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new 2275, 400 miles on motor, semi-mature driving, idles perfect and runs like a bat out of hell when floored. checked system for leaks and none found. timing is right on. 3.88 tranny.
my 2387 is bigger, same carbs and gets 25 easy.
any ideas? could the jets be too big?
the mileage was 13(SUX) no the brakes arent dragging either

1957 Vintage Speedsters(Speedster)

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What carbs?
Idle jet size?
Are you running rich?
Are you smelling gas while driving? While parked in the garage?
Smell the oil on your dipstick. Does it smell like gas?
How many turns out are you idle mixture screws?
With totally clean 40-44s, 50-55 idles, 120-130 mains, floats adjusted to 10.5-11.5mm, properly synced, you should be getting 20-26 mpg.
I get 20 mpg, but it seems my accelerator pedal is stuck to the floor.;)

Don't feel bad mine is a 1641 with a single solex 34 I have an average over 950 miles of 15.44 mpg. A lot of it highway miles 70 MPH 3000 RPM 85 ambient temp, engine temp at 170 to 190 93 octane fuel. I'm open to suggestions also no idea on cam or jest sizes. Gas gage dosen't work so this is accurate based on fuel purchased vs miles driven. Engine idles and runs great I'm happy the way it is but better range would be great.

Richard


Bob's motor has a large set of head's a good size cam this motor should make 150 plus hp and with a 8 gallon gas tank I don't know how many mile's it should get.It seem's everybody's talking what motor size they have but one thing's wrong we need to look what's inside . It's what combination of part's cam head's compression ratio ? Bob's motor's a
2275cc with 44's 125 cam 8.5 to 1 with a large d port head 42 x 37 valve's
I talked to mark h. yesterday I built his motor he said his gas mileage was about 15 to 17 mpg being his motor's a 2 liter it's quite a bit smaller than bob's motor
Wow, 13 is BAD. I have never gotten below 18.5 to 19. Usually 22-24. I have seen as high as 32 at 75mph on the way to Carlisle though! Final drive is 3.44:1.

Type1 2165cc, Weber 44 IDFs, webcam 86B, 1.5:1 rockers, 44 X 37 valves, and CR is 9.8:1. 140 mains, 60 idles, 200 air correctors, F11 emulsion tubes and stock 36mm venturis. 172 hp on Jake's dyno, with fan on.

A lot of this has to do with cylinder heads, as far as combustion chamber volume and compression ratio. Match porting manifolds, port shape and ESPECIALLY port velocity are what determine efficiency. You can take a big engine with big carbs, and without the whole system being designed properly, will run like SH*T. A small, round-port head simply can't flow enough mixture to those big cylinders and effectively chokes itself.

And don't forget the exhaust either, it needs to be designed as part of the system too.
I run the same basic carb setup as Danny P., except for 2.2 air correction jets. Tranny is 3.88 R&P with 0.82 4th. In town averages about 21-24 mpg and extended highway cruising can get over 32 mpg...
I've noticed that Webers are at their gas consuming worst at idle....If you're stuck in traffic a lot, you consume a LOT more fuel...Just a thought...
Bob,
Going smaller with the main jets may help a little.
I have an engine similar to yours and started out with Webers. (I've since changed to Delortos.) Here's the deal.
I spent lots of time with the Webers getting them to work.
Your Webers (Delortos are the same) run on the IDLE jets until way up into freeway speeds. Concentrate on your Idle jets until you get it to accelerate during normal driving without surges or flat spots.
Check your Idle Jets. They should be around 145 or 150's.
Also make sure your emulsion tubes are F11's . I started out with F7's. Nothing worked until I changed to F'11's then the magic began.
I spent lots of time setting these up with the use of a guage and O2Sensor monitoring the whole progression.
And... Lots of thanks to John at AIRCOOLED.NET for his patient advise as I tuned.
One more thing. After your initial set up (and making sure your floats are set up correctly <--Critical), change one thing at a time and test and record you progress.
Just my 2 cents;
Good tuning,
Greg
Ditto what Lane said--that's what I get too with my 1915 VS engine and at a leisure 60 mph on interstates I have seen as much as 32 mpg. Something ain't right at all with those engines and I'm sure the builder is as interested as you about what is going on to cause such abysmal gas mileage.

My new type IV is going to achieve close to 30 mpg at freeway speeds ---not bad for a 140 hp engine with monster torque.

Get to the bottom of that mileage and find out what the deal is. With our paltry 8 gallon tanks, mileage is extremely important to these cars in order to have have any kind of range at all. I plan 200 miles between fills, but at 13 mpg and 8 gallons capacity you are looking at less than 100 miles to a dry tank and a practical range per tank of maybe 75 miles. That's just not acceptable.

Hey Marty--what is your MPG on your new engine?----Jack
Geez....you drop by once a week and this is what's getting everyone excited. Well, here's my 2 cents:

13 MPG on that engine sucks. I agree with the "Dan and Stan" team: It's mostly in the idle jets, but we don't know what you've got for intake and exhaust systems or even what you're running for an ignition. all of that matters, big time.

Like Danny (and I'll cut and paste his stuff here and correct it for me cuz I'm basically lazy on typing):

I have a Type1 2110cc, Dellorto 40mm (best carbs on the planet), Engle 120 cam (hot street), stock rockers, 44.5 X 37.5 valves, and CR is 9.0:1. 160 mains (yeah, I know they're rich, and I like them that way), 55 idles, 180 air correctors, F11 emulsion tubes and 38mm venturis AND it's been converted to horizontal discharge tubes. 150 hp estimated, but in a 2000 pound car, it don't take no guff from anyone. At turnpike speeds and on the mains, my air/fuel ratio sits like a rock at 12.8

In addition, the intake manifolds are matched to the heads, the heads are ported elliptically and both were finish polished by me. I'm running a Berg extractor system (DP932) with dual quiet pack mufflers to balance intake with exhaust. EVERYTHING was carefully matched during the design phase. What you run for an exhaust is just as important as what you have on the intake side.

I get about 26mpg in mixed driving and it reaches 30+mpg on sustained 75mph interstates.

My gas tank can be stuffed with 8.3 gallons and will give me a consistent 240 mile range on a trip.

I agree with Stan: Pull your carbs and send them to Art Thraen and get them set up right.

gn
You need to jet/tune that thing. This is what I would do:

1. Adjust valves
2. Set timing
3. Verify fuel pressure by teeing in a gauge (want approx 3lbs)
4. Set floats
5. Verify main, idle, and air jets (they may be drilled out) and double check venturi sizes.
6. Synch carbs and linkage
7. Get yourself a wideband O2 meter and work on the jetting-you want high 12's under full load (pedal to the metal). If you do not want to get a wideband o2 meter then aircooled.net rents one and John will provide you with great help or you can take it to a local dyno and have then do some pulls and they usually will have a wideband o2 sensor to get your a/f readings. Before you do this though make sure there are no exhaust leaks.

If you need some knowlege about the subject then read this link
http://www.thesamba.com/vw/forum/viewtopic.php?t=293837&highlight=wideband

Your mileage should be easily double what you are getting now, plus if you do not take care of the rich condition then there is a possibility that the rings will never seat since you are washing down the cylinders with fuel.

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