Stroking an EA81

Zefy · Post by **Zefy** » Tue Jun 13, 2006 12:52 pm

a lot of that stuff on that ram engine isn't that important when it comes to a car...

don't bother using forged pistons and internals... its not really worth the money unless you plan to wind this thing up to 9k rpm on a regular basis...

just go with high CR ea71 pistons... a proven and cheap mod(as far as parts go)

if you want MPFI heads like the ram ones just get normal ea81 turbo heads... i don't know what that would do to the CR though... plaining those turbo heads would probably help boost it more... or maybe even shave the block a bit... if you make a custom intake manifold than expect a nice boost in power... there is a water passage running through the stock intake... helps during cold starts and such...

if you redirect it so it doesn't pass through the intake manifold (don't just block them off) than you can get a nice boost in power...

if you actually do this stuff you'll have one heck of a peppy ea81... no it won't be a match to a decent ejxx... but hey, you're gonna have something to boast about!

everybody does the ejxx conversion (heck i've got a ej22 and/or ej22t lined up for the 79 brat) but nobody cares for the eaxx's... it'd be way more original! plus you'll be able to laugh at all these guys when they bust a timing belt...

steptoe · Post by **steptoe** » Tue Jun 13, 2006 2:42 pm

I never had a chance to compare not worn out EA81 to my rebuilt EA81. The pistons were boxed as EA71/81. So much for being a higher compression piston. 40 thou off heads = 1.0mm, 1.0 mm oversize rebore , 16/56 Watson race cam grind. Went lots better, then rebuilt twin hitachis and manifold went on, loads better. Cost me $1000 in 2001 to build it myself , paid for heads serviced and cam grind etc.

Was on road a lot faster than an EJ implant would take me, that's for sure.

In me 84 Brumby

5 speed box helps driving too

smoov · Post by **smoov** » Tue Jun 13, 2006 4:26 pm

Sorry Gee, didn't mean to offend with my last post.

But I still cannot see the justification spending thousands of dollars with the intentions of trying to achieve any serious power gains from an atmo EAXX.

Don't get me wrong though. I'm all for cheap performance upgrades to the EA series, but if you're wanting to spend the money, you can't really go past the EJ transplant!

Bratgeebah · Post by **Bratgeebah** » Tue Jun 13, 2006 6:04 pm

sweet as smoov

jono
does a twin carb ea81 manifold fit all ea81 engines? Someone (aparantly in the know) told me twin carb manifolds only fit twin carb ea81 heads- something to do with the LHS and RHS ports being further apart from each other on twin carb engines and consequently the manifold is also wider.
Is that crap?
I'd love to hear that it is.

Gee

stinky · Post by **stinky** » Tue Jun 13, 2006 6:59 pm

I think they can be modded to suit a standard engine. I had a dual carb manifold on a standard engine ( came to me that way ) and I boxed and shipped it down to xaymacca who put it onto his standard engine.

so Yes they can. I have no idea what work was done to it to make it fit in the first place though

Having recently done the ej18 swap I'm definately an advocate of it. I had a genuine dual carb ea81 with reground cam etc and swapped it for the ej ... I'll never go back. The car performs so much better, and not just in the power stakes, but now I can come *close* to crawling up a steep 4x4 climb. I don't have to worry about carby starve on said steep climb and I can use the engine to brake me going back down said steep 4x4 hill without stalling.

I've owned a stock ea81, a webbered one, and a worked dual carb, and none of them compare to a completely stock ej18 in any way.

Bratgeebah · Post by **Bratgeebah** » Tue Jun 13, 2006 8:19 pm

Stinky

Out of interest, which went better, the webber or the dual carb?
Were they both worked or just the dual carb? How worked was the dual carb? Which setup did you like?

Gee

(ej's are better)

steptoe · Post by **steptoe** » Tue Jun 13, 2006 11:05 pm

I had no troubles and there were no tell tale signs of any changes to hole sizes. Take into account 1.0 mm shaved off each head may have helped.

Someone has also said the manifold will fit EA82 with a small bit of grinding where manifold touches top side of block !!

kwijmbo · Post by **kwijmbo** » Thu Jun 15, 2006 9:31 pm

go the worked ea81!

before i had the 13bt, i had a worked ea81. it wasn't enough poke for me, but we still managed to get a healthy 110hp outta it with cam work, head work, weber, exhaust, tighter valve springs, etc

it sounded TOUGH as. like a dirty wrx. some of you may remember it at my bbq debut a few years back.

it wasn't bad either. the cam grind i had on it was more top end. i managed to pull 205km/h (on a private road of course). sounded loveerrly.

i went up against a lifted ea82turbo (tim's) and with a mate in the car, was pulling away from him at 130km/h +

go the worked ea81. something nostalgic about it - and it won't cost u the earth.

Paul[/u]

steptoe · Post by **steptoe** » Thu Jun 15, 2006 11:39 pm

maybe you could build a few to order based on your experiences.

how was it crawling along dirt roads and in traffic ?

13bt....curious a rote ! mated to awd box ?

I coulda swore I saw (heard) a fwd rote powered MY 4 door sedan about 15 years ago... got me thinking I can tell you bog std look)

kwijmbo · Post by **kwijmbo** » Fri Jun 16, 2006 12:22 pm

yeah mate, 13b turbo mated to an ea82 awd gearbox with lib internals.

the ea81 was fine for city driving and very very fun when rallying on dirt roads, esp with an open diff!

used to get abt 11/12L per 100km fuel economy, so wasn't overly efficient, but a lot of fun to drive. at the end of the day if i were to do it again, i'd go for more a torque cam, smaller headers and go for acceleration over top end. Still, pulling 205 outta an ea81 with the 5 spd ea82 awd box was a lot of fun. altho that was running a 3.7. now i'm running a 4.11 but can now do 250+. God bless my 10,000rpm redline.

all on the private road of course

Paul