12G202 Head. Beyond salvage?

[svenedin]

I made a small mixture adjustment and went out for a test drive this morning that included some hills. Car seems to run very nicely. Much better than with the old head and leaking gasket. I think I have definitely got a bit more horsepower. I fixed the manifold to exhaust leak as well.

Those valve seats have been worn for decades. It has always had a sightly irregular idle even going back to when I was 17. I always suspected this was valve related and it was. Another thing I noticed is that the spark plugs are no longer fouled with oil coming down through the valve guides.

Setting up the mixture was so much easier than it ever has been given that the idle (with the mixture correct) is so much more even.

Now I have to tidy up the garage and the tools everywhere!

Stephen

[philthehill]

Did you eventually re-torque the head nuts after the first heat cycle?

[svenedin]

Yes but only maybe 3 studs moved before the click on the torque wrench. The re-torque was minimal. Car runs well. I have no gauges but I think it runs hotter. Engine sounds different. I have never had a radio so over 30 year of hearing that engine makes me quite attuned to it. It is more noisy at idle but less noisy at higher revs. It revs more freely. I found myself doing 50 up a hill whereas 40 would have been difficult. It is a huge improvement.

Stephen

[philthehill]

Well done.

[svenedin]

Well done.

Thank you. It has saved me quite a big garage bill. I would never have attempted this job without the help of the members of this forum. With the A+ studs and flanged nuts as well as the other upgrades (thicker walled rocker shaft, more modern valve stem oil seals, new valves, springs, guides, hardened valve seats etc) as well as the best copper head gasket I could get the car now runs better than it has in decades.

The car also now has its original carburettor installed after a professional overhaul (Glen from SUcarbs.co.uk who did a superb job). This carb had been sitting on a shelf in the garage for ages because it had worn throttle spindle bushes which is not a job I can do.

Incidentally, ages ago I posted about difficulties setting the valve clearances. As was suggested, when I looked at the contact surfaces of the rockers where they push on the valve stem, they were very worn. These are the pressed rockers and now that problem has gone too.

Gradually, my car gets better and better but it does take me a long time. Years in fact! It is getting to be a very mechanically sound shabby rust bucket but of course I love it dearly even if it does bite and lash out at me (bruises and cuts)

Stephen

[oliver90owner]

I started with engines that only revved to a few hundred rpm - some only 300rpm up to a max 1200rpm. I fairly quickly progressed to 8 and 11 thousand rpm engines and car engines (red line up to about 6500rpm).

My valve grinding gear (stone based) was bought over 40 years ago and I now have a few cutters for cutting hardened seats.

After over 60 years, I have a good idea of how tight, or loose, valve clearances are. I don’t rely on standard feeler gauges as they are often too wide with worn rockers. A mag stand and micrometer gauge can be used for this (and lots of accurate measurements on engines and elsewhere). It gets used with the lathe (which comes in handy for lots of jobs). These measuring instruments are part of my toolkit, these days.

All standard OEM parts are perfectly adequate when new (and often for a very long service life - if maintained properly). That includes valves/guides with proper minimum clearances.

The only really major change, with these engines, is the hardened valve seats for lead-free fuel. Driving gently may still allow perfectly adequate operation with non-hardened seats for low-mileage users.

Many Minor users, these days, have no idea how to set about repairs - hence the forums such as this - don’t have the tools for the job, are unable to access/understand a proper workshop manual and and are conditioned to spending lots of money at the specific dealerships. There are only specialists for these old classic/vintage vehicles - and they are few and far between.

PTH knows far more, than I, about these cars - but lots of things are common to all old iron. It’s now 70 years since I first started mending my brand new bicycle (Christmas present which had a flat tyre). Likely it was only a leaky valve - not a puncture needing the wheel being removed, in my bedroom early on Christmas day!

However, well done, even if the work has been a bit protracred.

[svenedin]

I started with engines that only revved to a few hundred rpm - some only 300rpm up to a max 1200rpm. I fairly quickly progressed to 8 and 11 thousand rpm engines and car engines (red line up to about 6500rpm).

My valve grinding gear (stone based) was bought over 40 years ago and I now have a few cutters for cutting hardened seats.

After over 60 years, I have a good idea of how tight, or loose, valve clearances are. I don’t rely on standard feeler gauges as they are often too wide with worn rockers. A mag stand and micrometer gauge can be used for this (and lots of accurate measurements on engines and elsewhere). It gets used with the lathe (which comes in handy for lots of jobs). These measuring instruments are part of my toolkit, these days.

All standard OEM parts are perfectly adequate when new (and often for a very long service life - if maintained properly). That includes valves/guides with proper minimum clearances.

The only really major change, with these engines, is the hardened valve seats for lead-free fuel. Driving gently may still allow perfectly adequate operation with non-hardened seats for low-mileage users.

Many Minor users, these days, have no idea how to set about repairs - hence the forums such as this - don’t have the tools for the job, are unable to access/understand a proper workshop manual and and are conditioned to spending lots of money at the specific dealerships. There are only specialists for these old classic/vintage vehicles - and they are few and far between.

PTH knows far more, than I, about these cars - but lots of things are common to all old iron. It’s now 70 years since I first started mending my brand new bicycle (Christmas present which had a flat tyre). Likely it was only a leaky valve - not a puncture needing the wheel being removed, in my bedroom early on Christmas day!

However, well done, even if the work has been a bit protracred.

Thank you.

I noticed some knocking yesterday and discovered that the exhaust system had shifted having been disconnected from the engine to do the head. This was despite me placing a jack under the silencer to support it. Anyway, once under the car I discovered some of the U-bolts that attach to the hangers were loose and the exhaust had small blows (soot marks) where the pieces join together (it is a 3-piece exhaust). I sorted all of that, taking the exhaust back apart into 3 pieces and re-sealing with exhaust paste (and clamps). No more knocking or blowing.

Anyway, today there was a train strike so a friend borrowed my car. 25 miles each way mostly on motorways (M23/M25). This evening I asked how the car went. Absolute perfect I was told, 60 mph there and 70 mph back. I was a bit shocked. I have not driven the car over about 55 mph for decades. It just would not have gone that fast before the head work.

I would say it has had a successful road test now!

Stephen