Doug's EA81 Rebuild stuff.

Subydoug · Post by **Subydoug** » Wed Mar 13, 2013 11:10 pm

steptoe wrote:Black is a great colour to hide oil leaks

Oil leaks?? Whats this thing you speak of?? Not on my beautiful new motor

Yeah, one of the reasons why I dont want to do it, though I remember my old YZ80 motor when I painted it black. Looked pretty good then.

If I make it look too cool I wont want to put the bonnet back on

.

Regards

Doug

YouTube · Post by **El_Freddo** » Tue Mar 19, 2013 4:51 pm

Subydoug wrote:Oil leaks?? Whats this thing you speak of?? Not on my beautiful new motor

Don't worry, if there are any oil leaks I'm sure the paint will keep them at bay

Cheers

Bennie

steptoe · Post by **steptoe** » Tue Mar 19, 2013 9:16 pm

well, I guess it was oil that leaked out of mine over 16 years, blended with all the dust about and preserved it within over 370,000km. It then got a bath, scrub to look like new, new oil seals and pan gasket and in 200km s will roll over 500,000km - still screamin' no oil consumption great economy

Subydoug · Post by **Subydoug** » Tue Mar 19, 2013 9:42 pm

Well I went and picked up a can of Black. What can I say, Im a sucker for looks

.

Havnt done anything to the motor for a while now. Going to order some big end bearings and some crank bearings tonight. Then when They turn up I should be able to but the case halves back together.

Hey Steptoe, you've messed around with cam grinds on the EA81's have you not? Worth it? Any gains in the top end that are really worth it? Nows the best time to consider it as the engine is apart.

Regards

Doug

steptoe · Post by **steptoe** » Wed Mar 20, 2013 7:42 am

yeah , top end ?? er, not really thort of that end of things coz never spent much time there, just to declutch and take another cog. My experience goes with a complete rebuild each time, rebore, the lot so can't compare say to a run in donk, then improved on by fitting a cam. 16/56 was by far the most flxible torquey grind - tore up long haul hills with a small load of sand, small by small mountain in tray, at eight k as if it were empty , so the moral of the story is if you are gonna load it up the 20/60 was a bit more breathless if loaded up - other wise it was a little bit more fun

I'd say the came improved torque at lower revs - something I was chasing

RSR 555 · Post by **RSR 555** » Wed Mar 20, 2013 8:55 am

Interesting read...
showthread.php?t=15246

Subydoug · Post by **Subydoug** » Wed Mar 20, 2013 8:57 am

Ok cool. I figured a torque grind would be probably the most pratical for this engine. Still dont think Il bother. Im never carring heavy loads. Reason I asked about top end is I do a lot of hwy driving and sometimes getting around trucks can be annoying. If the torque curve went on for another 500rpms it would make all the difference in the world. That being said I do think my current engine is a bit tired. The 4spd man made a fair bit of difference.

Regards

Doug

Subydoug · Post by **Subydoug** » Wed Mar 20, 2013 9:04 am

RSR 555 wrote:Interesting read...
showthread.php?t=15246

Hmm, yeah. If only it were easier to change the cam shaft

. Oh well, Will have a spare ea81 in a few weeks.......

Regards

Doug

Subydoug · Post by **Subydoug** » Tue Mar 26, 2013 10:41 pm

Just a little update, got this in the mail today,

Anyone seen one before? Its a little Weber throttle body. Should bolt straight up to my existing adaptor plate

.

Also started making up the electronics to drive the injectors. Stay tuned Toonga

.

Other then that, got some big end bearings on the way, along with some crank bearings. Should be here in a week or so.

Regards

Doug

RSR 555 · Post by **RSR 555** » Wed Mar 27, 2013 2:20 am

Subydoug wrote:Anyone seen one before? Its a little Weber throttle body. Should bolt straight up to my existing adaptor plate .

Yep.. seen on Ebay but not sure what they fit as the bottom doesn't look like the standard Weber pattern? They look like the base plate to replace worn out butterfly shafts on something european.. kinda BMWish

Subydoug · Post by **Subydoug** » Wed Mar 27, 2013 8:54 am

Hmm, Il have to measure the holes. It looks pretty close. Managed to get it for pretty cheap though so Not too fussed

. Certainly around the right size. That plastic part on the bottom is just a protection thing. It comes off. A little shorter then the weber, so hopefully I can stick the stock airbox back on top. Anyway, lots to do still. Figured better doing this then freezing my teats off outside. Hoping for some injector pumping tonight

.

Regards

Doug

RSR 555 · Post by **RSR 555** » Wed Mar 27, 2013 12:32 pm

Oh.. I thought the piece that has the protective cover was the top, like were the fuel bowl body would sit? Is your plan to make this fit the standard EA81 manifold?

Subydoug · Post by **Subydoug** » Wed Mar 27, 2013 8:02 pm

Yeah the plastic part goes to the bottom. If it didnt all the wording on it would be upside down

. Not sure yet. Maybe you guys can help me decide what to do. Here are my options. A simple analog efi setup with a single throttle body on the stock intake manifold. Easiest to do, just some bolting and slappn and its done. Other option is to make up a new manifold. Advantages?? could possibly make it breath a little better, though I do believe the heads are the limiting factor on this little motor, so It probably wouldnt make any difference. More work and probably no advantages.

Stick with the current weber 32/36 on the stock manifold. I really really like this carby. holds lambda like a champ and gives great throttle responce. It is way over kill for this little motor though. Cant remember the last time I actually had the secondary open. All opening it does is drop off velocity so the motor leans out slightly. I did think about making it so they opened together...but then I just left it alone and it was fine

.

Third option? I have a set of 34 ICT's that would sit nicely over the heads.......Doug Likes......

What do you guys think?

EDIT: also got given a 80's L series sedan 4wd today......it has a 5spd man (unknown condition yet). Maybe it will find its way behind my little ea81? I dont know if I like the 5spd more then the 4 spd. I like the gear spacing in the 4 spd better then the 5 spd in my vortex. What are the arguments for the 5 spd?

Or maybe just drop the lot into the vortex, make up some custom air bag suspension and hit up the beach in style

Regards

Doug

steptoe · Post by **steptoe** » Wed Mar 27, 2013 8:59 pm

When some have said a webered EA81 goes similar to running twin Hitachis makes you think the manifold is not a limiting factor. I went from twins to a single Volvo 2.3 litre efi throttle body and ran LPG via 2" pipework. I'd say it went no worse than the twins.
With all that, maybe running your weber efi throttle body will be enough without goin' into making or modifying a manifold beyond adapting the TB you just bought.

Subydoug · Post by **Subydoug** » Wed Mar 27, 2013 10:06 pm

Hmm, Well The weber certainly does run good. I have never driven a dual carb ea81 so I cannot really compare, and my old hitachi was knackered. I think with the stock manifold and EFI it will be fine. Like I said I pretty much never have the weber secondary open, even in sand, It feels like she doesnt go any harder. Just looked up the mounting for the 32/36, they are different to this little throttle body. Hmmmm, decisions, decisions, decisions........

Ha, looking at this little 34mm throttle body I think "no way is that big enough". So time for some math I suppose?

34mm throttle body, lets assume around 110 cfm.
110cfm is around about 3114853.1699cc/min

So how much does my EA81 use? not sure, but what I can work out is the point at which it will become too small.

So, standard ea81 engine capacity is around about 1800cc. The max RPM Ive ever revv'd to is around 4100, so lets say 4500rpm.
(1800x4500)/2 = 4050000cc/min at 100% VE.
Throttle body can only supply 3114853.1699cc/min.
So whats the max VE I can run before I start choking my engine?
100(3114853.1699/4050000)= 76.9% VE.

Hmmm, ~77% VE. What is the VE of an ea81 I wonder? I think im pretty borderline. 140cfm and Id be happy. Suppose I can just try it and see.

Regards

Doug

RSR 555 · Post by **RSR 555** » Wed Mar 27, 2013 11:48 pm

Subydoug wrote:Third option? I have a set of 34 ICT's that would sit nicely over the heads.......Doug Likes......

What do you guys think?

I like

Subydoug wrote:EDIT: also got given a 80's L series sedan 4wd today......it has a 5spd man (unknown condition yet). Maybe it will find its way behind my little ea81? I dont know if I like the 5spd more then the 4 spd. I like the gear spacing in the 4 spd better then the 5 spd in my vortex. What are the arguments for the 5 spd?

IMO not worth the hassle of making up the gear shifter linkages (incl 4WD lever) and the support for the centre bearing on the tail shaft. If you're changing to EJ then AWD D/R 5 speed (L.Series low range) is the way to go.

Subydoug · Post by **Subydoug** » Thu Mar 28, 2013 12:02 am

Yeah, I like the twin carbs. They look mean!

Not even sure if its a Dual range yet. Also I hear it has around 300k on it so its probably pretty knackered

. Rear swingarm and mustashe will fit the vortex nicely......

Anything you might want from it? Probably going to be chucked down the dump. Aparrently the body's in pretty good shape. Radiator is stuffed. Owner collected a roo. Motor probably toast as well because he continued to drive it

. Pity it isnt an RX :P.

Regards

Doug

Post by **TOONGA** » Thu Mar 28, 2013 6:34 am

Subydoug wrote:Yeah, I like the twin carbs. They look mean!

The cats out of the bag then

Subydoug wrote:Rear swingarm and mustashe will fit the vortex nicely

You will need the fuel tank as well, as I understand it as the 2WD tank is a different shape.

TOONGA

Subydoug · Post by **Subydoug** » Thu Mar 28, 2013 8:56 am

TOONGA wrote:The cats out of the bag then

You will need the fuel tank as well, as I understand it as the 2WD tank is a different shape.

TOONGA

No body said anything about twin turbo....

.

Already looked into the fuel tank. Mine has the hump for the diff, so it should be fine. The only thing that needs doing is drilling the mounting holes for the mustashe bar (as far as I know

) and finding a suitable powerplant. But thats later.

Regards

Doug

RSR 555 · Post by **RSR 555** » Thu Mar 28, 2013 2:41 pm

Subydoug wrote:Yeah, I like the twin carbs. They look mean!

And sexy !!

Subydoug wrote:Not even sure if its a Dual range yet. Also I hear it has around 300k on it so its probably pretty knackered . Rear swingarm and mustashe will fit the vortex nicely...... Anything you might want from it? Probably going to be chucked down the dump. Aparrently the body's in pretty good shape. Radiator is stuffed. Owner collected a roo. Motor probably toast as well because he continued to drive it . Pity it isnt an RX :P.

I'll have a look but nothing comes to mind off the top of my head.

TOONGA wrote:The cats out of the bag then

Subydoug wrote:No body said anything about twin turbo.....

Twin carby *yarn* but twin carby with 2 turbos.. tell me more.. I'm getting exited

Subydoug wrote:Already looked into the fuel tank. Mine has the hump for the diff, so it should be fine. The only thing that needs doing is drilling the mounting holes for the mustashe bar (as far as I know ) and finding a suitable powerplant. But thats later.

Fuel tanks are the same but the 2WD models do not have the mounting threads for the mustashe bar brackets or the tail shaft. For the mustashe brackets, I drill them out (body has spots were to drill out) and put rivnuts (nutserts) in there. Then you just need to make up the centre bearing mount for the tail shaft.