Uhh-Ohh…., My Ongoing 914 Build Adventures.... Options

[porschetub]

Sorry I forgot to check my carb specs. I do know the 55 idles just do not work. Tried that.

Definitely have 60's, 32, F26 in mine and I think 145 mains and 180 airs. Getting the 32 venturi's might be key to get the right velocities so all the jets/secondaries work right.

Getting the carbs right is like building a building - foundation must be sound or you are wasting your time. Start with good linkages (blueprinted), then right fuel pressure (3 psi), Then the right throttle plate height (once you get this do not change it!), then right float levels (blue printed floats). Then accel pump output, Then idles and venturis.

If you get all that then you tune using airs, mains and tubes. .....and then if you get all that right..... flat six nirvana!!

If you don't....... crap! It can be a serious PITA. Be patient and thorough. Performance Oriented tech docs are really good!!

(IMG:style_emoticons/default/agree.gif) ,good points made,I would add a good functioning ignition system and correct timing to that list.
So would it be safe to assume if the vents are changed to 32mm some of the low speed vacuum lost by the cams would be improved in this case ?,or are they simply just too large.
Perry pointed out this will decrease power @ the top end which makes perfect sense but that would be of benefit to the lower range you always drive in.
Correct throttle opening @ idle are hard to get right,I have found to achieve correct idle speed (950) I get ''run on'' and the engine takes a while to settle after the throttle is closed.
It is a saga to get all this right for sure (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) .

[Larmo63]

The carbs just seem to idle really well no matter what we do. Idle has never been an issue.

On another note, I checked my speedo cable with a drill motor and flat bit, it worked fine. Culprit was a wonky angle drive. I had a good one on another transmission, so I cleaned it up and installed it. Works fine. Also, the wires on my oil pressure sender were reversed, so I now have a green oil pressure light. Small steps, but easy fixes. My tach and Tach-Adapt need some looking into now.

[gereed75]

Had a chance to look back at my notes and confirm - 60 idles, 140 mains 32 venturis 180 airs 110 idle air bleeds. I worked a good bit with Paul Abbott when I was setting this up and he had just worked with another customer on a 2.4 Solex crammed motor with this same carb setup that made 195 HP on Jerry Woods Dino.

I agree with the idle thing, always seems pretty happy and I could not consistently get the expected lean best idle indications on all cylinders. Whatever. The AFR,s are really solid and it runs great, no hesitation or flat spots.

Have fun!

[porschetub]

Larmo great you have a good idle,you must be close to the sweet spot ,your transition from idle jets to main should improve with the smaller vents with little loss of top end power,you may find you can go back to 55's but 60's seem to be the norm,slightly rich is always better with our engines besides.
I have a strange jet combination but less displacement,stock cams and Zeniths so you can get weird running condition cause they tune different than the Webers.
I have been faced with a constant rich condition on idle jets,going smaller has made my engine run like (IMG:style_emoticons/default/stromberg.gif) ,know I will get there (IMG:style_emoticons/default/biggrin.gif) .
I have enjoyed this input as this isn't generally covered on here a lot,we have a few "6" builds going on so it will help others.
Lawrence what tach are you running ? there are two types and they run on different voltage input,the earlier tach's require jumper removed from the adaptor,the later tach retains the jumper, contact Bob @ Ashlocktech...super helpful guy.

[Larmo63]

Keith914 is a trooper. He went to Aase Bros. in Anaheim and sourced a set of 32 chokes for my carburetors on his own volition to make my car run right.

We took the carbs off and apart (again,) installed the smaller chokes, then 60 idles, some tuning, and it runs a lot better. This is a pretty involved process, but I think it is good to be pretty intimately involved with your carburetors. You know, you lay awake at night contemplating your jetting and tweaks that you think of, right?

I overfilled the oil tank a bit and had a little flood of oil that we won't talk about. (IMG:style_emoticons/default/headbang.gif)

All is good now. Car seems a lot more drivable and right.

[Larmo63]

I was told on the drives yesterday that my brake lights don't work. I'm trying to fix them; floor switch looks new (Bruce Stone did the pedal set) and there are two wires down there. One wasn't hooked up, I hooked it up and still no lights. I know this is a ground then off type switch, but does it matter which wire is hooked up to which spade on the brake light (by the pedal) switch? I have no idea how the wire was off the spade....

Help?

[Steve]

Might also be an adjustment. There is a goofy lever, washer, etc. that actuate the switch. Put an ohm meter on the switch to make sure it's good. It is most likely an adjustment since you replaced the pedals. I had the same problem with my rebuilt set from Bruce.
I bet we could fix it at the next cars and coffee in the parking lot. Let us know if you don't get it working by next Saturday and we will bring some tools.

[Larmo63]

No power to the switch with a test light and key on. Good fuse, everything else on the fuse works.

hmmmm

[ConeDodger]

Lawrence,

Glad to hear your running and driving it. The rest is just punch list details. Enjoy!

[Larmo63]

The little beast did pretty well yesterday on the drives. I probably shouldn't have pushed the engine as hard as I did, but you only live once.

The punch list is shorter and shorter.....

[76-914]

That's just a switched ground wire. Was the ignition on when you tested for 12v? I would just test for continuity across the switch when activated to confirm the switch is good/bad. You can also install the switch incorrectly and it won't ever work. Ask me how I know. Eyeball it when you press on the pedal to see if it is opening and closing. (IMG:style_emoticons/default/beerchug.gif)

[euro911]

The diagram I have is for '70/'71 (four-bangers). One wire at the brake switch has constant 12 volt power from fuse #8, the other wire travels to the driver's side rear brake light socket, then daisy-chains to the passenger side socket. The brown wire(s) in the wiring socket go to a ground buss.

[Larmo63]

With the key on, no power at either wire that goes to the floor brake pedal switch. The #8 fuse is good and powered.

[euro911]

Check all your fuses to see iffin you got a blown one ... (IMG:style_emoticons/default/confused24.gif)

If they're all OK, follow the wiring to see where it goes and if it's been disconnected (IMG:style_emoticons/default/unsure.gif)

Does either one of the wires have continuity to ground? (if so, that one would more than likely be the wire going back to the brake light socket).

(IMG:style_emoticons/default/popcorn[1].gif)

[forrestkhaag]

FYI. On the drive home in the fuel stop your brake light flicked on when your machine backfired. The again on second backfire. Bulb? Connection in light housing maybe. Cheers

[Larmo63]

After fiddling with my brake lights for a couple days, Perry just informed me that they only work with the key on. (IMG:style_emoticons/default/headbang.gif)

My bad. One wire WAS disconnected from the pedal switch. I fixed it Sunday, but I guess I never tested it with the key on. (I thought I did)


Now, onto the Tach issue. With my immense automotive skillset, I should have it figured out in less than a week.

[Larmo63]

Drove the car to Temecula without a hitch, and drove it today up to Newport, getting a lot of thumbs ups.

Carbs are fairly dialed in now, Ethan is going to drive the car and tune them a bit also. I drove into the garage with a big shit-eatin' grin.

Such a great sound emanating from this engine!!!!!! Pete Stout was right!!!!

[mepstein]

(IMG:style_emoticons/default/beerchug.gif)

[porschetub]

a lot of thumbs ups.
I drove into the garage with a big shit-eatin' grin.

Such a great sound emanating from this engine!!!!!! Pete Stout was right!!!!

Lots told u that ,it is always a wonderful sound...few motors like it really,the power to weight is the key point in these small (light) cars.
Every drive I have it's the same , (IMG:style_emoticons/default/stromberg.gif) eating grin and then you fix a bit more stuff and it just gets better eh.
Well done Lawrence have a wine on me (IMG:style_emoticons/default/beer.gif)

[horizontally-opposed]

Small-bore flat six with a sport muffler = one of the best Porsche sounds, period—and even better when the engine is closer to your ears than the muffler.

The only better-sounding 914 I've driven was a 2.2 w/MFI and a sport muffler. I immediately started pricing MFI...until I saw the price to acquire and set up a system. (IMG:style_emoticons/default/blink.gif)