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Jeffro
Joined: 22 May 2006 Posts: 3 Location: Texas
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Posted: Mon May 22, 2006 2:00 pm Post subject: modifications |
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Howdy from Texas,
Is there anyone here ever modified the 1977 - 924 Intake Manifold with a carburator and done away with the Fuel Injectors ?
Thanks _________________ JB |
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Khal

Joined: 26 Sep 2003 Posts: 4872 Location: Sunny and lovely interior BC, Canada
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Posted: Mon May 22, 2006 4:49 pm Post subject: |
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G'day, welcome to the 'board!
Yes, at least a few people have changed the fuel-injection for carb's.
My personal opinion is that it's not worth it. Here's a recent discussion <click>
Try the search. I know there's plenty more threads about this. _________________ '80 924 Turbo |
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stexch
Joined: 05 Dec 2003 Posts: 90 Location: Mankato, KS, USA
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Posted: Tue May 23, 2006 5:34 am Post subject: |
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| When I bought my '78 924 NA, it hadn't run in many years. After looking into the cost of replacing parts in the Bosch K-Jetronic system, I converted to 40DCOE Webers. I have been very pleased with the results. While the carb and the installation are not cheap, I've been told that once they are properly set up, you never have to touch them again. The vendor strongly recommended buying the tool to synchronize them. For those who object to this conversion, go through the archives and figure what percentage of the cries for help can be traced back to the fuel injection. |
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sequential

Joined: 18 Nov 2005 Posts: 500 Location: BANNED
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Posted: Tue May 23, 2006 5:46 am Post subject: |
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| stexch wrote: | | When I bought my '78 924 NA, it hadn't run in many years. After looking into the cost of replacing parts in the Bosch K-Jetronic system, I converted to 40DCOE Webers. I have been very pleased with the results. While the carb and the installation are not cheap, I've been told that once they are properly set up, you never have to touch them again. The vendor strongly recommended buying the tool to synchronize them. For those who object to this conversion, go through the archives and figure what percentage of the cries for help can be traced back to the fuel injection. |
I would prefer the carbs myself, but the vendor that told you , that once set you would never have to touch them again , WELL !!! i would love for him to give you that in writing and would have to provide you with a free family value chicken meal once aweek if not.
I do recommend the syncro tool , a box of jets ( or micro drill bits, use f11 emulsion tubes and get a lot of air corrector and main jets and idle jets) a dyno to setup correctly.. Webers are a bit finnicky, and will require some attention from time to time ( float level with that buzzy 924 engine ) THe best of the genre was the dellorto almost the same for power as the weber but with more modern parts and was less troublesome. But thread correctly and you will be happy that you did not repair the cis...
Ohh do not forget the cable kit for the choke, it is for cold starts and coldrunning, it makes a big difference. _________________ 928 gts prototype
baby blue engine block
steam in 1,2,3,4 sometimes
cold star issues while on stands
112 whp with new 4 valve head and MIS 2 |
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sequential

Joined: 18 Nov 2005 Posts: 500 Location: BANNED
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Posted: Tue May 23, 2006 11:56 am Post subject: |
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| sequential wrote: | | stexch wrote: | | When I bought my '78 924 NA, it hadn't run in many years. After looking into the cost of replacing parts in the Bosch K-Jetronic system, I converted to 40DCOE Webers. I have been very pleased with the results. While the carb and the installation are not cheap, I've been told that once they are properly set up, you never have to touch them again. The vendor strongly recommended buying the tool to synchronize them. For those who object to this conversion, go through the archives and figure what percentage of the cries for help can be traced back to the fuel injection. |
I would prefer the carbs myself, but the vendor that told you , that once set you would never have to touch them again , WELL !!! i would love for him to give you that in writing and if it is not true , he would have to provide you with a free family value chicken meal once a week.
I do recommend the syncro tool , a box of jets ( or micro drill bits, use f11 emulsion tubes and get a lot of air corrector and main jets and idle jets) a dyno to setup correctly.. Webers are a bit finnicky, and will require some attention from time to time ( float level with that buzzy 924 engine ) THe best of the genre was the dellorto almost the same for power as the weber but with more modern parts and was less troublesome. But thread correctly and you will be happy that you did not repair the cis...
Ohh do not forget the cable kit for the choke, it is for cold starts and coldrunning, it makes a big difference. |
_________________ 928 gts prototype
baby blue engine block
steam in 1,2,3,4 sometimes
cold star issues while on stands
112 whp with new 4 valve head and MIS 2 |
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Jeffro
Joined: 22 May 2006 Posts: 3 Location: Texas
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Posted: Tue May 23, 2006 1:00 pm Post subject: |
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Thanks Fellas for input,and for warm welcome,
Sorry it took me so long to get back with this thread....
I have a 77 1/2 924 that I drove for 3 years with a homemade Intake that someone had built outta steel pipe and I figured out that it wasnt gettin enough fuel to the 1st and last cylinders and finally took its toll..
So I found another 77 924 and all the parts were there - but couldnt get it to start ... It had been sittin for 11 years and I couldnt find an O-ring kit for the Fuel Distributer and gave up and had a guy mill the top of the Intake and I was furious cuz I told him to put a Side mounted Carb on it but instead he milled the top of the Intake -- I got it to start and Idles Fine -
But when I test it on the street, it spits and sputters -
So here is where I stand ->
I need to clean the Fuel Tank and Fuel Lines due to dead Fuel ......
I have used B-12 and Sea-Foam but with no luck....still spits and sputters
Any suggestions would be truly appreciated
I cant give up on this Machine and won't !!!!!
Thanks |
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Vince Ponz

Joined: 02 Nov 2002 Posts: 3581 Location: Florida
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Posted: Tue May 23, 2006 1:38 pm Post subject: |
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I have had carbs on for 23 years and never set them again. Cleaned a few times without changing the jets. Runs great. Cost of the change is a deterent. Only hope for a max of 140 hp. I suggest that you buy a 944 instead. I am not kidding. I also changed the pistons, I have a cam and a free flow exhaust, MSDS, etc.
These are slow moving engines. Do the same to a 320 BMW and it will fly away from you.
That said if you want to do it go ahead and enjoy yourself as I did. _________________ "Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock |
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Jeffro
Joined: 22 May 2006 Posts: 3 Location: Texas
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Posted: Tue May 23, 2006 1:51 pm Post subject: |
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Howdy Vince,
What kinda Carbs and where did you mount ?
Thanks |
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Vince Ponz

Joined: 02 Nov 2002 Posts: 3581 Location: Florida
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Posted: Wed May 24, 2006 3:59 am Post subject: |
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2 45 DCOEs on a weber manifold? and they mount on the drivers side. LARGEjets I think 30mm. _________________ "Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock |
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stexch
Joined: 05 Dec 2003 Posts: 90 Location: Mankato, KS, USA
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Posted: Thu May 25, 2006 11:20 pm Post subject: |
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| I went with 40DCOE's from Fast Freddy's. There's an installation kit that you can get that works well. The support for the throttle return spring was too soft, so I replaced it with a thicker piece (no biggie). While I really wanted the cool looking wire mesh air filters, I was advised that these are strictly for racing, as they let too much dirt in for street applications. |
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Vince Ponz

Joined: 02 Nov 2002 Posts: 3581 Location: Florida
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Posted: Fri May 26, 2006 11:16 pm Post subject: |
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I have the KN filters and bought them originally. Replaced them once as the rubber hardened and shrunk. Keep them oiled. You will like the growl when you stomp on the gas.
One problem though is the back one is a tight fit and you have to really swish it on. Once on you do not have a problem.
I use two springs to bring the carbs linkage to rest. If one breaks you have the other. Once it broke and stuck on full throttle. I shut down the engine and steered to the shoulder only to be reminded that it looks the steering wheel. Started the engine to release the wheel. Use two and feel safe. Don't put too much tension on the second as it is only a reserve. _________________ "Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock |
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dpw928

Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055
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Posted: Sun May 28, 2006 1:00 am Post subject: |
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Did you change the fuel pump? A carb can't handle the high pressure put out by a CIS pump and will cause overflow and leakage into the intake.
Dennis _________________ 81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black |
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sequential

Joined: 18 Nov 2005 Posts: 500 Location: BANNED
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Posted: Sun May 28, 2006 1:24 am Post subject: |
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| dpw928 wrote: | Did you change the fuel pump? A carb can't handle the high pressure put out by a CIS pump and will cause overflow and leakage into the intake.
Dennis |
He can use an adjustable FP regulator and use the superior cis fuel pump system with a return line _________________ 928 gts prototype
baby blue engine block
steam in 1,2,3,4 sometimes
cold star issues while on stands
112 whp with new 4 valve head and MIS 2 |
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dpw928

Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055
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Posted: Sun May 28, 2006 1:57 am Post subject: |
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Carbs only require 3 to 5 psi. Do they have regulators that go that low? Agree, the CIS pump is better.
Dennis _________________ 81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black |
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Joes924Racer

Joined: 03 Nov 2002 Posts: 11964 Location: Oregon, Denver Colorado native!
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Posted: Sun May 28, 2006 9:42 am Post subject: |
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Whats the mileage with carbs compared to the cis  _________________ 1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo. |
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