Balancer probs

ian.stewart · Post by **ian.stewart** » Sun Jul 29, 2007 6:04 pm

Been looking at my Balancer today, the key way is fubared after the timing gear let go,
Its a P5/6 balancer, so its not that common, With the mind working overtime I have looked into the possibility of Broaching a new Keyway 180degs opposite, I have a minuiteman at work so it wont be a problem with the keyway.
What I am unsure about is, Are P5/6 balancers neutral balance, I have looked at mine and at the moment I think its neutral, but I will have to take the injection timing wheel off to confirm,
Timing marks are easy to get around by using a stick on tape from Real steel will get around that one.

mrcheese · Post by **mrcheese** » Sun Jul 29, 2007 6:31 pm

I have no idea what you are talking about, but would something I have stripped from a P6 engine help?

I am in the process of a rebulid. It will end up as a 3.5 EFI. Anything left over will be scrap.

Paul.

The Original Tom · Post by **The Original Tom** » Sun Jul 29, 2007 6:40 pm

I was of the opinion that most people just scrapped the balancer? Unless its non-neutral, it won't actually 'balance' anything. Wouldn't getting your bottom-end balanced would be more beneficial? Having said that I bet its megabucks.

ian.stewart · Post by **ian.stewart** » Sun Jul 29, 2007 7:01 pm

No, the crank balancer is an important piece of engine hardware, There is a good chance of the crank breaking if you remove the balancer as it dampens the inbuilt destructive harmonics from a V8,

Post by **katanaman** » Sun Jul 29, 2007 8:42 pm

From what I can remember of my one Ian its neutral balanced. It has some drilling's on it but they are minor so can only be to balance itself. There aren't any offset castings on it to make it offset balance.

mrcheese · Post by **mrcheese** » Sun Jul 29, 2007 8:43 pm

For my education I would like to know what it is.

Paul.

Post by **katanaman** » Sun Jul 29, 2007 8:48 pm

http://en.wikipedia.org/wiki/Harmonic_balancer
there are better explanations out there but I cant find one right now. This will give you the general idea though.

ian.stewart · Post by **ian.stewart** » Sun Jul 29, 2007 9:29 pm

Cheers for that, Marki. that now sounds doable if I cant find another good damper, Another problem I have now thought of could be a timing issue with the 60-2 wheel bolted onto the rear of the balancer, I dont think they are equispaced so turning the wheel on the balancer may be a problem, athough I will have to look into the ECU and see if I can move the datum pick up delay in the timing.

Post by **katanaman** » Sun Jul 29, 2007 10:15 pm

If you mean the bolt holes for bolting on pulleys then yes it is 6 bolt equispaced so long as you broach the new slot in the right place you should be able to spin it round and keep the right timing. Its a role pin that stops stuff being put on out of sync not the bolt spacing.

Eliot · Post by **Eliot** » Mon Jul 30, 2007 6:21 am

what about pinning the crank? - seems easier..

http://www.superchargers4less.com/C6/index.htm

JP. · Post by **JP.** » Mon Jul 30, 2007 6:56 am

Well the flywheel is neutral balanced ( according to RS ) so that made me think the balancer is also neutral balanced.

ian.stewart · Post by **ian.stewart** » Mon Jul 30, 2007 8:56 am

Eliot wrote:what about pinning the crank? - seems easier..

http://www.superchargers4less.com/C6/index.htm

Thats not such a silly idea, I could probably get a 10mm scotch in there made from silversteel, d-mn sight stronger than a woodruff key, and used together, would probably do the trick,
Just to make the method clearer, I would usea bit piece of round 10mm ground stock silversteel, not pining thru the balancer and crank, but drilling a 9.5mm hole along the crank and balancer when assembled thru the circumfrel edge of both together, reaming out to 10mm, and inserting a short length of SS rod together with a dab of loctite, and retained by the big washer and bolt
But I suppose I would prefer to use a better balancer, if I can find one.
Ian

JSF55 · Post by **JSF55** » Mon Jul 30, 2007 10:52 am

I thought the lower timing sprocket was driven by this keyway?

ian.stewart · Post by **ian.stewart** » Mon Jul 30, 2007 12:22 pm

JSF55 wrote:I thought the lower timing sprocket was driven by this keyway?

The bottom sprockrt is driven by this, and I have every intention of driving the sprocket by the woodruff key, just want to locate the Balancer beter if I cant get one with a good keyway

kiwicar · Post by **kiwicar** » Mon Jul 30, 2007 1:21 pm

Don't know how relevent this will be but I had a mate many years ago with a high reving short stroke 850 mini (destroked 905) where the flywheel would smash up the woodruff key and leave the flywheel to spin!

Kind of exciting for the brief moments before he killed the ignition!
Anyway the way he got around this by lapping the flywheel onto the crank using firstly fine valve lapping compound and finishing with Brasso, he needed to start with a good match on the tapers but after that he did away with the woodruff key all together and relied on the fit of the parts and a long spanner on the flywheel nut. might work on the rover ballancer

Mike