Hey guys,

Just after a bit if help regarding reliability and driveability of the DCOE carburetors.

I currently have a stock L20b in a datsun 1600.

It is fitted with a set of DCOE 42 webers. Due to having no history on the carbs I would assume a rebuild would be in order.
Not only that but I also would need a linkage kit and they don't have filter assembly's so looking at 4x Ram tubes + Socks or ram flo's etc...

The costs of getting the dcoe's in order again will outweigh the cost of buying a BRAND NEW 32/36 weber.

This car will be driven every other day so I really want something fairly reliable and even reasonable on petrol.

So my question is, which would be the better option. Ive never owned a vehicle with side drafts so im not sure on how good they might be!

Thanks for your time.

What carb is running on the engine at the moment?

What future upgrades are you planning on?

If no future upgrades are in order I'd stick with the carb you have if it's running ok.

Basically just putting a 32/36 or twin sidedrafts will gain you virtually nothing(I'm sure there will be a gain if you to a run on a dyno before and after, but the seat of the pants feel will yield nothing. So don't expect a huge power increase) on a stock engine.

I would go twin dcoes myself, just because I love them. They look and sound great. But you would want to set them up properly with a centre pull linkage system.

_________________
When the sign says "don't feed the bears", man you better not feed the bears.

Car came with the DCOE's and manifold. I have recently purchased a new motor as the 1600 came as a roller.

I have Redline manifold, 2 dcoe 42 webers that were jetted for the l20b aswell as the linkages that are on the carbs only.

This is what I have here.


Currently motor is a standard L20b with Electronic dizzy, headers and exhaust. Ive got another block that im wanting to rebuild and spend some dollars on!

After looking at this picture again I think it already has made my mind up. Air rams and socks come at me!

Yes, get those trumpets and socks. Also a pressure regulator and electric fuel pump. A rotary pump is better than a pulse pump if your carbies are prone to flooding, and Webbers only need very low fuel pressure.
Move the coil a bit too in case the socks ever get soaked with fuel.

My last L series 1600 had an L20b with 32/36 downdraft carb. Didn't have the induction noise of a twin 45's but went just as well if not better, had better throttle response out of and in corners.

Also if you are after filters, give unifilter.com.au a call, they are datsun owners and still produce everything in Australia.

I run twin 40mm dcoe webers on my bluebird. Its got a l20b and is fairly standard.
Its my daily driver and although I love the sound, look, and feel of the twin webers as a daily driver the fuel economy sucks ! I can virtually watch my guage go down as I plant my foot.
I just bought a 32\36 downdraft to put on to ease the fuel bill but I just can't bring myself around to put it on.
Twin webers for me!...... At the moment anyway.

As far as reliability and drivability id normally recommend the 32/36 as it will be more reliable as its simpler in construction and will never go out of sync like a dual carb setup etc.
They can also come with chokes that work well and can be good on fuel if you use the primary butterfly only for economy.
You would still need to get a standard accel linkage, std inlet manifold, carb adaptor plate and a (low height?) air filter for it tho.
If your twin webers are already tuned (jetted and choked) to suit your L20B motor and u have linkages etc, id just use those.
They will have more room for improvement down the track.
P.s. if your not chasing every little bit of HP, to save some bucks consider leaving the rams off and just mounting two K&N/Redline oval filters...

A 32/36 works great, but you'll need a manifold, adaptor plate, air filter assembly and (most expensive) tuning.

Since your DCOEs are already jetted for your engine it makes tuning much easier, quicker and that means cheaper.
Cheapest way to get ram tubes is to ask an exhaust shop to flare some steel tubing to suit. Each one will need a little mounting tab. Put on some UniFilter socks and that's done.
Your carby linkages don't look complete. You can buy the bits bits you need easily enough, but the cost adds up quickly. If you're in Melbourne PM me and I'll see what I still have that you can use. You'll also need a throttle cable. Easy way is to cut the top off a cable type pedal arm (I used 120Y) and weld it on to your pedal arm. Then find a cable that's the right length, make a bracket and install it. I used a Patrol cable but there are plenty that can be made to work.
I ran a stock fuel pump for years with no problem- many others have too, as long as the carby float levels are correct. If you install an electric fuel pump wire in an LPG Safety Switch so that the pump can't keep on running with the engine stopped (like in an crash).
You won't be able to use the vacuum advance on your distributor with your DCOEs. It'll run without it but ideal is to get your distributor recurved to suit. This helps part throttle response and economy.
Speaking of economy, properly tuned DCOEs shouldn't be excessively thirsty. Of course, that depends how you drive.... and they do sound awesome....
You'll also need some form of oil catch can for the crank case ventillation hoses (middle of the rocker cover and middle of the block under the exhaust). You can buy 'em but really you want a volume of about 2 litres, ideally mounted so any oil can drain back into the block and with a breather cap on top. I've always made mine- it's not brain surgery.

Cheers!

Adapter plates are very cheap and you can use the existing manifold (well in the case of a 200B anyway). In my experience 32/36s are great, can be economical if your driving style allows that. I'd recommend that if you're after economy.

_________________
green200b - aka Alistair

The fleet:

Australia:
'80 200B GX - the green200b - hibernating
'81 RX-7 - 12A extend port - daily
'74 RX-2 - 13B bridgeport - cruiser

Europe:
'93 200SX - CA18DET - tourer

32/36 is out the window. Purchased a set of stacks last night. Need to sus out what linkages I need and order a couple of rebuild kits!

Fuel economy wise, its got to be better than my Skyline so that's a win!

Although I would never claim twin side draught as economical, they are very reliant on your foot for any economy.

I have 2 cars with sidedrafts Mikunis and there can be daily drivers. Key is HOT days heating the intake manifold at stop lights.
other wise they are great.
The 32/36 is a great daily driver carb and I would run the water line to the head also but most people that run sidedrafts plug the hole in the head if they were the heated stop type manifold. Going to a 32/36 youll say Damn Im going backwards.

a lot of people say dual need rebuilding but one on my yell car has been on there for 30years. just cl the jets so they don't back out and or the floats get stick(Tap the case till it fills back up)

my daily is 521 pick up so I don't put a lot of wear and tear on the sidedrafts now. maybe a 38/38DGES down drafts could be another option