The Fordson Tractor Pages Forum

Hi Folk,
As per my subject line "How soon after an engine rebuild does one need to re-torque the head"? Even after the engine was refitted to the Dexta and warmed up the head was not retorqued. The Dexta has less than a hour on the tachometer and not done any work other than slow cruising around the tractor club Shark.
Mervyn

It tends to depend a bit, but you should always do it after the first warmup (when the tappets also need resetting) then officially at 50 hours, but I would do it more to get the best sealing.
Sandy

Cool, thanks Sandy.

Our Cheshire club member Phil Moston is a Perkins engine enthusiast and specialist, and what he doesn't know about the earlier engines is not worth knowing. His recommendation for the 3 cylinder Perkins and Perkins derived engines (Dexta), which can have a tendency to blow the head gasket between cylinders, is to torque down at least 4 times after a rebuild with a few hours running between each tightening. If you have fitted new head bolts and studs, in addition they will stretch as the engine is used, so at least 4 tightenings in that case.

Hi Shepp,
Thank you for that valuable information. I must admit that those thoughts of blowing a head gasket has haunted me for several months now. Unfortunately/fortunately my Dexta is not a working unit but an exhibition unit that does very little running. We have a club social/work day in ten days time where I was planning to do the first re torque. I will need to find some heavy work like pulling a disc harrow or something. Its going to be a long while before I will be able to complete the four re torques as I live 60 miles from the tractor club. Nothing ventured nothing gained
Mervyn.

Very handy rule Shepp, hope Davie never needs it but if he does we now know it.
Don't forget to reset the tappet clearances after retorquing the head.
Sandy

Will do, thanks Sandy.

In hind site I don't recall us renewing the head bolts, is that a sin

It depends on the engine, but older engines generally don't need new bolts or studs (if they're in good condition) but check manuals about that for each engine. I can confirm that neither Major's nor Dexta's need new bolts or studs.
Sandy

Thank you for your input Sandy, much appreciated.

To be honest I rebuilt my Dexta engine 18 years ago and never re-tightened the head bolts!!
I worked it hard topping straight from rebuild and since then it's been as good as gold. Maybe I was lucky!

I think you have been very lucky! Probably worth doing anyway though.
Sandy