36 replies to this topic

[Cooperman]

The head is very unlikely to need skimming. It will probably just need cleaning and rubbing back with a sheet of emory cloth on a flat block about 3" x 5". Heads almost never warp. In fact I've not seen a warped A-series head in over 55 years of working on them. The block never warps. The only issue requiring skimming is when water erosion has happened and this is obvious when you emory block it down.

You will need a new head gasket and you need to check the valves and valve seats. Re-lap the valves if the seats are pitted, but if they are burnt you will need new valves and re-cut seats - a job for the machine shop.

Rather than pay someone to change the head gasket you will be better doing it yourself and spending the money on tools which you will need in the future. As a new classic Mini owner the sooner you get into DIY-mode, with the help of us on here, the better for your wallet  .

[WimpyMiniMan]

The head is very unlikely to need skimming. It will probably just need cleaning and rubbing back with a sheet of emory cloth on a flat block about 3" x 5". Heads almost never warp. In fact I've not seen a warped A-series head in over 55 years of working on them. The block never warps. The only issue requiring skimming is when water erosion has happened and this is obvious when you emory block it down.
You will need a new head gasket and you need to check the valves and valve seats. Re-lap the valves if the seats are pitted, but if they are burnt you will need new valves and re-cut seats - a job for the machine shop.
Rather than pay someone to change the head gasket you will be better doing it yourself and spending the money on tools which you will need in the future. As a new classic Mini owner the sooner you get into DIY-mode, with the help of us on here, the better for your wallet  .

I got a quote from the local machine shop of £250incl vat to have the head fully refurbished and converted to unleaded its an austin 1989 head so i think it is most likely leaded, so I think that is what I will do. Would you recommend a torque wrench for re attaching the head or do you think careful common sense will be ok? I have ordered a copper head gasket kit incl. other various seals which I'm sure will come in handy at some point. DIY was the route I was going to go down because I want to learn the process and have next to no money being a student! thanks for the advice!

Regards
George

[cal844]

The head is very unlikely to need skimming. It will probably just need cleaning and rubbing back with a sheet of emory cloth on a flat block about 3" x 5". Heads almost never warp. In fact I've not seen a warped A-series head in over 55 years of working on them. The block never warps. The only issue requiring skimming is when water erosion has happened and this is obvious when you emory block it down.
You will need a new head gasket and you need to check the valves and valve seats. Re-lap the valves if the seats are pitted, but if they are burnt you will need new valves and re-cut seats - a job for the machine shop.
Rather than pay someone to change the head gasket you will be better doing it yourself and spending the money on tools which you will need in the future. As a new classic Mini owner the sooner you get into DIY-mode, with the help of us on here, the better for your wallet  .

I got a quote from the local machine shop of £250incl vat to have the head fully refurbished and converted to unleaded its an austin 1989 head so i think it is most likely leaded, so I think that is what I will do. Would you recommend a torque wrench for re attaching the head or do you think careful common sense will be ok? I have ordered a copper head gasket kit incl. other various seals which I'm sure will come in handy at some point. DIY was the route I was going to go down because I want to learn the process and have next to no money being a student! thanks for the advice!
Regards
George

£250 sounds about right for the time and work involved, you could save costs on the machining by removing the valves( you will need a Valve Spring compressor)

Most of the money will be for cleaning and set up time...

You will need a torque wrench to torque initially after reassembling the engine and then again after the first heat cycle!

Hope this helps!

[gazza82]

They might need the valves to check the new seats but either way they must be kept in order or labelled so they go back in the same guide.

And an A-series is one of the simplest engines to change a head gasket. I changed one at 17 with little advise ... Just a basic tool kit and a workshop manual. And a long, long time before the internet!

Get a new bypass hose for the water pump too.

Edited by gazza82, 28 January 2016 - 11:25 PM.

[WimpyMiniMan]

The head is very unlikely to need skimming. It will probably just need cleaning and rubbing back with a sheet of emory cloth on a flat block about 3" x 5". Heads almost never warp. In fact I've not seen a warped A-series head in over 55 years of working on them. The block never warps. The only issue requiring skimming is when water erosion has happened and this is obvious when you emory block it down.
You will need a new head gasket and you need to check the valves and valve seats. Re-lap the valves if the seats are pitted, but if they are burnt you will need new valves and re-cut seats - a job for the machine shop.
Rather than pay someone to change the head gasket you will be better doing it yourself and spending the money on tools which you will need in the future. As a new classic Mini owner the sooner you get into DIY-mode, with the help of us on here, the better for your wallet  .

I got a quote from the local machine shop of £250incl vat to have the head fully refurbished and converted to unleaded its an austin 1989 head so i think it is most likely leaded, so I think that is what I will do. Would you recommend a torque wrench for re attaching the head or do you think careful common sense will be ok? I have ordered a copper head gasket kit incl. other various seals which I'm sure will come in handy at some point. DIY was the route I was going to go down because I want to learn the process and have next to no money being a student! thanks for the advice!
Regards
George

£250 sounds about right for the time and work involved, you could save costs on the machining by removing the valves( you will need a Valve Spring compressor)

Most of the money will be for cleaning and set up time...

You will need a torque wrench to torque initially after reassembling the engine and then again after the first heat cycle!

Hope this helps!

What sort of range torque wrench would I need? I've seen some from 30 - 230 nm but is this too high? Also that price was for hardened valve seats and guides as well.

[WimpyMiniMan]

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UPDATE: Just taken the head off ready to go to the machine shop - here are some pics which might help with diagnosis. Also can anyone recommend a torque wrench to buy for putting the head back on?

 

Cheers 

George

[gazza82]

It's often personal preference and what brands you have been bought up to use and trust ..

 

I've got a Draper 1/2" drive... 30nm to 180nm ... and it's served me well for a few years.

 

But a good quality 3/8" wrench should be fine as you only need to get to about 50 ft/lb on head bolts and as they tend to be shorter, you are less likely to over-torque. Get one with IMPERIAL settings ie ft/lb as that is what most Classic car manuals will use. You will need a higher rated bar if you plan to remove the crank-pulley and some of the suspension nuts. 3/8" also start lower and there are a few low torque nut/studs on an A-series.

 

Halfords Professional Range are good as they come with a lifetime guarantee.

 

Otherwise Britool, Sealey, Wera, Teng are all good brands.

 

What you must NOT do is get a really cheap one that is likely to lose its calibration first time .. and don't drop it or use it as a breaker bar ..

 

Some only torque nuts tight ... they don't work on reverse threads (like some stub axles).

 

 

I've bought a few tools from Justoffbase and saved a bit of cash ..

 

 

Just remember you always get what you pay for .. a cheap torque wrench isn't likely to be very accurate and could leave you with more issues that you started with ...

 

Hope you don't mind my little edit......Pete

Edited by Cooperman, 01 February 2016 - 12:47 PM.