Tweety's VW auto/Subaru EA81 conversion rebuild

It was 6 years ago I purchased my new Panther trike new. It had a 1916cc new engine and 40 year old VW full automatic.

For a few reasons I went EA81 Brumby engine. The engine got a supercharger ala Joels method of suck through SC12. Then EFI SPFI from USA (we didnt get that here) then I retired and dont want to do any major work on him anymore just tinkering.

So out it came along with the 003 auto. I purchased another auto (you have to be quick!!). Then took it to an auto specialist for new seals, gaskets, "O" rings and service. That cost me $418 and $450 for the auto. And apparently according to GV autos its in good nick.
The auto and diff were split to get to the "O" replaced there.
This is the unit painted and ready to put into the trike. I made up a meshring gear cover.



The following pic is of the new tranny diff where the axles bolt to. Note the bolt on flange. Then the next pic is of the older tranny (might be younger but its the original one in the trike) and note how there is no flange at all. So there are differences.





Bit odd. I thought they were all the same. By the way the two small holes are for an electronic speedo sender. I made up a new one on the new tranny.

This final pic is of the tranny and the EA81 manifolds. I am retaining the SPFI manifold (seen here painted on the left) which is 6mm bigger in overal diameter compared to the original manifold.



When I first installed the EA81 I had a 32/36 Weber carbie. This was ok and achieved around 30-34mpg. But it was sluggish. I was constantly using lots of throttle to get the second throat opening. The auto didnt help here. So this time I've purchased a Weber 38/38 synchronic carb new. Both throats open at the same time. Some people swear by them others say they chew too much fuel. The bonus is that both weber carbs use the same mount footprint. So if its a guzzler the swap will happen.



THE ENGINE

The boys at Ausubaru have been great. Experience means everything. The cam will be a 16/56 with .235" lift. A 20/60 cam is better for higher revs. I'm after high torque at low revs. The EA81 - if you check the list of Jap engines you'll find the EA81 has the lowest max torque point at 2400 rpm. It's still no powerhouse especially hooked to an auto. But it has great reputation for reliability and long life some up to 450,000 kms.
A slight increase in compression is desired- better for torque. Standard is 8.7:1. Upon taking the heads off both head gaskets had small leaks so it was time anyway to rebuild. EA71 pistons from earlier Subies are several thou higher on the crown and will raise comp to 9.0:1. SPFI pistons higher still raising it to 9.5:1. And EJ20 pistons have the same bore but superior oil rings etc. (That info is a bit over the top for me but I tried).

My builder is to suss out all options. SPFI pistons from USA only etc. He pointed out that with that desired cam you wouldnt want to raise the compression too much. EA81 lovers know that the heads have very few options to improve performance. So a slight port and polish and 3 step valve grind is all we can do. I've left it in his hands. With superior breathing, large carbie jetted right, good exhaust and an auto that operates as it should Tweety will be ready for many warm weather rides.

BIG PROBLEM!!!

I just realised the Differential housings are different.
Below is the new diff without mounting holesfor the frame bolts.



Then there is the old diff housing with the mounts.



Then there is the frame mounts in this pic.



What this means is that both auto box/diff assemblies are going to have to be taken to the auto shop. Both diffs split from the auto and swapped so I have the old diff and diff housing in the new auto. drat!!!!

Why didn't you fit the SPFI instead of the carb?

The SPFI system worked but had its issues. Everytime I tested a sensor (MAF,Throttle, temp) they were faulty or not working in range. So everytime I had to send away to USA and some sensors are expensive even from their junkyards.

In short I feel, after having the SPFI system on for several months, the system needs soemone with more knowledge of electronics, has the energy and youth to work on it and the patience.

I've recently retired. I am going back to what I know- simple mechanical solutions like carb. I buy new, carbie being the weber 38/38 was purchased new. Stress elimination is what is the objective. Stress- the reaosn for retiring early. Less lifting of the body to fiddle. Tweety is to get more body mods as time goes by, to make our already comfy and warm existance even more so. Not ruling out woodgrain side body designs...
The SPFI is ideal is anyone is wanting to buy it. Minus the intake manifold. I've been working on cars all my life, Lotus's, Zephyrs etc its time to stop lifting the bonnet...err...body.

SPFI ssytem less manifold (available from USA) $250 + postage suits ea82/81 manuals, spares etc

I can't see how you managed to have problems with EFI let alone "stress free" with weber progressive, they got to be rated as one of the the worst carbys, and i completely agree on that as I had experience with weber progressive, piece of shite!

im my whole experience with EFI, which been a large portion of my life. Only had personally a MAT sensor open circuit did not effect the running just a CEL, couple of O2 sensors die but they have a finite life span and an ECU playing subtle funny games, but with on board diagnostics it makes fault finding a piece of cake.

On the other hand, only few cars I had with carby, all had problems and worst was Lada and Escort which were my experience with weber progressive.
Only way I could get those damn things to start in winter was warming the carby with a hair drier 😬

best carby i found actually were stromberg in terms of setting and mostly forgetting.

vlad01 wrote:I can't see how you managed to have problems with EFI

If you follow Tonys thread over on Ausubaru the fuel injection system was just electrical problem after problem, the down side of working with a system that age and one that is not common in Aus unfortunatley meant swapping parts was no easy task.

A shame because it had such potential.

Yep and that is a very very old EFI system and not all that sophisticated (especially in terms of today's units). Fair enough.

age shouldn't be a problem. Most of the stuff i work with is still 80s /early 90s tech with modern touch where needed and I among others in our group find this is a sweet spot for EFI tech because the simplest vs most flexible ratio is the highest not to mention highly documented so info and expertise are plentiful.

But then again suby are one of those obscure things that have their info well hidden to general public.

I even have access to alfa romeo tunes but not suby ones. but who has an alfa?? Still though to redo a whole EFI system, including loom and sensors and connectors is very straight forward and relatively in expensive if you do it your self.

anyway, that said I had a type 3 with Bosch d jet. its like it was abandon because no one could figure out what was wrong.

15 min I worked out the problem and ordered new pump. Some more minor issues more, missing pump relay and the dizzy was out by some 30-40º.
Bamm! 1st go it started, one of the most reliable systems I owned.

Thanks guys for your understanding.

At 30 yo these SPFI systems were one of the early birds. As Joel mentioned I had heaps of posts on Ausubaru detailing the issues. Has Ausubaru guys attend and ride around in the pass seat with wires hanging out all over trying to locate issues.

As for age I took out a throttle sensor. The tiny disk the 3 small arms rest on was totally worn from how many spins in its 25-30 year life? I was lucky to have one contact from Canada send me another that he knew he had to test prior to purchase as "they pack up easily". An MAF was not working correctly - go to Rockauto and look up EA82 MAF SPFI...$400 USD !!. Temp sensor- a rare beast if you can find one. Luckily mine was fine as you can easily test it. Injector- purchased one from a subie friend that imported the throttle body for his LPG brumby cheap...try buying one from US. $500+.

Anyway you cant compare horses with donkeys. Cant compare an Alfa with a Subaru etc. The weber I have is 38/38 not progressive but synchronic. I had a 32/36 progressive myself before supercharging and it was sluggish and second hand. Never again. My 38/38 cost $450 new from Weber performance Mordialloc. If I want a 32/36 then a similar amount is ok.

I've messed with going outside the square too many times. In fact going synchronic is outside the square enough. But to go to a different brand of carbie to what 95% of subaru owners go to from the stock Hitacki is messing too much.
I'm nearly 60yo. Knees arent so good. Havent got a shaggers back, more like a Lotus back lol, they are low cars and spent a decade working on the buggers.

The ea82 SPFI I fitted to my trike was originally a kit. There is nothing wrong with it but it's purpose was to near eliminate toying with the engine to achieve reliable pleasure times. It didnt do that. Carbie, engine 6 wires for dizzy, alt and oil pressure and kickdown...now that's smiple! It will be garaged of course. I dont think I'll have problems going this way but appreciate your views

ouch! MAF!

I cringe when ever i look at MAF based systems. MAP is so much easier to work with, tune and reliable.

Vlad01. I concur.

My original MAF was definately faulty. So I ordered another one from Rockauto- a leading parts supplier in USA. It was under Subaru EA82 SPFI and had the correct part number - every number and letter.

In the meantime I sent the old one away for checking hoping I could, for a small sum get a spare out of it.

The Rockauto refurbished one arrived hence placed it in a box and waited for another injector to come as well.

A few weeks passed. I then put it all together and found that the openings to the Rockauto MAF were about 3mm larger in diameter, small enough not to notice, large enough to cause a concern. It also had a meshed intake which one could mistake as being a progressive upgrade to the original.

I made enquireis with ASMB Subies forums and found that the MAF wasnt off a Subaru. So email Rockauto- "sorry, its over 30 days- no return possible". Even though it was listed under Subaru ea82 when in fact it was off a Nissan "truck" believed to be known as a Pathfinder model here. Total loss $450 AUS

Got my old one back- not fixable. Found another at a wreckers in US- $200 worked correctly. Compared the two. It was understandable why Rockauto got them mixed up- all numbers matched exactly EXCEPT on the Nissan one there was a number 3 barely seen just inside the bakerlight cap. You wouldnt look for it. But they sold me the wrong part listed under the wrong car and should have refunded/allowed return. I embarked on a mission for several months slamming Rockauto every time there was a chance.

That's cars for you. I mean take for example Triumph Stags. There was one restored on TV the other night- top show. Their workshop had every conceivable tool at their disposal. But do you think they had on that a/ would fit onto one particular head bolt slightly hidden under part of the head shape? and B/ tough enough to get a proper grip on the head of the bolt to undo it? What was the engine designer thinking? Certainly not thinking of the poor buggar undoing that bolt.
Lotus engines bothered me just as much. Other cars that have slight differences with each month/year. After 40 years working on vehicles trying to get used engines to run correctly not knowing what the insides were like in condition etc its time for rest time. I'm burned out.

Today I'm taking my old auto trans/diff to the auto trans place that did the work on the other one. I know it works well except engine over revs in first gear when full throttle, likely an adjustment issue. New gaskets and seals etc. Then I'll use that for the trike and ponder on the very good transaxle I have serviced with new seals sitting there out of a type 3, the one without the mounting holes in the diff housing.

In the end you have to laugh. Get the tranny in half way towards its home in the trike and sat there staring at the diff housing wondering where the mounting holes were. My initial thought was that part of the housing was unboltable surrounding the torque converter but closer look saw it was a work of art- all one piece that should one day be in an auto museum lol. Laugh now- didnt laugh then.

This gives me a good idea.

Without good ideas we would be only with women.

Does anyone know the automatic diff ratios of the 411/312 final drive - tried the net- limited infon all sites. And I assuem the 003 trans in 411/412 and type 3 are the same????????????

tweety wrote:Without good ideas we would be only with women.

Does anyone know the automatic diff ratios of the 411/312 final drive - tried the net- limited infon all sites. And I assuem the 003 trans in 411/412 and type 3 are the same????????????

hahaha 😂

I think type 4 diff were slightly lower ratio compared to type 3.

Was just looking into suby EFI systems a bit more, geez they are odd balls compared to most cars. what the hell is a JECS type connector? they some come crazy injectors thats for sure.

Only connectors I know of is EV1, USCAR and odd ball Delphi type connector.

My idea is maybe I could provide suby conversion harnesses? show car quality ones of course.

Final Drive ratio for the type 3 auto. "003" model is approx. 3.67 (Exact ratio is 9:33 = 3.6666repeating).
Don't know what the "type 4" (i.e. in Aust., Kombi of that time: '69 to '74?) version is.

http://www.thesamba.com/vw/forum/viewtopic.php?t=317203

that might help

thanks for that link.
If thats true, that the type 4 sedan had 3.9:1 then a few trike owners woukld seek out the type 3 diff inards into the type 4 housing to drop the revs at 100kph about 200rpm.
The auto with 295/50r15 tyres runs at 3200 rpm at 100kph. This is too high for a lightweight trike. Drop it by 200rpm then a further 150rpm with the 275/60r15 tyres and you have a decent drop in cruising revs.

For me its all too much trouble and money.

Besides being an older fart I dont go over 80kph....lol....and risk future fines according to some haha

original auto trans with new seals etc is in situ.

Bit of progress. A friend made up the adapter to go between the larger SPFI manifold and the 38/38 Weber synchromic carbie. The opening is more than double that of the ea81 manifold.

Reconditioned engine is to come in about 2 weeks. It is being built for towing, high torque at low revs. And the third pic is the stock manifold compared to the SPFI. 6mm bigger diameter

nice work!

thanks Vlad01

the manifold and adapter is at the engine builders so he can mount them on the recoed engine. as you likely know when shaving heads the manifold bolt holes might need to be ovalised a tad.

should have it back within a week. pics to come then

Ok some news. My EA81 is at the balancers getting its balance of course.
The block was a mystery. The engine builder found that on one side of the Subie block had 11 thou clearance from the top of the piston to the block face and on the other side 30 thou. 19 thou difference.

So it's been milled. His calculation revealled 9.5:1 compression will come. Stock pistons oversize. torquey cam for low revs.

And some bling is here. there valve covers were stipped by me and sent off for copper then double chrome coating. At under $200 the pair - worth it for a trike with an open engine.

Got my ea81 engine back. rebored now 1820cc. 9.5:1 CR, balanced, new torquey cam, new everything.
Now waiting for the intake manifold because the heads and block have been shaved therefore moving the intake mounting holes closer together. Another engineer has the manifold now and he has to ream the holes 2.5mm each end towards the other end, allowing the manifold to line up the bolt holes.

Engine is in and ready now for the manifold. Porsche radiator to purchase after xmas. radiator size for the 911/996 "centre " radiator is 620x170x41mm 41mm in/out of the radiator means reducers needed to fit the 32mm hoses.

Getting there.

geez that engine sure came up clean!

Yes it did. it was washed and painted "clear" by the engine builder.

The engine is in now. Waiting on manifold.

I bet it will go a whole lot better with even CRs all round and a better cam too.

Yes it should .

Seeing as its hooked up to a type 3 auto I prefer low down torque so the "punch" is at low revs. I had a weber 32/36 prgressive a few years ago and was disappointed. I had to rev the engine too much to get that punch- the second throat to open.

I've put up with s/hand engine all my life- never got one fully recoed. I've had around 90 cars. Including 8 VW's. 2x types 3 (fastie and squareback, beetle , Tiguan and Golf series one diesel and the trike was a 1916). Am 58yo. This engine will see me out. Hence doing it properly. The SPFI might have been ok but was complex and the wiring and sensors were 30yo and costly to renew....to another s/hand piece which is a gamble. I'm happy to go with the 38/38 weber synchromic, another boost at low revs. in fact that new carbie going on will b the magic in the new arrangment. But it will need jetting.
Some say the 38/38 suitable for the Jeep/Holdens and Ford 6's is too big. But all the reading I've done say otherwise. I mean they use them in Datsum 1200's. And owners swear by them.

In fact if I owned my old 1916 reckon one of them would suit??

In the meantime I'm wondering if the hole for my old O2 sensor (when I ahd SPFI ) on the exhaust could ouse anothe rO2 sensor and use it to guage correct mixture for this engine. But I'm getting ahead of myself.

Nothing beats have a properly rebuilt, blueprinted and configured engine for a older vehicle.

I haven't had any of my car's engine rebuilt but I have picked up some virtually new old ones and it gets me excited to hopefully get one built by Duggan's balancing in Melbourne next year. A mild one but blueprinted and balanced to perfection!

Sometime you get lucky with an old car that had that wednesday built engine with perfect balance though. I recently picked up an old car like this and its the smoothest thing i have ever driven, smoother than my old boss's passat, kluger and his new audi and the dozens of new hire cars I have driven over the years. And its old and has an engine layout thats inherently out of balance.


anyway, yes you can fit a wideband and gauge to your exhaust bung and jet your carbs to get the right AFR. Cam and engine configuration will alter your AFR.

I found with tuning EFI engines that even a simple sports exhaust and extractors on totally stock engine can make them breath 10-20% more and run very lean as of result. Like 17-20:1 AFR lean!! So retuning is necessary and critical.

Tweety PM sent. Paul

I didnt get your PM paul.

Engien is installed and complete except for the Porsche radiator (911/996 Centre type 620mm x 170mm x 41mm) 3 x 6inch thermatic fans. All to be purchased in February (or I dont get Chrissy pressies).

Here is one end of the ea82 SPFI manifold now reamed inward by 2.5mm (each end meaning 5mm total) to allow ofr the shaved block and heads.







oops

Do any of you guys have tips on first start up? Got some from the Ausubaru guys. This engine has been rebored, new cam, brand new oil pump, etc. So I presume the oil pressure light going out would be the most important thing yes?

There is a good article on Kombi Klub
I will try and link

Have a read here

http://forums.kombiclub.com/threads/running-in-new-motor.49472/

Thanks Bizzarre,

Info was "Gold". think I'll remove spark plags and coil lead and crank for a few seconds to get oil pressure up prior to starting.

Very informative.

Tony

yes, plugs out and crank til oil light goes out and for good 30-60 sec more.

start and immediately bring to 2000 rpm or there about and hold it there for 15-20 min. This will break in the cam and initial break in for the rest of the engine. This rpm heaps break the cam in and keeps it splashing with oil spray critical for break in.

Dump the break in oil and let it cool off for hour or so.

refill with new break in oil, fit new filter.

Start it, readjust anything if needed and proceed to break in.

Drive it with lost of varying rpms and loads. Do some standing starts flat stick to full rpm, allow overrun til a crawl. Repeat several times. Then do the same but in a high gear and plant it of from just idle, really lug it to load the shit out of it and allow it to climb the rpm to max, repeat couple of times.

Continue driving is various conditions, heaps of hills in different gears, lots of overrun. Don't be afraid to get the rpms happening.

Do this for 500km, dump the break in oil, readjust what ever is needed and fill with same brand oil, but normal running oil of correct grade.

👍

You will notice the break in oil to have a metallic look to it, this is normal. Goes to being clean after break in, even after the first normal oil change.

First normal oil change should be at a short interval, something like 1500km then normal intervals after that.

oh yeah, dont pre-fill the oil filter on the first time. you'll have problems getting it primed.

it need to be dry so the oil pump can purge the air out of the oiling system without complications. You end up with an air lock between the oil pump and filter thats a pita to overcome sometimes.

Thanks for that Vlad.

I've written to Penrite. They told me that their running in oil is perfect for this process. They didnt tell me to dump it after initial run in with another new filter but will take your advice as there will be lots of moly and filings in there.

They sent me this advice-

lubetech@penriteoil.com

Your enquiry:
Have a Subaru Brumby engine EA81 being totally rebuilt with rebore etc. New oil pump, asling what oil you would recommend. Older style design engine, rockers, OHV, flat 4 etc. originally Subaru recommended 15W-40 when new. Synthetic??

Based on your enquiry regarding your vehicle our recommendation is:

Following the running in period (500 km on our Running In Oil SAE 15W-40) I'd go to a semi synthetic, rather than a full synthetic. HPR Diesel 15 fits the bill, despite the word "diesel". The diesel detergent properties will not be an issue in the "dirty, older engine" as it is clean and new. Petrol rating is API SL, so this is fine for the engine given its year of manufacture. Another advantage of HPR Diesel 15 is its availability -it's a widely used oil, with lots of protective zinc.
You can go synthetic later on perhaps.
Regards,
Alan Jeffery

Now I think that is good service. Also I knew the Penrite owner Mark Diamond via his mechanic in the 1980's and they are one well oiled company. pun intended. lol FYI Mark raced one of 25 AC aces (pre cobra) cars in Oz and USA. He had a Ford Zephyr engine and Toyota 5 speed. I owned Zepyrs at the time. Cheers

yeah I still would dump it on initial cam run in and then go with the 500km interval like they said on the 2nd fill of run in.

Being a flat tappet engine older style I'd expect more wear metals to be present in the first run than a more modern low friction engine design such as roller rockers, roller lifters etc... Hence the cam run in dump oil. I dont think having too much metal is good for the rest of the run in.

unrelated but interesting anyway. I have re-broken in 2nd hand engines which were not officially broken in by factory and certainly a granny owner wouldn't break em in properly.

when I fill with the penrite break in oil.

2 things I try to achieve.

flush out old incompatible oil and its additive chemicals, as run in oil is only zinc additives and not much else. Its basically base stock oil.

run in the engine to my operating conditions 😂

Amazingly the engines always show clear signs of breaking in even though they may already have 100,000 on them. certain components in the engine flex, move, load up different if the engine is really put though its paces compared to if its only putted around.

I get that classic break in metallic oil on the first to second dump and it clears to nothing normally by 2nd or 3rd oil change. Get a UOA done after its settled and results show perfectly low wear rates and engines of mine goes years of abuse to live 300+ and counting.

gearboxes do the same for me, they produce metallic oil on the first run and come clean from 2nd onward. but i dont run anything than normal oil in them 1st and then with teflon additive there after so i guess they get stressed pretty hard then lol.

Yep,
Worth the few dollars for another 4 litres of run in oil after cam break in.
Appreciate the advice. Looking good for Feb to buy the Porsche radiator and 6" fans.
Tony

Engine running. Once we figured out the dizzy was 180 degrees out that is. Anyway here is a video of it running.
Start really easy. Early indications are that jetting is either correct or near to right. low down torque is apparent. wont know much more for a while.

nice!

Running in has finished. Done about 1100 kms. Still varying speed though. Running rich so needs a tune. Instant starting with the choke then choke off after 10 seconds and can idle nicely. Gee its nice to have an engine that idles the same faultless way everytime.

Economy, bearing in mind I've been running it in but 26 mpg is impressive for me. Likely easily hit 30 mpg once loosened up.

Have now got engineers report. No hiccups there. Engineer had to do a "stability test to find out the angle of the balance point. In Tweety's case it was 62 degrees. Something required for ADR's for trikes. Trike weighs 660 kgms.



Ready for a trip up the mountains





The engine has a lot more low down torque with that 38/38 carb and torquey cam. Mid range power has increased. Top end- dont know yet, havent tried.

Just an update for those following this thread.

I have known the 38/38 carbie is running rich at all revs. I'm not wanting to fiddle with float levels etc, rather Weber performance give it a dyno and fix it all at once.

We headed off for a trip from Euroa Vic to Mt Kozzy, Batemans Bays, Orbost and Mt Hotham then home. We towed a 300 GVM motorcycle camper trailer and trike now weighs 660 kgms. So total weigh is around the same as a Brumby ute = 1 ton. But this is a VW auto and a larger carbie than the 32/36 commonly used, larger manifold from a SPFI USA model and wind resistance of the trike roof.

And all those hills. But was very impressed with the recoed EA81. economy ranged from 10.3 to 11.1 L/100 kms or 25-28mpg. Very good result.

Power seemed disappointing at higher revs. Then when we got home I discovered that the two gears of the carbie throats were touching the new adapter. About 75% throttle only. Ground away some alloy and boy- revs out nicely indeed.

Another issue I had was the auto kickdown. The VW unit has both vacuum and electric. My electric unit switched on at half throttle making it compete with the vacuum unit so hunting gears was annoying. Adjusted the switch to come on only at full throttle seemed to have fixe dit.

Went for a ride without towing for a picnic at Yea welands on Sunday. Achieved 8.7 L/100kms or 32.5 mpg. This gives the 48 litre tank a range of 550 kms. Which is really good. My 1916 would not get over 420, the supercharged version of this EA81 210kms (slurpy) and the sPFI version 380kms although the SPFI version had faulty internals.

All in all it was worth the work to get the reco, higher compression, 38/38 carbie and larger manifold.

very good!

Pity you weren't doing the blower setup now that everything is rebuilt and sorted, nice work.
Just out of interest I have an ea81 in my kombi with a progressive and never had an issue, I think they are a great little carb, bus will sit on 120 with 30x9.50 tyres stock gearing, sounds like a Cessna with the twin straight thru pipes 🙂

660 kg's is a lot of weight for a motor/trans and 3 wheels? That's only 100 kg's lighter than a 6 volt Beetle.

The supercharger drank too much fuel and was hard to dyno successfully to get it running efficiently at all revs. Nothing beats a factory set up blower. It was fun at the time. It lifted the front wheel easily but no one saw it due to the black smoke and raw fuel out the exhausts lol

My ea81 has the sPFI manifold being 6mm larger in diameter. Add the 38/38 weber and it was a real gamble if it ran well and response was better. it was a success but I also dont know if the new cam a 16/56 (I think) high torque at low revs contributed a lot to this. Obviously better breathing, two throats operating all the time, 9.5 CR and short exhausts all help.

These trikes prior to 2011 were not allowed to go over 450 kgms then the restriction was abolished allowing imports weighing 700 kgms or so (Ford focus or Peugeot engines. Boom trikes and Touroz are the two in mind. I recall those days and how Tweety would hop over bumps. Now ithe suspension (airbags) works much better with the added weight. The important thing was the roof was constructed with the C of G not changed. And dig this, there is only 65 kgms downforce on the front wheel.

Now the engine needs a tune with jetting only (rich). But we went over the mountains from Vic to Cooma, batemans bay and Orbost then Euroa. Towing 300kgms camper (about a ton all up weight) we got 10.3-11.1 L/100 kms or 25-28mpg. I was reasonably happy with its performance BUT I didnt realise until we got home that the two small gears on the carbie throttle were hitting the custom adapter. I only had 3/4 throttle. And man did that make a difference!! Consider that the original 1916 never achieved those economy figures without towing. But I'm not on here to turn you guys away from your babies...🙅

yeah you'll never get good economy out of a SC setup due to parasitic losses. Turbo you certainly can, and even improve economy further as it does in a way recover lost energy from exhaust heat and uses that to improve volumetric efficient and overcome some pumping losses. Oh and increase thermal efficiency via boost.

thats why turbo 4 cyl today get such great economy and power to boot.


Anyway this little adventure of yours really did come out with great results.

i've been digging this thread, everything just done so well and out of the box thinking.

Thanks vlad01.

Strange how everything changes when you retire. I ran a business for 18 years. So a lot of items were deductible etc. But when you retire you ahve different priorities. Reliability so you can board your vehicle anytime and drive/ride. 40 years with my head under bonnets has come to a close- almost.

I love the tinkering. Tweety is always a project in action. A different more efficient windscreen, another sunroof etc. But it is comforting that the engine is soooo nice and strong. Start up with half choke- immediate start, off with the choke and idles perfectly. Suppose the 9.5:1 CR has a lot to do with that.

Now to the garden. And thats what retirement is like- a mix of activities. Make sure you guys have damn good engines in your vehicles when you retire because engine woes is not what you want.

Now we tour around. We just got home from Portland. 2 weeks ago Batemans Bay. Tweety is like a magnet for people. I do get tired of the questions. Thats how it is though.

I only started my working life few or so years ago and I already focus on reliability and tinker free engines and vehicles.

But I'll be under the bonnet for long time, finish one car, move to the next and not have to touch the one before it for years to come lol. Only problem doing it this way is its frustration free and you run out of space quick lol

Something most satisfying having something you built that you just can't kill or fault for years and years. Looks like your trike will be like that from now on. Enjoy it!

Enjoyed the read mate, congrats on getting your ride all sorted and happy! Would be a big weight off your shoulders I reckon.

Thankyou also for reading the thread.

The trike engine is well and truly broken in. That little ea81 is a nice little donk. If you dont need a kick in the back performance otherwise go EJ. If the ea81 has really good CR 9.5:1 good breathing (the optional at the time twin carb) or larger SPFI manifold etc and its running "on song" it has enough power. If it was a 4 speed manual it would have "more" than enough power for this weight of 660kgms and a early beetle. And being of the older generation it is easy to maintain myself.

And that was the original objective. The fuel consuption was all along done with fingers crossed but it is clear that without the right carbie jets I'm getting 10.3-11.5 L/100kms and thats impressive with an auto towing a camper.

Thanks again. Feedback is a nice thing to get.