Your 32/36 was tuned incorrectly. They will idle, cruise and exxsellerate very well on a 2-liter. In fact 32/36 is slightly smaller than stock L2OB Carb. 32/36 is usually an improvement over a worn-out stock carb.

 

For a high perf 2-liter,1-1/2 inch SUs are a bit small. For 7000 rpm use, move up 46mm Hitachis from the 240Z tuned appropriately.

[metalmonkey47]

For the record, 38/38 is NOT ENOUGH for a high revving 4. I run out of power around 5800. Just not enough air flows through those little barrels. 

 

 

Z car SU's would be amazing. 

[DAT510]

Coming from the guy with a LZ23, Id consider SUs as well.

I've got a LZ22 and the 32/36 was awesome for day to day driving. You're not gonna road race every day, so why get a racing carb?

I love how the 32/36 is progressive. meaning the first 32mm barrel gets used for 90% of driving, only at WOT does the 36mm barrel get used. Great on gas.

There are synchronous linkages for the 32/36 btw.

I wonder if you would retro fit a progressive linkage on a 38/38 

[MicroMachinery]

On my LZ22, I ran so lean with a 32/36 that it wasn't even funny. I had no power until I threw some 38mm side drafts on.

[hobbes_the_cat]

Pretty sure truck guys can run twin sidedrafts as long as you get the short manifold. I think mikuni makes the short mani.

I love my twin webers, I think they're pretty easy to work on. Not good on gas tho.

[EricJB]

What manifold are you running the 32/36 on? If stock, is the adapter just bolted on, or did you carve out a plenum and blend it all together? 

 

Cannon made a high rise intake that had nothing to do with performance. It was the manifold you got when you bought dual DCOE's for a 521/620. I ran one on my 521 for a long time, but never tried it on anything with power brakes. No clearance problems.

 

The only experience I have with SU's are the ones on my 411sss. Not feeling the love for those. They are OK, but remind me of The old Solex Kadrons we used to run on bugs. Simple and primitive. If I could find an intake for it, I would put DCOE's on it in a heartbeat.

 

Once you run DCOE's you will never want to go back. My .02

[jovial_cynic]

I had 38mm SUs on my LZ2.1.  They ran great, but they did run out of breath in the upper range.  I considered going bigger, but then problem w/ the bigger carbs is that you lose a bit of the bottom end power.  

 

I think the only way to take advantage of the whole power band is via EFI.  

[hang_510]

  You want simple and reliable, SU's all the way.  Get a set from Ztherapy and be done with it.

I can tell you for a fact that the ZT carbs are worth every penny. 

 

I went down the DCOE road at one point and gave up on them.  Hard to get real dialed in.  Mikuni's seem to work better once they are set up correctly but are on the upper end of the dollar scale.

 

ZT - SU masters

 

 

LOL i went with dual DCOE webers over mikunis (had both)... because jets were easier to get

havent tweeked on em for almost 2 years.

 

can get almost 25mpg (Canby this year)

[hang_510]

Need some info......

 

I have read that running a single DCOE causes cylinder 1 and 4 to run lean due to runner length.

a Lynx manifold $olves the i$$ue

[Ratty260z]

Bike carbs (yamaha R1 carbs), best bang for your buck when it comes to individual carbs easy enough to tune, make good power, cheap and the sound... oh the sound.

[exit64]

ZT - SU masters

 

 

LOL i went with dual DCOE webers over mikunis (had both)... because jets were easier to get

havent tweeked on em for almost 2 years.

 

can get almost 25mpg (Canby this year)

Dan Garrison in Ptown is the Mikuni man.  Once he does his magic, same thing.  Set it and forget it.  I just picked up a 411 with so much extra bling it would make your head spin.  Custom SS exhaust manifold, 44mm Mikuni's NOS, Solex air filter NOS and a super unobtainium Nissmo R16 intake.  I will be posting up some pics of the build in that section soon as the temp climbs out of the single digits. And just to keep this thread on track, here is a little CL time sink for Hooligan to investigate.

http://seattle.craigslist.org/est/pts/4240152937.html

[jvb5577]

While this subject is up I would like to know if there is any good having a manifold like this one without a balance tube?

 

[banzai510(hainz)]

jvb I have this manifold at home. I never tried it but I dont like it.

I like the single pair as one removoves them its still all set up and linkage dont have to be fucked with

Get a 1 pc type DCOE or PHH type manifold.

 

Buy SUs  ar ea working unit or forget it. I think most are worn out junk

 

 

Hooigan I say get a 38/38and just call it good. Its simple and bolts right o the carb adapter. done live with it. otherwise go PHH or DCOEs

[Hooligan]

The SUs that are listed on Craigsist is tempting.... just worried about getting into another "needs rebuild" ordeal. Running a DCOE I would just buy new that way there was no worries about that

[EricJB]

When I bought $950.00 48DCOE's for my truck, the float on one was bent and way too low. And they can t ever jet them for your application. So don't assume "new" means ready to run. But it will mean they don't need rebuilt.