Help! I think I just made a very costly error...

GreatOldOne · #1 28th May 2006, 11:14

Guys,

I've just started dismantling the engine. Head came of fine, everything was going hunky dory until I tried to turn the crank to see what the cylinder bores where like - forgetting that I'd left the fly wheel bolts in the back so I wouldn't loose them.

Well, one of the bolts caught on the engine stand, bent and popped the side out of the mounting flange:

There wasn't that much resistance, which was funny... I can only guess that the was a crack or a flaw already there and I just made it worse.

What I need to know is just how bad this is. I can't see if this flange is an integral part of the crank, or if it's a part than can be replaced on it's own. I have a funny feeling (well, more a feeling of dread) that it's going to be former, which I would assume means a new crank - Ouch...

If this is the case, the next question is (and this may sound insane), but could I use some JB Weld on it? According to the packaging, it'll withstand 4,000 1b/in. of pressure:

Thanks in advance,

Jason (GOO)

GreatOldOne · #2 28th May 2006, 15:59

The more I look at this, the more I think I may get away with it - here's why:

The threaded portion of the flange seems to be intact (I can thread a bolt in there no problem, all the way through) - the bolt seems to have only been in half a turn or so, and has popped the non threaded portion - so when I torque down the bolt in there, all of the pressure will be going into solid flange, not a join.

MartinClan · #3 28th May 2006, 17:07

If that were me I would get another crankshaft. I guess you could get one from the E30 zone for Â£not very much. Several reasons

1. Peace of mind
2. The forces on those bolts when the crankshaft is rotating at 6000 rpm must be huge
3. Flywheel exiting through bell housing and footwell not good!
4. Crankshaft and flywheel are balanced to a very fine tollerance.

All IMHO of course

Robin

Patrick · #4 28th May 2006, 17:11

Personally I would replace it as Robin's said its not very expensive getting parts on E30Zone. It's one of those things that will probably hold for a while but eventually it may break off.

GreatOldOne · #5 29th May 2006, 13:30

Yeah, having slept on it, it'd madness not to replace it. You now what it's like - you've just fudged something up big time, and you start casting around for quick fixes...

Ah well. Guess this means a complete rebuild now...

GreatOldOne · #6 30th May 2006, 11:20

How much is a reasonable price for a 2nd hand crank? I've just been offered one for Â£70 inclusive of delivery for a guy on e30zone...

MartinClan · #7 30th May 2006, 16:58

Â£70 seems OK to me IF it's in perfect nick. The problem would be if the journals needed regrinding - then it will start to get expensive.
If the seller is a "regular" on the E30 zone you should be able to find his previous posts and see what sort of replies he has had. I believe there is also a good and bad sellers list - could be worth checking out...

Robin

GreatOldOne · #8 21st June 2006, 12:57

Hey guys - back from holiday, and the engine faries haven't been to sort out my mess.

I've managed to secure a crank from an E30Zone regular, but in order to swap the old one out, I'm still at square one - and the reason why the old crank got fudged in the first place.

I need to get the big nose bolt out of the crank, to remove the main timing sprocket and the lower timing belt cover. Problem is, with the engine out on a stand, the crank free to rotate and the huge torque the bugger is tightened to, it's a seemingly impossible task.

I can lock the old crank up - I'll just have to make a plate or something that can bolt on the flywheel flange and stop it from moving. I can take the engine off the stand. But the torque issue is going to be the killer. I don't think I'm going to be able to get enough leverage on my breaker bar to get the bolt off. There are torque multipliers, but they're bloody expensive, and seemingly impossible to hire.

So - does anyone have any ideas?

Patrick · #9 21st June 2006, 13:22

Quote:

Originally Posted by GreatOldOne

Hey guys - back from holiday, and the engine faries haven't been to sort out my mess.

I've managed to secure a crank from an E30Zone regular, but in order to swap the old one out, I'm still at square one - and the reason why the old crank got fudged in the first place.

I need to get the big nose bolt out of the crank, to remove the main timing sprocket and the lower timing belt cover. Problem is, with the engine out on a stand, the crank free to rotate and the huge torque the bugger is tightened to, it's a seemingly impossible task.

I can lock the old crank up - I'll just have to make a plate or something that can bolt on the flywheel flange and stop it from moving. I can take the engine off the stand. But the torque issue is going to be the killer. I don't think I'm going to be able to get enough leverage on my breaker bar to get the bolt off. There are torque multipliers, but they're bloody expensive, and seemingly impossible to hire.

So - does anyone have any ideas?

A question for e30zone I think, anything useful in the Haynes or Bently manuals?

GreatOldOne · #10 21st June 2006, 13:46

Quote:

Originally Posted by Patrick

A question for e30zone I think, anything useful in the Haynes or Bently manuals?

Haynes & Bently only tell you it's tightened to 410Nm, and that replacement is the opposite to removal. Bently mentions that you require a 'special tool', but it seems to think you need a special tool for everything...

I asked on E30Zone - and here's the reply:

http://www.e30zone.co.uk/modules.php...wtopic&t=38070

I'll give it a go - It's not as if I can damage the crank any more, eh?

I just need to find someone with a more suitable mass than me to bounce on the breaker bar...

Patrick · #11 21st June 2006, 13:51

"special tools"

good luck with it

peterux · #12 21st June 2006, 21:19

Ok, I have never had to undo this nut but here is what i would do.
The best things for undoing tight nuts is a very long lever. For difficult hub nuts I have found that a length od scaffold pole works really well.

So here's the plan......... take, borrow, acquire, two lengths of scaffold pole. In one, drill two holes near one end to line up with your flywheel bolts. Mount this pole with the long end touching the ground. Take the other pole and slip it over your breaker bar and socket on the crankshaft nut.

Should be a piece of cake, then?

good luck!

Peter

GreatOldOne · #13 23rd June 2006, 08:32

Went and bought a length of aluminium bar last night (Â£4, B&Q), and got the bolt out last night using the method suggested over at e30zone.

It was remarkably easy in the end! You just slip a suitably sized length of bar into the bottom end of the engine so it rests length-ways across the three cast 'webs' that hold the crank bearings between cylinders 3 & 4. Then you turn the crank until the counterweights on 3 & 4 are resting on the bar. Add breaker bar to the bolt, bounce a few times et VoilÃ*! One bolt removed.

The alu bar will deform as you do this, but it takes all the punishment. The softness of the bar saves the counterweights from being marred or scratched (not that it matters on this crank, as it's coming out - but it will on the new one when I put it in)

Pfft. Who needs special tools....

Patrick · #14 23rd June 2006, 08:35

Well done!

JG · #15 23rd June 2006, 11:15

Well done.

John

GreatOldOne · #16 27th June 2006, 08:29

Managed to get all the pistons and the fubar'd crank out last night. It's a shame I managed to bugger it, as apart from the flange everything looks fine on it. All the journals look great, no scratches or anything. Even the bearing shells look good.

Hmmm. It's all a learning experience, eh?

Oh - top tip - A tesco's cardboard wine carrier makes a great place to store pistons, and you can write which piston is which on the carrier.

No, I didn't watch too much Blue Peter as a child. Honest

MartinClan · #17 27th June 2006, 19:00

Quote:

Originally Posted by GreatOldOne

No, I didn't watch too much Blue Peter as a child. Honest

Hope your'e not going to use stickey back plastic and spent toilet rolls when you re-assemble it...

Robin