Which (between the two) engine is more reliable, M10 or M20

[petroscf]

From your experience (if you have experience with both engines) which one has less problems?

[nas80]

mate, thats an open question, i think it completely relies on how well its been looked after - regular servicing / warm up - cool down time etc etc.

why you asking?

[petroscf]

Well, I am considering all options for future improvements...(mad guy I am...I have hrdly driven the car with the new carb+filter setup!!!)

[Reck]

I have no experience with an M20 so can't comment on that engine. I DO have experience with abusing an M10 though.. I'm on the lookout for a new engine so I haven't been taking great care of this one;

1) Radiator burst on my way to an exam. Had to drive for 5~ miles or so with NO water in the engine (radiator burst at the bottom so petty much all of it drained out). That was a year ago.. Done about 8000 miles since then.. Still going!! I don't know if this is a fluke or what, but I've never seen an engine run for that long without any cooling.

2) Numerous festival trips last year carrying 4 people + camping gear in the boot and on the roof.. Up and down hills in the blistering sun - and this is after the above incident.

3) Used a cheap oil filter with no return valve over winter.. In really cold weather it could take 15-20 seconds for oil pressure to rise, and I would normally start driving straight away. Still good!

So yeah.. The claim that the M10 is bulletproof is completely true in my humble opinion.

[nas80]

i knackered the valve stem seals on an m10 and this caused it to puff blue smoke when coming on off the throttle.

Poor m10 it wasnt really its fault, i knew i was going to change it for an m50 so for the few months before hand i ragged the nuts off it, and i compounded the problem by sticking a mini oil breather filter directly on the rocker cover which i think caused pressure build up / dried out the seal.

m20's i have no experience of really, from scanning the tech help section it seems they more likely to have problems with the k-jet system?