CRANKSHAFTS

This forum is about the Fordson Dexta, Super Dexta and Petrol Dexta.
Post Reply
Tubal Cain
Site Expert Team
Site Expert Team
Posts: 418
Joined: Wed Apr 16, 2008 8:47 pm
Location: PEMBROKESHIRE WEST WALES

CRANKSHAFTS

Post by Tubal Cain »

A number of parts suppliers are advertising replacement crankshafts for the Dexta engines. cheaper than the cost of a regrind. However as the replacements are not supplied with counterweights presumably the intention is that the weights from the original crankshaft are meant to be fitted.

This raises a question as to whether or not the crankshafts then require to be re-balanced? My gut instinct is that they should be balanced however, possibly other members can put me right.

Gerald

Bluebilly
True Blue
Posts: 66
Joined: Thu Aug 15, 2013 5:01 pm
Location: Waterfoot, Glasgow, Scotland

Re: CRANKSHAFTS

Post by Bluebilly »

I would imagine that modern crankshafts for low revving diesel engines would come balanced and there should be no need to add weights from your old crank. My question would be, how would you know where to add or remove weight to ensure it is balanced? Balancing machinery is not difficult if you have the equipment to measure vibration and know how to plot onto a polar diagram, and I'm guessing not many of us have the facilities and the analysis gear to carry this out. Thinking a little deeper, if there is a need to balance the crank, what about the flywheel and clutch? No point in balancing one without balancing the lot.

I'd go with your gut Gerald and I'm sure it is safe to assume that they come balanced and ready for fitting.
1948 E27N
1958 Dexta
Roadless 75
TEF 20
MF135 multipower
MF 165
MF 240
SAME Solar 60

russelm
True Blue
Posts: 362
Joined: Mon May 17, 2010 2:42 pm
Location: Nottingham

Re: CRANKSHAFTS

Post by russelm »

I cant see it being necessary to balance such a low revving engine to the degree of accuracy you refer to.

That said, I do know of an outfit that would do it for circa 150 and would balance the full assembly including rods, pistons, crank pulley, flywheel and clutch plates.

That said, I have not found crank re-grinds that be that pricey! (do mains and big ends need doing, any pics?)
Mark Russell - 1959 Standard Dexta - Work In Progress!

Post Reply