Pigford's Red Zed - long term projext XYZ

[paul doran]

Did you have the crankshaft balanced after the welds were cleaned up?

er what was that about balancing

[Dark Skies]

Did you have the crankshaft balanced after the welds were cleaned up?

er what was that about balancing

Oh. That doesn't sound ... er ... I'm sure it'll be fine.

Nitrous you say?

Hmmm. You should get some balloons in. For medicinal purposes, like.

[RALPHARAMA]

With Mark's views on brakes, in the unlikely event he actually gets over come with adrenalin and opens the taps, he'll not be able to stop again, so whether the engine shakes itself to pieces or not will be irrelevant. McVities will be ringing the leutine bell

[shrekward]

I thought Huntley and Palmers were Mark's sponsors?

[Pigford]

Balancings for girls....

I don't intend doing long distances on this one, so a few vibes won't hurt

I didn't have the thick end of £300 for a 'proper job' so I'm gona see wot happens

Guinea - Pigford will report on findings

[RALPHARAMA]

I don't intend doing long distances on this one, so a few vibes won't hurt

The balancing of a crank isn't to save the pork being bruised, but to save the engine from being shaken to pieces. If the crank is out of balance then it will fuck it's own bearings and, if far enough out, could even threaten the integrity of the castings holding them.

If it's been welded by someone unfamiliar with welding cranks, have you checked to see that it hasn't been distorted by the localised heating?

I'm not sure how cranks are balanced. I wonder if it is done dynamically of statically. I would guess that the webs are drilled to balance rather than adding weights

[Dark Skies]

I had Chris Appleby do my Z1000-H way back when. It was done dynamically, as I recall - which is why I had to send along the crank with nothing unbolted for a "real world" scenario. Engine ran as sweet as a nut when rebuilt. No vibes anywhere.

[Pigford]

Hmmmmmmmmmm, OK then, how do you go about static balancing

Can this be done without the use of any SPECIALIZED kit

I may be round to yours Ralphy, if we can do this between us

If not, suck & see

[RALPHARAMA]

I've had a quick nose around the winky wanky web and found an absorbing thread on static balancing a triumph crank.

It appears that one needs a set of knife edge beams, accurate scales and a lot of time. To be honest I really don't have the knowledge and certainly don't have the beams

I would like to learn how to. I would guess that the beams would be used in conjunction with a surface plate and mine ain't big enough for a zed crank.

[Dark Skies]

I'm not sure there's such a thing as static balancing - what purpose would it serve? With something heavy and fast moving like a crank you need to figure out the balance during motion in order to eliminate (as best as one can) harmonics. You're only going to be able to do that by spinning the crank.

When I had mine done I also had the main bearings replaced and new rods and pistons and gudgeon pins put on (so it was all starting out new from scratch). I gather Chris would have assembled the crank without the conrods but with new bearings and the rotor fitted, spun it up and drilled / removed / pressed weights in as appropriate. Presumably the conrods would have been matched up too - otherwise the good work would have been undone. I guess they must then weld it up afterwards - since I recall the rods didn't have split shell bearings and you wouldn't be able to fit them after welding. Not sure how they then take into the account of the welding / balancing.

Here's something on balancing you may find informative:

http://www.rpmmachine.com/engine-balancing.shtml


It amused me that they spelt 'Precision' as "Presicion".

[chrisu]

Hmmmmmmmmmm, OK then, how do you go about static balancing

Can this be done without the use of any SPECIALIZED kit

I may be round to yours Ralphy, if we can do this between us

If not, suck & see

[Pigford]

I think this is a conspiracy........

In other words, when ever an engine is rebored, and a new set of pistons is used, the assembly (crank included) should be balanced... My arse

As Ralphy found out, even Wiseco pistons varied in size by a fair margin, falsing him to get a rebore, matched to the pistons

I'm gonna whack it back together & give it a blast..... It ain't gonna be revved over 7000rpm that often, so it'll be fine

If it was for a race engine, then OK, but....

[RALPHARAMA]

The problem, Piglet, is that having welded it you will have unbalanced the crank. Yes pistons vary a bit, but remember what they are made of ... aluminium a very light material. By welding the crank you will have added filler material, steel, which is heavy, which will make more difference. Truthfully I think that your biggest potential for pain and grief will be distortion as a result of localised heating from the welding process. If I were you I would get your crank sat on a set of vee blocks on a surface plate and clock in the inner bearing surfaces to see if any distortion has been introduced by the welding.

It ain't gonna be revved over 7000rpm that often, so it'll be fine

If it was for a race engine, then OK

I thought from your earlier pix you were going to give it a NOS habit.

If you weren't tuning this engine why have the crank welded? If you are welding the crank then it's not a matter of just blowing some sparks at it Soz to bring in reality

Tuning is never a cheap game, which is why I leave it alone. It's no good just buying the glamour bitz

[Pigford]

........... .............. .............

[paul doran]

Balancings for girls....

I don't intend doing long distances on this one, so a few vibes won't hurt

I didn't have the thick end of £300 for a 'proper job' so I'm gona see wot happens

Guinea - Pigford will report on findings

they will if it explodes