# Nissan BlueBird T12 1.6L - twin carb setup



## Mafarrico (Dec 21, 2020)

Hello,
I'm the happy owner of an 1989 Nissan BlueBird T12 1.6L. I would like to improve a little bit the BHP output ... What would you suggest, regarding carb improvements ?

Thanks,

Nuno


----------



## rogoman (Dec 16, 2004)

Hopefully this link may be of some help for your quest:


Setting up and adjusting SU/Hitachi carbs on the Datsun Roadster


----------



## Mafarrico (Dec 21, 2020)

rogoman said:


> Hopefully this link may be of some help for your quest:
> 
> 
> Setting up and adjusting SU/Hitachi carbs on the Datsun Roadster


Thanks, Rogoman! what about replacing the original cabr with an dual barrel carb ? any experience with this kind of set up?


----------



## rogoman (Dec 16, 2004)

Mafarrico said:


> Thanks, Rogoman! what about replacing the original cabr with an dual barrel carb ? any experience with this kind of set up?


Naw, can't help you there. My experience goes back in time to Holley carbs that I used to build/tune for Detroit iron. Today it's fuel injection.


----------



## Mafarrico (Dec 21, 2020)

rogoman said:


> Naw, can't help you there. My experience goes back in time to Holley carbs that I used to build/tune for Detroit iron. Today it's fuel injection.


Ok, thanks!  I'll keep digging and try to sort this out.


----------



## smj999smj (Jan 1, 2006)

One thing that always works on Nissan engines for a little more power is to advance the ignition timing 3-5 degrees over the factory spec; if it starts to ping, back off a little. As far as the carb, some people go with Webers, but the Hitachi carbs are actually pretty good. You could experiment with drilling out the main fuel jets a little.


----------



## rogoman (Dec 16, 2004)

One nice thing about the holley carbs that I used to work on is that the metering blocks had screw-in main jets, screw-in power valves, screw-in air bleeders and even screw-in idle air bleeders. The floats were adjustable with a screw on top of the fuel bowls and a cap screw on the side that can be removed to watch the fuel level when adjusting it. You could even adjust the pumpers for the squirters. So they were so easy to tune. I used to go to junk yards and pick up holley carbs of various CFM ratings, clean them up and build good functional carbs.


----------



## smj999smj (Jan 1, 2006)

Rogoman...that carb might be a little much for his 1.6L!  But, seriously, though....the problem with a Holley is that you'll probably have a hard time adapting it to the intake manifold. One would have a much better chance getting a Weber kit to fit it, if one insisted on getting rid of the stock Hitachi carb. The other thing is that unless we are going to be doing a lot more work, especially in the camshaft department, swapping to a different or larger carb probably isn't going to do to much and may actually hinder performance. Too big of a carb and the engine will bog down on you. Nissan engineers were pretty good at engines back in those days, as well as matching them up to transmissions, gear ratios, etc. Don't expect to do a little to get a lot of performance increase out of a GA16 engine. Go one size up on the main jets, if you wish, tweak the ignition timing, use premium gas and call it a day, IMO, leaving the rest of your money in your wallet.


----------



## rogoman (Dec 16, 2004)

smj999smj said:


> Rogoman...that carb might be a little much for his 1.6L!  But, seriously, though....the problem with a Holley is that you'll probably have a hard time adapting it to the intake manifold. One would have a much better chance getting a Weber kit to fit it, if one insisted on getting rid of the stock Hitachi carb. The other thing is that unless we are going to be doing a lot more work, especially in the camshaft department, swapping to a different or larger carb probably isn't going to do to much and may actually hinder performance. Too big of a carb and the engine will bog down on you. Nissan engineers were pretty good at engines back in those days, as well as matching them up to transmissions, gear ratios, etc. Don't expect to do a little to get a lot of performance increase out of a GA16 engine. Go one size up on the main jets, if you wish, tweak the ignition timing, use premium gas and call it a day, IMO, leaving the rest of your money in your wallet.


I think you misunderstood. I was just comparing the Holley to the Weber for ease of tuning. No suggestion for the OP to use a Holley, LOL. Just some idle talk to pass the time away.


----------



## smj999smj (Jan 1, 2006)

rogoman said:


> I think you misunderstood. I was just comparing the Holley to the Weber for ease of tuning. No suggestion for the OP to use a Holley, LOL. Just some idle talk to pass the time away.


I know....I was just picturing that big, 4-barrel bolt to his GA16!


----------



## Mafarrico (Dec 21, 2020)

Hi, thanks for the advices ! I guess we will start with the ignition timing and size up the main jets ...  ... any kit available (for the main jets) or we need to drilled it ?


----------



## smj999smj (Jan 1, 2006)

I would just drill them unless you can find jets for it. One used to be able to get different size jets from Nissan years ago, but that was a long time ago and I don't know if that's still the case?


----------



## Mafarrico (Dec 21, 2020)

smj999smj said:


> I would just drill them unless you can find jets for it. One used to be able to get different size jets from Nissan years ago, but that was a long time ago and I don't know if that's still the case?


I found this site : "160 - CARBURETOR for Bluebird T12 Nissan Bluebird - Auto parts"
With a lot of parts for nissan ... I believe drilling it is the way to go ...  ... the original carb needs some maintenance, will use this maintenance to check the jets and do some work on the main jet. Will keep trying to check if we can find a twin barrel carb that fits the T72 16L.


----------

