EA 82 twin carbs been done?

[Step-a-toe]

Has anyone here done, had or heard of the twin Hitachi's off EA81 being run on an EA82 single intake port engine?

Given the EA82 is more free willing to rev, also takes on the valve configuration of the EA81S with intake valves directly below the manifold...

I reckon it could be a pretty interesting NA set up

Edited May 28, 2020 by Step-a-toe

[DaveT]

I don't remember if I've seen anyone do it with an EA82.   Since the 81 & 82 are the same displacement -
I would think that the 2 carbs would need to be slightly smaller, because the CFM through each would be about half of what the flow through the normal setup would be.  The Hitachi carbs are a nightmare to deal with, probably better off with something you can get jets for, like webers?   From what I remember from numerous threads, the ultimate power limiter on the EA 81 & 82 is the ports in the heads.

 

[el_freddo]

Yes it was a common conversion in ausubaru for those that got their hands on the elusive twins. 

You getting that old now Steptoe?  

Cheers 

Bennie

[Step-a-toe]

Common on EA81 Bennie,

I am asking EA82, and gave reasons

Dave the twin Hitachi's came as a set pair for exact purpose of being twins, from memory one is etched L and the other R

I put a set after overhauling them, on my EA81 rebuild with 16/56 .235" lift - absolutely amazing, sweet look and tune

It also coincided with my fuel gauge falling faster for some odd reason

Had nothing to do with fuel use. Highway gave 8.5 litres per 62 miles

Turned into a fire feather - at 140 kph indicated, throttle was still light and wanted more and I was going up a long incline !!

[el_freddo]

45 minutes ago, Step-a-toe said:

Common on EA81 Bennie,

I am asking EA82, and gave reasons

I was talking EA82 but didn’t specify, sorry! 

Cheers 

Bennie

[Step-a-toe]

Really? Never recalled anyone doing this...

I do recall EA82 carb and manifold on EA81 for something with a little less wear on things, but not other way

[ferp420]

duel carbs are so hard to tune i fought them on my vws for years webers dolardos and different carbs i had laying around  everytime pulling them off and replacing with the single weber

also there more of a high hp set up giveing you more top end while not doing much in the low end

at ether end of the power band your still limited by the design of the heads so there isent alot to gain unless your porting the heads and instaling better exhaust you wont see much gain at all

if you want any power from a ea82 you have to mod the entire engine from the block to the tail pipe i dont know of any one who has the magic formula for the ea82 i dought anyone has spent that much time with it

i can say this dumping more fuel down the throught of your ea82 wont give you more power just wash the oil off the cylinders

[Subarule]

Dual carbs on a 4-banger? Why?

[silverhelme]

1 hour ago, Subarule said:

Dual carbs on a 4-banger? Why?

Why not? I used dual  SU's on my '64 Mini Cooper.

[Step-a-toe]

12 hours ago, Subarule said:

Dual carbs on a 4-banger? Why?

Could also ask why 250 cubic inch sizes ran a single throat BV1 Stromberg

Two carbs turns things into a double pumper

one carb not have to work so hard, twin carbs cruise at light throttle at 60 mph and I think you get a better VE out of the earlier opening stages of a throttle.

i used to mechanically lock in the secondaries to open earlier. Adverts for Fugly EA71 models referred to the four cylinder boxer as " quadrazontal"

i then had a quad throttle quadrazontal

[ferp420]

the fuel injection system will give more power all the way through the powerband on a stock engine than any carb it has its limits but the heads are more limiting than your fuel system unless you have some kind of monster engine than the duel carbs will kill your performance and your drivabulity

[Step-a-toe]

The twin Hitachi's with manifold were rumoured to be only for the EA81S. I don't know if they were factory on the standard EA81 valve arrangement at all, but they do make a big difference on the standard EA81 despite what others say about restrictive heads.

I chuckled ferp when you mention VW twin carbs because when I fitted the twins to my EA81, not only was I feeling a bit cross eyed, seeing double, all of a sudden my front end started sounding like the back end of a 2.0 VDub bus

Every machine shop seems to be able to boast building race engines. One engine builder I spoke to about the EA81 was quite complimentary about the EA81 saying it's valves were quite big for what they were, and really couldn't improve on them bang for buck wise. But we know about the aviation industry modifying or casting their own heads and roller rocker gear....

The beauty about carbs that just bolt on is old school, but ain't it great ?

Downunder, I know of only one complete EA82 spfi system, and two manifolds only . The manifolds are great for propane onto single port EA81 and 82. I have one set up for an EA81 turbo propane on standard engine - shelved in development

In comparison there are a few EA81S and fair few more twin carb conversions about

[el_freddo]

On 5/28/2020 at 10:42 PM, Step-a-toe said:

Really? Never recalled anyone doing this...

I do recall EA82 carb and manifold on EA81 for something with a little less wear on things, but not other way

Hmmm... you might be right on that one. But then what model did the EA82 twins come from? 

Cheers 

Bennie

[Step-a-toe]

So, I wonder how many others have gone carb converted to MPFi engine for simplicity ? No ECU, no wiring, just old school enginuity ?

Forget the compression differences for this, just head and manifold swap.

I ran carb block, turbo heads, cams, and twin port intake off either MPFI or turbo and simple enough to rig up Impco propane system. For years I ran the recommended sized propane carb , the 125, and J / Cobra converter for the 1800 and it's CFM needs. Then one day I fitted up the bigger L converter and 200 series carb - typically fitted up to around 4.0 litre sixes. My propane teacher ran same on his 351 F100 !

Unfairly to R and D , at same time used turbo crossover exhaust, gutted the exhaust side of a turbo to use as an adaptor between engine pipe and turbo exhaust.

Somewhere in the mix was a stuck open ( slightly?) EGR valve, or its vacuum operation that caused a sick idle and some hard to describe drivability issues ( due to memory)

My clearest memory is taking off from a single lane set of lights behind a WRX, suddenly two lanes approaching a roundabout, me inside lane, well aware the two lanes go back to single in about 100 metres..

passenger window down, WRX beside, and then when I hit 5000 rpm in second, everything came together, deep roar and she just blew off the rex before lane thinning and 80 K speed limit breached

Thus was all in prep for EA82T install, I still wanna go back there some day .....

Edited May 29, 2020 by Step-a-toe

[Step-a-toe]

2 minutes ago, el_freddo said:

Hmmm... you might be right on that one. But then what model did the EA82 twins come from? 

Cheers 

Bennie

That ! Was just single EA82 carb and manifold onto EA81..

Or do I have a typo somewhere??

[el_freddo]

Well to be clear/clear this up: 

my first post here was trying to say that those who found the elusive twins were putting them on the EA82 back in the hay day of ausubaru. 

I failed to say they were specifically putting them on the EA82. 

Then you said that you didn’t recall anyone doing this but do recall EA82 intake and single carb on EA81. 

Now I was asking which model the EA82 twins came from... or what aftermarket product were they using?? 

I hope that helps. 

Plus in these situations “EJ” is always the answer  

Cheers 

Bennie

[Subarule]

On 5/28/2020 at 12:39 PM, silverhelme said:

Why not? I used dual  SU's on my '64 Mini Cooper.

It'll still be a little 4-banger. You can put a horse harness on a mule but it'll still be a mule.

[Step-a-toe]

7 hours ago, el_freddo said:

Well to be clear/clear this up: 

my first post here was trying to say that those who found the elusive twins were putting them on the EA82 back in the hay day of ausubaru. 

I failed to say they were specifically putting them on the EA82. 

Then you said that you didn’t recall anyone doing this but do recall EA82 intake and single carb on EA81. 

Now I was asking which model the EA82 twins came from... or what aftermarket product were they using?? 

I hope that helps. 

Plus in these situations “EJ” is always the answer  

Cheers 

Bennie

I can only guess the twin carbs put on EA82 all those years back, came off EA81 engines imported from Japan and sold by those specialising in this practice.

Sorry for any confusion anyone

[Step-a-toe]

5 hours ago, Subarule said:

It'll still be a little 4-banger. You can put a horse harness on a mule but it'll still be a mule.

And said mule suddenly got bigger

[Step-a-toe]

Hey Bennie...

Are you any good at posting up links to discussions on EA82 using twin carbs (off anything will do for starters) ?

I went factory twin carb or TC as the Brits liked to dub things, prior to the internet for me in 2000. Had to pick the brains, or rather, get a visual of the fuel hook up from under the bonnet if a Subaru specialist who sold me the sad looking twins. An employee had same. Just needed a minute, when his boss who had just cleaned me of hundreds , asks me not to take up his workers time.

That was the last time they got anything out of me

[el_freddo]

Hey Steptoe, 

i cant find discussions of the twins on the EA82, but subius (I think it was) had the twins mentioned in his signature on his L series in tassie. And I’m sure Fang had a set on his L series too. But I can’t find those references. 

Lots of EA81 twin carb talk though. Easy to search using google: “twin site:www.ausubaru.com.au”  

Cheers 

Bennie

[Step-a-toe]

Wondering if it your memory playing tricks.

Subius eh??

I'll try him on er cough FB....

[Step-a-toe]

Yep, confirmed , Sam indeed ran EA81 twins on an EA82.

Well there you go. I will interrogate him on his opinion on the success of it.

 

[Mack Truck]

i have a Weber 38/38 syncro carb on my EA-82 and it works well.  I would not try to mate to old EA-81s on there when the one carb does fine.

[Turkeyberry]

I too run a dual 38 and it's fun especially on highway stretches and anywhere you can let it go and just floor it