Ea81 Weber upgrade

MuZ · Post by **MuZ** » Sun Jul 14, 2013 9:34 pm

Since buying my brumby a few months back I've read a fair bit about the weber conversion. I'm considering giving this a go but before I do I was hoping someone can give me an idea about what the power gains are going to be like, what happens to the fuel economy and how to get the most out of it.

I'm just keen to make sure that the gains are going to be worth it at the end of the day.

Cheers

Rodeo4jake · Post by **Rodeo4jake** » Sun Jul 14, 2013 10:43 pm

G'day mate,
This is only my opinion & others here are happy with their Weber carbs. My brother & I both have Brumbys. I have a stock carb & he has a Weber on his. I have to say that after driving both, mine goes slightly better. I wouldn't bother with this mod until all other mechanicals on your car are perfect. Only then might you get some sort of benefit from it.

Cheers Jake

Post by **TOONGA** » Sun Jul 14, 2013 10:44 pm

power gain yes, fuel economy... don't tromp the second barrel all the time and yes you have fuel economy.

I know that the 32/36 is a great carby and even better when tuned and jetted properly.

and that's where the argument always begins tuning and jetting

TOONGA

Subydoug · Post by **Subydoug** » Mon Jul 15, 2013 9:15 am

Hey MuZ,

I got a 32/36 on my old wagon as well. I replaced the stock one with it in the hope to improve my shocking fuel usage (was around 14l to the 100kms). Weber dropped it to around 11-12l/100km. Wasn't till I swapped to the manual tranny that it went to something decent. Now on a bad day Il get 10l/100km in the city. Usually get 8-9/100.

As far as performance goes, unless your doing dyno pulls and drag times you probably not going to be able to tell. Properly tuned with other supporting changes to the engine and It would probably flog the pants off the stock Hitachi.
Driveability is very nice (think Rolls Royce

), install was quick and simple.

Few other things I noted, If you swap the throttle linkage on the carby for the stock one you don't have to modify the cable stop bracket, and you get 100% throttle. With weber's linkage I was only getting about half throttle.
Return spring in my weber is crap, I run another spring to really slam it back on the idle.

Regards

Doug

MuZ · Post by **MuZ** » Mon Jul 15, 2013 12:05 pm

Thanks guys, I think I'll hold off on the webber then, think I might go for an exhaust upgrade instead, I've read that you can get marginly better fuel economy from the right exhaust plus some power gains

sublime · Post by **sublime** » Mon Jul 15, 2013 5:31 pm

The Weber is really about improving drivability rather than any noticeable increase in power. The idle, in particular, is a vast improvement over an old, troublesome 'craptachi'....

And they sound cool too! No need to change if the Hitachi is running OK though...

Subydoug · Post by **Subydoug** » Mon Jul 15, 2013 6:42 pm

Cant argue on the weber induction note!

Rodeo4jake · Post by **Rodeo4jake** » Tue Jul 16, 2013 11:08 am

Hey guys,
When I first got my Brumby it ran terrible & was slow,fuel economy was also bad. Try 360kms a tank or so. It had 196000kms on the clock. Looking at all things in the engine bay I could tell a lot had never been touched. So I decided on replacing the dizzy cap & rotor, plugs,leads, air filter & both fuel filters. At the same time I set the timing to 10 degrees btdc & started running 98 octane fuel. End result to all this was a massive gain in performance & I now get 500 kms plus out of every tank. Idle is fine& no probs with drivability/smoothness.
In my opinion if need be I would rebuild hitachi before spending the dollars & time trying to get a weber to work right. At the moment we are going through the process of trying to get brat87s weber to work well & we're considering going back to the stock carb. He wants his to run & drive like mine.
All other things in your engine need to be replaced or be in good working order before looking to a weber to solve problems.

Cheers Jake

MuZ · Post by **MuZ** » Fri Jul 19, 2013 7:59 am

At the moment the brumby is running like a dream, since buying it I've replaced everything in the ignition system bar the dizzy itself, replaced all the filters, cleaned out the carb and run CEM oil and fuel additives through it to clean everything out (if you haven't heard of CEM additives I highly recommend them, expensive but amazing results http://www.costeffective.com.au/)
I'm currently getting around 480km from a tank.

I was mainly after the weber for power gains, but if all I'm gonna get it a sweet induction note, I think I will pass untill the hitachi shits itself. Or there are no more performance options available to me.

steptoe · Post by **steptoe** » Fri Jul 19, 2013 9:21 am

Someone expecting me to Grrr

GRR about a tank measure ??

609km on 175.70-13 tyres , fresh EA81 hitachi, plugs leads, rotor and cap, highway cruise speeds 20/60 cam to the real Brumby tank to empty , splutter, splutter stop.

Never refilled it to measure its capacity from empty

Subydoug · Post by **Subydoug** » Fri Jul 19, 2013 9:23 am

For better performance you probably gain a few hp's with just the weber only, probably up to around 70-75BHP, but with a tad bigger exhaust, maybe 1-3/4 to 2 inch, 3 angle valve job and port matching the manifold to the heads that might get up to around 80-85hp. I dare say with the hitachi it would start to become the bottleneck before too long.

Due to the nature of these motors I really think the cost of the parts vs performance gain is too steep to justify it. Your best bet for a better performing Brumby is an engine conversion to something like an ej18 or ej20. Good MPG and way more poke.
If you would prefer to keep the old ea81 (and I cant blame you, I love the little motor in traffic

) and would like more performance you will probably have to end up pulling the motor apart and doing every little thing that helps the big picture.

Jake, yeah Ive conked out on the side of the road outa gass after around 350km's before too. Unfortunately, when I decided to have a look into the condition of the hitachi someone had tinkered with it previously. Think gutter bolts and butchery

. Weber bolted up and was running great within a day.

My best fuel economy gain was swapping out the 3spd auto for the 4 spd manual. I think I paid around $200 for everything and did the swap in a weekend. Made all my money back within a month from not buying fuel

.

If your friend BRAT87 chimes up Im sure some of the guru's on here cam get him up and going.

Regards

Doug

scoobymine · Post by **scoobymine** » Fri Jul 19, 2013 10:31 am

I'll put my two bobs worth in here. I reckon the Weber conversion on my Brumby has improved performance no end. I have the confidence on long runs to overtake, especially when you can give the pedal a kick and the second throat comes in. Trips to Perth are much more comfy with the knowledge that you can get morons off your arse in 110 zones. In saying that, I'm lucky that the speed limit is 110 just near where I live, and she loves it. My Weber doesn't love constant city driving. The Weber is a low cost power upgrade, and if you convert your original air cleaner, it give s a smoother run and easier to tune.
If you do want a Weber, be smart and purchase it from The U.S, the price difference is huge. Also, how much money do you want to invest in a car that's 20-30 years old. Buyers don't want to know how much you've spent when you come to sell it.
Anyway the Weber gets a thumbs up from me.
P.S Economy is OK if you're not lead footed.