Ea81 weber 32/36 or 38/38

[tweety]

So the spfi on my ea81 has come to an end. Lets move on.

 

I did once have a weber 32/36 on my engine of my auto trike. It was ok but with the automatic transmission  it was somewhat sluggish. Low down torque and power is my quest.

 

I am seriously considering a 38/38.  I am going to retain the larger SPFI manifold some 6mm extra diameter (I think) and can open up the adapter plate a little also.  I have a good flow through exhaust and may shave the heads at a later date.

 

So, given the better airflow over the ea81 and the sluggish VW auto box  would I be better off going the 38?  I dont really want to drop too much in mileage.

[jono]

maybe, this time, stick with the norm on the old girl. The jet sizes people have supplied about the place are mostly for the 32/36 ?

 

When you make adaptor, don't do what i forgot once - that the butterflies need room to move under the base line, and I think it helps if that adapter has two corresponding round holes directly below each trottle plate..think

 

It is a pity that the whole thing needs dissembly* to swap in a cam change as you probably know this might assist with your low end torque needs

 

* the sump has to come off, can't recall if block needs splitting once valve tension off lifters and you rattle lifters away from cam

Edited March 8, 2014 by jono

[El Presidente]

If your going to go carb and its gonna see traffic or DD, go with a 32/36.

 

The 38/38 is a great carb but its not for an everyday use car..or trike. Your gonna get the best performance out of the ea82 SPFI system, so even if you have to start over from scratch, do that. The sluggishness of the system is from two things: low compression of the stock ea81 and, from what I hear, the ea81 cam timing doesn't complement the ea82 ecu timing and fuel maps. I had an ea81 with a ea82 spfi on it and I knocked .020" off each head and I noticed a considerable difference in how it behaved. Even if you go back to carbs, bump the compression on that ea81, you wont regret it. 

 

Josh

Edited March 10, 2014 by El Presidente

[tweety]

thanks guys.  I am going 38/38. Reason being the auto trans makes take off mundane. I think I need that low down extra torque the 38/38 gives. also the spfi manifold will give better breathing.

 

The engine will eventually be replaced with an engine with a mild cam and shaved heads. This being the case the 38 is suited. Yes you have to split the block. Better for me to buy another engine and build it up at my leisure then drop it in. The 38 I'm told can have smaller jets for more economy still providing good performance off the mark, say 120's instead of 145 mains.

 

Jono there is a few pics on this site that clearly shows a spfi manifold and Holley 5200 mating up. 5200 same as weber 32/36.  the holes you speak of can have the center of the adapter cut out between the holes.  This pic shows the wedge adapter too.

 

[El Presidente]

I'm not sure where your geting your info, but its wrong. The 38/38 will not give you better low end torque, its not designed for that,its designed for top end power and getting there quick. If your going for MPG's a 38/38 will be a rude awakening, because your going to see you mileage take a serious dump. There's a reason why everybody runs 32/36's..38/38 is pretty much off the table unless your doing drags or long run high rpm stuff. To make more power you need good fuel delivery and SPFI is the best hands down but a 32/36 is a second.  The 38/38 runs smaller jets because its a slightly bigger carb. This doesn't mean your going to get better MPG's. You could jet down a motorcraft 2100, or even a holley double pumper 750, if you still think a bigger syncro carb will help you. The engine still needs a certain amount of fuel to maintain proper air/fuel ratio no matter what and is based on engine efficiency and size. A 32/36 can handle way more air than an EA81 can move. The more efficient the engine the better the MPG's.

 

I really think you aren't understanding that the air flow restrictions are in the heads and not the intake or exhaust. Yes the stock intakes(both carb and SPFI) are horribly inefficient, but whats worse is the head designs on both the EA81 and EA82. If your looking at buying another engine, just go with an ej18, you'll get amazing milage and lots more power with a much simpler wire install. They are cheaper to run as well and almost as bullet proof as an EA81. If you still want to go through with your current plan, please post updates.

 

Josh

[tweety]

thanks Josh. I will keep upates as they happen but not for a while. The EA81 is out and the VW auto and axle assembly is coming out also for some work. that will obviously be the first thing on the list.

 

Then specs of the trike to my cam builder.  possible ej20 pistons etc.  the 38/38 has been purchased. if mpg is woeful I'll just put a 32/36 on it, no drama.

 

Be interesting.  thanks for your views. good to hear difference in opinions and they are taken on board.

[tweety]

El Presidente was correct.

 

I've done about 6,000kms since the rebuild. My best mileage has been 23mpg (australian gallons) worst 19mph. and thats running gently on the throttle. Once with a 32/36 prior to rebuild it got 28mpg to 34 mpg

 

The power down low is remarkable. Mid range eg kickdown from 3rd to 2nd is great. 

 

With much thought, the 32/36 would have been the better choice and am hunting a 32/36 down at the moment.  WHENEVER YOU DRIVE THROUGH SMALL TOWNS OR CRUISE ON LIGHT THROTTLE YOU WOULD ONLY BE USING THE SMALLER THROAT.  It just has to be more economical. My dyno guy told me that he couldnt tune in the 38 ideally...that some jets just dont go low enough if that makes sense for the 1.8 litre. Never mind, it comes off soon.

 

By the way the timing ended up being 13 degrees BTDC and 29 degrees high revs.

 

So the message is clear. go the 32/36 weber.   cheers.

[rdweninger]

Thank you for the update.  We appreciate your feedback.

[tweety]

Istalled a 32/36 used in very good condition today. Following jets- 

 

Primary-      air 165  mains 130, idle 55

 

Secondary    air 160, mains 140, idle 50

 

Runs very well. No hesitation, spluttering or rough idle. Very happy with that. Seems a little rich at idle when cold. Not much black smoke but smells rich. when warm its fine. anyone got comments on the jet sizes?

 

My assessment of the 2 carbs is-  from stationary to the forst 30 yards or so the 38 would be quicker but not by much. As for the rest of performance they are the same IMO.  Having a smaller primary throat for economy makes me feel better, as most times thats all I use. So am expecting an decrease in fuel usage.  I'll wait a few weeks then repost here my economy figures.

 

By the way. I have a weber top hat air filter adapter seen here. that has a 90mm tube to cold air intake large cone filter. I took it off today for a short burst to see any difference and boy- there is a good deal more power. In fact substantial.  I'm going to replace this system with a 9 inch doameter chrome filter body with paper element. (pic 2). Anyone know of a better idea for an air filter free flowing?

 

 

Edited July 4, 2015 by tweety

[Loyale 2.7 Turbo]

Istalled a 32/36 used in very good condition today. Following jets- 

 

Primary  air 165  mains 130, idle 55

 

Secondary  air 160, mains 140, idle 50

 

... anyone got comments on the jet sizes?

 

My EA82 runs with 140 in Primary (Low) Stage and 162 in High (Secondary) Stage main Fuel Jets; it runs rich when its cold, especially for not having a Choke, But also that issue fades fast as it warms.

 

Kind Regards.

[tweety]

Thanks Loyale 2.7

 

Keep those jet sizes going guys.   I dont have a choke either. Bare in mind I'm running a spfi ,amifold think it is 6mm more in diameter. Might not make any difference though.  And 9.5:1 compression ratio.  Think might buy a few more jets and see how it performs.  Also re: air filters.  The ramflo type apparently is better as air gets drawn from directly above the throats as opposed to filters that have a solid top and air needs to be drawn from the sides. Makes sense to me.

 

 

Edited July 5, 2015 by tweety

[tweety]

  Loyale 2.7 Turbo.  Thankyou for your contribution to my many questions over the months, you have been a great help. 

 

Re:  Main jets on your ea81   140 primary and 162 secondary.    162 seems really high compared to others I've read about mainly 140 on both mains as many weber kits come with the 32/36.  Wondering why so large. The reason I'm wondering is the following

 

 I have a spfi manifold that I want to retain. It's 6mm large in diameter than the stock ea81. I have 9.5 CR on a brand new engine.Recently I tuned it all up timing at 13 degrees (set on a dyno with the 38/38 on it. ) I went for a test ride and 120 kph was achieve quickly before starting to run out of puff.  Then I took off my cold air intake which comprises of a weber cap on top of the carbie to a 65mm tube about 700mm long to a large cone filter. And it was much more powerful.

Hence a Ramflow air filter will be purchased and the snorkel will be taken off. I think this is a good move. However, for the sake of maximum economy and power I was wondering, due to my set up with the spfi manifold....would a larger main jet for the secondary be approapriate? As you have?

 

I have currently 135 primary main and 140 secondary main. My plan could be to put the 140 in the primary main, then buy 145,150,155,160,165 mains and try them al one at a time in the secondary main jet.

 

What do you think of this idea and how did your ea82 run performance and economy wise in the ea82. Just wondering about the potential of my engine with the larger secondary main jet

Cheers.

[Loyale 2.7 Turbo]

Loyale 2.7 Turbo.  Thankyou for your contribution to my many questions over the months, you have been a great help.

 

You're Welcome!  

 

I really appreciate your nice comment.  

 

---

 

 

... 162 seems really high compared to others I've read about mainly 140 on both mains as many weber kits come with the 32/36 ...

 

The full explanation is here:

 

~► http://www.ultimatesubaru.org/forum/topic/71510-ideas-on-swaping-a-weber-carb-on-ea82%C2%B4s/?do=findComment&comment=1027086

 

Kind Regards.

[tweety]

Read and read and read many thread son this topic of jets for the 32/36.

 

I can see your reasoning for the 162 secondary main jet.  My engine is running superbly on its low revs primary jet of a 130 If I change that to a 140 and raise the 140 in the secondary to 155.  that would make total 195

 

As for the idle jets. might leave the primary as is at 55 and raise the secondary to 60...at least play around with the secondary idle jet.

 

I've ordered a jet pack on ebay. should be here in a few days. Also ordered a ramflo air filter.

[jono]

I certainly hope you get a pack of little jets instead of a back pack jet pack

 

Tony, you tweeted off just after saying "it was much more powerful" ...I was expecting times for the new 0 to 120 compared to the old !

 

With your manufacturing abilities and ability to adapt from one thing to another without any indication you could be a fuss pot .any chance you can make up an air filter case that sits directly over the carb throat and sit flat like a wrecked angle panel filter or round pancake like Toyota Corolla ?

Almost a flat funnel shaped mounting ?

 

The ever resourceful Jes to the rescue once agan

[Loyale 2.7 Turbo]

... I can see your reasoning for the 162 secondary main jet.  My engine is running superbly on its low revs primary jet of a 130 ...

 

I'm glad that you understood that I went thru many "Trial and Error" tests on my Wagon, prior to decide which main fuel Jets were the most perfectly working ones; but you must keep in mind that all the Tests I did, were done with the 1.8L Engine moving a heavyweighted Wagon body, with certain amount of added Load; which delivers Different Results than testing another 1.8L engine, moving a Lightweighted Trike.

 

Long story Short: You must do your Own tests. 

 

Too big main fuel Jets, will make the engine to Waste the Gasoline, Too small main fuel Jets, will make the engine to Loose some of its potential...

 

Good Luck with the Jet Sizes' Test. Please don't forget to share the results here with us.

 

Kind Regards.

[tweety]

err, thankyou Jonno,  I don't take times of travel. My butt's force against the seatback is my guide.

 

I've ordered a ramflo air filter. allows air input directly vertically down the throats of the carbie. tick and yes....I'm a fuss pot. for our USA friends (true meaning of the word as we have fought alongside each other for decades now)  "pot" comes from the word potty being good at cooking, or inhaling something green. and fuss meaning one has class in eating or dining, a perfectionist in character and handsomeness. A perfect pot of food cooked in a restaurant. Add them all together I'm a dizzy handsome dude that eats well......yeh Jonno..I'm a "fuss pot"  

 

Loyale- yes I read you.  My Lotus engine I owned had twin weber dcoe40's and was pretty handy at tuning them. I'll make changes one at a time etc.  My understanding through reading heaps of stuff has improved on the DGV. eg ideal turn out of the mixture to be 11/2 - 2 turns and mine is 2.5 turns out so have to go up on the idle jet 5 points so that will go up from 55 to 60.  Hoping to get it down to under 2 turns out.

 

140 is the start for primary mains as per some suppliers of the carbie like redline. so will go from 130 to 140 there.

 

I think ideally it means 140 left (adds up to 280 same as Hitachi) but will try 145 and 150 for the secondary mains.

 

Airs will leave them at 160-165 as read they have less effect on issues and are in the ballpark but could go higher say 175.

 

Secondary idle is for the smooth transition from primary throat to including  secondary throat opening. .So 50 there will remain unless there is an issue.

 

Think I have it covered. Yeh will print my results. Really cold here -2 to 9 degrees C so wont be for a while.   Tony

[Loyale 2.7 Turbo]

... 140 is the start for primary mains as per some suppliers of the carbie like redline. so will go from 130 to 140 there.

 

I think ideally it means 140 left (adds up to 280 same as Hitachi) but will try 145 and 150 for the secondary mains ...

 

Great Plan, Kind Regards.

[tweety]

Progress-  two changes made. A ramflo air filter. This gave the ea81 the same increased output after I took off the snorkel set up. Sprayed a bit of that filter oil on the foam and easy install.

 

Then I took out the 4 x 5" long motorcycle baffles in the exhausts. These had washers welded inside them to duplicate the same exhaust outlet as the stock Brat/Brumby exhaust size. The exhaust now only comprises of an effective muffler. Test ride, gee I'm making progress here. Lots more pick up.

 

Should get a box of jets soon. But even at this stage the pick up/response is superior than the 38/38. I have an idea of hooking up a micro switch to a dash light to let me know when the second throat is opening. Think this could help me to be more economical. The transition isn't noticeable.

 

[tweety]

Today I got in the mail a box of jets from the USA and a colortune unit.

 

Jets in my 32/36 carb were Primary- main 130,idle50,air 165

Secondary-main 140,idle 60, air 160

 

I attached the colortune to the number 1 spark plug hole and found, after warming the engine, that it was colored light blue at idle. Meaning the mixture screw needed turning out anti clockwise until a Bunsen Burner blue color was achieved. Having done that I turned the engine off and counted the turns the mixture screw was out....3.5 turns..wow!!

 

So this now required for the primary idle jet to be changed to a larger jet to achieve 1.5-2 turns on the mixture screw. I ended up with 65 as my primary idle jet and 1.7 turns out with that mixture screw. This gave me the mid blue color on the colortune device. At this stage the device has paid for itself IMO. Took the trike for a run,much more power and smooth as...

 

Reading the colortune guide it is not unusual to see yellow color from the device when under acceleration particularly fast revving due to the accelerator jet squirting fuel. So rich under those circumstances is ok. What I did, when the engine was idling was place a screwdriver on the secondary jet lever to see what color the device would be when that was revved without the primary throat opening more than idle. It went very yellow. = lean. I needed more air.

 

Next step I made the following changes- primary main from 130 to 140, primary air from 165 to 180, secondary main from 140 to 145, secondary air from 165 to 180.

 

 

So at the end of the task I ended up with-

 

Primary- Main jet 140, idle 65, air 180. This gave a rich blue color with the colortune from idle right up to 3000 rpm. Very happy with these jet sizes.

 

Secondary- main jet 145, idle 60, air 180. This gave good revving result with rich blue on the device when revved over 3500 rpm after the yellow color went away afer accelerator jet finished operating.

 

Test ride. Wow, never had this performance with the 38/38. No hesitation, not surging etc. Really nice. Then WOT, very good, the engine howls. I'm of the opinion however that the secondary mains could be raised to 155 or 160- even 165 from 140. Would I need a larger air jet as well to do this? It just lacks a little at top end. Not much though.

 

I'm going to leave it now for a few runs to see how it impacts overall. I'm also of the view that the SPFI manifold might well be allowing a performance advantage now. That's how it feels.

[Loyale 2.7 Turbo]

... I'm of the opinion however that the secondary mains could be raised to 155 or 160- even 165 from 140. Would I need a larger air jet as well to do this? ...

 

Not necessary, I raised the Secondary to 162 with same Air jet,

 

but I don't have a Colortune...

 

Kind Regards.

[tweety]

Thanks Jeszek, I thought so. I'll try some larger jets. Colortune is a handy tool for your toolbox. This is a comparison Stock from Redline for the Subaru is on the left, mine on the right: 3 days later far right

 

Primary Main: 140 .....................140 ...140

Secondary Main: 140 ................... 145 ...155

Primary Air: 170 ..................... 180 ....170

Secondary Air: 160 ....................180 ....180

Primary Idle: 50 .......................65 ....60

Secondary Idle: 55 .................... 60 ....55

Edited August 2, 2015 by tweety

[Loyale 2.7 Turbo]

Both Air Jets @ 180 and Both Main Fuel Jets @ 140 is a good Bet for your EA81.

 

In my own humble Opinion.

 

Kind Regards.

[Loyale 2.7 Turbo]

Thanks Jeszek ...

 

You're Welcome!

 

 

... I thought so. I'll try some larger jets. Colortune is a handy tool for your toolbox ...

 

Yes of Course, I really Want and Need one, to fix other people's cars.

 

However I don't believe that such thing is available here,

 

nor that I could afford one... Kind Regards.

[tweety]

some fine tuning today.(sic)

 

Se my last post. Jets on the far right are the new ones. Went on a short trip and only used the primary throat and got 25mpg (Aust) an improvement over the 38/38 of 19-23mpg (Aust). But am wanting bit better economy than that. The trip involved cruising at 70mph (110 kph.

 

Of course other factors involved with this is gearing...no overdrive. 3100rpm @ 60mph. Minor parachute effect of the trike roof.

 

But I'll plug away. Certainly achieved a lot to date. I'ts revving great and power is way up on the 38/38.