1979 510 l20b weber install

[damninhell]

I just got a deal on a downdraft weber, the guy said it's ready to drop into a Z, but instead I want to fit it into my 79 510. I need some step by step guide on how to fit this.

I know i need an adapter plate:

http://www.ebay.com/itm/Weber-Carb-Adapter-Linkage-kit-Datsun-Nissan-LUV-/251125467234?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a783e8862&vxp=mtr

but do i need the linkage kit?

 

keep in mind that this is my first carb that i'm installing.

 

[laotsu]

You can use the linkage off your stock carb, but you are probablly gonna need an intake adapter.

[datsunaholic]

You're going to need an intake adapter, a choke cable, and an air cleaner at a minimum if all you have is what's pictured.  Linkage can come off your existing carb, but you will find that adding a spring may be necessary.  I've never liked the feel of the stock Weber springs, they don't return to idle worth a damn.

[LenRobertson]

I think there are probably adapter plate kits on eBay without the linkage for much less money. Maybe they are available from some online parts source, but I don't know where.

 

It looks like this Weber is a manual choke version, so you will need to get a choke cable kit too.

 

I don't know if you got an air cleaner with the carb. If not and you don't want to buy the little rectangular air cleaner kit (more $$$), there is a post somewhere here on Ratsun on modding your stock air cleaner to fit the 32/36.

 

We'd love to see pics of your 510 too!

 

Len

[datzenmike]

If ready for a Z... car? 240Z? They had dual downdraft carbs (not in north America) so won't the jets be set for half a 6 cylinder.... about a 1,200cc motor?

[ggzilla]

Naw, carburetors don't work that way.

 

The jets are sized for the venturis. Which are fixed on a Weber DGV 32/36 at 26/27. All engines run good at between 12:1 and 14:1 air/fuel ratio.

 

Fine tuning with a non-emissions carb means slight adjustments for air flow (what Mike is hinting at), small changes in the main jets, and especially the emulsion tubes and different accelerator pump jets. Or bigger changes for long-duration cams. When you start lean burning (over 14.7:1) then the jetting becomes very tuned to individual engines, but that mostly applies to emissions carburetors.

 

So as long as the carb is liberally jetted for a stock-type engine in the first place, you can run it on various displacements as-is. But if you go from a wild 240Z engine to a stock 240Z engine then the carb won't run quite right. Or, from stock L14 to stock L20B one jetting *can* work on both, but if the jetting is on the lean side it probably won't work correctly in the other engine.

 

The good news is that Weber DGV is tuneable and can be jetted to work well on 1.2 liter to 4 liter engines.

[damninhell]

took off my egr housing.... fckn co2 nightmare

[damninhell]

I ask the guy who sold me the carb and he said :

 

i asked our carb expert and he said all jetting was left alone as it originally came from the factory. unfortunately, he doesn't know what those specifics are as in jet numbers, etc. if you can find that info for the carb when it was new then you'll know what it has now. fyi, it was first used in a redline conversion kit designed to replace the s/u carbs the 240s and 260s came with if that helps

[Rays74]

The smog legality question must be addressed too.........will the carb pass the evil eye of the visual test, and will the engine pass the sniffer test with it? Weber's have a rep for being initially jetted on the "fat" side which won't help........

The SP (Smog Police) are not friendly in these So Cal parts 

[LenRobertson]

The smog legality question must be addressed too.........will the carb pass the evil eye of the visual test, and will the engine pass the sniffer test with it? Weber's have a rep for being initially jetted on the "fat" side which won't help........

The SP (Smog Police) are not friendly in these So Cal parts 

I'm curious if hacking a stock air cleaner to fit on top of a Weber helps in getting through smog testing (that is if it is jetted lean enough). Or are the inspectors wise to that trick? I remember being in LA many years ago when the air was so bad during an inversion it literally made your eyes burn, so I understand the need for pollution controls on cars. I wonder how many young people living there realize how bad it used to be. Or maybe it still gets bad in LA. I sure can't think of any reason for going back to check! But it doesn't upset me that I live where I don't have to deal with the inspection process. I don't even know how the regs in the WA State counties that do test apply to Datsuns - anything before a certain year exempt, or does the year keep moving forward? Luckily it isn't practical to set up testing in all the rural counties with populations of 10,000 or so. Some good things about living in a hick county.

 

Len

[ggzilla]

Thank goodness not everywhere in So Cal requires smog testing. If it does, then that Weber won't be allowed.

[damninhell]

I Piece together the car again and i have a exhaust leak coming from in between the headers outlet and the tail pipe. I know I am missing a "donut" but the guys at every auto parts store keep showing me the wrong gasket. Does any one know the part number for the flange donut that looks like this

Is there some kind of alternative that i can use?

[ggzilla]

That is not a header gasket.

[ggzilla]

It is exhaust pipe gasket, not a normal maintenance item.

 

The exhaust pipe fits up into the exhaust manifold, and the pipe has a compressable steel ring that seals it. NAPA sells the aftermarket style as in your photo.

[damninhell]

Can you get me a part number or better yet a link, I just check there site and came up empty

[damninhell]

i was reading one of my manuals and found this:

 

Step 12 Disconnect ExhaustManifold to Pipe Flange Exhaust
Hanger
oL 20B and Z seriesPeople Only L 16 and 18 go onto next
step Jack up the driver s left side of the vehicle Ch 13 Pt I
Proc I Raise only the front left wheel a little offof the ground then
support that side well Take a drop light underneath with you
Lie underthe engine compartment looking upat the bottom of
the exhaust manifold find the flange where the manifold and exhaust
pipe meet Three nuts on studs hold them together tight enough to
prevent leakage Newer nuts are madeofbrass or stainless steel that
inhibit rust Squirt some penetniting oil on the nuts and threads Use
a14mmL series or I7nun Z series socket on as many extensions
as you have and maybe a universal swivel joint to reach the nuts and
remove themall Ifany nuts are hard to turn off use more penetrating
oil and wait Ifa stud breaks off in the manifold keep going its a
drag to fix but easier with the head off Bag and label the nuts exhaust manifoldltlange
Now pull down on the exhaust pipe Make sure the flange clamp isn t bound Ifthe pipe won t drop away
from the manifold follow it back to one ortwo bracket hanger s that connect s to the frame or crossmember
Use the necessaiy wrenches and sockets 12mm or l4mm and penetrating oil to release the pipe

maybe i have a leak some where else ine the manifold?

[damninhell]

tried it again, it's still leaks at the same spot, im gonna call it quits and take it to a muffler shop unless someone else has some input.

[ggzilla]

Go down to your local NAPA store and they will fix you up with the manifold-to-pipe gasket.

[damninhell]

got the datsun running, with the new weber carb but this thing will not tune properly, I can't get lower then 1800 rpm without this thing trying to turn off on me. this guy said it sounds like an air leak, but he could have be referring to that damn exhaust leak i still have. I'll post up some pictures of my installation maybe you guys can spot a mistake

[Tristin]

You can check for air leaks yourself. You can do a couple different things. With the car running:

 

1. Fill up a spray bottle with some very soapy water and spray it around the base of the carb... anywhere theres a seal and such. If you see the spray making bubbles, then you know air is leaking from that area. 

 

2. If you have a mini blow torch, turn the propane on, but do not ignite it, then run the torch tip in all the mating surfaces and such. If your engine bogs down and wants to stall, then you have a leak in that location. 

[damninhell]

hhhmmm, i just found and old thread Where GGzilla said:

 

Stock Datsun specs for fast idle are in excess of 2000 RPM. So it won't hurt anything to "run fast". I like to set it at 1600 RPM only so that it is quieter.

so, i'm thinking i don't have a problem, but I will try those pointers anyway tristin

 

here's the link to the quote http://community.ratsun.net/topic/16680-hitachi-carb-high-idle/

 

[datsunaholic]

fast Idle is for when it's cold.  Once it's warmed up it should be below 900 RPM.  It still sounds a lot like a vacuum leak, but it could also be the idle jet isn't working and you're having to idle it on the main jets.  This is that manual choke one?  It won't go into idle unless the choke is fully open.  If it's a used carb the idle jets tend to plug up from old gas sitting in them.

[damninhell]

it's a rebuilt carb and the choke is fully open, imma check for leaks today after work.