EA81 mods

subie_1st_timer · Post by **subie_1st_timer** » Sun Apr 13, 2008 9:37 am

i know i know i'll get told to bung a EJ in, but for now i wanna look at getting a little more outta the EA81 and getting it running right, cause so far im happy with it besides a couple of little issues.

a) the hitachi carby buggered, car still drives fine but the secondry side dont seem to be working properly so when you wanna give it a kick in the guts to overtake etc she just coughs and farts and 4000rpm seems to be about it. think this is due to the LPG that was running through it.

looking at getting a weber 32/36 conversion, hear these really liven up the EA's and fuel economy isnt really effected.... like to hear your thoughts here.

b) sump gasket leak. only minor but noticable. can this be removed without removing the engine from the car cause i noticed you can get to mode of the bolts but the back ones.

ok they the issues, now for the mods.
i not interested in doing a big rebuild, but more thinking if i open up the breathing a little better then this will help. seen the plane boys do this and they seem to get a nice little hp figure out of them.... anyone share any pics on a modified EA81?
I been thinking of doing something along the lines of a dual carb VW setup, but fitting smal throttle bodys (from a hyundai or daihatsu etc) instead of carbs, stock injectors from the same 4cyl and adapting a simple ecu setup, i know people who have used megasquirt ecu's systems with good results, im only looking at simplicity here.

other side of the fence the easiest breathing mod is the weber i mentioned before as its all bolt on, but i like getting in there and fabricating too so hense why i been thinkign the TB option.

anyway can anyone share anything on the humble EA81. cheers

steptoe · Post by **steptoe** » Sun Apr 13, 2008 11:28 am

You have gas system, make the most of it. If your bottle is out of date someone up your way was doing them $75 for the inspection on ebay !

Original date stamp fits in the bottles compliance plate squares. A retets stamp looks like an 18kg tall gas bottle outline with inspectors number inside the bottle outline. either side is a date like 04 (bottle shape) 08 splashed with paint sometimes too

I have thought in the past of cutting the two head ends off a manifold and welding tube ends to each so that a throttle body and plenum can be connected using silicone tubes to join and running LPG. Fittings also needed to allow water to flow between. This would eliminate the manifold flow restrictions. Actually made a Volvo 2.3 single TB fit a manifold and it ran like my twin manifold but bogged down as too big TB. Go for dual butterfly TB to fix the low down bog off

subie_1st_timer · Post by **subie_1st_timer** » Sun Apr 13, 2008 12:31 pm

i dont want to run the LPG.

i figured a ecu, injectors and tb's off a similar sized engine (eg excel 1.

should be easily adapted to a twin tb setup on a EA. i remember capa used to sell twin tb setups for excells with good results, thats another thing that got me thinking for the EA, just a matter of hooking up all the sensors and getting the inlet manifold made.

i also seen a couple of the plane boys using 2 barrel Holleys? anyone gone this way before instead of a weber?

ANOTHER idea i thought of was to use a single barrel carb on each side (one each head). Old falcons used a 1v stromberg and i found them not bad little things and be easy as to adapt and fit up.

have to draw up some designs and post them up. maybe can figure out what would work better

Gannon · Post by **Gannon** » Sun Apr 13, 2008 1:05 pm

Dont make your manifold pipes too big, or you will sacrifice huge amounts of low end torque

Busdriver · Post by **Busdriver** » Sun Apr 13, 2008 2:02 pm

Just a thought, what about using 4 carbs and inlet manifolds off a old jap 4 cyl. bike? Anything from the late 80's around 1100 or 1200 cc's should have big enough carby's. Not too sure how you would hook up throttle linkages, but it seems like you are pepared to do a bit of fiddling around whatever you decide.
Also have you thought about the LPG hard enough? Do you know that it has a much higher octane than petrol and that an engine tuned to run only on gas, and therefore not a compromise, can make more power than petrol? eg. timing of ignition and valves can be heaps more advanced? Not to mention the price gap of both fuels.
Best of luck anyway and keep us posted with pics of your progress.

subie_1st_timer · Post by **subie_1st_timer** » Sun Apr 13, 2008 3:14 pm

yeh i understand everything about LPG... one reason i dont wanna run the LPG is if ya run out and ya out in the middle of no where ya cant exatly fill up. besides the government will put LPG price up soon so the price of getting the LPG all sorted and running right the savings wont be there to make up the cost.

currently finding out the CFM of a couple of 1v stromberg carbs...they will be the simplest option if goin a custom dual carb setup...

littlewhiteute · Post by **littlewhiteute** » Sun Apr 13, 2008 4:04 pm

Any pair of single barrel carbs should be more than ample.
eg: Single Stromberg from a Falcon six, even a baby 200 (3.3 litre) would surely be able to supply one bank of about 900 cc.

subie_1st_timer · Post by **subie_1st_timer** » Sun Apr 13, 2008 6:33 pm

thats the plan, if one strommy can feed a 4.1ltr then jetted right should be fine for one per bank on a EA81