4 replies to this topic

[traineecollins]

Hi all,

I’m considering having my totally standard MG Metro engine fully rebuilt, but with a few choice upgrades, mainly for longevity and reliability.

The engine is in an MG Metro that is slowly being refurbished (my slow & low budget version of restored 🤣). Namely duplex timing chain & verniers and perhaps an Avonbar 5 speed gearbox.

The engine is a pre unleaded engine with the larger valves and I have been considering having the head ported during the rebuild. Would an otherwise standard MG engine benefit from this? It does have a slightly ported (not by me/ replacement oem inlet) and Maniflow 1 3/4” exhaust.

At the last dyno tune up, she made 74bhp.

I want a largely original car, and not wanting to start the chase syndrome of, change this means change that etc

Cheers

[ACDodd]

Yes the MG metro responds well to a good cylinder head. Consider another 9or so hp on tap by fitting another head. Assuming of course that the rest of the engine is in fine fettle and it’s tuned properly.

Ax

[absx2]

Is the engine smoking of using a lot of oil or running badly ?

How are the cold cranking pressures ?

Is there a problem with the motor or gearbox ?

If there isn`t I would leave it alone and spend the money on other things. 74 bhp sound like a healthy MG Metro engine to me and I have managed to run one to 136000 miles before oil consumption got a bit much.

I have another with over 100K that has been ragged hard for the last 30K or so and on changing the diff and fitting a central oil pick up pipe I measured the crank to find no wear.

I can`t say the same for the bores but it goes like stink and doesn`t smoke so I`ll drive it on.

 

I`m just trying to point out that sometimes it`s unnecessary to chuck time and money on a problem that doesn`t exist.   

[traineecollins]

I can’t say I have noticed any smoke, and when out with friends I often check with them if they saw any when following.

In terms of oil useage, I’m not sure what is normal?

Would a top up from near min to full after 300 miles sound right?

It doesn’t leak oil badly, only a weep from gear selector and even lighter weep down a clean gearbox casing at the clutch end of the block (above drain plug)

Cheers

[Cooperman]

The standard head is much better when given some minor improvements.

Typically just remove most of the valve guide bosses, smooth out the 'short-side radius, de-shroud the inlet valves a little and smooth out the combustion chambers. Just doing that improves the ability of the hed to flow mixture in and exhaust out much better.

You should measure the combustion chamber volumes, calculate the volume you need for your desired compression ratio and then have it skimmed.

Obviously fit new valve guides and have the valve seats re-cut.