EA81 Overhaul thread

Get the most out of your Engine / Gearbox with these handy hints ...
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Silverbullet
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Post by Silverbullet » Sat Jun 18, 2011 5:57 pm

A little update, I now have absolutely everything I need (including an air compressor :mrgreen:) to finish the engine build! :-D And I've pretty much got the whole week free, looking forward to getting some major things done this week, finally :mrgreen:

I'm just about to go out there now, but another question about bearing crush for littlewhiteute; when I undo one bolt and see the gap emerge, should it be a certain size gap or no gap at all? I don't know since the manual says absolutely nothing about it. I can check it as well since I've discovered I was using the torque wrench incorrectly and have to do the big end bolts again :rolleyes: should only take 10 minutes though.
Will it ever end!?
-EA81 TWIN CARB!!!!
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-2" lift
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littlewhiteute
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Post by littlewhiteute » Sat Jun 18, 2011 9:28 pm

If you undo one bolt, a gap will appear at the parting face.
Typically 2-6 thou, if you have no gap then there is no interference fit of the bearing within the rod bore.

The bearing is held within the bore from being larger in OD than the bearing bore ID. The tangs are for assembly only.

Here is a link:

http://books.google.com.au/books?id=2vY ... sh&f=false
Regards

Gary ;)

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Silverbullet
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Post by Silverbullet » Sun Jun 19, 2011 6:38 pm

This update is not as cheerful as I would have hoped :( As you can see by the pics I have rejoined the crank-cases. But it seems I'm going to be cracking it apart again :???: Here's why:

Getting everything ready to re-join the halves, I had everything laid out in order so it would be quick and easy. When I went to check the torque specs for the 3 different sizes of bolts, the book had the sizes 6, 8 and 10mm listed...my bolts were 10, 12 and 14mm. That's the first problem and I should have not gone any further, but stupidly I did and I regret it. I took the highest torque rating (10mm in the book, 29 to 35 ft/lbs) and applied it to the 14mm bolts, middle to the 12's and lowest (3-5 ft/lbs, our torque wrench doesn't even go that low!) to the 10's. This could end up being a long story so to cut to the chase, one of the 10mm bolts (there's two only around the front oil seal) stripped it's thread, and it was the last bolt on the last torque step :evil:
Also the two case halves seem to be mis-aligned by quite a bit (1.5 - 2mm), didn't think of checking this when I was torqe-ing the bolts but it's very obvious. The crank turns over fine clockwise, but sometimes if you turn it the other way one of the big end nuts gets caught on something and jams the whole crank until you turn it clockwise again, not good. If the two halves are twisted I'm assuming this would impact the main bearing halves alignment?

I think I'm going to get a helicoil for that one stripped thread and then split the block again, re-do it and get them aligned properly this time. Since the book is useless for this, what torque setting should I use for the 3 different sizes of bolts? Keeping in mind our wrench only goes down to 20 ft/lbs.

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Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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steptoe
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Post by steptoe » Sun Jun 19, 2011 10:02 pm

there are torque settings for the M6 , M8 and M10 as a general rule of thumb and there is a list of each of these items and its torque. I have not compared the two to see if all M6, M8 and M10 match the generalised torque specs. Those M6 babies are just a bit more than finger tight really at 5 foot pounds - guess you know that now!

Paranoidal steppy once bought an inch pound torque wrench just to prove to self it can be measured by a tool. Shoulder tight, elbow tight, wrist tight and pinky tight vary from muggins to muggins. 12 inch pounds = one foot pound , I think.

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Silverbullet
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Post by Silverbullet » Sun Jun 19, 2011 10:34 pm

Thinking about it tonight I realized the book must have been talking about the thread size not the head/socket size...wish it was more clear :???: Definitely know 5 ft/lbs is just snugged up now, off to find an M6 kit I think.
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
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steptoe
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Post by steptoe » Sun Jun 19, 2011 11:55 pm

steep learning curve you are taking us on there - imagine you are an apprentice mechanic and this was a customers car - yer boss out front explaining the delay and your backside fearing his greasy size nine Blunny

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littlewhiteute
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Post by littlewhiteute » Mon Jun 20, 2011 6:01 am

All fasteners are referred to by their thread size.

A 6mm bolt generally has a 10mm head, 8 has 12, 10 has 14.

If the crank turns freely, I'd say the rods are hanging up in the crankcase because they have no pistons on them to allow them to swing where they should go.
The little end of the rod is unsupported so the big end bolts get caught up in the crankcase.

I can't see how the halves are out of alignment, there's two dowels for that reason. And it would be near impossible for the halves to be out of line since the shafts would help self align the case halves.
The halves could get out of alignment axially but not radially.
Regards

Gary ;)

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Silverbullet
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Post by Silverbullet » Mon Jun 20, 2011 1:14 pm

That's interesting thanks for the info littlewhiteute, you seem to have all the answers! And steptoe of course ;) I understand now about the thread sizes, had a bit of a "DUH!" moment :rolleyes: Also makes sense about the big ends being caught up because they are loose, good news as well.
I'll have to take a pic of the crankcases alignment, it may not be much but it looks more than before I took it apart. The "step" of the misaligned parts is only on the top and back of the engine, down where the sump is the two parts are flush. Maybe it's fine and I'm just making a fuss about nothing, it's happened before :rolleyes:

For the stripped thread since it's only 5 ft/lbs at the most (practically nothing) could I get away with making a new thread out of epoxy? :oops: Completely dodgy I know and I wouldn't do it normally but dunno when or where I can find a helicoil, and if everything else is ok (alignment) it's alot of bother to fix one thread that doesn't do much.

steptoe if this was a customer car I would ask my boss why he's getting a first year apprentice to build an engine...if I still had a job by this stage :mrgreen:

*edit* Never mind, I must have been imagining it, the cases are a bit off but all the seams are completely flush where it counts (oil pump housing, where the oil seals go etc)
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
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Silverbullet
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Post by Silverbullet » Mon Jun 20, 2011 6:58 pm

Managed to sort something out for that bolt, it wasn't stripped really badly so I could get some torque on it, just hope it holds!

Just did the pistons, and (almost) everything went without a hitch. Only thing that went bad was the piston rings popping out of the compressor before they got into the bores...then the ring compressor exploded :???: Managed to get them all in and gudgeon pins in. I made a special tool (see pic) for putting the pins in, it has an aluminium tip with an OD about .1mm smaller than the pin with a peg on the end which is about .1mm smaller than the ID of the pin. Just enough to hold the pin in nicely by friction but slips straight out. The steel part which leads to a knurled handle is the same Dia. as the aluminium tip so the whole thing can go straight through to line up the small end with the piston. I also froze the pins before I put them in, made life so much easier they just slipped straight in!

Everything is reconnected! ready for external components.


Ring compressor in place
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Ready to tap the piston in
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It's in!
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Both on this side went in easier than expected
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Tool I made to make putting the pins in easier
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First pin installed! went in very easily, and this was #3
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Engine back on the bench
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Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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steptoe
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Post by steptoe » Mon Jun 20, 2011 7:02 pm

There is an instructin in the Gregorys as to which block face should face down onto bench when assembling - and I think this has som bearing on how things hang and clear things internally

Do you have a manual? Think you do - which brand? Gregorys, Haynes, Factory ?

Bearing / engineering supply jonts sell the helicols or other brand names, so to auot parts chains. The more you fiddle the more you buy....

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steptoe
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Post by steptoe » Mon Jun 20, 2011 7:07 pm

How does it all turn over now?

Did anyone tell you to oil up the pistons and rings prior to ring compressor fit-up?
If not, I just thought of it now as I see no mess :-)

Looking good, and brings back memories

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Silverbullet
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Post by Silverbullet » Mon Jun 20, 2011 8:17 pm

Yep plenty of clean engine oil, ended up with a puddle on the shed floor :rolleyes: Everything turns over really nicely, nice and smooth. Thinking I'm going to get good compression after this :p
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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steptoe
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Post by steptoe » Tue Jun 21, 2011 8:46 am

Everyone has bed in procedures too. Mine has been to find a mountain and drive up it with revs closer to labouring than revving with less throttle than more if you get my drift. Then some highway run where 60 does not get in anyones way, step up to 80 then 100, back down to 60, squeeze through 80 to 100 again. Take a phone, torch, tools and a mate/dad just in case you forgot to do something and it lets you down. New oil presure switch time too

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Silverbullet
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Post by Silverbullet » Tue Jun 21, 2011 6:05 pm

Yeah I was wondering about break in too, will see what I can do but there aren't many mountains around here ;) Might have to go up to Mt. Lofty and back the long way down the freeway.

Definitely replacing parts like oil sender while the engine is out, also getting a new clutch (old one is still good but a few years old, don't want to risk having to change the clutch with engine in car) Thermostat (old one is jammed open) Idle solenoid I think it is, wire is on the verge of snapping...sure I'll think of something else too :rolleyes:
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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littlewhiteute
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Post by littlewhiteute » Tue Jun 21, 2011 7:10 pm

The correct way to load the rings is to accelerate the engine from 30mph - 50mph and coast to 30, (50 - 80 kph) repeat 10-12 times.

Don't baby it, don't trash it, don't sit on one speed for long periods.

If the engine is clearanced correctly, and the bore finish is a match for the ring type, you'll be run-in after about 1 hour of varied load and speed driving.
Regards

Gary ;)

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Silverbullet
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Post by Silverbullet » Wed Jun 22, 2011 10:46 pm

Have replaced the flywheel housing and front/rear oil seals. How do I go about torque-ing the crank pulley bolt at the front? Manual says to do it after the flywheel is in place but has no tips on how to keep everything still while I put the huge torque on it.

After the seals the engine was back on the engine stand, now I have to work on it minus 50% of the floor space :rolleyes: Everything is ready to put the heads back on tomorrow, just have to spend some time cleaning up the mating surface on the block. How should I do that? And how clean does it have to be? not enough room around the studs go get much in there but I assume it has to be very clean for the head gasket to seal properly. And no I'm not going to attempt to get the studs out, I can tell some of those studs are part of the block by now. Since the rocker arm assembly bolts are part of the torque sequence I'll finally be able to start taking things out of the boot of the car! :-D I've pretty much got everything except the engine in there.

Have to say, seeing the heads go back on tomorrow will feel like the start of the home straight for me, hearing her start up is within sight! After that it's basically just external components, a few bolts here a bit of sealer there, new oil sender, clutch and thermostat over there :o
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
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El_Freddo
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Post by El_Freddo » Thu Jun 23, 2011 1:34 am

littlewhiteute wrote:The correct way to load the rings is to accelerate the engine from 30mph - 50mph and coast to 30, (50 - 80 kph) repeat 10-12 times.

Don't baby it, don't trash it, don't sit on one speed for long periods.

If the engine is clearanced correctly, and the bore finish is a match for the ring type, you'll be run-in after about 1 hour of varied load and speed driving.
^ Agree with that - but the 1 hour thing is new to me, I'd still give it the usual 500-1000km oil change and while in that period not sit on the same engine speed for a long time - this reduces the chances of glazing the bore, a glazed bore is not good!
Silverbullet wrote:Have to say, seeing the heads go back on tomorrow will feel like the start of the home straight for me, hearing her start up is within sight! After that it's basically just external components, a few bolts here a bit of sealer there, new oil sender, clutch and thermostat over there :o
Don't let over excitement get in the way of the work you still need to do to properly rebuild this engine. Just make sure you do everything that is needed to be done! And don't get your hopes down if it doesn't fire up first time - this always gets me :(

Other than that it sounds like everything is happening well.

Cheers

Bennie
"The lounge room is not a workshop..."
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steptoe
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Post by steptoe » Thu Jun 23, 2011 9:26 am

Steptoe crank pulley bolt involves a bit of silicone sealer under the flat washer-like head of the bolt and as tight as can do when in car, in gear handbrake on. Been using method for ten years or so.....
Good clean up for block surface is a bit of dressed all round 38 x 19 mm pine, just a short bit with wet and dry grit paper grey stuff, bit of CRC556/WD40 to spray around, wrap the wet and dry around the bit of timber and work around the studs and face. Wipe away any grit from bores please

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Silverbullet
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Post by Silverbullet » Thu Jun 23, 2011 12:28 pm

El_Freddo wrote:Don't let over excitement get in the way of the work you still need to do to properly rebuild this engine. Just make sure you do everything that is needed to be done! And don't get your hopes down if it doesn't fire up first time - this always gets me :(

Other than that it sounds like everything is happening well.

Cheers

Bennie
Don't worry Bennie I know all about that, it's why I'm having to rebuild this in the first place :rolleyes:
Jonno looks like someone used your crank pulley method before this; the area around the bolt on the pulley was covered in silicone :o
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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Silverbullet
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Post by Silverbullet » Thu Jun 23, 2011 2:38 pm

Never mind, looks like I'm going nowhere today, see pics

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Literally no room to get socket over the nut...why couldn't they just put the bloody thing 5mm higher??? :evil:

What can I do? there's no way I can accurately get the correct torque on it, actually I can't get ANY torque on it :( Do I need to go out and try to find some special tool to get in there?

Just when I thought the hard part was over lol
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
-Custom paint job
-2" lift
-Full custom re-wire
-L series front end
Image

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