Ea81 Weber upgrade
Ea81 Weber upgrade
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
I'm just keen to make sure that the gains are going to be worth it at the end of the day.
Cheers
- Rodeo4jake
- Junior Member
- Posts: 297
- Joined: Fri Oct 19, 2012 5:42 am
- Location: Tylden Victoria
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
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
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
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

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
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...
And they sound cool too! No need to change if the Hitachi is running OK though...
Old Boxer Tricks
1980 Brumby
1978 4WD Station Wagon
1974 DL Sedan
1974 GSR Coupe
1980 Brumby
1978 4WD Station Wagon
1974 DL Sedan
1974 GSR Coupe
- Rodeo4jake
- Junior Member
- Posts: 297
- Joined: Fri Oct 19, 2012 5:42 am
- Location: Tylden Victoria
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
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
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.
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.
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
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

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

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
- Junior Member
- Posts: 170
- Joined: Wed Dec 24, 2008 3:52 pm
- Location: Vasse W.A
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.
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.