Want to Rebuild EA81

555Ron · Post by **555Ron** » Sat Dec 29, 2012 8:07 pm

TOONGA wrote:Get another manifold but make sure your carby fits

I would go to the EA82 manifold like most of the Americans do. they are newer and have less porosity (from age) and are a bit bigger in the port areas you will need to modify a few things but from what Ive read it is worth it. sadly the link I had was on the hard drive that crashed

TOONGA

Cheers, I didn't know that the Ea82 manifold will fit. Shall look into it. I already have a Webber and adaptor plate for the narrower stud style from memory.

steptoe wrote:and you are aware the head studs on EA81 are of M11 aren't you ?

No, I wasn't but I am now thanks. The lower studs coming out the bell housing for the gear box seem to be something a little funky too as I couldn't get the M10 bolts I bought to bolt it to the stand thread in to it. Probably shouldn't have assumed they would be M10 in hindsight.

Going to go the minimum over size on the bores and fit Ea82 Injected pistons to up the compression. Because...
https://www.youtube.com/watch?v=dceB3SKBw9w

steptoe · Post by **steptoe** » Sun Dec 30, 2012 7:19 am

M10 they may be on the bell housing , but what pitch are they and did you buy 1.25mm or 1.5mm ?

555Ron · Post by **555Ron** » Tue Jan 01, 2013 8:16 am

steptoe wrote:M10 they may be on the bell housing , but what pitch are they and did you buy 1.25mm or 1.5mm ?

Must have bought 1.5mm because the ones in the bell housing were finer. I just used a G clamp rather then turn around and buy the correct bolt. I've decided to let who ever does the machining on the engine do the helicoils but I'll have to throw in some studs so they know what to put in. I'm a bit space limited so don't have a pedestal drill so I'm not going to get them straight if I do it. I've got a compressor next to my bed head to run my blasting cabinet which I just bought. I think I'm going to put everything I own through it because it makes everything new again

.

I've been cleaning today and looking at the heads...

The 4 steps circles looks like the heads were cast then the seats machined. Will it be ok to use my dremel to die grind and sand these flat.

I think I will have the blocks and heads all polished up to the point where I will send them off to be machined next week. Anyone know of someone that's really good with Ea81/Subaru stuff for the heads and camshaft? Seems like 16/56 0.235" cam profile is what I'd like, oversize EA82 SPFI pistons and I'm not real sure what to do with the heads. Porting, I see oversize valves might be available?

I just want to be careful and make sure I get the engine I want, that will drive well with no flat spots and bit of extra go over stock.

littlewhiteute · Post by **littlewhiteute** » Tue Jan 01, 2013 8:54 am

You're better off with a carbide burr in a die grinder.
A Dremel with a sanding drum will be ok for finishing.
Your heads do have a lot of overhang in the inlet ports.

The most important part of any port is the valve seat area and either side of it, including the valve head.

Brumby Kid · Post by **Brumby Kid** » Tue Jan 01, 2013 9:40 am

Tony Knight at Knight Engines (Adelaide)
Steve at Rusing sun (Adelaide)
Do NOT get a 16/56 cam.
Here's why. I would prefer to see you go to an engine shop who knows what they are doing and for ten to suggest a place to get your work done. Then they will collaborate on what is the best grind for your engines new specs, and what you want.
So for me I asked for an engine that would be nice and torquey for 4wding.
He then took into consideration of my new compression and bore size and made something suitable.
Or 16/56 is ok if you just want something off the shelf. But with what your doing I would get the cam done properly.
Have you seen the work that was done to my engine yet?

Cheers Cam

littlewhiteute · Post by **littlewhiteute** » Tue Jan 01, 2013 10:23 am

Brumby Kid wrote:Tony Knight at Knight Engines (Adelaide)
Steve at Rusing sun (Adelaide)
Do NOT get a 16/56 cam.
Here's why. I would prefer to see you go to an engine shop who knows what they are doing and for ten to suggest a place to get your work done. Then they will collaborate on what is the best grind for your engines new specs, and what you want.
So for me I asked for an engine that would be nice and torquey for 4wding.
He then took into consideration of my new compression and bore size and made something suitable.
Or 16/56 is ok if you just want something off the shelf. But with what your doing I would get the cam done properly.
Have you seen the work that was done to my engine yet?

Cheers Cam

"get the cam done properly", what does that mean?

16/56 has a duration of 252, and a lobe centre of 110, fairly general mild grind, just above standard.

56 being the closing point is the most important part, any cam grinder knows what works in different engines.

555Ron · Post by **555Ron** » Tue Jan 01, 2013 11:25 am

littlewhiteute wrote:You're better off with a carbide burr in a die grinder.
A Dremel with a sanding drum will be ok for finishing.
Your heads do have a lot of overhang in the inlet ports.

The most important part of any port is the valve seat area and either side of it, including the valve head.

Thanks Gary, just got back from Bunnings with a carbide burr bit, a tungsten tool and some new sandpaper bits. I'll have a crack today if I find someone cool and suitable - weather man says it's going to be 40 degrees.

Or 16/56 is ok if you just want something off the shelf. But with what your doing I would get the cam done properly.
Have you seen the work that was done to my engine yet?

I have looked around a fair bit about what can be done and went right through your build thread. I just think that going off and doing something 'custom' might backfire. Steptoe has had his cam ground 16/56 and liked it (seems like a pretty popular profile) so I will be asking for that. What's popular might not be 'best' but I'm thinking there would be a reason it's popular. And if it isn't giving the desired results, there's the large knowledge base to draw from to fix it.

littlewhiteute · Post by **littlewhiteute** » Tue Jan 01, 2013 12:19 pm

555Ron wrote:Steptoe has had his cam ground 16/56 and liked it (seems like a pretty popular profile) so I will be asking for that. What's popular might not be 'best' but I'm thinking there would be a reason it's popular. And if it isn't giving the desired results, there's the large knowledge base to draw from to fix it.

It's popular because it is mild for a mildly modified street engine. The wilder grinds are pigs to drive at low speed.

I have a Datsun engine that will get a 37/71, 288, 240 @ .050, 107 LCA, .460 lift.
Power band will be 3000 - 8000. Too big for an EA81 with it's restrictive intake.

steptoe · Post by **steptoe** » Tue Jan 01, 2013 12:45 pm

The EA81 came out a long time ago and all its hot ups were also worked out a long time ago. My 16/56 was an excellent all rounder cam grind from slow mud slinging to revvin' the tits off it. I was warned not to go any bigger numbers in case I hit some big highway hills with bigger tyres. Despite the warnings, some years later Ian Watson ground me a 20/60 which I found to be a peppier cam, torquey, grunty, good economy 609km from full to cough* ,*cough splutter in the BrumbyE

No vac advance on the 20/60 cam either

Its down side showed up when towing a 5000l water tank on a bigger trailer and anytime I had a heavy load - just started to get a bit breathless at higher end of its rev range, maybe down lower too ? And ran hotter ..... when suffering

An engine builder may dial in a cam right to your specific needs if you can be specific, and if your needs change ....?
Anyway, it is just an EA81

On the valve and head work , not wanting to put you off or nought, but had a few engine builders say the EA81 never really suffered by its head or valve set up in the flow dept - already quite generous. The downfall is the inlet manifold or rather the one carby hole in it

555Ron · Post by **555Ron** » Wed Jan 16, 2013 10:16 am

Ok, the engine is off getting refurbed but the engine builder has rung and told me that installing ea82 spfi pistons will decrease the compression ratio as he has looked into it. I've had another look and my info says that the gudgeon pin to piston top is higher on an ea82 spfi piston and does increase the ratio. Can someone confirm this. And are the ea82 spfi piston distinguishable from their ea82 cousins if he gets it wrong?

steptoe · Post by **steptoe** » Wed Jan 16, 2013 2:09 pm

the dish of the piston crown might need to be cc'd to get answer

YouTube · Post by **El_Freddo** » Wed Jan 16, 2013 4:47 pm

555Ron wrote:Ok, the engine is off getting refurbed but the engine builder has rung and told me that installing ea82 spfi pistons will decrease the compression ratio as he has looked into it. I've had another look and my info says that the gudgeon pin to piston top is higher on an ea82 spfi piston and does increase the ratio. Can someone confirm this. And are the ea82 spfi piston distinguishable from their ea82 cousins if he gets it wrong?

I don't know how the gudgeon pin being higher in relation to the piston top helps with compression, that to me would mean less compression. Unless you've got to use a particular con rod with it. The secret might also be in the length of the connecting rod - and this could be what the mechanic is missing.

The joys of a custom build through a mechanic...

Cheers

Bennie

dfoyl · Post by **dfoyl** » Wed Jan 16, 2013 6:02 pm

The EA71 pistons are the ones to use to increase compression.

steptoe · Post by **steptoe** » Wed Jan 16, 2013 6:22 pm

Funny that coz the pistons I got for my rebuild of EA81 claimed they were for EA71, EA81 - a compromise maybe from the after market world. The factory EA71 pistons may be what is needed ?

555Ron · Post by **555Ron** » Fri Mar 29, 2013 8:12 pm

Well, still waiting for them to bore it at the reco shop, they never seem to be in much of a rush...

Next issue. The head studs, does anyone know where you can get them aftermarket? Most were bent like a banana and the local bolt shop is more tailored to industrial. They are 125mm m11 x 1.25mm with 40 mm threaded at each end. Genuine are $18 ea... Thinking about getting some old ones gold plated but my plated nuts and bolts seem tighter which would alter the tension on the heads after they are torqued to spec. Ideas?

Brumby Kid · Post by **Brumby Kid** » Fri Mar 29, 2013 8:17 pm

I went for genuine and got a good price.
My engine builder and I couldn't find any aftermarket.
He said he could get some ACL (I think) but they would have been twice the price.

Cheers Cam

steptoe · Post by **steptoe** » Fri Mar 29, 2013 9:04 pm

Is that a FROG price? At the end of the day the extra spent on new genuine will be forgotten - mind you - never forgot the 2000 price to visit workshop and replace one thread in M11 - $60 !

littlewhiteute · Post by **littlewhiteute** » Sat Mar 30, 2013 6:22 am

What is the difference between an EA71 and an EA81 piston?

Does the EA71 have a domed piston?

The EA81 engines I've had apart are ALL flattop pistons.

555Ron · Post by **555Ron** » Fri May 03, 2013 4:38 pm

Gary, I think the only difference between EA71 and EA81 pistons is the height from gudgeon pin to the top surface of the piston. I haven't seen any EA71 pistons that had a domed top surface. But I may be wrong...

Ok, just to give this a bit of a bump... the dream is still alive.

I have my engine back - I dropped it off in January and after a lot of waiting and frustration I got it back today. Can anyone see where they have F'd up?

No putty back together this weekend. They said they checked the end float - I'm not an expert but I would have thought checking it would involve meshing the gear of the crank and cam together in a block half which won't work with the gear on backwards. If not... how do you check it?

Cam specs. Apparently not quite what I asked for but close. I can't even remember the specs I gave it seems like forever since I handed it over...

Custom made 1 piece tailshaft for the 5 speed gearbox conversion. I think it is 2 3/4" steel with replaceable uni joints. It is definitely ultra heavy duty - I hope it fits in the tunnel.

Ended up with Wiseco 0.5mm oversize pistons. They look nice - shame to hide them in the block.

And the block halves...

Cleaned the flywheel with glass bead...

Upon further research I find that later Subaru's came out with 8 3/4" clutches. (one on the right is 8") Little bit of digging around in my parts pile and I find this. I'll clean it up and have it machined for the 5 speed conversion. From memory, the outer face where the teeth for the starter motor is has to have 1.5mm machined off it. Then reface the clutch plate surface? Is this correct?

Also got a power steering pump. Got it gold plated and have a rebuild kit on the way from Japan. Will get someone to do the rack for me. Things are happening, just not real quick!

Silverbullet · Post by **Silverbullet** » Fri May 03, 2013 5:59 pm

Oooooooooooh me likey that one piece tail shaft! how much did it cost ya?

4 months is a ridiculous waiting time

Don't care how busy they are that is unacceptable IMO. Obviously don't know much about Subarus if they put the gear on backwards, and telling you they checked the end float like that...something smells fishy here.

I like seeing a collection of bits in readiness for some upgrades, looking forward to seeing this come together