Jump to content
HybridZ

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


datfreak

Recommended Posts

After some reading in the setup and jetting area i read that 45mm webers should never run less than a 34mm Venturi (choke) now im running a 32 as are a few ppl i know and weber recommend a 36mm. :shock:

Is anyone out there running a 36mm venturi in their 45 webers? If so whats the power delivery like' date=' any flat spots.[/quote']

 

I run 32 mm chokes in my 45 dcoe with very good results.

I have very good throtle response and good power from 3500 up.

Engine is a stock 280 block, unmodified N42 cly head, mid cam with a header and of course the webers.

I had the cars setup using 36 mm chokes, they are to big unless you have a high hp race engine.

With the 36 mm chokes, I had poor drivablity, no bottom end and not enough motor for the high rpm range.

Link to comment
Share on other sites

  • Replies 837
  • Created
  • Last Reply

Top Posters In This Topic

Hey guys' date='

 

was trolling round the net to pass some time and happened upon the weber site. After some reading in the setup and jetting area i read that 45mm webers should never run less than a 34mm Venturi (choke) now im running a 32 as are a few ppl i know and weber recommend a 36mm. :shock:

 

Is anyone out there running a 36mm venturi in their 45 webers? If so whats the power delivery like, any flat spots.

 

If not im keen to get this done along with planing my P90 to try and get compression into the 10s.

 

Thanks[/quote']

 

 

Me. No problems that I have noticed except I seem to run rich mostly and idle is poor under 1000 RPM. No dyno or A/F ratios to give you. Seat of the pants dyno says power is very good from 3.5K to 8.5K with flat top pistons and e31 head with something like a Schneider 17038 and like 10-11:1 compression on my track/autocross only car. Works good enough for me.

Link to comment
Share on other sites

  • 1 month later...

I wasn't aware the engine could hold up to those kinda rpms, are you balanced and blueprinted?

 

I also found a great site to get all the weber parts we need without havn' to deal with the TEP people of California.

 

http://www.PegasusAutoRacing.com

 

They even have a "new style" rebuild kit for the DCOE's which use rubber gaskets for those who want forced induction.

 

From the catalog I have they seem to have all the jets anyone would desire.

 

 

Still dont' know why this isn't a sticky.

 

-Ed

Link to comment
Share on other sites

  • 4 weeks later...
Guest Ricklandia

Newb here...

 

Getting back into the Z scene after 20 years away (had a 260Z years ago, stolen, trashed - a sad story). Got a line on a 240 and at this point I am debating to keep it stock, or just to have my fun. I've always been interested in triples (Weber, Mikuni) but wondering if they would be "street" practical on a stock L24 motor? Say what you will, but I'm not really that interested in high HP, more just the look and sound. I know I'll get flamed for that but there it is. Also, where would be a good place to look for a complete set? (manifold, carbs and linkages) Any URL's? Thanks!

Link to comment
Share on other sites

I wasn't aware the engine could hold up to those kinda rpms' date=' are you balanced and blueprinted?

 

-Ed[/quote']

 

No balancing and blueprinting. Nothing fancy here. You wouldn't believe what _wasn't_ done to this motor. Just rings, bearing and seals. I did pay the extra $20 for the ring set with a chrome top ring though. Other than that, the bottom end is pure stock 20 year old parts. Stock flat top pistons are relieved for plenty of valve clearance though and I run an itty bitty steel tilton flywheel.

Link to comment
Share on other sites

  • 3 weeks later...

New b check out MSA for package deals or buy from a hybrid member, you'll get much better service that way than deal with TEP in Cali.

 

Stick shocked you can run 8k on stock bottom end. I though the harmonic dampener was only good to like 7,500rpm.

 

wow... I'm not that brave yet.

Link to comment
Share on other sites

I am planning on using SK Racing, Weber Clones, with forced induction, around 12 PSI of boost from Eaton M62 Supercharge with intercooler.

 

I have checked to see what I have now.

tripple 45 MM Carbs

34 MM Venturi

Jets

Mains 135

Tube F11

Air 165

Idle 50

 

If I calculate using the area of the jets from increased air flow of

1.8 times more air @ 12 PSI of Boost

 

Mains 180

Tube F11

Air 155

Idle 65

 

I really feel that these are larger than I need. Any of you Weber experts please give me your input.

Link to comment
Share on other sites

  • 1 month later...

Thought I would post this up. Just finished running 3/8" SS hard lline for my fuel. I added a return line this time and SS valve to use as a regulator. Also plumbed up a fuel pressure gauge in the engine compartment with a bunch of AN fittings. I have it dialed in at about 3.5 psi right now. I also switched my idles to a 50F9 that helped hiccup on low end immensly. The car also is putting out alot more vaccumn gettn' about 27 on my gauge. Took it for a test drive and It can now be put in second gear and do 20mph with out violently lurging. Alos gained alot of low end torque.. I can let my clutch out without givn' it gas. Still awaiting my Mallory Dizzy... still on backorder till the 9th.

-Ed

Link to comment
Share on other sites

  • 3 months later...
  • 2 months later...

I have a set of DCOE 45 152s I am putting into a 240Z with a cammed L24....

 

The carbys came off of an L28 flat top with mild compression and a mild cam.

 

I think I need 32mm chokes to start tuning these beasts...but they have 36mm chokes installed. Does anyone here have a set of 32mm chokes to fit DCOE45s...Money or trades....

Link to comment
Share on other sites

I have a set of DCOE 45 152s I am putting into a 240Z with a cammed L24....

 

The carbys came off of an L28 flat top with mild compression and a mild cam.

 

I think I need 32mm chokes to start tuning these beasts...but they have 36mm chokes installed. Does anyone here have a set of 32mm chokes to fit DCOE45s...Money or trades....

 

 

You can run the 45s on an L24, but you will need smaller chokes. 32mm are probably your best bet. I don't have a set of 32s but I do have a set of 30mm chokes for 45DCOEs that you can have. I too was running the 45s on my original L24 until I got my Rebello 3.0L built at which time I obviously swapped them for something a bit bigger (38mm to be exact :)).

 

PM/e-mail me for a price if you're interested.

Link to comment
Share on other sites

  • 5 months later...
  • 3 months later...

So I bought a 1973 240z with Triple Webers to add to my 240z fleet.

Hauls arse at wide open throttle.

Triple 40 DCOE 151 carbs

Stock L24 block and head

 

poPs and pOps and POps at idle or high idle.

 

Fuel pressure is 5psi

Runs stock Weber horns

I put on a new distributor, rotor, cap, wires, plugs.

Cant tell much from the new plugs, they look ok, but have some oil fouling (worn guides?)

It has a Crane XR700 and I adjusted that and replaced the ground wire.

It has no vacuum advance, only mechanical.

I set the TOTAL advance to 32BTDC (maybe more :)

I checked all valve clearances and they are within spec.

I drained the fuel and refilled with 100LL Aviation fuel.

I sprayed vulcan death spray into the Triple carb intakes to try to clean.

I removed and cleaned all the jets, and checked the float levels.

I farked with every adjustment on the carb and...

..... it still poPs and pOps and POps at idle or high idle.

 

Pulls great at wide open.

 

Air Corrector Jet = 002? (or is that 200)

Emulsion tube = F11

Main Jet = 115

Idle jet says 45F9

 

I happen to run it tonight in the dark.

I cant get the idle down low enough, it wont go below 2500 once it is warm.

After just barely a minute at this high idle the HEADERS were CHERRY RED... GLOWING RED LIKE MAD HOT....

 

Perhaps a "lean pop" from too lean idle jet?

I see no reason why it needs to run red hot at high idle.

Seem like I am on the backside (lean side) of the Stoichiometric curve.

 

Do the jet sizes I found in these carbs seem out of whack?

Tj

Link to comment
Share on other sites

  • Administrators

Hmm...your specs are very close to mine.

72 240.

Stock L24 with 91k.

Compression is nice and even, no smoke etc.

2 1/2 exhaust

Triple 40 DCOE's (I did a fresh rebuild on them about 6 weeks ago)

27mm Chokes

Emulsion tube = F11

Main Jet = 115

Idle jet 45F9

82 ZX Dist, Total advance 35BTDC

Mallory HiFire VI ignition

Temp is rock solid @ 1/2 the gauge... no matter what it's doing.

I only run 91 octane gas... it hates the 87 or 89 stuff.

I have just started driving my car to work for the last 3 weeks and the thing runs like a top!

No flat spots and idles great. A little lean on the top end though but that is fine I wanted more low / midrange.

So to answer your question, it sounds like you are in the ball park for your jetting.

What size chokes are you running?

Vacum advance not hooked up... right?

Vacum leaks?

Float levels good?

Fuel pump, electric or stock? 5 PSI sounds a little high.

What you are describing to me sounds like a vacum leak.... maybe?

Anyone else want to chime in :D

Link to comment
Share on other sites

Easiest/cheapest way IMHO to figure out what your tripled car is doing is to install a narrowband one wire O2 sensor into the exhaust and read the voltage with a voltmeter. I used a $25 Bosch O2 and a $6 HF voltmeter and a $2 O2 sensor bung from a local exhaust shop, and I learned more about what my car was doing in the next 2 weeks than I had in two months of trying to read plugs and smelling the exhaust, etc. It's not as good as wideband, but it will get you into the ballpark. .8V is about right for WOT at about 13:1 AFR, and I think about .5 or .6 is right for cruise AFR of about 14:1. I was always concerned about the WOT, and not the cruise. I tried to look it up online but couldn't find the narrowband voltage/AFR scale anywhere...

 

TJ- "Can't get the idle down after its warm" is a familiar problem to me. When I first installed Mikunis I had a situation where I'd drive my car to an autox 2 hours away and when I'd get off the freeway it would idle at 2000 rpm. Drive around for a bit and it would suddenly drop down to normal again. The problem in my case was the carburetor synchronization was way off. In fact I had to shorten one of the linkage rods because I couldn't synch them the way they were installed on the car (I pieced together my linkage).

 

Dan, the fact that you need to run premium is weird. At 9:1 compression you should probably be able to run 87 without any trouble. I was just at my brother-in-law's place and he was able to run 87 with 35* total advance on the ZX distributor with SU's. There shouldn't really be any reason that the triples would make your car more likely to ping. You might be very lean up top if you're getting pinging on 89 octane. But you'd know for sure with a ~$30 investment.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...