very true....I'd say it's the one job worth shelling out for....other jobs could be achieved at home with patience and a good reference book....
Aluminium case and balanced internals would mean not having to split the case for quite a long time indeed
I think you will get a lot of satisfaction from the process...but as @zed has pointed out, once you've balanced the components, having everything 'dynamically balanced' will make for one smooth running, long lasting engine...it reduces stress on all the chief components, including the case itself...keep us posted as you go along
Well, the case and crank are at The Engine Shop, ready to be collected. May see if they can do the crank.
Well, I got my scales, and set to work using a small collection of files. I only managed one rod, which took me more than an hour! Any tips to speed things up? To see photos, I have uploaded onto my Type 1 Engine rebuild post.
Dynamic balancing isn't just done to the crank... It is done to the whole rotating mass!! So crank, pulley, pulley bolt, crank drive gears, flywheel and bolt, and the clutch pressure plate with bolts... The whole lot is assembled and put in a machine that spins it up and measures any run out/imbalance... Bit like a tire balancing machine, but a whole lot more expensive The actual cost of getting it done should be around £100
According to John Maher, if you do this and subsequently have to replace the clutch (perhaps a more common occurance for drag-racers?) you need to strip the engine and start again. He says he starts with bare crank and builds it up balancing at each stage. The end result is that if you take off the clutch the rest is still balanced, so balance up a clutch and fit and it won't be far out. £120 + VAT + courier to the middle of nowhere and back so perhaps £180 all in. Do you think this is overkill Paul?
If it's an all out race engine then I can understand the thinking... But if you spec your components properly in the first place then you wouldn't be swapping pressure plates. Unless you had one fail As for the cost, it's always going to vary from shop to shop!!