Morris Minor Owners Club

With a depth gauge like this. You need 8mm to be sure.
Regards
Declan[frame][/frame]
And if you have to sink a valve:[frame][/frame]

Thanks, looks like I'm going to be tool shopping again!

Measure first! At a pinch a lump of plasticine would do the trick. If you stick with the standard 948 cam - you may get away with less than 340 mm - since it has less lift on the exhaust lobes than other cams.......

Okay well after filing down the water pump, and putting the standard 12g940 head on (measured by test building without a gasket and using the plastacine on the valves trick) I have an engine that turns over by hand its a bit resistant on tdc I'm guessing this is down to compression as this only really became apparent after the plugs where put in, so I am 99% sure everything clears. Although this hasn't stopped me looking for a 998 head as a back up.

A few studs need repalacing (rear water inlet for the heater & theromstat) and a new set of manifold nuts are on the list for tomorrow, to replace the worn ones I have reused from the original warped head, but after trying to get it to turn over and start, although the cooling system was incomplete, as I planed a very short test burst to see if it fired and there are no calamities, and then to connect the cooling system again, (after a snapped stud is delt with) nothing happened it turned over, no sound of valves and pistions hitting during turn over at slow speed, which was good but no ignition.

I'm going to do a compression test tomorrow to see if the head is a tight fit, I did a spark test yesterday and all was fine, but will also repeat tomorrow / in the morning, but if nothting shows up and and all is good does anyone have an idea of what it could be? I have the firing order as 1,3,4,2 and have got numberer one lead position, by taking the dizzy cap off and pulling out the plug in the first cylinder and when i can feel the compression build up on my thumb, checking which plug the rota points to. It's got electronic ignition, and is running a brand new red rota arm, the fuel pump is also electronic and working fine, the coil is fairly new, but i will check if it has a spark, the manifold is attached and the carb is working., the vacuum advance is new (under 6 months old) and all was working until I pulled of the 1098 head that had destroyed the mpg and was running badly.

To be honest I'm stumped! Any pointers would be great fully received again, and thanks again for all the info so far.

Valve gaps set to 12 thou inlet and 15 thou exhaust? Pour some petrol down the carb and crank it up.

Well all gaps set, with gauges, and tried the petrol trick, still nothing. Then a calamity of two studs snapping, has lead to the head being whipped off again! and me wishing I had not removed the 1098 head how ever bad it was running! I had managed a new top speed record of 80mph but had drop to an average of 30 mpg from the original 45 ish mpg.

I have been given a small ray of hope in the form of a ex auto grass ported and polished 998 head, so the 12g940 swap is on hold, and this is going on just so I can use the car during the week. I do have to drill out the main hole of the heater take off, and drill and tap the rear heater take off take stud holes, as this has not been done. Other wise it's not a bad looking head condition wise, All be it most likely just as restrictive as the original 948 head, it's definitely in better internal condition than the standard 12g940 which had a very corroded thermostat pot, and has caused me to want to beat it to death with a sledge hammer as it likes to snap brand new studs for the heater and thermostat flush to it's casting causing me no amount of utter annoyance, and dismay, as now it's a drill and tap issue.

I think after three days of both the 12g940 heads fighting me at the roadside, helpful folk talking to me about tue car, one guy shouting at me and making me jump, hence the first heater stud breaking! they are now on hold until I get a 1275 block ready for the car. I'm also a bit concerned about the water ways matching up, and making sure that the car is coolant leak proof, as it's my daily driver. I will keep you posted on how the 998 head goes on, or if I succumb to the lure of the 15 or so extra bhp and try the 940 again, but as Sunday is a day I need the Car I have Saturday to get it all working.

Snapped studs are entirely down to you using too much force on them. Use the correct short ring keys for tightening the nuts - by sensible hand pressure only. The non-starting was nothing to do with the 940 head - and waterways are not an issue. The 998 head will be fine -and 30 mpg is not bad for a general run-around Minor. 45 is beyond belief......