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Home > 998cc > Second hand head preparation

snowfruit

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Ireland

Right, this project has been a long time coming, but as I'm expecting the body back from the painters this weekend things are once again progressing. All the various parts I had collected so far for the turbo conversion are now appearing out of their various corners once again.

I bought a 12G295 head off eBay last year that had apparently been in some one's shed for a long time. What preparation would you all recommend I perform the head to get it ready for use, i.e. the valves and springs where all still on the head, should I use these or replace with new items, what needs cleaning, etc.? <- or should I get a pro to do all this?
Also is it worth spending the money on getting it converted to unleaded as opposed to running it with lead additive? I think Morspeed quoted me £155 last year to do the conversion and to clean the head up at the same time.

http://mini.twisted-design.net/blog/


Tom Fenton
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Fearless Tom Fenton, Avon Park 2007 & 2008 class D winner

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If it has been sat for a long time the valve stem seals will almost certainly have gone hard and will need replacing.

It is always a good idea whilst a cylinder head it off to inspect the valve seats. If they are very badly pitted then they will need recutting, otherwise simply grinding the valves into the head will suffice. Also whilst the springs are off check the sideways movement of the valve stem in the valve guide, if this is excessive then new valve guides will be needed and then the valve seats will need to be recut to suit the new guides.

None of this is especially difficult to check if you know what to look for but if you are not sure get someone with an experienced eye to look over it for you.


On 29th Nov, 2016 madmk1 said:


On 28th Nov, 2016 Rob Gavin said:
I refuse to pay for anything else


Like fuel 😂😂


snowfruit

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Member #: 557
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Ireland

Thanks for that Tom.

Any recommendations on whether to convert to unleaded?

http://mini.twisted-design.net/blog/


Tom Fenton
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Fearless Tom Fenton, Avon Park 2007 & 2008 class D winner

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Only you can decide that, you'd need to balance how many miles you will do per year and the cost and arseache of having to put additive in all the time, with the cost of converting a head.

Personally I'd convert any head on a car of mine to unleaded to save the hassle, but that's just me.


On 29th Nov, 2016 madmk1 said:


On 28th Nov, 2016 Rob Gavin said:
I refuse to pay for anything else


Like fuel 😂😂


andeh

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Dont fit inserts into 295 heads, within a short amount of time the head will crack. I think your best bet is to use additive.

If it were me i'd replace the valve springs with ones matched to the cam and have the seats cut. If its for use in a turbo i might also concider having a large exhaust valve seat cut if your using std valves (i think i'll help keep valve temps down??)

I've seen the future and tbh its Pie


snowfruit

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Ireland

I do have a turbo exhaust manifold. But if you have a solution that saves cutting the bulkhead I'm all ears.

Thats the first time I have heard about valve inserts causing the head to crack?

http://mini.twisted-design.net/blog/


Vegard

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On 19/06/2006 20:38:14 andeh said:

Dont fit inserts into 295 heads, within a short amount of time the head will crack. I think your best bet is to use additive.



Why will it crack? More than 940 or 163 heads?

My experience with lead free inserts and Minispares race-valves that the valves wear. The original lead free A+ valves are fantastic, but race-valves do wear a lot. I'd use a small amount of additive with standard/race valves (not a+) and lead free inserts.



On 13th Jul, 2012 Ben H said:
Mine gets in the way a bit, but only when it is up. If it is down it does not cause a problem.



snowfruit

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Ireland

On 19/06/2006 18:45:28 mini1071s said:

One question though, have you already got a turbo exhaust manifold as I may have a simpler solution for you if you still have the old std mini one than the adaptor which saves cutting the bulkhead.


Whats your alternative Peter? I would love to hear it as I don't particularly want a bulk head box...

http://mini.twisted-design.net/blog/


andeh

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On 20/06/2006 10:01:12 snowfruit said:

Thats the first time I have heard about valve inserts causing the head to crack?


I thought that was pretty much universally known that 295's have a bad habbit of cracking with exhaust inserts. I know i wont be fitting them to mine.

Duno where it came from exactly, but its just something i've picked up over many years. Maybe it is another unture rumour.

I've seen the future and tbh its Pie

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