EA81 Unequal Length Headers

Willy Fisterbottom · Post by **Willy Fisterbottom** » Thu May 29, 2014 10:00 am

I got this nice set of Unequal Length Headers made up yesterday for my 1977 2 door GL running an EA81 and am in love with the new angry sound coming out the exhaust

Pics show the the old stock set next to the new, although the orignal set is slightly unequal and gave a slight offset beat, the new set gives the much loved EJ20T note and everybody that has an EA should have a set. The new set has over twice the difference in length of the standard set. The sound makes the hair on the back of my neck stick up. Performance has increased! The custom unequal length header goes from 1 3/4" at the exhaust port on heads to a 2" collector, previous header was 1 3/4" at the exhaust port to an 1 3/4" collector. She used to run out of breath at 80kmh in 2nd gear, I can now rev it to 100kmh before shifting (I don't have a Tacho yet so I don't what the revs are but she is spinning along)

Post by **Bantum** » Thu May 29, 2014 12:27 pm

Looking good - got any installed pictures ?

Interesting to note that it looks similar to later model turbo exhausts route, must be something to do with better flow & pipe volume ...

I might try it on the Brumby next time ( needs a new one ) ...

P.S. - Did you get it made in Stainless ?

Cheers, Bantum ...

Willy Fisterbottom · Post by **Willy Fisterbottom** » Thu May 29, 2014 12:39 pm

I will take some installed pics and post here.
You would get better flow with the original route using 1 ¾” into a 2” collector you would get even better flow with Equal length headers using 1 ¾” into a 2” collector but, it would sound like a inline 4 cylinder . The whole point of this exercise was about getting the angry offset beat from the exhaust caused by the unequal lengths. The turbo models only use this route as it is the most convenient way to plumb the turbo up.
I got this one made up out of standard mild steel as I wasn’t sure how good it would be, next set will be Stainless and mandrel bent. I think I’ll see about making a few and selling.

Bantum wrote:Looking good - got any installed pictures ?

Interesting to note that it looks similar to later model turbo exhausts route, must be something to do with better flow & pipe volume ...

I might try it on the Brumby next time ( needs a new one ) ...

P.S. - Did you get it made in Stainless ?

Cheers, Bantum ...

AndrewT · Post by **AndrewT** » Thu May 29, 2014 2:42 pm

Screw more pictures...we need audio

steptoe · Post by **steptoe** » Thu May 29, 2014 3:31 pm

run outta breath at 80 in second ? Think you are running out of revs ? I know I was happy with EA82 Y pipe on my EA81 4 speed stretching third to 110kph GPS, an increase from 100.

My 5 speed (not as fast ratios) EA82 in Brumby likes a change at 60, will buzz out to 80 if pushed but its doin something like 6000rpm. Where is the max rec, dot on your speedo for 2nd gear, and what sort of EA81 is this you have done it on ??

Silverbullet · Post by **Silverbullet** » Thu May 29, 2014 5:41 pm

That looks awesome

I think we need a video or sound byte of this setup in action to make a fair judgement though

Willy Fisterbottom · Post by **Willy Fisterbottom** » Thu May 29, 2014 6:05 pm

steptoe wrote:run outta breath at 80 in second ? Think you are running out of revs ? I know I was happy with EA82 Y pipe on my EA81 4 speed stretching third to 110kph GPS, an increase from 100.

My 5 speed (not as fast ratios) EA82 in Brumby likes a change at 60, will buzz out to 80 if pushed but its doin something like 6000rpm. Where is the max rec, dot on your speedo for 2nd gear, and what sort of EA81 is this you have done it on ??

It was only running out of revs because it was trying to squeeze out of the 1 3/4" pipebefore the muffler, admittedly she is screaming at 100kmh in 2nd.

I am running an EA81 out of a late 90s Brumby (Black rocker cover, electronic ignition and I hydraulic lifters), I rebuilt the Hitachi, I never liked the Webber on it. It is hooked up to a 5 speed that I swapped out of my 1982 MY hardtop. 2 videos have uploaded to the Ausubaru facebook page, sounds sweet through a decent stereo with lots of bass.

Post by **TOONGA** » Thu May 29, 2014 8:51 pm

Very nice work simple but elegant.

I would warn that people wanting these for their EA81 motors with a catalitic converter would still need a catalytic converter so perhaps a set made that stop at the "Y" join so a high flow catalytic converter of some description could be fitted.

I would like to see these made for EJ motors as well

you could use the same principle and even have the dual ports flow via a "Y" join into bend. then a single 2 inch pipe bent the same way you have done the EA81 bends.

any chance of a non facebook video

TOONGA

steptoe · Post by **steptoe** » Thu May 29, 2014 8:59 pm

yeah, what is facebook anyway ?

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 7:27 am

TOONGA wrote:Very nice work simple but elegant.

I would warn that people wanting these for their EA81 motors with a catalitic converter would still need a catalytic converter so perhaps a set made that stop at the "Y" join so a high flow catalytic converter of some description could be fitted.

I would like to see these made for EJ motors as well you could use the same principle and even have the dual ports flow via a "Y" join into bend. then a single 2 inch pipe bent the same way you have done the EA81 bends.

any chance of a non facebook video

TOONGA

Yes if you had a cat converter and for some reason wanted to keep it you woud put it after the collector (Y join).

N/A EJ Unequal length headers are readily available on ebay starting from $250

http://www.ebay.com.au/itm/EMPIRE-PERFO ... 2a3bb9b705

Once I get a better video I'll uploaded it to my youtube channel, the video on facebook is to dark but sounds good, one of them is a hillclimb not far from where I live and I had a bit of fun. until then here is 2 videos from youtube to wet your appetite, unfortunately not EA's but you'll get the picture.

https://www.youtube.com/watch?v=fEcjIcp2BgQ
https://www.youtube.com/watch?v=phf07oHkiZs

RSR 555 · Post by **RSR 555** » Fri May 30, 2014 8:15 am

Hey Willy.. why are the exhaust flanges both turned the same way? I know there are extra stud holes in the cylinder head but I'd suggest making them as per the original, so on the later model Brumbys it will fit without the headaches

Oh and btw.. good work and love that sound

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 8:36 am

RSR 555 wrote:Hey Willy.. why are the exhaust flanges both turned the same way? I know there are extra stud holes in the cylinder head but I'd suggest making them as per the original, so on the later model Brumbys it will fit without the headaches

Oh and btw.. good work and love that sound

Good spot mate, It was done because the hole was a bit shagged and the stud pulled out. I didn't have the right Helicoil on hand at the time so I just swapped the studs. This engine is out of a late model Brumby and has 4 holes per head at the exhaust flange.

RSR 555 · Post by **RSR 555** » Fri May 30, 2014 8:49 am

Willy Fisterbottom wrote:Good spot mate, It was done because the hole was a bit shagged and the stud pulled out. I didn't have the right Helicoil on hand at the time so I just swapped the studs. This engine is out of a late model Brumby and has 4 holes per head at the exhaust flange.

Yeah I was thinking this was the reason why

The later model Brumbys have that anti back fire piece attached to the exhaust port that can't be turned, well it can but then the pipe up the back of the engine doesn't line up anymore.

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 9:11 am

This engine is one of the last EA81 engines with the black rocker cover, hydraulic lifters and electronic ignition and it dosent have the anti back fire piece on it.......

RSR 555 · Post by **RSR 555** » Fri May 30, 2014 9:31 am

It would have a one stage of it's life. As all with black rocker covers had this due to newer emissions laws. This spacer piece can be removed without any trouble but you can't put the original headers back on without it, as the exhaust now hits the engine crossmember. Also on the later EA81 engines, you'll normally see a 3/4" metal pipe section come off the back of the inlet manifold, this is where the anti back fire pipe goes back in to the engine.

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 9:59 am

Yeah not sure mate, all I know is this engine was in a boat before I bought it. It had this sticker and a barcode on it but I can't find any reference to the code on it "EA81G7"

Post by **TOONGA** » Fri May 30, 2014 6:11 pm

Willy Fisterbottom wrote:Yes if you had a cat converter and for some reason wanted to keep it you woud put it after the collector (Y join).

N/A EJ Unequal length headers are readily available on ebay starting from $250

http://www.ebay.com.au/itm/EMPIRE-PERFO ... 2a3bb9b705

Once I get a better video I'll uploaded it to my youtube channel, the video on facebook is to dark but sounds good, one of them is a hillclimb not far from where I live and I had a bit of fun. until then here is 2 videos from youtube to wet your appetite, unfortunately not EA's but you'll get the picture.

I have a set of the ebay headers on my brumby and they have cracked at the joins twice. while they sound great there are way too many joins and pipes for my liking. the way you have made your headers is how I would want a set made for an EJ motor. They are simple, elegant and efficiently made.

TOONGA

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 6:36 pm

TOONGA wrote:I have a set of the ebay headers on my brumby and they have cracked at the joins twice. while they sound great there are way too many joins and pipes for my liking. the way you have made your headers is how I would want a set made for an EJ motor. They are simple, elegant and efficiently made.

TOONGA

Fair enough mate, interesting because I was thinking of making a set from mandrel bends but that would have many joins.

RSR 555 · Post by **RSR 555** » Fri May 30, 2014 7:08 pm

Pretty sure that's an imported EA81 engine, so it probably didn't have that pollution crap on it.

I think mandrel bends wouldn't give you that much more power that you'd need to worry about it. Keep it simple.. which worked so well for the EA81 for many years

Willy Fisterbottom · Post by **Willy Fisterbottom** » Fri May 30, 2014 7:32 pm

RSR 555 wrote:Pretty sure that's an imported EA81 engine, so it probably didn't have that pollution crap on it.

I think mandrel bends wouldn't give you that much more power that you'd need to worry about it. Keep it simple.. which worked so well for the EA81 for many years

I was thinking it may have been an import too.
I was thinking mandrel for ease of making more as I don't have a pipe bender but stuff it, I'll buy one