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ea81's.. why'd they change em


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now were talking...:D

 

GD - And there is no reason that a pushrod engine could not be designed to go just as fast as any OHC - it's just a matter of buiding it. It would be more expensive, and have more moving parts - but anything is possible.

 

Thats pretty much what I said. It is possible to go as fast as any ohc with pushrods, but it takes more work, so much that it isn't really practical once you get up past 8000rpm. Just please stop comparing an ea81 with a cam, decked heads and high comp pistons to ea82s when only a few people have even experimented with cams in ea82 cars, and haven't tried decking heads etc. I'm sure that with cams, higher compression, and a big carb thatll push more than the spfi, an ea82 would be up where qmans ea81s are. The fact is the ports on an ea81 dont flow any better than ea82s, and pushrods aren't going to give your car superior power over ohc. All that matters at normal rpms is the cam profile. It really won't make a difference unless you start playing in the upper rpm ranges, which is not what qmans ea81s are created for. He wants low rpm power for off-roading. At least this is what I have heard him say on the board, talking about torque-grind cams.

 

If you want a good powerful 4x4ing/torquey motor go with an ea81.

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He has both actually - a high HP one in a non-lifted street Brat, and a torque ground one for the silver off-road Brat. I have yet to ride in the street Brat - but I hear it's a beast.

 

I was never comparing them to EA82's - I'm simply addressing the previous statements about how you can't get high HP from an EA81 - it's been done. It is in fact easier than an EA82 - there's only one cam - no tendancy to blow gaskets - etc.

 

I have nothing against EA82's - I just don't personally want to deal with em. And people saying that my EA81's are stuck behind UPS trucks is just wrong. In reality there isn't much difference between the EA81 and EA82 vehicle (power wise) if you consider the whole package. They both are pretty gutless really. If tuned right they are adequate, and more than capable of passing.

 

And this thread was "why did subaru change...". Well - in reality - there's no good reason - since these engines are not playing in the "over 8,000 rpm" range. They swaped slightly more complex valve train (that hasn't been a problem) for unreliable timing belts, and crappy headgaskets.... it's all in the intrest of progress tho, and the consumer is the one who has to pay the price.

 

GD

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Guest taprackready

pushrods= used forever, old technology

ohc= the way the world works today

 

 

 

Think of thisway. Planned periodic, expensive maintence. Who wins. Dealers, parts suppliers. Pushrod engines are so reliable that it doesn't require $400, every 60,000 mile timing belt changes.

 

Bill

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Yes - whining about changeing belts IS for suckers - I completely agree. On the other hand - a consumer whining abouy PAYING to have his timing belts changed every 60k IS NOT a sucker. You have not considered the economics of the situation.

 

I have no problems changeing belts. But I do have better things to do with my time. That and the fact that the EA82 never came in any body style I like leads me to not own one.

 

GD

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OHC engines have fewer moving parts.

 

Fewer moving parts=fewer problems

 

The reason ea81s don't normally experience the typical problems that can result with pushrod motors is that subaru did such a good job designing and building them. They had two generations (I think) of pushrod flat fours before making the ea81, so they had worked out all the kinks. The ea82 was the first OHC motor that subaru made, so it was really sort of an experiment. A better comparison in the interist of fairness would be between the ea81 and the EJ18 because in both cases, the design had been refined a great deal by then.

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Actually - there was more than 2 gen's of pushrod engines before the EA81. Not sure how many - but there was the 1100, the 1400, and the 1600 at least.

 

I agree with snowman tho - the EA82 was an experiment. But that doesn't make it an unfair comparison any more than 10 years of R&D leading to the EJ makes it unfair for comparison as well. The EA82, while certainly not as well designed as it could have been, is from the same vintage, and so in that respect is more fair a comparison than an EJ. Also - it wasn't the first OHC engine ever made, and I'm sure Subaru had a look at a few OHC engines before building the EA82 - I would also guess that they probably hired some engineers that had built OHC engines before, and knew how to design them. There's no reason for them to eat timing belts except bad design, and lack of intrest on Subaru's part of fixing it. I'm sure that if enough money was thrown at designing it, a kit could be built to upgrade an EA82 with the ablility to go 100k+ on a set of timing belts. 60k was obviously deemed "enough". and they moved on instead of fixing it's problems. They did fix some problems tho - the head's were redesigned twice - and they still crack.

 

GD

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There are just as many plusses and downsides to each that I can't understand why anyone would put down or raise the other.

 

the stuff about high RPM shifting, who needs to shift at 7 grand?

 

does that make an OHC engine a *clear* advantage? who cares?

yeah, less moving parts, but depending on which company your car is made by or what year it's made, it could be an interference design. and when a belt goes, your screwed. there's just as many downsides as upsides depending on which company you are choosing your engine design from. on an even scale of every car manufacturer, I think it shouldn't be an issue of saying this is better or that is better.

 

I've seen fast pushrod v6s and fast late 90s thunderbirds... seen fast mustangs and fast import DHOC cars...

 

I say, buy the engine you know the most about working on and like.

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  • 3 weeks later...

I'm new in here and have been lately considering what the idea of ea82 is... in my home country, people don't seem to worry much about the differences between 81 and 82. Maybe because there isn't many older soobs left, and they just don't know if the ea81 would actually be a better "daily use motor".

 

After reading the road tests of Leone (my87) from the local car magazines, I thought it could be a good idea to change the ea82 of my becoming car to the older ea81. The good points of the ea81 seem to be:

 

- better gas mileage

- no need for a belt change

- the HP specs are what the manufacturer tells

- torque at lower rpm's

 

The magazine didn't get the promised 90 HP out of the ea82, but 14 less ! So it's just as powerful as my current ea71 1,6 litre engine, but 1,6 eats much less gasoline :D Ea81 is said to have 82 HP@5200 and I believe it's more close to the truth. It also should have maximum torque of 134 Nm @ 2400 rpm. That's quite low rpm IMHO! Those specs are for european models with compression ratio of 8,7.

 

It's funny to read that road test anyway, they simply didn't like the engine at all. It consumed oil, was powerless and they couldn't get the gas mileage any higher than about 25 mpg.

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Thanks, beauregaardhooligan! Unfortunately the article is in Finnish, so I should translate it. But we'll see about that some day if I happen to borrow it from the library again..

 

One thing they wondered about the ea82 was the astonishingly broad range of at least some kind of torque. I have noticed the same thing in my 1,6 litre model. You can let rpms go to the idle range or lower, even with fourth or fifth gear, and then step on the gas pedal. The motor starts to pull smoothly without protesting at all.

 

Visit our club's homepage if you like :D

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I hear what you're saying about the low torque range, Scoob. That's what makes the EA81 so attractive for off-roading. High rpms produce wheel spin.

With my dual range 4speed in lo, FERTHER will walk up moderate hills at idle!

Those Coates heads sure do look great! I'd imagine a set would cost more than most of our cars, though.

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Look there it goes....... oh no, we missed the boat.

 

The reason we switched to OHC from OHV was for emissions, that was the only reason. you can get mad power out of any engine out there, even one cylinder 2 strokes. but to get the power out of an older engine and still pass emissions is a tough thing to do. switching to fuel injection, which seems to have been forgotten on the EA-82 is one of the major factors in its increase in horse power. and because its more accurate it can also pass emissions. the only thing that changes engines in industry is emissions, if we still had the same emission standards as we had in 1985 we would still be using 1985 engines, the only pushrod cars left for the most part are larger cars, with 30 year old engines, ie buick 3.8, and trucks. which are in a different emission class so they can pollute more than cars.

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As for why the EA81 became the EA82... I don't know for sure how valid this is, but the story I've heard from different Subaru mechanics was that Volkswagen discovered that other then being water cooled, the EA81 was painfully close to being a clone of the old classic air-cooled Beetle engine. So much so that internal parts such as cranks and pistons and cams were interchangable.

 

Again, I don't know how actually true this is, but VW supposedly sued Subaru for patent infringement, and won. Thus the EA82 with OHV and hydrualic lifters was sufficiently different to satisfy VW. Anyone ever heard more about this?

 

James in Central TX.

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My ea82 wagon can drop right down to 4-500 rpm and keep pulling up hills iwithout any use of the gas pedal. In fact I have felt the engine pretty much stop and then chug forward and keep going.

 

and scoob555 its possible that the magazine measurements were at the wheel wereas the manufacturer claim was likely at the flywheel. You are comparing apples to oranges. Also, you have not tested your 1.6l, it is possible that this motor makes less than it's rating as well.

 

my engine is running 270 000 km and other than new timing belts and an o2 sensor there has been no bolt turned on the motor. It revs happily, pulls hard, and doesn't burn or leak a drop. In fact the oil pan is starting to get surface rust :D

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