R1 Carbs, Smog Clean Up

[frank88]

Hi Guys,

 

I've just bought a set of R1 4XV '98 carbs so I can start removing some unnecessary crap from my engine bay.

Can I get rid of the bits labelled in my pic below? What actually is A to C!? I'm assuming D is carbon canister?

I don't need to run a cat or any emissions anything over here because it's a historic vehicle so i don't need to worry about that.

 

 

 

Cheers,

Frank

[Crashtd420]

Well you may want to keep A....

Isn't that the coil?

[frank88]

Haha well this is exactly the sort of info I need. I'm used to much more modern engines!

[Crashtd420]

https://www.carpartsmanual.com/

 

Keep this website handy, it will help... plus you can use the part numbers to crossreference factory nissan parts....

Most may not be available but when web searching it will point you in the right direction.....

[frank88]

7 minutes ago, Crashtd420 said:

https://www.carpartsmanual.com/

 

 

Thanks, what a great website! I have got a haynes manual too so will start looking through that as i go

[datzenmike]

Keep D. It's benign in operation. While it collects gas fumes when the engine is off, and sends them into the intake to burn when running, it has zero effect on engine performance. Removal will just cause gas smells.

 

B & C are the air supply and control for the 'smog pump' mounted just below the distributor. All it does is inject oxygen rich air into the hot exhaust flow in the exhaust manifold to help burn off any unburned fuel. You can tear it all out, pump and all, just make sure that no hoses to the intake are left uncapped or it won't start and run. The metal pipes on the exhaust manifold can be cut off short and using a socket, unscrewed and pulled out. You're in GB so you should easily find 4 metric pipe plugs to neatly fill the holes and make it not only unnoticeable, but neat.

 

You don't show it, but you also have an exhaust gas recirculation EGR system but because it has it's own manifold bolted to the intake AND the PCV valve (something that vitally should be kept in operation) it will require a bit more work to remove and do it right.

 

Forget the last I guess you are replacing the intake with one from Bogg Brothers????

[frank88]

Thanks Mike. Yes I am. Just need to work out the details in terms of what nipples I want on the boggbros intake

[datzenmike]

You'll need a vacuum supply for the brake booster but I recently learned that there are electric vacuum pumps on some Volvo models and other makes. This would solve this nicely. I haven't figured out what to do about the vacuum advance for the distributor yet, which I think is vital.

 

I'm working on my own manifold (don't laugh, I learned a lot what not to do) ....

[banzai510(hainz)]

A along with the ballast resisitors are surely needed!!!!!!!!!!!!!

[620slodat]

45 minutes ago, datzenmike said:

You'll need a vacuum supply for the brake booster but I recently learned that there are electric vacuum pumps on some Volvo models and other makes. This would solve this nicely. I haven't figured out what to do about the vacuum advance for the distributor yet, which I think is vital.

 

I'm working on my own manifold (don't laugh, I learned a lot what not to do) ....

 

A slight sidetrack here. Datzenmike, you mentioned vacuum pumps that certain Volvos have. Can you tell us what models and years have them? OK, sidetrack off.

[datzenmike]

 

[frank88]

2 hours ago, datzenmike said:

You'll need a vacuum supply for the brake booster but I recently learned that there are electric vacuum pumps on some Volvo models and other makes. This would solve this nicely. I haven't figured out what to do about the vacuum advance for the distributor yet, which I think is vital.

 

Yea I am pretty sure I'm going to use an electric vac pump. From the builds I've read about in the R1 thread, most people don't bother with vac advance and if so then I don't want ugly nipples there for no reason. Maybe there is space underneath instead?

[datzenmike]

You don't need vacuum advance if running full throttle. But for everything else (lower cylinder filling) the engine craves more advance. Less fuel and air takes longer to burn so the spark needs to be advanced. Running without it you are basically running it retarded (compared to what it really needs) and fuel is wasted out the exhaust pipe. Having the correct advance at partial throttle improves your engines ability to pull you along at cruise speeds and improves over all mileage.

 

In the far past vacuum advance was run off the intake vacuum which is a perfect indicator of engine load but in the 60s this was changed to ported vacuum signal from above the throttle plate. This gives no advance at idle but as the throttle opens, exposes the port to intake vacuum from below. The problem is the distributors were also modified to work with this system and switching to manifold vacuum will result in excess advance. Reducing the initial advance to correct this will reduce over all top advance. Basically the distributor must be re-curved.

[G-Duax]

The problem with using one of the electric vacuum pump, is how do you activate it when the engine needs it ?

Throttle switch ?

Doubt it, because vacuum advance is not dependent on just throttle position.

In Japan, people like SK Sanyo, and HKS use a small vacuum manifold, that a small hose from each runner connects to, then one hose to the distributor.

You don't need large 1/4" fittings & hose, or even 1/8" fittings.

Any industrial pneumatics supply sells 10-32 threaded fittings, that will use the same small hose that is on the distributor.

The 10-32 ports can be inconspicuously drilled & tapped into each runner, since the threads on the fittings are only about 1/8" long.

The same industrial suppliers carry small multi-ported 'logs' like a fuel log, just smaller, with the same 10-32 threads.

So you would need 9 of these small hose barb 10-32 fittings, a manifold, or log, and a few feet of small hose, and you will have a true engine vacuum control of your advance.

 

A small 10/32 hose barb (this one for 1/16" hose:

 

These are also made in 5mm thread size, if you want to keep your Datsun all metric.

 

The Japanese have been doing this for decades........

[frank88]

Thanks for the info, really helpful. I think boggbros will put nipples on the runners for free when I get the manifold made but getting a small log and doing it that way sounds good. The electric vac pump is for the brake booster.

[datzenmike]

The vacuum pump would never be used for the ignition advance, just the brakes.

 

Intake vacuum would be the best as it rises and falls with load or throttle input. I just have to make it compatible with the distributor. I heard the same.... individual vacuum lines to some sort of collector manifold and then to the vacuum advance on the distributor. Rather than welding in bungs I'm going to drill directly into the port near the head and thread it to take cheap ready made brake lines.

 

[frank88]

I've just read this on the retrorides forum where the guy has put tubes where the old water lines (i think) were then simply linked straight to distributor. Claims it works fine but then people claim not running them is fine, as it running from one tube so it's hard to know what works best. I think collector manifold will work fine, but I do like the simplicity of the photos below:

 

 

 

[datzenmike]

My water line is higher up under the black domes. comes in on the far left and out a larger hole on the right.

 

 Does it link all the carbs through those center black holes?

 

[frank88]

Yea they are daisy chained across all 4. Mine should arrive on Wednesday so I'll check mine.

 

I'm not sure what the markings are on the carbs but I know from 98-99 The R1 was the 4XV model and from 99-01 it was the 5JJ model over here but no one seems to know if the carbs themselves are different

[datzenmike]

Mine has a 3 wire throttle position sensor.

[2000subaru]

What is Boggbrothers asking for a manifold?  I have admired their work, just haven't been in a place to ask about pricing yet.

 

[datzenmike]

https://www.reddit.com/r/Datsun/comments/v1vbf/just_received_my_manifold_from_bogg_brothers_to/

 

For '72 510 6 years ago shipped about 450 US

 

June 14 '12. $100 was shipping

Got my manifold from Bogg Bros this morning and it is absolutely gorgeous. If you guys are wondering what your $400 gets you, check out my crappy pictures.

 

 

 

 

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[frank88]

6 hours ago, 2000subaru said:

What is Boggbrothers asking for a manifold?  I have admired their work, just haven't been in a place to ask about pricing yet.

 

 

I emailed them in September and the price is £190+vat so £228 gbp. plus whatever carriage is.

 

Should work out cheap for you guys at the moment? There was a news article the other day which said somewhere was trading £1 to $1 which is mad for us.