June 26, 200421 yr Has anyone ever heard of the place? http://www.ramengines.com/index.html A little pricey, but if you want the best for your EA81... They have custom made heads and intakes and forged piston sets. EDIT: Sorry for the huge pics...
June 26, 200421 yr I've heard of them. My only concern besides price would be that aircraft engines only need power at a constasnt rpm, so they don't necesisarily need the low rpm grunt that cars do. Just some food for thought!
June 26, 200421 yr yeah, those are the best EA81's you can get. But they're built to make peak hp at high rev's, and hold those rev's at high altitude for a long time. Probably not the best for street use unless you like cruising at 6000rpm and dont like shifting. -Brian
June 26, 200421 yr Author I was not necessarily looking at the long blocks but the custom dual-carb manifolds and forged piston kits. The bore and stroke are the same, but the cam profiles in those motors is what sets it apart from a torquey low-end setup... who says you need to run the same cam? Anyways, the peak torque curve usually comes at about 2k rpm for these motors, and torque is what is needed for crawling. Just imagine if you added a turbo or supercharger to that motor and had it tuned...
June 26, 200421 yr Gearing is whats needed for crawling. Our 80hp EA81's will crawl no problem, but the 4spd D/R has to be replaced. Which most have done recently. An engine like this would be better suited in a nice EA81 Coupe, or Hatch to race on some tarmac somewhere And yeah, a turbo would be super sweet on a setup like that. -Brian
June 27, 200421 yr hmm those look like stock ea81 heads with bosses welded to 'em and the stock port stopped up..any industrious guys out there could replicate that...
June 27, 200421 yr I'm sure as heck going to try . Gonna build me a tig welder from an alternator and get some bits for my die grinder. $1000 can buy a lot of labor if I'm working for myself..... GD
June 27, 200421 yr A New Zealand company also builds performance parts for the EA81 and their site includes dyno graphs. http://www.sub4.co.nz
June 27, 200421 yr Yeah - but the SUB4 heads are way different - custom cast - they are dual intake AND exhaust, and they have two spark plugs per cylinder. Really crazy stuff. The RAM heads are just dual intake, and are not custom castings - they are heavily modified stock heads. GD
June 27, 200421 yr Thats why Ram heads are about half as much as SUB4 heads. They are way easier to make!
July 31, 201510 yr Didn't someone on here actually get one of these motors at one time? I thought I remembered a thread from around 2005 where someone got one. I wonder how well it held up. I have thought about getting their pistons and heads when its time for me to do a rebuild.
August 3, 201510 yr yeah, those are the best EA81's you can get. But they're built to make peak hp at high rev's, and hold those rev's at high altitude for a long time. Probably not the best for street use unless you like cruising at 6000rpm and dont like shifting. -Brian No airplane engine ever has cruised at 6k rpm. It is so rare to ever get a propeller driven engine above 2800 rpm. The never exceed rpm on most single engine Cessnas is 2900 rpm. The little experimentals that people are putting ea's in certainly don't turn 6k.
August 3, 201510 yr good bit of info to chew on there Lucas. Sort of makes sense to have the engine cruise at its torquiest rev for fuel efficiency, longevity, reliability etc
August 4, 201510 yr Seems like I remember reading 3600 rpm. That might have been for take off for all I remember.
August 4, 201510 yr good bit of info to chew on there Lucas. Sort of makes sense to have the engine cruise at its torquiest rev for fuel efficiency, longevity, reliability etc In the airplane world is most about fuel efficiency. On the smaller cheaper single engine airplanes ( any Cessna 100 series, piper single engine) they don't have any gear reduction for the prop so the tip speed of the prop is a huge issue. The 172 I fly regularly has a prop governor that controls the prop pitch. Prop pitch is used to control rpm more than the throttle.
August 4, 201510 yr Hmm, I take that back Reading in here http://www.recreationalflying.com/threads/subaru-ea81-conversion.8488/ the guys have the poor little EA81's flying at some higher revs than torque figure some nice home truths, some comment on the EA81S described as a rally engine ... enjoy
August 4, 201510 yr Those SUB4 guys in NZ created some DOHC EA82 heads at one point... Crazy good fabrication. It would be interesting to see how much power one could get out of a built EA82T with these heads and a spider manifold...
August 5, 201510 yr Ron @ Ram performance was great to work with. He is quick to respond by email. He builds more than just aviation motors. He builds all performance motors. I think the FB page is "Ram performance engines" I had him do my heads. Hopefully i will have the car up and running this week. He told me the biggest bang for the buck is to get bigger valves. I asked him to raise compression. I did my own port and polish. I couldn't afford his flow balancing at this time. I also had him weld the cracks in the head near the valves. He sand blasts the head so any polish work will have to be redone after he has it. Turnaround time was about 3 weeks.
August 5, 201510 yr Ron @ Ram performance was great to work with. He is quick to respond by email. He builds more than just aviation motors. He builds all performance motors. I think the FB page is "Ram performance engines" I had him do my heads. Hopefully i will have the car up and running this week. He told me the biggest bang for the buck is to get bigger valves. I asked him to raise compression. I did my own port and polish. I couldn't afford his flow balancing at this time. I also had him weld the cracks in the head near the valves. He sand blasts the head so any polish work will have to be redone after he has it. Turnaround time was about 3 weeks. Good to know! Now I just have to decide if I stick with the crummy old EA81T or start saving my dimes for an EJ swap...
August 5, 201510 yr Yes great info. I've been contemplating having them install larger valves and do some port work on a pair of ER27 heads for my built shortblock.
August 5, 201510 yr hmmm, and many years ago when I got my first Sube, asked of my trusted, aging , race caring machine shop guy - felt EA81 valves were big by some standards and they would be good enough ??? Wonder what the compromise is when going bigger valves ?
August 6, 201510 yr Another good question Jono, We have all done the "bolt the bigger carb on" thing, as I did with my 38/38 and defied advice from those that have done it....to see if it can be done. But really, modifying a stock engine id more a science isn't it? That's just my view. I mean in basic terms allowing an engine to breathe better eg larger exhaust and larger manifold. But even these mods can have traps. Make an exhaust too large with little back pressure and it causes issues. How much back pressure is ideal? How do you measure that pressure? From where the exhaust exits the head or 3 metres away? Manifolds- does bigger mean better? Often it does but does it on a ea81/2 when is really more of a unique design? At 6mm bigger diameter my SPFI is likely double the volume of the stock ea81...does that have negatives? or real proven positives? Who knows? No one has posted not to use that manifold....so again, pioneering stuff and I love it as long as it works lol. To date for example a 65 on the idle primary jet was installed and a 70 is likely ideal. The 65 allows for the mixture screw to be 1.75 turns out....what is the goal. But I haven't seen a weber 32/36 use a 65 jet yet nor 70....mainly 50-60 max. So is that due to the manifold size? The short trike exhaust? The 9.5:1 compression ratio? Will the larger manifold contribute to better ecomony or worse? So with the above, will bigger valves be wonderful or other things should be taken into consideration? Its a science
August 6, 201510 yr Here is their new website:http://www.ramengines.com/page1.php I've been to RAM's facility, they have a test stand and can run an engine in their shop and it's been a few years but I think they can and have done some testing. Given the aircraft market they're appealing too it seems likely they would have done some testing.
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