-6 venturi sizing |
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-6 venturi sizing |
mb911 |
Nov 29 2017, 07:41 AM
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#1
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914 Guru Group: Members Posts: 7,159 Joined: 2-January 09 From: Burlington wi Member No.: 9,892 Region Association: Upper MidWest |
I am starting my carb build for 2.4 s piston solex cammed engine. In my research it looks like 34mm venturi sizing is correct. Any feedback from those that have been there?
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gereed75 |
Nov 29 2017, 08:31 AM
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#2
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Senior Member Group: Members Posts: 1,284 Joined: 19-March 13 From: Pittsburgh PA Member No.: 15,674 Region Association: North East States |
My motor is a 2.4 mod Solex (DC30) JE 9.5 CR T distributor (crane optical) stock heat exchanger, heads ported to 36 intakes, stock exhausts (33 - 34 IIRC). Intake manifold port matched to head and carbs.
My 40 Weber s are set up with 32 venturis, 60 idles, 180 airs 140 mains 110 air bleeds and I think F26 tubes. Car runs really well. Tuned using O2 sensor and A/F's are all in the 12 - 13.5 range. Carburetes cleanly from low RPM up to a 7200 limit. 34's might work but I suspect you will sacrifice some torque and low speed and transition smoothness. Worked with Paul Abbott at Performance Oriented on this set up. Followed his blue printing procedures to a T. One of his customers had this motor with this setup on a dyno and as I recall it made 195. |
mb911 |
Nov 29 2017, 10:52 AM
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#3
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914 Guru Group: Members Posts: 7,159 Joined: 2-January 09 From: Burlington wi Member No.: 9,892 Region Association: Upper MidWest |
That helps that is what I will go with to start.
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johnhora |
Nov 29 2017, 01:29 PM
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#4
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Senior Member Group: Members Posts: 873 Joined: 7-January 03 From: Derby City KY Member No.: 107 Region Association: None |
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914Toy |
Nov 29 2017, 01:45 PM
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#5
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Senior Member Group: Members Posts: 727 Joined: 12-November 17 From: Laguna beach Member No.: 21,596 Region Association: Southern California |
32's are a good "street" choice, 34's will likely give acceleration hesitation.
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brant |
Nov 29 2017, 01:45 PM
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#6
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914 Wizard Group: Members Posts: 11,739 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
it depends so much on how you intend to use it
if you want torque in the mid range, or hp at redline. I ended up with 35mm venturi's on my 2.0/6, but its all about HP at redline for our set up, and we determined that after trying 32's, 34's, 35's, and 36's on the dyno. not the set up you'd want on a street car brant |
mb911 |
Nov 29 2017, 02:05 PM
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#7
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914 Guru Group: Members Posts: 7,159 Joined: 2-January 09 From: Burlington wi Member No.: 9,892 Region Association: Upper MidWest |
Mine will be all street. I have 27mm venturies so will just machine out to 32 and use that as a starting point.. Then probably do some jet drilling.
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gereed75 |
Nov 29 2017, 02:40 PM
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#8
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Senior Member Group: Members Posts: 1,284 Joined: 19-March 13 From: Pittsburgh PA Member No.: 15,674 Region Association: North East States |
The chart calls for 135 mains. This would probably work out ok in combo with the F3 tubes. I think that the F26 tubes lean out the mains at a lower rpm than the F3 tubes and thus you get a similar transition with either combo - smaller mains not leaned by the emulsion tube or larger main leaned earlier by the F26 tube.
I think I have too much spare time today!! |
porschetub |
Nov 29 2017, 03:19 PM
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#9
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Advanced Member Group: Members Posts: 4,725 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
Great replies here,when I was researching it seemed the 34mm will work with a 2.7 better,for example earlier on I ran 32mm on my 2.2 and it felt flat until the rpm climbed,started to pull hard but generally it was time to change gear anyway.
It was definitely harder to tune and just seemed fussy,I realized my mistake and when to 30mm....things came together then so that's where I'am now. Good luck Ben. |
914Toy |
Nov 29 2017, 04:49 PM
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#10
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Senior Member Group: Members Posts: 727 Joined: 12-November 17 From: Laguna beach Member No.: 21,596 Region Association: Southern California |
34's work well "street" in my 2.7 with 40 Webers.
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Larmo63 |
Nov 29 2017, 06:27 PM
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#11
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Advanced Member Group: Members Posts: 4,267 Joined: 3-March 14 From: San Clemente, Ca Member No.: 17,068 Region Association: Southern California |
We had issue with the 34s that Paul Abbott specified. I changed them to 32s on a 2.4S spec motor, and it runs much better.
Do 32mm..... |
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