Newbie Question 2: Weber Carburetors |
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Newbie Question 2: Weber Carburetors |
amfab |
Jul 28 2016, 02:24 PM
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#1
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Member Group: Members Posts: 393 Joined: 17-May 16 From: Los Angeles Member No.: 20,004 Region Association: None |
I just bought a 74 2.0. Previous owner says previous owner rebuilt it out to 2.1 a few years ago but there is no documentation. Regardless, it IS a GA with 3 bolt intakes so I will assume at least 42mm intake valves.
It came with dual Weber 36idfs with 32 venturis. The motor seems a bit anemic at the higher RPM. To me—quite an amateur at this kind of stuff—it kind of makes sense because the throttle bodies seem a bit small for the motor (it seems that a lot of the type 1 guys use 36idfs on sub-2 litre motors). I just had the car tuned up and it runs very nicely, but not a lot of power and it flattens out fast above 4kRPM I considered megasquirt, but because I have linkage and manifolds I was thinking going the easier and cheaper route of 40 or 44 idfs. After doing a bit of research, my thoughts are either 40idfs with 34 venturis or 44idfs with 36 venturis. Just a little more oomph will be able to carry me until I eventually do a six conversion in a couple years. Are 44idfs too much carb for the 2.0 (or possible 2.1)? Unfortunately, there is no documentation on the cam either. I (and my mechanic) are thinking its stock or close to it. Any advice would be greatly appreciated. Thank you -Andrew |
rhodyguy |
Jul 30 2016, 08:16 PM
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#2
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,092 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
What is the actual rpm where it stops running out of steam? If your car runs cleanly from a stop with no snapping, popping, stutter during transition, backfiring on decel you're doing well. Do you drive around at 5k? In all likelyhood, sizing up the venturis might bring a set of new issues.
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amfab |
Jul 30 2016, 10:38 PM
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#3
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Member Group: Members Posts: 393 Joined: 17-May 16 From: Los Angeles Member No.: 20,004 Region Association: None |
Just tuned up, car runs nicely, A little stumble now and then when taking off, and when cruising it can feel kinda hesitant at times.
Pops on decel when not fully warmed up. Pops quite a bit going downhill, Torque kinda fades away around 4200-4500 Im almost never over 5K cuz it feels useless. This may just be what these motors feel like. I haven't driven another 914 since My 73 I had 30 years ago. |
Elliot Cannon |
Jul 30 2016, 11:04 PM
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#4
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914 Guru Group: Retired Members Posts: 8,487 Joined: 29-December 06 From: Paso Robles Ca. (Central coast) Member No.: 7,407 Region Association: None |
Just tuned up, car runs nicely, A little stumble now and then when taking off, and when cruising it can feel kinda hesitant at times. Pops on decel when not fully warmed up. Pops quite a bit going downhill, Torque kinda fades away around 4200-4500 Im almost never over 5K cuz it feels useless. This may just be what these motors feel like. I haven't driven another 914 since My 73 I had 30 years ago. If it stumbles coming off idle it could be wrong size idle jets. Which ones do you need? Idle jets are relatively cheap. Buy about 4 different sizes and give them a try. You will get real good at changing them out. (IMG:style_emoticons/default/biggrin.gif) |
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