Decision time, Fuel injection or carb(s) |
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Decision time, Fuel injection or carb(s) |
srreality |
Apr 29 2016, 01:26 PM
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#1
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Member Group: Members Posts: 73 Joined: 14-July 15 From: Colorado Member No.: 18,957 Region Association: None |
I've reassembled most of the project car I bought last fall........1973 914-4 1.7 liter. I'm in the process of restoring/rebuilding the suspension and brakes. The next big thing on the list is engine rebuild. I can't do the work myself, but have a good engine builder locally. Question is, rebuild the fuel injection (car sat in a "sealed" storage container for 8 years) or convert to Weber(s). If I'm going to convert to carbs, the engine rebuild needs to include a different cam, so good time to decide. This car will be a very nice "driver" not a show car or track car, so complete originality is not necessary. Functionality and driveability are. The thin air here in Colorado begs for more HP, but the budget doesn't allow for "wild" things. What say Forum? Spend $ on fuel injection rebuild or convert to carbs?
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Mark Henry |
Apr 30 2016, 01:01 PM
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#2
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Carbs have their place, they are easier to tune with wild cams and can be made to work well.
Like FI most bad experiences have been with improperly set up systems, mostly due to lack of knowledge or poor mechanicals. That said I do like FI (IMG:style_emoticons/default/shades.gif) |
stugray |
Apr 30 2016, 03:19 PM
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#3
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Advanced Member Group: Members Posts: 3,824 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
BTW, the Le Mans-class-winning 914 had carbs because it was a SIX. Apples and oranges. What reason was that? It was a race prepped 2.0L six ... (IMG:style_emoticons/default/confused24.gif) But WHY did the six have carbs instead of FI? You think the engineers just picked that option at random? damesandhotrods might be correct that it was to make them slower than the 911s, but I think it was to give them maximum tune-ability for racing. Carbs have their place, they are easier to tune with wild cams and can be made to work well. Like FI most bad experiences have been with improperly set up systems, mostly due to lack of knowledge or poor mechanicals. That said I do like FI (IMG:style_emoticons/default/shades.gif) This was the correct answer. They used carbs because you can adjust them to fit any needs as you tinker with the engine. Back then you could not easily tinker with the ECU in the FI systems. Now that teenagers can understand a Megasquirts and we can tune our hotrods with our phones we forget that. |
Dave_Darling |
Jun 24 2016, 03:49 PM
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#4
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914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
But WHY did the six have carbs instead of FI? You think the engineers just picked that option at random? The race car had it due to homologation. The purpose-built race cars had been running MFI for a while by that point. The street car had them because they pulled the motor out of a 1969 911T, which had carbs, and stuck it into the 914 to make the Six. It was cheaper to use what they had on hand than to re-engineer things for the motor they decided they were putting into the car. They kept the carbs in the 911T model through the 1971 model year--it was the cheap 911, and they used the cheap way of getting fuel in. The higher-performance 911s (the 911E and 911S) both went over to fuel injection in the 1969 model year! They were charging more for those, and they expected more performance out of them--so they went to MFI instead of the cheap and easy carb setup. Carbs were used because they were cheap. FI was used when the system needed to be better--offer better throttle response, better power, maybe even better fuel economy... Now, that does ignore the fact that the 911's MFI setup is rather different from the D-jet used on all 1.7 and 2.0 914s, and the L-jet used on all US-spec 1.8s... But that is a different argument. --DD |
stugray |
Jun 24 2016, 04:04 PM
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#5
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Advanced Member Group: Members Posts: 3,824 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
But WHY did the six have carbs instead of FI? You think the engineers just picked that option at random? The race car had it due to homologation. The purpose-built race cars had been running MFI for a while by that point. The street car had them because they pulled the motor out of a 1969 911T, which had carbs, and stuck it into the 914 to make the Six. It was cheaper to use what they had on hand than to re-engineer things for the motor they decided they were putting into the car. They kept the carbs in the 911T model through the 1971 model year--it was the cheap 911, and they used the cheap way of getting fuel in. The higher-performance 911s (the 911E and 911S) both went over to fuel injection in the 1969 model year! They were charging more for those, and they expected more performance out of them--so they went to MFI instead of the cheap and easy carb setup. Carbs were used because they were cheap. FI was used when the system needed to be better--offer better throttle response, better power, maybe even better fuel economy... Now, that does ignore the fact that the 911's MFI setup is rather different from the D-jet used on all 1.7 and 2.0 914s, and the L-jet used on all US-spec 1.8s... But that is a different argument. --DD Hmmmm..... Then maybe I should take the carbs off my 2056 race car and put the D-Jet on it? Why not? Its better..... |
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