Uberoo Posted July 8, 2006 Share Posted July 8, 2006 why is it that the EA81 and EA82 motors only rev to about 6000 rpm?They have a very short stroke and are horizontaly opposed so they should balance really well.so why the low redline? Quote Link to comment Share on other sites More sharing options...
GLCraig Posted July 8, 2006 Share Posted July 8, 2006 who says you have to stop reving at 6k, I know I've taken my EA81 over 7K in some rallyXs Quote Link to comment Share on other sites More sharing options...
Uberoo Posted July 8, 2006 Author Share Posted July 8, 2006 i thought the motor really didnt rev past 6k?saab B202 have alot more stroke.Almost 1/2" more and they could easily rev to 7k assuming you replaced the lifters and the computer.8k if you put in solid lifters and all that.so whats holding subies back? they have solid lifters(some) Quote Link to comment Share on other sites More sharing options...
jeffast Posted July 8, 2006 Share Posted July 8, 2006 the cams are bad with delta cams you can get a ton of high end but you lose all the lowend power Quote Link to comment Share on other sites More sharing options...
mikeshoup Posted July 8, 2006 Share Posted July 8, 2006 The engines just don't make power up to that point. They're torquey beasts made for street, and not for high revs. Anyways, SPFI EA82s have a redline at 6500. So, I guess that's better. Its not like you're gonna make power up to that point. If you wanted to make power higher in the band, put a new set of cams, recurve the disty, put in solid lifters, and you could probably take it fairly high. Quote Link to comment Share on other sites More sharing options...
Uberoo Posted July 8, 2006 Author Share Posted July 8, 2006 low down torque is nice but 2.64" stroke and 3.62 bore is an odd combo for torque...hey does anyone make stroker kits for subarus? Quote Link to comment Share on other sites More sharing options...
Phizinza Posted July 8, 2006 Share Posted July 8, 2006 low down torque is nice but 2.64" stroke and 3.62 bore is an odd combo for torque...hey does anyone make stroker kits for subarus?It is, and that's why I assume the EA81 diesel was a failure.There is one or two places in Australia that make stroker kits for EJ engines, but not EA's... too old I think. My original dual carb ea81 (higher flow heads) revs freely upto 7500rpm, I think it will go higher but it starts to make a "different" noise at about 7K.. By different I mean not tapping, rattling, or clacking. But it just makes a different noise that I am not happy about. But really shifting at 7K is pretty good with the 15" wheels I have at the moment. That way it doesn't drop below 4K in the next gear... And the power curve seems to level out after 4K. But it is very loud at 7K, which can be fun sometimes. (seems these engines sound like V8's people get blown away when you rev that high! ) Quote Link to comment Share on other sites More sharing options...
waimaks Posted July 8, 2006 Share Posted July 8, 2006 5k-6k rpm is painful sounding for my ea81 and ea82. Zoom Zoom Boom Zoom Zoom.. I mean, I havn't seen what the powerband on these things looks like, but I'm pretty sure it dissapears around 5k anyway? Quote Link to comment Share on other sites More sharing options...
keltik Posted July 8, 2006 Share Posted July 8, 2006 I've been meaning to ask this question too. Most 80's vehicles i see with inline 4's have at least a 6,200 redline. I know most of it is design but my old mans 1974 MG pushrod v8 would hit 7,500 without blowing up. Would the relatively low redline be related to the boxer layout? Quote Link to comment Share on other sites More sharing options...
Uberoo Posted July 8, 2006 Author Share Posted July 8, 2006 does the subaru suffer from a lack of enough air or fuel at high rpms.so in that way it can't support combustion?at 7.5K and above?or are the valves floating by then so no power?I do like the subi motors and I probally would never rev an engine to 8k but theoretically it should rev that high given its stroke.also the saab I mentioned that reves to 8k doesnt have an torque by that time either.the saab is also built for low/mid range power... Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 8, 2006 Share Posted July 8, 2006 Just takes some tweaking - mostly cam profiles and such. The aircraft guys run the EA81's at 8k all day long. GD Quote Link to comment Share on other sites More sharing options...
joostvdw Posted July 8, 2006 Share Posted July 8, 2006 at 7k to 7,5k your valves start to float, I've had my EA82T up to 7-and-a-bit-k and sounded alright (just very loud ) If you want high rpm's go for desmodromic (do you spell it this way? don't know for sure....) heads that would rock... Quote Link to comment Share on other sites More sharing options...
SOOBOUTLAW Posted July 9, 2006 Share Posted July 9, 2006 Installing new valve springs can help make a peppier motor at higher revs, due to lack of valve float bogging the motor. Especially if you can find some hi rev(8k) dual springs. Quote Link to comment Share on other sites More sharing options...
85Sub4WD Posted July 9, 2006 Share Posted July 9, 2006 If I was going to really rev the engine - Id make sure I had a good set of forged pistons and rods (chrome top ring too) before I did so, and that they were really well balanced, as some have lost rods ~7.2k on EA82's - remember that the rods and pistons are cast aluminum - I think ramengines sells all that stuff for aircraft use, but it should work fine for road use - they also sell stainless steel valves (not sure of the advantage there), and stiffer springs - not to mention other cams and anything else you can imagine for these engines - but it comes at a price realize economy was forefront for these cars - not so for saab, or any of those other companies (or for Subaru today) - Subaru used a more harmonically stable design, and cheaper materials to deliver comporable performance (to Honda/Toyota) to a more expensive engine to manufacture - not to mention the fact that these engines were supposed to be gas savers too - having power at the low end can be advantageous too when it comes to getting you off the line, so dont completely dissmiss the stock power curve either - RPMs really arent a good judge of an engine's capeability - they just make a lot of noise Quote Link to comment Share on other sites More sharing options...
Sparkless Posted July 9, 2006 Share Posted July 9, 2006 I rarely rev my old wagon (with auto trans) above 5000 rpm. That's way above the torque curve and any marginal HP I might gain with a stock motor. It sounds like hell at anything above 4000rpm, anyway. Quote Link to comment Share on other sites More sharing options...
daeron Posted July 9, 2006 Share Posted July 9, 2006 i drive an 87 ea-82 with an auto (its a gl-10) and rev that thing as high as my throttle lets me... i recently had the muffler off (and discovered i have an empty shell of a catalytic converter) and i thought the motor sounded great at all RPMs... just, that the automatic gearbox wouldnt let the bloody thing move. i am sooo convinced that i want a five speed in this car...i drive about 100 miles a day, delivering pizzas, in a section of my county that i hate with a passion because of the way the traffic has been engineered.... and without being able to determine throttle and gearing independently, im going insane. ESPECIALLY in the rain (2wd:mad: ) because i cant use my gearing without doing so at high throttle, so i spin my tires all the time.. and in south florida, summertime == rain.. at least, if we are lucky. Quote Link to comment Share on other sites More sharing options...
Phizinza Posted July 9, 2006 Share Posted July 9, 2006 EA82's (at least here in Aus) have there red line at 6.5K rpm... And I take my dad's to it at least once everytime I drive it... Good o stretch it's legs, ya know? Quote Link to comment Share on other sites More sharing options...
keltik Posted July 9, 2006 Share Posted July 9, 2006 Oh yeh forgot about the ea82s. I know Waimaks' vortex starts beeping at 6.5k and we've hit 6.8 a few times in it. But im on his side for saying the ea81 sounds sick above 5k. If someone wants to send me a sound clip of theirs at 7k id be interested to hear it. (edit) ok just watched an old vid of my prelude floating valves at 6,500rpm. Also just got out of a Holden ute that wouldnt rev past 4,000rpm. Subarus might not scream like Hondas but they arent that bad. Quote Link to comment Share on other sites More sharing options...
calebz Posted July 9, 2006 Share Posted July 9, 2006 EA82's (at least here in Aus) have there red line at 6.5K rpm... And I take my dad's to it at least once everytime I drive it... Good o stretch it's legs, ya know? It varies in the US.. the dash tach shows a different redline for auto and manual.. Quote Link to comment Share on other sites More sharing options...
HATCHY Posted July 9, 2006 Share Posted July 9, 2006 Ive only got my ea81 to like 5700 after that ther was no speed incline. and no power. It just sounde like the motor wanted to explode. lol everyone around me was looking with horror, becuase it was so loud especially with the weber. it sounded like a damn weedwaker, or a lawnmower lol it was great.. But ive never got my motor to 600o ever. iof course my motor has been drivin hard and is really old now. like damn near 200k on her Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 9, 2006 Share Posted July 9, 2006 The EA81 hydro lifter engine in my Brat (original) will easily hit 7k, and sounds just fine. It will lose power after 5, but will rev right up past 7. I generally shift at 5.5 in it. It's getting fuel injection right now As for the EA82 tachs - it seems to depend on the engine. My 5 speed sedan redlines at 6. The SPFI 87 Auto coupe I have right now redlines at 6.5 on the dash, and the 90 loyale 5 speed pushbutton I parted a few weeks ago - it's dash says 6.5 also. I have to assume that carb was 6, and SPFI was 6.5 regardless of transmission. GD Quote Link to comment Share on other sites More sharing options...
85Sub4WD Posted July 9, 2006 Share Posted July 9, 2006 The redlines for EA82 engines were all at 6k until the SPFI engines - I know 86 carbies were 6k - not seen any 86' SPFIs (rare) to know - but Im 99% sure everything non-carby 87+ is 6.5k redline - they changed the valve springs and cam profiles with the SPFI/later turbo design, so valve float is not nearly as much of an issue with 87+ cars (much stiffer springs). 87 carbies and 86 SPFIs are probably somewhere inbetween the two note that FI and carb EA82 pistons from 85-86 (sans SPFI) all were 9:1 CR, where as later ones used a 9.5:1 CR too - so there is something else to consiter when reving - I think the SPFI bottom end is a *bit* beefier than the carby one, but Im not 100% sure good luck Quote Link to comment Share on other sites More sharing options...
Phizinza Posted July 10, 2006 Share Posted July 10, 2006 Well My dad's 85 carbed touring wagon redlines at 6.5 My mates 88 carbed touring wagon redlines at 6.5 And our 87 carbed sports wagon redlines at 6.5.. So I guess they were just to lazy to put the other dash's in. Oh, and we never got SPFI, but we did get MPFI and turbos. Dunno what they redline at. I will have to get a clip of my dualie reving for you. I'l get three clips, inside, under the hood and at the rear Quote Link to comment Share on other sites More sharing options...
PoorManzImpreza Posted July 10, 2006 Share Posted July 10, 2006 yeh I rev my carbed ea82 all the way to 6.5k and past if I'm overtaking..sub engines love to rev they just need the air to do it..heard of ea82ts making power to 8k, but those are just whisperings on this board.. Quote Link to comment Share on other sites More sharing options...
calebz Posted July 10, 2006 Share Posted July 10, 2006 Mine made power past 7k 7300 is where something let loose. Still haven't looked to see what it was. Quote Link to comment Share on other sites More sharing options...
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