2056 mild carb settings, new tune advice needed |
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2056 mild carb settings, new tune advice needed |
RFoulds |
May 8 2023, 05:58 PM
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#1
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Green Teen 66 Group: Members Posts: 837 Joined: 10-August 09 From: La Quinta, CA Member No.: 10,656 Region Association: Southwest Region |
Now that the milder 2056 is in the car, I could use some advice on carb tune.
compression is at 8.8:1, valves are 44/38, cam is Webcam 86a. Weber IDF 40's have 37mm venturis, 135 mains airjets 200 F11 emulsion tube I am told by the builder that I should step down to 34 venturis, but, have no idea where else to start. Car will go to a good tuner soon enough, just want o have a good starting point. |
nditiz1 |
May 8 2023, 06:22 PM
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#2
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Senior Member Group: Members Posts: 1,190 Joined: 26-May 15 From: Mount Airy, Maryland Member No.: 18,763 Region Association: MidAtlantic Region |
I would start with 115 mains, 28 vents, 50 idle.
Once you get the baseline for the engine then you can move up and down with the vents and mains. Vents will move your powerband. The higher vents you go the less punch off the line you will have, BUT you will carry the power to redline, whereas with 28s you will have a lot of punch, but fall on its face ~4700 |
r_towle |
May 8 2023, 07:18 PM
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#3
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Custom Member Group: Members Posts: 24,585 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
Agree with above
Venturis are fir airflow volume and speed Smaller venturis offer faster yet less air at low rpm 28mm is right for Street application I think it has always been up by 2mm each time. I have a box of multiples of each part….each motor is different, and your elevation also matters. 28mm vents Tune idle jets, f-tube, and main jets to your needs. |
930cabman |
May 9 2023, 05:57 AM
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#4
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Advanced Member Group: Members Posts: 3,138 Joined: 12-November 20 From: Buffalo Member No.: 24,877 Region Association: North East States |
I would start with 115 mains, 28 vents, 50 idle. Once you get the baseline for the engine then you can move up and down with the vents and mains. Vents will move your powerband. The higher vents you go the less punch off the line you will have, BUT you will carry the power to redline, whereas with 28s you will have a lot of punch, but fall on its face ~4700 (IMG:style_emoticons/default/agree.gif) Starting small generally works better in my experience. With a 37 venturi you may not be getting the necessary signal. My recent 2056 with similar specs runs great with 28 vents. I have considered 30's but too many other fish to fry these days |
VaccaRabite |
May 9 2023, 08:33 AM
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#5
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Yeah. 37mm and 34mm vents are HUGE. They make sense for a race car running WOT all the time, but not for a street driven car. Vent size will change your powerband also. I had 44's on the car with (I think) 32 vents and the car made a ton of power above 4K and was a total dog until 3500 rpm. When I necked down to 40s with 28vents powerband moved to a much more usable range.
Start at 28mm. 50 idles. You may need to go up to 55 idles. I tried 60 and started coking up spark plugs. Most of your driving is on the idle jets. I had 120 mains on my 2056 and it liked those. F11 is fine for emulsion tubes. Zach |
sportlicherFahrer |
May 9 2023, 08:51 AM
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#6
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Nothing to see here. Group: Members Posts: 1,088 Joined: 18-April 05 From: Tacoma, WA Member No.: 3,945 Region Association: Pacific Northwest |
I have a very similar engine combo in my '73 currently aside from the heads having stock valve sizes. At sea level I am running 40 IDFs with 32mm vents, 125 mains, F11 tubes, 50 idles, and 200 air correctors. Power band starts waking up at about 2500 and pulls strong through to 5700 or so. My engine also has AA forged rods, Web single coil valve springs, solid rocker spacers, MSD ignition, 2.0 SSi's, and a Triad muffler. The whole combo seems to work pretty well for a carbed car. Runs relatively cool, has good idle performance, and great response in the power band.
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RFoulds |
May 11 2023, 04:18 PM
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#7
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Green Teen 66 Group: Members Posts: 837 Joined: 10-August 09 From: La Quinta, CA Member No.: 10,656 Region Association: Southwest Region |
Anyone have some 32 vents to sell? Cant seem to source them right now.
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sportlicherFahrer |
May 11 2023, 04:32 PM
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#8
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Nothing to see here. Group: Members Posts: 1,088 Joined: 18-April 05 From: Tacoma, WA Member No.: 3,945 Region Association: Pacific Northwest |
Looks like they may be in stock at CB (IMG:style_emoticons/default/confused24.gif)
https://www.cbperformance.com/product-p/6395.htm |
930cabman |
May 11 2023, 05:28 PM
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#9
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Advanced Member Group: Members Posts: 3,138 Joined: 12-November 20 From: Buffalo Member No.: 24,877 Region Association: North East States |
Or Pegasus, generally has most any Weber stuff
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RFoulds |
May 11 2023, 05:31 PM
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#10
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Green Teen 66 Group: Members Posts: 837 Joined: 10-August 09 From: La Quinta, CA Member No.: 10,656 Region Association: Southwest Region |
Looks like they may be in stock at CB (IMG:style_emoticons/default/confused24.gif) https://www.cbperformance.com/product-p/6395.htm Unplaced on order but they only had 2. |
nditiz1 |
May 11 2023, 06:47 PM
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#11
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Senior Member Group: Members Posts: 1,190 Joined: 26-May 15 From: Mount Airy, Maryland Member No.: 18,763 Region Association: MidAtlantic Region |
Pierce manifolds is my go to for all weber parts. I'm pretty sure i have 32s. You can try them out. If you want to use them then buy me a replacement and have them shipped to me.
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rfinegan |
May 12 2023, 06:27 AM
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#12
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Senior Member Group: Members Posts: 973 Joined: 8-February 13 From: NC Member No.: 15,499 Region Association: MidAtlantic Region |
Pierce manifolds is my go to for all weber parts. I'm pretty sure i have 32s. You can try them out. If you want to use them then buy me a replacement and have them shipped to me. ^^^^GOOD GUY^^^^^^^ I just checked my 40s for 32’s for the same reason this morning.... |
930cabman |
May 12 2023, 09:40 AM
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#13
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Advanced Member Group: Members Posts: 3,138 Joined: 12-November 20 From: Buffalo Member No.: 24,877 Region Association: North East States |
+1 with Pierce, they always have
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GBX0073 |
May 14 2023, 11:15 AM
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#14
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Member Group: Members Posts: 164 Joined: 21-December 20 From: Illinois Member No.: 25,007 Region Association: Upper MidWest |
Randy Congrats on getting your engine back looking forward to all the future updates as you get her Tuned.
Reach out to Rick Hunt on FB thinking he may have a source of printed venturi's Edit Update talked with Rick 3D printed venturis still in development phase. |
Spoke |
Sep 5 2023, 06:28 AM
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#15
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Jerry Group: Members Posts: 6,990 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
Hijack:
On my 2056, I have some popping when the engine is pre-warm. No popping after warmed up. If I run anything less than 93 octane, I get a lot of popping. Carb settings: Weber IDF 40 28mm venturis, 115 mains Idle Jets: 50 airjets 200 F11 emulsion tube Recently adjusted valves (didn't change anything) No vacuum leaks. No info on cam or valves. (2L heads) Suggestions for adjustment? |
rhodyguy |
Sep 5 2023, 06:34 AM
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#16
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,089 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
For starters get a set of 32mm Venturi. Go thru the preinstall procedure. Baseline the carbs. Timing must be set and valves adjusted correctly.
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nditiz1 |
Sep 5 2023, 08:15 AM
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#17
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Senior Member Group: Members Posts: 1,190 Joined: 26-May 15 From: Mount Airy, Maryland Member No.: 18,763 Region Association: MidAtlantic Region |
@spoke
I get popping out of my carbs until fully warm. It's worse during the colder months. Everything is probably fine. Only other thing i could think of is linkage, what linkage are you running? Almost seems like it could be related, but usually the hex bar goes out of adjustment warm, not better (IMG:style_emoticons/default/biggrin.gif) |
Spoke |
Sep 5 2023, 12:54 PM
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#18
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Jerry Group: Members Posts: 6,990 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
@spoke I get popping out of my carbs until fully warm. It's worse during the colder months. Everything is probably fine. Only other thing i could think of is linkage, what linkage are you running? Almost seems like it could be related, but usually the hex bar goes out of adjustment warm, not better (IMG:style_emoticons/default/biggrin.gif) @nditiz1 Nick, I have the cable system by Racer Chris. Both sides seem to open at the same time. I'll go back and check all adjustments and synchronize the carbs. |
Spoke |
Sep 7 2023, 09:47 PM
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#19
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Jerry Group: Members Posts: 6,990 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
@nditiz1
Checked all adjustments and synched the carbs. No popping on the drives today. Not sure if it was the adjustment or the fact that one of the studs on cylinder 1 holding the carbs on the head had completely backed out and was laying on the tin. It must have been off for some time. Put it back in and tightened all 5 other studs. None were tight... |
930cabman |
Sep 8 2023, 05:42 AM
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#20
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Advanced Member Group: Members Posts: 3,138 Joined: 12-November 20 From: Buffalo Member No.: 24,877 Region Association: North East States |
@nditiz1 Checked all adjustments and synched the carbs. No popping on the drives today. Not sure if it was the adjustment or the fact that one of the studs on cylinder 1 holding the carbs on the head had completely backed out and was laying on the tin. It must have been off for some time. Put it back in and tightened all 5 other studs. None were tight... "none were tight" (IMG:style_emoticons/default/screwy.gif) many of us have been there before |
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