116 replies to this topic

[Brent J]

Ok. This is the most embarrassing admission. I didn't zero the vermia. I just checked and they are all 5mm out. I am a deadset idiot! I cannot believe I posted the figures and it didn't even sink in.

I'll re-measure and post up the revised measurements.

[Brent J]

 The correct measurements...

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[I'm a Red Motor fiend]

You might have to play with a new key and one of the products mentioned above to get it to fit in the irregular keyway. I would fit a new balancer to and if you only build up the key where it sits in the crank a new balancer should fit snug?

[Lc69]

I think it's already been suggested, but it might be best to get some key steel and make a new key with a step in it.

[Brent J]

As a side note, since I had the car jacked up, I figured id drop the tail shaft to test one of the earlier suggestions in the thread (i.e fouled tail shaft uni's).

 

The forward uni is smooth as butter and the rear uni is pretty good but did tighten ever so slightly at full articulation. I gently pulled off the caps to inspect the needle bearings and they were all present and intact.

 

Therefore I think it is back to ignition / tune or perhaps clutch / flywheel.

 

I did find this however will under the car.. Looks to be a bit too tight to me! Probably restricting some of the fuel flow I would think.

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Edited by Brent J, 23 April 2017 - 09:31 PM.

[grumpy xu1]

I'd say that you're right about the restriction, I'd guess the metal pipe needs to go towards the engine & then I'd fit some new non kinked hose both ends it's 5/16". Wouldn't be surprised if when you fix the balancer issue that your vibration is gone too, Gary.

[I'm a Red Motor fiend]

I think Gaz may be right too. If you can move your balancer by hand imagine what it's doing when you are on and off the throttle.

[grumpy xu1]

I'd fix 1 thing at a time to know what fixed the issue, had 2 engine mounts die in the cluby a few months ago, wouldn't know apart from reversing. Thought it would be really noticeable, but balancers usually do some moving around when stuffed. Gary.

[Brent J]

Hi Nichos,

 

Thank you for the suggestion. I will do a visual on the engine mounts our of curiosity, but Gary is right. I'm focusing on getting the balancer re-installed and the fuel line kink sorted. I take it for a test drive, see what the result is, then move onto the next lead!

[Brent J]

So baby steps forward. I received two Woodruff keys and a harmonic balancer in the post. I also picked up some Loctite 680 and Devcon.

I had to rob a small bank to pay for the Loctite - $55 for 50ml!!!

 

The new keys slide in and out of the balancer keyway quite easily.

 

The new balancer fits much more snugly onto the crank than the old one. The new key fits into the keyway on the crank more or less the same as the old one. Its snug at the foot of the keyway, but the upper shoulders of the keyway are worn.

 

I then decided to measure the combined depth of the keyways and compare that to the height of the new key. Note: the new woodruff key height is the same as the old one.

 

Difficult to explain, but for a really snug fit, the key could be about 0.9mm taller. My theory is that the centripetal force of the crank causes the key move outwards in the assembly allowing it to rock about in the crank keyway. Id like to keep everything as firm as possible...

 

So, I might find a local engineer that can make up a taller key for me.. or should I just leave it and be happy with the 0.9mm. Maybe I am being too fussy..

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Edited by Brent J, 25 April 2017 - 05:37 PM.

[grumpy xu1]

I would get the bigger key at least for the piece of mind mate. Don't think you'd regret that, much cheaper than a balancer through something hard to find. Gary.

[Lc69]

Just check the maximum temp and compressive strength of your metal epoxy.
Some products will not be suitable.

[I'm a Red Motor fiend]

Don't leave it with that much movement, it will just continue to flog everything out. I know it sucks big time, but if that was mine I would be fitting another crank.

[S pack]

Don't leave it with that much movement, it will just continue to flog everything out. I know it sucks big time, but if that was mine I would be fitting another crank.

Agree, going by those measurements the inside diameter of the new balancer hub is .92mm larger than the outside diameter of the crank snout.

The inside diameter of the balancer hub should be a couple of thou smaller than the inside diameter of the crank snout.

Edited by S pack, 26 April 2017 - 08:05 AM.

[rexy]

I think those measurements are showing the height of the keyway not the overall ID and OD?
Are you patient? If the engine doesn't owe you big dollars I would get hold of some tool steel and make my own key to snug fit. You should be able to hand shape it with patience. Loctite it up and see how you go.
What are the measurements of the crank snout OD and balancer ID ? (not at the keyway)

[grumpy xu1]

I'd look into rexys process mate, heaps of good suggestions in this post though. Gary.

[S pack]

I think those measurements are showing the height of the keyway not the overall ID and OD?
Are you patient? If the engine doesn't owe you big dollars I would get hold of some tool steel and make my own key to snug fit. You should be able to hand shape it with patience. Loctite it up and see how you go.
What are the measurements of the crank snout OD and balancer ID ? (not at the keyway)

Upon looking at those pics again you are correct Rexy.

I should have gone to specsavers lol.

[Brent J]

Rexy is right fellas. My measurements were the height vs. trough of the keyway, not the ID or OD. I did a partial test fit of the Balancer and it is a very snug fit to the crank which is good.

 

I have engaged an engineering / machining company in Capabala to make up a custom woodruff key for me. I feel that this is the next best thing to pulling the engine out of the car.

 

I appreciate all the good suggestions. Will chime in again once I get the new key.. Now I just have to be patient! I'm keen to get it all back together to see if it resolves any of my problems!

[Brent J]

So a small update - I managed to have a key machined up to better fit the worn keyway on the crank. I also had the key made a little taller by 0.5mm as per my posts above to make the entire assembly a bit more snug.

 

The key now fits quite firmly in the new balancer and also fits better in the crank keyway. I missed up some high temp high compressive strength Devcon and applied it into the keyway when fitting the new key. I've left it to cure for about 72 hours before ill fit the new balancer over the weekend...Ive re-taken all the measurements I took previously and so far it looks like the balancer should now be a much firmer fit..

 

Looks good so far, but the test will be how it handles heat, vibration, dynamic loading etc....

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Edited by Brent J, 19 May 2017 - 04:36 PM.

[Brent J]

I have a question ....

 

I faced up the new balancer and it seems like it will be tough to access it from the front nice and square on as the bottom of the radiator support more or less lines up perfectly limiting front on access.

 

How have others typically fit new balancers?

How far does the balancer get pressed on, i.e, press till it stops... clearance with the seal?

 

Cheers,

Brent

Edited by Brent J, 19 May 2017 - 04:39 PM.

[warrenm]

It's been along time since I fitted one in the car without the crank snout being threaded, but if you undo the engine mounts, jack the motor up, I think you can get enough clearance,then tap,tap,tap with a 4lb hammer & a block of wood. 

Balancer goes on until it stops.

[LC-GTR-1969]

I have had the wollowed keyway issue before...

 

I fixed it by stepping a new key- machining the new key with a step in it, then I used LOCTITE primer and then LOCTITE 660 retaining compound over the crank snout and within the keyway. 

 

I had previously read about some rally guys doing this in Miatas and the fix worked for years, so at the time I gave it a go... It never failed me with plenty of high rpm runs.