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Guest Message by DevFuse

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Anyone interested in EA-81 HI-PO rebuild kit?

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17 replies to this topic

#1 Guest_SubieSTORMTROOPER_*

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Posted 07 August 2003 - 02:06 AM

I'm talking with a few different airplane companies recently, one being a Washington based company, and one being a machinist from Canada, and am considering putting together a HI-perfomance EA-81 engine kit, based on the mods used firstly for airplanes that use the EA81 motor..

The high performance kit would include 2-cylinder heads, 1-intake manifold, 8-valve lifters, 1-reground high performance cam shaft.

the cyllinder heads intake ports are opened up another 1/8" using a tapered reamer, as is the intake manifold reamed inside as well, and then rotary filed, and smoothed. The flow is incredibly better, as the car reaches max hp faster, and the hp are increased significantly. The crazy thing about it, Is that this guy in Canada is willing to let the kits go for cheap, like $600. The cool thing is, our stock carbs would still bolt up, which means so would the Smog shiot, so we could potentially have street legal ea81's with 110+ hp!

whaddya guys think?

#2 Guest_cole098_*

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Posted 07 August 2003 - 04:58 AM

I think I would be willing to work some over time to buy that kit...Joe

#3 Guest_jon61484_*

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Posted 07 August 2003 - 07:18 AM

$600 sounds like what I'm saving up for.


#4 Guest_carfreak85_*

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Posted 07 August 2003 - 09:58 AM

just make sure it will bolt up to the EA81T motors too!

#5 Guest_rXSNRG_*

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Posted 07 August 2003 - 10:02 AM

I'm interested...

#6 Guest_LostWater_*

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Posted 07 August 2003 - 10:11 AM

Will this be compatible with our webers? and if they are, what kind of gains would then be realized?

Thanks and Kindest Regards,


#7 Guest_qman_*

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Posted 07 August 2003 - 10:30 AM

Somethings to consider...
First, HP is not torque. If you want a topend racer than High horse power is the answer. If you want an off road climber than HP is not the answer. HP comes in later in the power band. Torque comes in much sooner. All the engine builders for the ultralights need high HP for high RPMs.

Second, that sounds like a decent price. Will it come with gaskets and everything needed to install it?


#8 Guest_Caboobaroo_*

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Posted 07 August 2003 - 10:36 AM

man, thats not what I need, I need one for my EA71...:rolleyes: do they make kits for them too?

#9 Guest_SubaruJunkie_*

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Posted 07 August 2003 - 11:47 AM

Russell, just slap a EA81 in there and forget about the 71.

$600 sounds like a screamin deal for the complete package. Is this guy willing to take a core and do the same mod's to them? I want to get a set of EA81T heads with the MPFI boss's and have that same work done, then do the CIS conversion to the EA81.

Does this guy expect a certain amount of pre-orders and a huge down payment? Or is he willing to make kits to order??


#10 Guest_jcdenton_*

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Posted 07 August 2003 - 12:30 PM

it sounds like a good Idea, but...
this kit should be tested on a <span style="text-decoration:underline">vehicle</span> to see if it has negative effects (this stuff is made for planes not cars)

also what do you think of how a webber 38 would work with this? the main problem with the 38 is that the manifold won't flow enough to benifit from it over the 32/36. how much more does it flow?

why not open the exhaust ports too?

other than that it sounds good.

maybe add some other sutff to this set? 1.6L pistons, FWD distributer, 170 or 180 thermostat?

#11 Guest_SubieSTORMTROOPER_*

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Posted 07 August 2003 - 12:38 PM

I was a little tired when I posted last night. Not a complete rebuild kit, sorry. Just exactly what I listed there. I imagine that the turbos would not be left out of the picture, as many of these soobie airplane guys use a EA-82 turbo in the EA-81's, so they can have a water cooled turb. Also they have a custom fab'd manual wastegate control which would be cool to have as well. The price's of these kits would be actually reduced to about $500 with bulk orders. We did not discuss anything about core's, but that would prolly make things much easier on his side, maybe pricewise, as well.

Q- You are absolutely correct about the torque/hp thing. The 110hp would kickin later at about 4000rpm +/- 500. But what will be beneficial to the off-road clan, is the incredibly improved breathability of the motor. I've been out playing in the mud plenty of times, and I know you hate that initial bog in first gear that makes you stall when you're trying to climb out of or over something. With the intake mani opened up a bit, as well as the heads, you will feel immediate throttle, which means accessing the low-end torque on demand. It wont feel as much like a snotty-nosed kid trying to play the trumpet.

Brian- another idea, is that this guy not hell bent on copyrights or anythig like that, he's willing to share info on how exactly these gains are acheived, so we can make this info avalable for us, too. There's another site that I found, that I posted on here before that tells about how to maximize the performance of an EA-81, which tells exactly how to do up the heads for increased performance, which i'm sure you can apply to the turb heads...the site is: www.jodel.com
you gotta go under engines/Subaru2

I'll keep you guys updated on this, and see what's up on the parts core

#12 Guest_qman_*

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Posted 07 August 2003 - 02:52 PM

What is beneficial for us is low RPM torque that allows us to off road at low rpms. I am not one of those guys that feels you have to fly over obstacles to get by them. I am working on the problem as we type.


#13 Guest_bushbasher_*

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Posted 07 August 2003 - 03:20 PM

In essence, hp is torque x rpm. You increase torque at a certain rpm, you increase hp at that rpm. This is why a v8 can have 300 lb feet of torque, but only have 200 hp, because everything is at a lower rpm, whereas a honda can have 200 hp, but only 110 lb ft of torque, because rpm is so high. But qman is right, airplane motors have a top end oriented power band, which would be useless for off-roading because we don't have the gear ratios to keep it in the power band. But would I be correct to say that better flow is better at low rpms too? In that case maybe we could use the nice heads and manifolds, with the stock cam, or get the guy to grind low-end cams?

#14 Guest_SubieSTORMTROOPER_*

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Posted 07 August 2003 - 03:23 PM

I'm a "Tread lightly" kinda guy myself, I just know that a better throttle response, and increased overall hp would help access more of what the engine is capable of in low-end, maybe not a momentous gain, but at least a snappier start-up. If someone were to come up with a plausible way to help out our gearing ratios and such, then I wouldn't try and focus on trying to compensate with more power and response.

I do know that there are some planetary/spur reduction kits that they use between engine to propeller, just not sure if there is a possiblilty of using those for automotive purposes....

#15 Guest_SubaruJunkie_*

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Posted 07 August 2003 - 05:54 PM

I think a kit like this would better benefit people who want to race thier EA81's. I want to make either a street racer or rally car out of my brat, and i need the power at high RPM's. Anyone know what a kit like this would do to our redline? If power isnt made until 4000, can we take the car to 6000 safely?

For off-road use... if you have your car propperly tuned, you can do almost anything. My stock EA81 in my wagon, when tuned propperly, will follow anyone with a weber. If you have the timing just right, and everything set just right then you shouldn't have any dead spot on takeoff. Increased compression, and increased exhaust flow will do the job, coupled with a Weber and that is almost all you need for off-roading. For extreme angles, EFI is the way to go.


#16 Guest_SubieSTORMTROOPER_*

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Posted 07 August 2003 - 05:59 PM

IN an article I read, the airplane guys cruise their soobs at 6000rpm for lengths of time, but I would make sure what's in the case isn't too old...

#17 Guest_SubaruJunkie_*

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Posted 07 August 2003 - 06:09 PM


any word on roller rockers?


#18 Guest_SubieSTORMTROOPER_*

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Posted 07 August 2003 - 06:25 PM

not sure about the rockers...for the dual port heads, he'll fab up a new cam, for the regular heads just spiced up, I think you sent in you cam and lifters to be redone. The EA-81 isn't a hydraulic lifter engine, I guess he calls the rockers "lifters"? or what.. but I imagine if they want you to send em in, that there is some modification required..

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