Weber jets??All who live for their triples please read this

[T-Bone028]

Thanks Leon, I'll check out Zedyone's post.  

 

AZGhost...I do have an AFR gauge hooked up, but I have yet to set it up for data logging (need to buy DB9 cable and USB adaptor).  I'll have to find some open road and try flooring it from 1300-1500 RPM in 4th or 5th gear to try and look at the AFR's at that initial RPM range.

 

I have F16 E-tubes sitting on the bench to compare to the F-11's I currently have installed.  I'm actually waiting on 36mm chokes, 145 mains, and 195 airs to be delivered this week so I have a lot of work/tuning this weekend.

Edited June 11, 2013 by T-Bone028

[AZGhost623]

F16's no good on these cars. I would stay away from them and just keep trying out your F11's

[duragg]

F16's no good on these cars. I would stay away from them and just keep trying out your F11's

Ha

Explain...  Did you try them F16s?

Darn F16s weren't even worth sharing a 6-pack to change out...

Edited June 12, 2013 by duragg

[steve260z]

Thanks Leon, I'll check out Zedyone's post.  

 

AZGhost...I do have an AFR gauge hooked up, but I have yet to set it up for data logging (need to buy DB9 cable and USB adaptor).  I'll have to find some open road and try flooring it from 1300-1500 RPM in 4th or 5th gear to try and look at the AFR's at that initial RPM range.

 

I have F16 E-tubes sitting on the bench to compare to the F-11's I currently have installed.  I'm actually waiting on 36mm chokes, 145 mains, and 195 airs to be delivered this week so I have a lot of work/tuning this weekend.

Let us know how those 195s do....I'm currently running the 160s. Need to purchase the wideband. Maybe stupid question but here goes....Since I don't have welding unit is it possible that JB Welding the sensor bung would work??? Too much heat? If not I can get it welding in. Just a (dumb) thought.

[Lazeum]

FYI, I'm not using a bung on my car since I don't need to track afr all the time. I use an exhaust clamp, it works well.

http://www.innovatemotorsports.com/resources/news3.php

 

 

The clamp is not so good at idle but I set it up with rpm, not afr (some do it differently though) 

[T-Bone028]

Received the 36mm chokes and additional jets I ordered today, and installed them.  Ended up trying the F16 e-tubes I had, along with 145 mains, 185 air.  Started her up and noticed that the change from 33's gave me a slightly leaner idle, which was good, because I was previously around 11.8 - 12 AFR's at idle, and with the 36mm's I was at about 12.8-13 AFR at idle.  I made no changes to my idle jet or idle mixture screw.  Cruising idle AFR was better as well.  

 

From 1st gear and stomping the throttle, bog was clearly present and she bucked like crazy and then took off.  I noticed I no longer had wheelspin in 1st or 2nd, but the car did accelerate marginally quicker through the rev range.  Couple of runs to reproduce the bog, and I was able to see I was registering completely lean on the AFR gauge at initial WOT.  AFR from 2500 - 7000 was right in the 12.2 - 12.8 range.  Which was good.

 

Brought her back into the garage, and switched the F16's out and put in F11 e-tubes, along with putting in 135 mains, and 170 airs because I didnt feel like wrestling to pull out the 145 mains/185 airs in the F16's.  Took her back out and did the same tests...at initial and sudden WOT, the bog was still there but not nearly as dramatic as previously.  AFR's were in the 13.3 - 14 range.  Wheelspin was back in 1st and 2nd gear, and acceleration was very good.

 

As it sits in the garage:

 

40 dcoe

36 mm chokes

135 mains

170 airs

F11 etubes

45 pump nozzle

55 exhaust/bleed back

 

Tomorrow, I'm going to change to:

 

145 mains

185 airs

"0" exhaust/bleed back

 

Hopefully those tweaks will richen the AFR's a bit, and give a little more juice for the initial pump shot.  Overall, the change from 33 to 36mm chokes is positive.  Feels like faster acceleration through the rev range, and in my experience, it felt dramatically quicker 5500-7000 RPM.  At this point, I would say I havent lost anything by switching to the 36's, and streetability at low RPM's and partial throttle is still good.  The 36's definitely brought back the bog that I had previously tuned out, but I'm hoping with some more tuning, I can improve the initial WOT response further and get a little more power with a slightly richer AFR.

 

I'll give a deeper review after I make some more jetting changes.  Cheers!

[steve260z]

Great. Did you think the car drove smoother and rev'd more freely with the 36s?. I have the same bog under 2,500rpm WOT.

That was the result on my 3.1L.

One jetting difference is I'm running 160 air correctors. Think I should be running something like 185s? 

 

Here http://joltfreak.tripod.com/id28.html

 

It suggest main jet + 50 for air corrector size. I'm running 145 mains so air corrector would be in the 195 range.

steve

[T-Bone028]

I actually purchased a 195 air corrector, but didn't try them out yet. From what I had noticed previously when I followed the main +50 rule, I would go slightly lean in the upper rpms. My config was happy with main +40. hence the 145 main / 185 airs I'll be trying first. I'll report back soon.

[T-Bone028]

Aside from having a MAJOR problem with my Float pivot pin arm breaking off, today was a step in the right direction.  When I initially starting rebuilding my carbs, one of the float pivot pin support arms broke off.  I was naive to think JB weld could fix it, but after taking the cover off this afternoon to install "0" pump jet exhaust/spill valves, I saw that the JB weld was peeling off and was ready to fail any day.  It now looks like this (not my pic but you get the idea): 

 

 

That was a major downer, especially since I just made all the jetting changes I wanted to try.  Here's what I changed today in bold:

 

36 mm chokes

4.5 aux venturi

145 main (from 135)

170 air

F11 etube

40 or 45 pump jet (cant remember)

55F9 idle

"0" exhaust/spill valve

 

I quietly cried to myself about the float pivot arm for a while, went back down to the garage and said F**K it and took her out anyways (minus 1 full pivot arm).

 

Upon sudden WOT from a standing start, hesitation/bog was still there but DRAMATICALLY reduced.  Wheelspin was apparent and more like a burn-out once I got out of the .25 second bog hole.  Yesterday, with the 55 exhaust/spill valve, the bog lasted for about half a second.  I think with a larger pump jet (I'm thinking about 55 or 60) I'll be able to make the bog at sudden WOT all but imperceptible. 

 

AFR's at WOT were a little too rich with the 145 mains and were in the mid 11's in the middle RPM range, and about 12.2-12.4 at 6-7K RPM. I think I can live with it though until I pick up 140 mains to test.  

 

I'm now happy to say I'm very satisfied with making the change from 33's to 36 mm chokes.  Very drivable at low speeds with AFR's in the high 12's low 13's, and as long as I dont slam the throttle open it runs just fine at low speed and cruising.  I think after I buy larger pump jets, I'll be done for a while.

 

BTW, does anyone have a spare DCOE carb top they want to sell me?

[AZGhost623]

So duragg took my Z for a spin today after the local datsun meet up this morning for breakfast, and he has certified it as been a good setup So ill stop worrying about my setup now and focusing on other things now.

 

DCOE 45 / 152 36 choke 145 main 180 air 70F9 Idle F3 Tube 00 Pump Bleeds 55 Pump Jet

 

Edited June 17, 2013 by AZGhost623

[steve260z]

Aside from having a MAJOR problem with my Float pivot pin arm breaking off, today was a step in the right direction.  When I initially starting rebuilding my carbs, one of the float pivot pin support arms broke off.  I was naive to think JB weld could fix it, but after taking the cover off this afternoon to install "0" pump jet exhaust/spill valves, I saw that the JB weld was peeling off and was ready to fail any day.  It now looks like this (not my pic but you get the idea): 

 

brokentopcover.jpg

 

That was a major downer, especially since I just made all the jetting changes I wanted to try.  Here's what I changed today in bold:

 

36 mm chokes

4.5 aux venturi

145 main (from 135)

170 air

F11 etube

40 or 45 pump jet (cant remember)

55F9 idle

"0" exhaust/spill valve

 

I quietly cried to myself about the float pivot arm for a while, went back down to the garage and said F**K it and took her out anyways (minus 1 full pivot arm).

 

Upon sudden WOT from a standing start, hesitation/bog was still there but DRAMATICALLY reduced.  Wheelspin was apparent and more like a burn-out once I got out of the .25 second bog hole.  Yesterday, with the 55 exhaust/spill valve, the bog lasted for about half a second.  I think with a larger pump jet (I'm thinking about 55 or 60) I'll be able to make the bog at sudden WOT all but imperceptible. 

 

AFR's at WOT were a little too rich with the 145 mains and were in the mid 11's in the middle RPM range, and about 12.2-12.4 at 6-7K RPM. I think I can live with it though until I pick up 140 mains to test.  

 

I'm now happy to say I'm very satisfied with making the change from 33's to 36 mm chokes.  Very drivable at low speeds with AFR's in the high 12's low 13's, and as long as I dont slam the throttle open it runs just fine at low speed and cruising.  I think after I buy larger pump jets, I'll be done for a while.

 

BTW, does anyone have a spare DCOE carb top they want to sell me?

Holy crap. I broke mine today too!!

I was looking at all the weber retailers and didn't see any replacement tops. They gotta sell them...No way we need to buy another carb. What timing are you running? Initial and full?

steve

[T-Bone028]

AZghost, that's awesome, I think I'm running well, but don't have another triple Weber Z to compare it to.  Its nice that you and duragg seem geographically very close to each other.

Steve, you can buy a replacement top from piercemanifolds, but its for either a 151 or 152 with platstic floats.  Part number 31734.198, $98.00.  Interesting enough Pierce lists the same carb top part number for both the 40 151 and the 45 152...I would call pierce to just to verify what you are getting before you were to order.  I cant recall if you ever listed your 40 DCOE model. I have a 40 dcoe 2, so I'm looking for anything that originally used brass floats. Most tops should be interchangeable, but it would be great if I could find a used 40 dcoe 2 for cheap so everything could match.

I actually "fixed" the issue today by using a nail instead of the pivot pin. I cut and filed a nail down to replace the pivot pin, and made it like an interference fit that went into the remaining good float arm pin hole. The other end where the split arm broke off is where the nail head is. It's actually a very tight clearance between where the stock pivot pin sits within the carb body, so if my "new" pin were to move the nail head would help limit movement by pressing itself against the carb body.  The float rotates smoothly along the pin/nail and feels secure so I'm happy for now.  Took her out for a long spirited drive and everything felt normal.   I need to run to the hardware store to pick up a brass nail and redo it though.  Just used a regular nail for my very professional R/D.   The pivot pin doesn't see any real load (just vibration), so I'm hoping it will be ok while I continue to hunt for a top. 

From a timing standpoint, I'm at 13 degrees at idle, which should be 31-32 total.  Still need a helper to determine where I am timing wise at full advance. I'm using a maxima dizzy with E81-20 module and msd 6a, vacuum advance is disconnected.  Keep in mind I'm running a 3.7 LSD...not sure what your rearend gearing is but maybe shorter gearing might help "liven" her up.

I'll try to take pics soon of my float arm/pin "fix".

Edited June 16, 2013 by T-Bone028

[steve260z]

Good idea. I can see that....Yes, I have 18s with brass floats as well.

(I JB'd mine..Ha!)

 

See how long that lasts. I expect seeing the broken off piece laying in the fuel bowl soon.

steve

[steve260z]

Btw, how the hell do I use this?

Am I suppose to open up the diaphragm to allow more air through?

Obviously, if I place it over the air horn the motor dies...The only air traveling through 

is from the tiny hole.

 

Thanks

steve 

Edited June 16, 2013 by steve260z

[Leon]

Btw, how the hell do I use this?

Am I suppose to open up the diaphragm to allow more air through?

Obviously, if I place it over the air horn the motor dies...The only air traveling through 

is from the tiny hole.

 

Thanks

steve 

 

Steve, buy a real flowmeter, the Unisyn is junk (as you can see). I gave my last one away. Get an STE SK syncrometer and it will make your life a lot easier.

[Dat260]

Not to Highjack this informative thread. Steve260z if you want I have an extra one. PM me if interested.

[duragg]

I broke a pivot arm once too

Dared a machinist / welder friend to fix it and he did.

 

SK snail gauge is required equipment for triples

[AZGhost623]

So its been about of week of tearing up the roads out here, and decided to go through everything just to make sure everything looked ok. Turns out, Im having some weird sync issues with the SK snail gauge. Carbs 1-4 is right at 5 on the gauge. Cylinders 5 and 6 are at 10. What would cause it to be a 10 on the snail gauge? I dont think a vacuum leak because that would make the reading less rather than more. ?

 

Anyone have some ideas on what I should check? Yes the bleed screws are turned all the way in.

[duragg]

So its been about of week of tearing up the roads out here, and decided to go through everything just to make sure everything looked ok. Turns out, Im having some weird sync issues with the SK snail gauge. Carbs 1-4 is right at 5 on the gauge. Cylinders 5 and 6 are at 10. What would cause it to be a 10 on the snail gauge? I dont think a vacuum leak because that would make the reading less rather than more. ?

 

Anyone have some ideas on what I should check? Yes the bleed screws are turned all the way in.

They move all the time.

Reset linkage to even all out. This is a very regular check and adjustment.

 

It is imperative that the throttle pedal meet a firm STEEL stop in the floor before the linkage maxes out under the hood.

Also that big spring could be bending stuff.

[T-Bone028]

I would also check linkage.  Perhaps the linkage arm for the rear carb slipped on the linkage rod?