Fitting an Unleaded head

[SvMinor]

Is there much involved in fitting an unleaded head, ie, things I would need to know in advance before changing them over. its a used head so would I need to get it skimmed, if so is this costly to get done???

[chrisryder]

it's about as easy as taking off the existing head and refitting!

the one thing to look out for would be the oil feed through the head up to the rocker posts. make sure that the hole in the head will be under the pillar with the hole in! i believe different heads have different places for holes, so it's a good idea to check before you starve the rockers of oil!

if it's second hand, it's a good idea to at least check it for flatness. and ideally get it ground flat (dunno where or how much). the head could be cracked too, which could render it scrap. not sure how much crack testing costs these days, but it could be worth looking into.

remember to grind the valves in before you put the head on too.

[bmcecosse]

Why are you doing this? There really is NO need for an 'unleaded' head on a Minor - UNLESS you plan to flog it mercilessly on the Mway?? Otherwise - just set the exhaust valve gaps to 15 thou - and check/reset them every 3000 miles. Will that be more than once per year for you ? And ALL heads have the oil hole in exactly the same place............

[kennatt]

how do you know the head has been converted difficult to tell by looking,just leave yours alone twill be ok just as bmc says.

[aupickup]

i do between 10 to 14 thousand miles a year in my mog, some motorway, mostly general driving, and still got a leaded head on
as bmc says no point

especially as most of you on here do not cover great milages

[simmitc]

We agree on many things, and differ on others, which is entirely healthy, and we're still friendly. My preference would be to fit an unleaded head. However, the one you have is an unknown quantity. It certainly needs skimming. A firm close to hear charges £60 + VAT for crack testing a head, takes a couple of days. Many Minor Traders offer guaranteed exchange heads, which would be a safer option - assuming that the rest of the engine is good.

[minor65]

I agree totally with BMC, I thought of the idea of converting mine but not worth it , unless you are doing big miles/major motorway driving. Use unleaded fuel and adjust exhaust tappets to 15 thou as mentioned.

[SvMinor]

Ok then I think I will just keep mine as is.

[linearaudio]

And another endorsement!! Thrashed mine mercilessly for 3 1/2 years, long hauls at 70+ included. Exhaust gaps haven't changed yet! Don't go worrying about problems until (unless) they occur!

[bmcecosse]

Is that on the 940 head la - or an earlier head??

[linearaudio]

Is that on the 940 head la - or an earlier head??

Majority on the 940 head, though I initially abused the 1098 head for about 8000 miles with no detrimental effect! I am looking at that very head right now, with the valves removed, as I am currently using it as a surface plate to lap some hydrostat drive pistons on- and the valve seats are fine- much better than on my old A+ 998 Metro's, which did seem to eat valve seats!

[bmcecosse]

Ha! Very much the same experience as my own engine - although it was a 295 head before the 940. And yes - despite much hammering - the valve gaps remain unchanged.....