R1 Carbs (lots of pics)

[DADZSUN]

My vote is for 3.

 

Your second set of pictures look about the same angle as mine and there has been zero issues. Being bike carbs they are used to operating at angles.

 

You can also consider shortening the runners (the last run that connects to the carbs). A shorter run will lower the carbs a bit and also move them more to the middle where the hood is a little taller.

 

PS: I noticed that you are running your rad pipe in a manner which I previously did, and what I now believe is incorrect (if your rad is sensitive to coolant direction of flow). Based on the Nissan diagram below the hot coolant exits from the intake manifold and therefore feeds the top of the rad (at least my rad seemed to prefer it that way). Also, if you run a thermostat you need to provide an intermediate pipe from the intake manifold to the internal/backside of the thermostat.

 

[VintageRice]

4. Download free CAD drawing program off the interwebs, spend night and day learning it and measuring a gasket with a micrometer on you computer desk, finally email the file to a guy with a C&C plasma torch setup(cheapest option for cutting) and get finished flange sent to you in the mail later that week for around $50!!

 

AKA..........What I did.  :D

[VintageRice]

ps, yes cutting all those angled pipes needed to make your runners 1.angle up, 2. angle in, and 3. go from round(r1 side) to oval(Ka side, well on my sohc anyway) a ll within like two inches of length

is a BEOACH.

 

 

So have fun!   :D

[Kirden]

I would shorten the runners as Dadzsun mentioned. According to Bogg Brother's you want to avoid any chance of pooling. This is what killed the idea of a draw-thru turbo for me. Especially for a daily driver, pooling can cause some real issues. Racing gives the fuel that pools time to evaporate, but running errands means more fuel pools and doesn't evaporate. One misfire and you end up blowing your manifold/carbs to shit. Ok, so that's worst case scenario, but that's what scared me away from it.

 

I understand using the cut stock manifold to save on a flange, but the angle is pretty horrible for placing runners on. If possible, I would find a new flange and shorten the runners moving the carbs in and giving more room for angle adjustment.

[Parkinglotslider521]

Got my carbs on. Idles at 15-16:1 afr's but as soon as I open the throttle my afr's go crazy, then lean. Carbs are synced perfectly. 1.6 mains, stock motor with header and baby cam. 12* base timing.

 

HELP.

[DADZSUN]

Got my carbs on. Idles at 15-16:1 afr's but as soon as I open the throttle my afr's go crazy, then lean. Carbs are synced perfectly. 1.6 mains, stock motor with header and baby cam. 12* base timing.

 

HELP.

 

Are you running a wideband O2 sensor?

 

Your post #1161 indicated you needed two more needles, did you swap all 4 so you're certain they're consistent?

 

Can you provide a little more info like:

• What RPM and speed (load) was on the car when you opened the throttle
• How much did you open the throttle
• Up to what RPM
• What kind of A/F number did you see (ie: what is 'crazy')

With that information its a little easy to figure out which circuit (pilots, main, or needles) is out of whack.

 

Here's a posting on another forum which explains quite a bit: http://www.turbosport.co.uk/showthread.php?t=103402&s=fd57c6cb37c6ad82e5ebeeccdef45ba7&p=1204751&viewfull=1#post1204751

[Parkinglotslider521]

Alright here it goes.

All the needles are stock. They are used but in perfect condition.

When cruising at any rpm and speed the motor runs smooth with around 14:1 air fuel ratios as long as I'm no more than 1/4 into the throttle. If I go to WOT at 2k it will build maybe 1500 rpm with low 13:1 afr's then at around 3700 suddenly go lean and bounce back and forth from 17 to 14.

And yes I have an AEM wideband.

[Parkinglotslider521]

Just noticed something. Carbs 2 and 3 have fuel slowly coming out of the needle jet at idle. 1&4 don't. Not sure if they need to have fuel coming out at idle, but it is currently idling between 14:1 and 16:1 @ 900rpm. If I lift the slides on 2 and 3 while idling the fuel stops and it goes lean. Any thoughts?

 

Edit: just sprayed starting fluid in 1 & 4. Revs smooth for a few seconds. Either the needles are sticking shut or the float bowls need readjustment. Best guess. Some more experienced thoughts would be awesome. Will I get a reply quicker if I post titties?

[Stupid_fast]

Parkinglotslider521,

 

I have similar problems with mine(L20b, mild race cam, headers, big valves).  What circlip setting are your needles at?

'stock motor'? ? L20b or ?

All four of mine pour fuel in at idle.  I don't know if its normal, just roll with it.  Idle should be solid and only have 0.1-0.3 afr deviation with a big cam.

You should have set your floats before you put the carbs in ... set to yamaha spec 6mm height. 

The wavering AFR kind of suggests either a passage is blocked or your needles are not the same. 


Main jet should be selected for high RPM 4000-6000rpm.   Main jet/ top end mix must be 1-2 steps from perfect BEFORE touching anything else or you will never get it tuned right.
Going lean at a certain RPM I think is due to the cam getting in its efficient range.  Mine leans out a ton right at 3k during initial tuning. 

Needles should be mid position or slightly raised to select main jet.  Aim for between 12:1 and 13:1 for N/A engine or however it pulls best.

http://factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,lower_rpm_engines.html
 

 

 

tip- Don't care about low end richness when selecting main jets.  your low RPM will just be rich.  Ignore it.  Set main jet for high RPM mixture 4000RPM to redline you can worry about low end LATER. 



Also, if you post tits I won't be able to view this at work. ;)
 

[Parkinglotslider521]

i have stock non adjustable needles. ill be coughing up the cash for adjustable needles soon, but for now shims will have to do.
stock l16. its running like poo. i do believe it is the float settings. hopefully ill get it adjusted right tomorrow. sounds like its running on 2 cylinders now, but i just got home from a 13 hour day so it will have to wait.

 

Edit: reset the floats. Revs way smoother. running a little lean at idle tho. ill update after i drive it. just went out to find a flat tire. 

 

Double edit: set all the floats at 6mm, and it runs beautifully except top end. from 5k up it starts to miss. ill get it figured out eventually. My biggest problem was the fact that one of the slides was different than the rest! it had one tiny hole and one large hole in the bottom, facing front to back instead of two big holes on either side of the needle. luckily i have a couple spares, so i swapped it out.

 

Oh, and for the record my carbs don't have any fuel coming out of the needle jets at idle.  

[Jester]

So The choices are:

 

1. Cut a hole in the hood and make a scoop. (hoods are getting harder to find!)

2. Buy a flange and start over. ($$$+time and I miss my dime!)

3. Try it with angled float bowls and possible fuel pooling. (Meh...)

4. ???

 

 

L series bell housing to tilt engine the other way. 

[VintageRice]

Took Speedy to the 1/8th mile for giggles.

 

[DADZSUN]

Does anyone have any spare carb parts? I was playing with needle adjustment when two of the slider's clips which hold needle's spring-loaded 'hat' broke.  I need a new complete slider assembly.

 

Also, any suggestions where to get the adjustable needles? I've got only 1 circlip location on my needle so I can only adjust via spacers.

[DADZSUN]

Your car sounds good Vintage - actually it sounds a lot like mine. You were pulling hard on that Civic in that one short clip.

[buzzy]

If using the RX1 carbs, are you able to take all the wiring off them? the 2 sets I have seen seem to have a lot of 2 wire plugs coming off each carb. But not sure if I can remove it or need to look for other carbs? They arnt injector plug just a random wire almost looks like a temp sensor in each carb?? as seen in the top of thecarbs in the pic below

 

[crewy]

After reading this forum it seems like everyone has about the same problem. My car is in WA with my kid with SU on them. I'll wait until it get to me in Cali before I start my R1 adventure. I already have a set and and will be making my own flange. I'm making 2sets cuz I also have a KA as well. I have a feeling ill be on here more then I used to be following these setup. But I do have a question thou. Why isn't there a water runner thru these carbs like we have on our stock carb manifolds. Just a question. As far as vacuum. I think I'm gonna do what that other guy did and tap into all of the tubes. It looks like most of the R1 carbs are from yrs 98/2001. Well until the next question pops up best wishes for the past guys and us future guys with the R1 set up. Oh ya DADZUN u still gave the KA intake

[Stupid_fast]

You can run water through these carbs.

 

Personally I live in California so its pointless the car never sees temperatures low enough to need it. 

[DADZSUN]

... Oh ya DADZUN u still gave the KA intake

 

I do still have the KA24e Bogg manifold for sale. I'm kind surprised no one has snagged it yet, I would have killed for one 18 months ago.

[crewy]

How much for the manifold DADZSUN and to possibly ship to WA. Let me know my KA is in Cali but my car is in WA with my kid working on it. Thanks Stupid_Fast. I was just wondering thats all and what about vacuum like most manifolds. Will probably start out with the L16 1st with the carbs and the later in time with the KA. What yr carbs are best to use off the bikes.

[Stupid_fast]

A quick search shows carbs only came on the 98-01 models.

[crewy]

So 02 and later are then throttle bodies

[Parkinglotslider521]

Just for the record: l16, possible mild cam, 11* base timing. I had to drill my jets out to 2.0mm's with the needles at stock positions, and stock main jets.

Now that its dialed in all I can say is ERMUHGERD she pulls hard (for a datto)

 

has anyone had any problems with fuel filler neck collapsing under vacuum? One of my couplers did. Bought the stuff from O'Reilly auto parts.

[DADZSUN]

Quick update with my setup.

 

About a month ago I played with the R1 needles to drop/lean out the cruising A/F and somehow managed to bust a couple of the plastic clips on #3 slider which holds the plug/spring/needle in place. The car idled fine but when I applied any load I could tell the car was missing a cylinder.

 

I've managed to source replacement sliders and the car is running well once again. I'm still 12.6 on the wide band during cruising with a little less spacers (only one clip on my needles so I have to play with the spacers), I'll wait until fall to see if the cooler air will lean her out. Otherwise, I'll try a smaller main jet for next year (24->22 I believe) because WOT initially sends the A/F to the 11 range until it pulls back to 12s.

 

I think there's still some potential to squeeze out of the KA24e. The idle is good (L series blue top electronic dizzy currently) but there's still a little miss - Megajolt is in the plans using the R1 TPS and running a custom ASP crank pulley with a provision for EDIS trigger wheel (how I'll fasten a steel ring to an aluminum pulley has yet to be determined). Best 0-60 time I've pulled is 7.2 seconds according to my Speedhut speedo GPS. I'm confident high 6's are possible but the upshift to 3rd is what's killing the 0-60 number. Otherwise, this car runs like a 0-60 mid 6 second machine. She pulls pretty hard from 3-5K but definitely runs out of breath approaching the 6K which is a little surprising considering the JWT cam and short R1 manifold runners and lack of cat.

 

Oil pressure has been high with my KA. I switch from 10w-30 dino to 5w-30 Mobile 1 synthetic and it's been better (80-85 psi at 3K when hot). 10w have a hard time getting under 90 unless I was idling. With synthetic my idle is just under 20psi. 

 

Mileage wise, the car is certainly more thirsty than the original L16 which was shocking good. I haven't done official numbers yet (approx mid 20MPG) as the engine is barely at 1000km and I'm still honking on the throttle plenty.

 

The Megajolt will be my last substantial investment for the foreseeable future as I've recently purchased a new companion for my 510, a '73 Celica. Plans are to make it the mellower cruiser with a 2/3RZ EFI swap, rack & pinion, power brakes, stereo etc... Basically it will be the anti-510.

[Stupid_fast]

Got some single taper #6 mikuni needles to try out. will report back with results.

[red13]

just found this forum and decided I probly going to run  a set r1 carbs.  however I need to get the intake made. I got a line on a few manufactures that might do it.  Just want to see if anybody had some dimensions for me and also if anybody would be interested to do maybe a group buy thanks.

One place i talked to said they could cut out the intake plates with material provided for $50 for the first and $25 for the second so anybody wants to do this or know someone that can do it cheaper let me know