Value of Engine Balancing

[Alan]

Just make sure you don't take it all off the same side

[Charles P]

Just make sure you don't take it all off the same side

Roger that!

[AustinWood]

Another benefit of balancing is the reduction in vibration transmitted to the chassis.
Because the steering box is bolted to the chassis beside the rear engine mounting vibration is transmitted to the steering column. On longer journeys this makes the fingers tingle and/or go numb.
My engine is balanced and on Sunday I drove down from Blair Atholl to Melrose in one go, 120 miles. It took 4 hours only stopping once to clean the windscreen.
At the end of the journey I had no finger problems.

[Bob Culver]

When purchased in 1940 my RP had unfortunately been fitted at 40,000 miles with an exchange recon engine. My father noted one of the conrods was of much more robust pattern than the rest and meticulously reduced to match using the local grocers scales for comparison.

Was there a significant change somewhere during the 1930s?

[Ruairidh Dunford]

Remax rods are considerably more robust than Austin.

[Bob Culver]

Thanks Ruairidh
 
The heavy rod carries the Austin logo whereas others just letters MF, but even these seem not to be a set! Do not appear to have been remetalled.
 
Can understand the demand for aftermarket axles and cranks but surprised conrods were also available. Possibly so many were mutilated by filing and dented by the much used crude straightening jigs that it was more simple to fit a new rod than sort used ones.
 
Most parts of a Seven have a well made appearance as do 1 1/8 conrods, but many of the later are quite motley looking!

[Howard Wright]

Hi All

Sorry to resurrect this very old thread.  I’m starting to get ready to build my special engine.  It has a billet 1 1/2” crank and Nippy rods.  The crank, flywheel, clutch etc are with the Machinists to be dynamically balanced.  I’ve now set up a rig to balance the con rods similar to that shown earlier in the thread. My kitchen scales (well protected with cling film) read down to 1 gram.

My little end readings (holding the big ends in the rig) are all within 2 grams.  The rods with big end caps (but minus the bolts and nuts) vary by 12 grams.

Question 1 How close should I get the readings (to within a gram??)

Question 2 Where is the best place on Nippy rods to take material from?

Cheers

Howard

[Chris KC]

Howard,

I'm not sure I'd use a kitchen scale for this - just because it displays grammes doesn't mean it is accurate at that resolution.
You can get nice little digital jewellers' scales off eBay for a tenner or so.

As for how much variation you want to allow it depends how patient you are - I think I'd be aiming for no more than a gramme.
But in the light of your third question, I would rather accept a tad of imbalance than take metal off somewhere it really should not be taken off of.

Where is a question I'll leave to others, but wherever you remove metal do so smoothly & try to avoid making any 'nicks'.

[Zetomagneto]

Howard, You can adjust to some degree by the thickness of the washers under the rod bolt nuts.
I would take the heaviest and adjust the 3 others to that.
Best Wishes Gene

[Ray White]

I would have thought the accuracy of the scales is not as important as getting everything to match.