Weber tuning questions - please read if you have a Weber!

[briankk]

Yes, the DGV and DFV are mirror images.  But neither one is intended to run sideways.  If you want to run a Weber in this orientation, you need a small IDF or IDA carb.  I'd start with an IDF 40 and the smallest chokes available and fiddle with it.

 

Both of John Passini's books, red and green, are available on Amazon.

Now that I think about it, there was/is an 36IDF, once used on Maserati V6 engines, sometimes found on X1/9 Fiat hotrods, be the best place to start. IMHO.

Edited August 15, 2013 by briankk

[Leeroy]

Really not sure why you think the weber is sideways... But you are entitled to an opinion!

 

One question for you, how does the throttle linkage work if you turn the carb 90º?

Edited August 15, 2013 by Leeroy

[ferox]

O.C.D. you need to look into the procedure for static timing your vehicle, then fine tune it with a timing light.  Without the timing set correctly, you can't tune your carb correctly.  There are three basic things you need for carb tuning at a minimum 1) Correct timing 2) Correct idle mixture 3) Correct idle speed. 

 

Tuning is an iterative process meaning when you adjust one of those three things you have to check the other two and make adjustments if needed.  Keep running through the iterations until you get everything dialed in.  The distributor is used to set static time and adjust timing, but those are achieved by looking at the rotor in relation to the electrodes in the cap and to adjust the degree of the flywheel while using a timing light, respectively.  The hold-down bolt on the disty is just that and nothing more.  It can be used as a reference once you have you engine timed, but you can't use it to time the engine.  I would also recommend installing a throttle return spring even temporarily while you tune.

 

If your engine isn't timed correctly, adjusting the carb is pointless.

Edited August 16, 2013 by ferox

[briankk]

Really not sure why you think the weber is sideways... But you are entitled to an opinion!

 

One question for you, how does the throttle linkage work if you turn the carb 90º?

 

On the model DGV Weber, the barrels should go down the road side by side, shoulder to shoulder, with the fuel pickup in back.  Think driver and passenger, as in a car, not rider and passenger, like on a bike.

 

The throttle linkage must be fiddled until it works, no bolt up solution I know of. 

[briankk]

Really not sure why you think the weber is sideways... But you are entitled to an opinion!

 

One question for you, how does the throttle linkage work if you turn the carb 90º?

 

Oh, never mind.  I give up..

[ferox]

On the model DGV Weber, the barrels should go down the road side by side, shoulder to shoulder, with the fuel pickup in back.  Think driver and passenger, as in a car, not rider and passenger, like on a bike.

 

The throttle linkage must be fiddled until it works, no bolt up solution I know of. 

 

On an ea71 with the barrels lined up the way it's installed on O.C.D.'s engine and every other ea71 & ea81 the primary and secondary are oriented symmetrically on the manifold.  If they were lined up the way you insist, then the primary would be closer to the #2 and #4 cylinder and the secondary would be closer to #1 and #3.  With it oriented for fuel delivery symmetry, the throttle linkage and fuel intake are lined up perfectly for stock configuration.  

 

On an inline or v-type engine with manifold(s) sticking off the top or the side of the engine the orientation you're talking about would provide fuel delivery symmetry, but not on a Subaru flat-4.  Even the Weber kit designed for the Subaru has the carb oriented with the primary in front and the secondary in the back as well as the stock Hitachi carb.  If you're exasperated with this situation, well....it's not us.

[briankk]

On an ea71 with the barrels lined up the way it's installed on O.C.D.'s engine and every other ea71 & ea81 the primary and secondary are oriented symmetrically on the manifold.  If they were lined up the way you insist, then the primary would be closer to the #2 and #4 cylinder and the secondary would be closer to #1 and #3.  With it oriented for fuel delivery symmetry, the throttle linkage and fuel intake are lined up perfectly for stock configuration.  

 

On an inline or v-type engine with manifold(s) sticking off the top or the side of the engine the orientation you're talking about would provide fuel delivery symmetry, but not on a Subaru flat-4.  Even the Weber kit designed for the Subaru has the carb oriented with the primary in front and the secondary in the back as well as the stock Hitachi carb.  If you're exasperated with this situation, well....it's not us.

Heh... I get exasperated trying to explain "sideways"...  The DGV, and others of it's ilk, were designed for use on inline or V engines.  No doubt that they will bolt up to Soob manifold, but they're not intended to run that way, is my point.

 

That said, I know nothing about Soob manifolding and fuel distribution, can't speak to that..

[briankk]

Heh... I get exasperated trying to explain "sideways"...  The DGV, and others of it's ilk, were designed for use on inline or V engines.  No doubt that they will bolt up to Soob manifold, but they're not intended to run that way, is my point.

 

 

That said, I know nothing about Soob manifolding and fuel distribution, can't speak to that..

 

OK. looking around on the board, I found this:

http://www.ultimatesubaru.org/forum/topic/71510-ideas-on-swaping-a-weber-carb-on-ea82%C2%B4s/

where a guy in oz mounts a Weber sideways on an EA82 and seems happy with the results.

 

If it works, it works, never mind the theory...

[O.C.D.]

Appreciate the thoughts Briankk but these do mount as I have done.  The adapter can only mount this way unles myself and 1,000's of others make a custom adapter.  Still though, the manifold is designed as such:

 

Adapter on the base of the DGEV 32/36:

 

For Subaru EA applications this is how they mount.

Edited August 16, 2013 by O.C.D.

[Loyale 2.7 Turbo]

...

 

OK. looking around on the board, I found this:

http://www.ultimatesubaru.org/forum/topic/71510-ideas-on-swaping-a-weber-carb-on-ea82%C2%B4s/

 

where a guy in oz mounts a Weber sideways on an EA82 and seems happy with the results...

 

Hey! ... I am the Guy who wrote that Writeup and Shoot all those Photos,

 

and very Respectfully and Kindly, let me Tell you that You're Wrong once again, in two things,

 

First: I do not Live in oz, I Live in Honduras, Central America (Between Caribbean Sea & Pacific Ocean)

 

Second: The Weber Carb I Mounted on my Subaru "BumbleBeast", is Not Sideways at all.

 

Kind Regards.

[djellum]

I think the point thats trying to be made is that the proper alignment for the carb would be with the bowl in the rear of the carb so that turns and acceleration wont affect the way the carb works.  on my DFV if you take a tight turn with the clutch in the motor idles down, and it wouldnt do this if the carb was running left/right orientation.  I would still prefer this to the other alignment though cause that can cause stalls under heavy breaking.  Holleys used to do that and it was scary enough to have a panic moment without adding a dead car with no steering to it.  with the orientation I have now it only rarely makes a difference, and I have tuned it out enough so that doesnt kill the motor, just bogs down a bit.

 

our adaptors run the carb front to back because the stock carb was running the same direction.  im sure others were side to side, though I havent seen any.  

 

the shape of the manifold shouldnt matter, otherwise v8-4 barrels would have problems with the rear cylinders when the secondaries arent kicking in.  im sure the extra 1 inch of distance that the mixture has to travel makes little difference.

[Dinky26]

Okay, I've read these postings on the Weber swap, mine is still in the box, have not had time in the past 3 weeks to play with it. I did read the instructions that came with it, not very gratifying read. Let me just say I'm thoroughly confused on which way it should be mounted, both claims seem to have their validating reasons. Mine is going on an EA81.

[Dinky26]

Okay, I've read these postings on the Weber swap, mine is still in the box, have not had time in the past 3 weeks to play with it. I did read the instructions that came with it, not very gratifying read. Let me just say I'm thoroughly confused on which way it should be mounted, both claims seem to have their validating reasons. Mine is going on an EA81.

 

 

. I'll just have to see what things look like when I pull my Hitachi off.

[Loyale 2.7 Turbo]

~► http://www.ultimatesubaru.org/forum/topic/71510-ideas-on-swaping-a-weber-carb-on-ea82%C2%B4s/

 

This Writeup is for an EA82, but is almost equal to the EA81, the main difference is the Adapter Plate.

 

Kind Regards.

[briankk]

Hey! ... I am the Guy who wrote that Writeup and Shoot all those Photos,

 

and very Respectfully and Kindly, let me Tell you that You're Wrong once again, in two things,

 

First: I do not Live in oz, I Live in Honduras, Central America (Between Caribbean Sea & Pacific Ocean)

 

Second: The Weber Carb I Mounted on my Subaru "BumbleBeast", is Not Sideways at all.

 

Kind Regards.

Oh yes, I was up 'till 1:00 am reading about your "Bumblebee", have bookmarked it separately for further reading..

 

I do apologize for putting you in Oz, I was on with my brother there about something, got my wires crossed.

 

Back in the day, I was involved with racing, knew a lot of Formula Ford people, who lived and breathed the Weber 28/36 DCD, the ancestor of the carbs we are discussing here.  I had quite a Weber library for a few years, tossed it all about five years ago..

 

I do remember that Weber was adamant about the orientation of the carburetor with respect to vehicle travel, which I was trying to point out.  That said, never mind the theory if what you have done works, as I reckon yours does.  I hope it works out of OCD as well.  If I were to try to go that route, I'd be inclined to begin with a 36 IDF.

 

That said, I'm pleased enough with the SPFI on my Loyale to leave it there.  IMHO, Weber carbs are OK for racing, FI has 'em beat for street use.  I once had an Alfa 1750 Berlina, and two engines for it, one with the Spica mechanical FI, one with 40 DCOEs, could swap engines before lunch.  I live in CA, the Weber engine wouldn't smog..  After a while, I sold the Weber engine, the FI worked better, especially as the weather changed..

 

[Loyale 2.7 Turbo]

Oh yes, I was up 'till 1:00 am reading about your "Bumblebee", have bookmarked it separately for further reading..

 

I do apologize for putting you in Oz, I was on with my brother there about something, got my wires crossed...

 

No Problem.   

 

I Know the Fuel Injection is a Far Superior and Modern Technology than Carburators, but if you want to Upgrade a Carburated EA Engine, you have two ways:

 

► One is Keep it Simple, even Simpler than Stock, by installing a Weber Carb, which also allows to remove tons of stuff from the engine bay.

 

► Other way is more Complicated, by retrofitting the Fuel Injection intake manifold and all the Wiring related to it, ECU, etc... 

 

Both ways will improve the Performance of the EA engines that came factory with stock Carburators for Sure.

 

My personal vote is Always for the Weber, because three factors: one is the Honduran Climate is very stable and only goes from Warm to Cool, it is Never too Hot nor too cold; the other factor is that I Really Love to see Clean and organized engine Bays, the Less Stuff - The Better for me; and the Last Factor is the Huge and Bold Boxer Engine Roar that comes from a Weber Carb's throat under full Acceleration... is Priceless! ... and Louder than a Horn for sure  

 

Kind Regards.

[Gloyale]

Yes, the DGV and DFV are mirror images.  But neither one is intended to run sideways.  If you want to run a Weber in this orientation, you need a small IDF or IDA carb.  I'd start with an IDF 40 and the smallest chokes available and fiddle with it.

 

Both of John Passini's books, red and green, are available on Amazon.

 

Dude.  You aren't getting it.   EVERY soob that has a Weber conversion runs in this orientation.  It will not fit on the manifold rotated 90 degrees.

 

The "kit" offered by Weber for these particular cars comes setup to run this way. 

 

This is how it is designed to work on this motor, and your insistence on telling us why years of experience, 100's of cars, and Weber themselves are WRONG,.........is a bit of a distraction from, and a disservice to the OP and his problem.

[briankk]

I know of a kit, offered by Redline, that contains a Weber, I know of no conversion kits offered by Weber themselves.

 

Now it is possible that Weber has changed the construction of it's carb so it works sideways, this could have happened after I quit paying attention.  It seems unlikely to me, but it's possible.

 

Go look at the VW sites, the 'other' boxer 4 engine, where IDA and IDF  Webers are mostly used.  Look at the 6 cyl Porsche, for whom the IDA3C was invented.  The stock Corvair engine intake has the same problem as the Soob, one little hole to feed 3 cylinders on each side.  The answer on the Corvair was to machine off the top on the manifold and put and IDE3C on each side, you could build a 300hp 'vair that way, I know, I've driven one..  Wonder if the EA 81 or 82 could be done similarly?  Would there be any point?  Are the valves big enough to move a lot of air?

[Loyale 2.7 Turbo]

Subaru Built (one year only - 1982) a Race Version of the EA81S for the Safari Rally RX, which came factory with reversed valves (As the Twin hitachi carb on intake version) also came factory with two Weber Carbs, each bolted directly to each Head.

 

But Subaru already had the Turbo EFi setup (Started to Sell in Japan in 1982, worldwide in 1983) so they Dismissed that Twin Weber carb setup for production vehicles, in favor of the Turbo EFi setup.

 

Kind Regards.

 

Edited August 17, 2013 by Loyale 2.7 Turbo

[Loyale 2.7 Turbo]

I know it is off-topic, but in order to share information:

 

Photos of the 1983 Subaru RX "Safari Rally" Version:

 

 

 

But a Year before that (1982) Subaru Sold their first EA81 Turbo EFi for JDM,

 

Look the Backwards Stencil "Turbo" on purpose, Under the Front Bumper:

 

 

 

I've seen very Few of those Turbo EA81 Sedans in Honduras.

 

Then Subaru Sold the Turbo Worldwide since 1983:

 

 

Also the Turbo Mood took Subaru to even sell the Tiny Subaru Rex

 

(a 3/4 Scale Justy with only two Cylinders - Very Popular in LADM -Latin American Domestic Market-)

 

With Turbo; in other markets is Known as Subaru Sherpa and later as Fiori:

 

 

 

So, no more Subaru Carburated engines for racing development since then.

 

All this info and Photos are taken from the Legendary Thread:

 

"Strange & Weird Subaru Stuff"

 

Which have Much more... Kind Regards.

Edited August 22, 2013 by Loyale 2.7 Turbo

[Gloyale]

I know of a kit, offered by Redline, that contains a Weber, I know of no conversion kits offered by Weber themselves.

 

Now it is possible that Weber has changed the construction of it's carb so it works sideways, this could have happened after I quit paying attention.  It seems unlikely to me, but it's possible.

 

Go look at the VW sites, the 'other' boxer 4 engine, where IDA and IDF  Webers are mostly used.  Look at the 6 cyl Porsche, for whom the IDA3C was invented.  The stock Corvair engine intake has the same problem as the Soob, one little hole to feed 3 cylinders on each side.  The answer on the Corvair was to machine off the top on the manifold and put and IDE3C on each side, you could build a 300hp 'vair that way, I know, I've driven one..  Wonder if the EA 81 or 82 could be done similarly?  Would there be any point?  Are the valves big enough to move a lot of air?

 

I find way more VW's with the setup same as we use.

 

And as has been pointed out, sitting it with the seconday on one side, and the Primary on the other would put the main fuel sorce closer to one set of cylinders.  This will work with the IDF series, but not with the DGEV.  The IDF are synchronus barrels (parallel) not Sequential like the hitachis and the DGEV

 

Ever check out were the bowl is on a Hitachi?  On the side.  Granted the float pivot is in the rear, not on the side like the DG.

Edited August 17, 2013 by Gloyale

[Loyale 2.7 Turbo]

Back on Topic, during all this Decades being an Old-School Subaru enthusiast and Mechanic, I've seen only One (1) Subaru EA engine, with a Sideways mounted Weber Carburator; by the way, it is a Custom Made intake manifold; I saved a Photo of that engine on its engine bay, for your Viewing Pleasure:

 

[Gloyale]

It's rotated 18.7 degrees off center

 

Won't work.

 

 

 

 

LOL

[Loyale 2.7 Turbo]

You know... One Side and its pair of Cylinders, is more Forward than the Other Side and its Pair of Cylinders; (To allow space side by side on the Crank for the connecting rods) that is the Reason why the intake has that Angle.

[Gloyale]

You know... One Side and its pair of Cylinders, is more Forward than the Other Side and its Pair of Cylinders; (To allow space side by side on the Crank for the connecting rods) that is the Reason why the intake has that Angle.

Yes I understand.

 

Even the factory intake and carb base is a bit off.

 

I was joking.........that it wouldn't work.

 

Although I'd like to know if that is the synchronus  or sequential DG on there?  Or is that an IDF?