Morris Minor Owners Club

Can anyone diagnose this fault please:

Newly rebored 1098 (+60) engine, new pistons with electronic ignition kit fitted, working fine till today

After a 10 mile journey (still working fine) the car developed these Symptoms; working erratically, like firing on 3 cylinders, but none of the spark plugs have oil traces, colour of deposits on spark plug brown/grey, spark present on all plugs.

I thought: Could it be valve settings?

Any more ideas pl...

varoius people have had trouble with elactronic ignition mark, steve

Yes, I'd go back to points and condensor if you're having trouble.

What else have you done to the engine? Unleaded conversion, bronze valves? Is it still misfiring?

Sounds more like fuel starvation - check tank for vacuum, and pump for ticking! Although I am no fan of leccy ignition - it usually either works fine or fails completely. +60 pistons must have been hard to get - where did you track them down ?

cheers for that bigG. I'd never looked at the prices for a set of pistons, but having seen that (£170 incl VAT) I'll make sure to buy some more second hand engines!!!

I've often wondered about this + 60 thou increased the capacity to 1148 from 1098 does the extra 50cc make any difference?

I used to have a sprite we bored out to 1380 from 1275 but that had powermax Pistons and gas flowed head. hot cam and LCB big bore exhaust and webbers. We worked on it on a rolling road and got it up to 94BHP. Now that made a difference! But my mate could still get away in his cooper S with NO injection .

Happy Days

rayofleamington wrote:cheers for that bigG. I'd never looked at the prices for a set of pistons, but having seen that (£170 incl VAT) I'll make sure to buy some more second hand engines!!!

I happen to have been spending some time looking for new pistons lately...

The extra 50 cc will make no obvious difference - but £170 for pistons - geeeeeessss - have to go for a lie-down!

Me too! that is very cheap indeed compared to my sidevalve +.60 pistons

...and my Omega 73.5mm pistons which were £280 a set!

Aye - but the Omegas are a bit special - these are just standard pistons. Can't comment on the sv pistons - but maybe they had to be specially made ?

Back to my problem......actually it was a blown up gasket!!! between cylinders 2 and 3.

Could anyone judge what could have gone wrong? The engine is practically new, rebored, new pistons and rings, faced C/Head, new water and oil pumps

Quite odd since my late father had travelled 100s of 1000's of miles without this happening once!!

The gap between cylinders 2 & 3 is a common place for the gasket to fail as it's much thinner there.

Maybe it was a poor quality (or faulty) head gasket? Are you sure that the block face & head are true and was everything torqued down properly?

was it re-torqued after 500 miles?

Before you replace the head, make sure that both head and block are clean, flat and have no marks at all where the gasket seals around the combustion chambers. Any doubt means a light skim (min 0.005") to correct.

On our 1380, with 11-stud 12G940 head, I use the composite gasket from Mini Spares - GUG702560HG - cost £7.36 + VAT.

Make sure that you have the 'standard' higher tensile studs - they have a point on the top, and use 50 lbf. ft torque.

No sealant of any description, torque initially, then again when warmed up, then again after 100 miles, maybe again after 500/1000 just to be sure!

I now use high tensile head studs from Mini Spares torqued to 55 lbf. ft, but did not for the first 15/20,000 miles and had no problems.