EA81 intake manifold

Dean.nabbe · Post by **Dean.nabbe** » Sun Jul 06, 2014 6:58 pm

hey guys...

i'm going the Weber 38DGAS upgrade... plus custom extractors and 2" exhaust...

does anyone know where i can source a performance intake manifold or tell me a donor car to look out for that will fit..

thanks

YouTube · Post by **El_Freddo** » Sun Jul 06, 2014 8:03 pm

There are no performance manifolds available, and there's nothing that I know of that fits from another vehicle other than an L series manifold - but with that you need to do a bit of other work too:

There's a coolant line from the top of the block under the manifold where the carbie mounts that goes to under the thermostat housing. On the EA82 manifold this thermostat housing is on the front of the manifold, not the rear. If you're running PS you need to run the top rad hose through the belt for the PS

You also need to re-route this coolant hose around the dizzy as the factory hose will rub on the dizzy.

This is steptoe's image, stolen to show you what I mean - the dizzy is very close to the thermostat housing.

Steptoe has put a bolt through the coolant hose below the thermostat housing, you can just see it in this image. He's then run a new pick up point as clearly seen - this is for his LPG setup but the same can be done for this coolant passage

Probably a good idea to read here -The definitive(?) Weber conversion thread.

If that doesn't answer your questions I think we're in trouble

Cheers

Bennie

Willy Fisterbottom · Post by **Willy Fisterbottom** » Sun Jul 06, 2014 8:16 pm

Interesting setup Mr Steptoe has there. When I used an EA82 manifold on a EA81 I turned the dizzy 90 or 180 degrees so the vacum advance diaphragm cleared the thermostat housing.

Dean.nabbe · Post by **Dean.nabbe** » Sun Jul 06, 2014 8:24 pm

performance was probably a bad choice of words....i'm just after a manifold that will compliment the 38DGAS carby and extractors..

Willy Fisterbottom · Post by **Willy Fisterbottom** » Sun Jul 06, 2014 8:46 pm

The EA82 manifold will be more complimentary as it has a bigger hole for the base plate and less restrictive (make sure you get the right base plate) but Like I said on your fb post, my re jetted single EA81 Hitachi eats webers for breakfast

YouTube · Post by **El_Freddo** » Sun Jul 06, 2014 9:50 pm

Willy Fisterbottom wrote:The EA82 manifold will be more complimentary as it has a bigger hole for the base plate and less restrictive (make sure you get the right base plate) but Like I said on your fb post, my re jetted single EA81 Hitachi eats webers for breakfast

Interesting about re-jetted webers. I've heard a rebuilt Hitachi goes just fine - probably the reason why Subaru put it there in the first place

Cheers

Bennie

Willy Fisterbottom · Post by **Willy Fisterbottom** » Sun Jul 06, 2014 10:41 pm

El_Freddo wrote:Interesting about re-jetted webers. I've heard a rebuilt Hitachi goes just fine - probably the reason why Subaru put it there in the first place

Cheers

Bennie

Yeah mate, IMO Hitachi carbies are way under rated. Set up and jetted right on a stock manifold, there is no benefit putting on a Weber. Bolting on new Weber in place of a old Hitachi in need of a rebuild will give a good improvement but its cheaper, easier and more satisfying setting up a Hitachi. I'll have to dig up my notes with all my jet sizes.

Post by **Bantum** » Sun Jul 06, 2014 10:51 pm

Yes I'd be interested to know your jet settings as well Willy ...

Cheers, Bantum ...

Willy Fisterbottom · Post by **Willy Fisterbottom** » Sun Jul 06, 2014 11:09 pm

OK, I'll look for the piece of paper I scribbled bit on somwhere in the shed.

steptoe · Post by **steptoe** » Mon Jul 07, 2014 9:07 am

as long as it was not on a roll

the jetting for most carby cars was more a compromise to suit a multitude of climates and altitudes surely ? Many carb cars benefit from a localised tuning, then go for a trip of all regions and sometimes that fine tuning may not be so happy. I used to get that with my 465 Holley dropping 600m to sea level - would get pinging on country highland fuel at sealevel

Bolt ?? That was a 1/8 BSPT jammed in a 1/8 NPT threaded taper hole !

Willy Fisterbottom · Post by **Willy Fisterbottom** » Mon Jul 07, 2014 4:45 pm

steptoe wrote:as long as it was not on a roll

the jetting for most carby cars was more a compromise to suit a multitude of climates and altitudes surely ? Many carb cars benefit from a localised tuning, then go for a trip of all regions and sometimes that fine tuning may not be so happy. I used to get that with my 465 Holley dropping 600m to sea level - would get pinging on country highland fuel at sealevel

Bolt ?? That was a 1/8 BSPT jammed in a 1/8 NPT threaded taper hole !

Factory jets are set like you say a compromise for climates and altitudes but also emissions, fuel economy and factory restrictive air filters and exhausts.

Dean.nabbe · Post by **Dean.nabbe** » Tue Aug 19, 2014 10:18 pm

did you find the specs for rejettin the Hitachi Willie? i'm curious now

Willy Fisterbottom · Post by **Willy Fisterbottom** » Thu Aug 21, 2014 8:11 am

Yeah I did but I'm at work ATM.
Shame they did't make these for a EA81

steptoe · Post by **steptoe** » Thu Aug 21, 2014 8:37 am

If you had one of these EA71 manifolds what stops you from cutting it in half and run one side per EA81 head ? - apart from the need to plug up the holes found once cut - plate up each end with an air balance and water transfer port each side join with rubber hose ??

anyone got one of these Weber manifolds ?

YouTube · Post by **El_Freddo** » Sat Aug 30, 2014 1:06 am

steptoe wrote:anyone got one of these Weber manifolds ?

Willy's probably got five stashed away somewhere

Cheers

Bennie

henpecked · Post by **henpecked** » Tue Jan 13, 2015 10:06 pm

Dean.nabbe wrote:did you find the specs for rejettin the Hitachi Willie? i'm curious now

been a looooong time at work ??

taza · Post by **taza** » Tue Jan 13, 2015 10:37 pm

Keen to know this. My Hitachi has been rebuilt ~2 years ago. Running massive ignition timing.. no wonder the brum keeps up with an ej25 outback..

Willy Fisterbottom · Post by **Willy Fisterbottom** » Wed Jan 14, 2015 5:33 am

I think you'll find your answers in the thread in the link below

showthread.php?t=25429

henpecked · Post by **henpecked** » Wed Jan 14, 2015 10:44 am

Willy Fisterbottom wrote:I think you'll find your answers in the thread in the link below

showthread.php?t=25429

thank you

JP147 · Post by **JP147** » Thu Jan 15, 2015 9:11 pm

Later model EA81s did come with a larger manifold like an EA82 and these fit with no mods. I have seen 2, my car has one and I saw one at u-pull-it. For these you use an EA82 carb adaptor.

If you just want to use the normal EA81 manifold, I have an adaptor for your carb type for sale in the for sale section of the forum.