940 head - couple of questions

[GeorgeHurst]

Hi,

I'm currently preparing my 12G940 head to put on my 1098 and have a couple of questions about its condition.

Firstly, the thermostat housing and all the waterways look to be quite rusty (see Image 1), is this the norm or do I need to clean this up somehow?

Secondly, I have given the combustion chambers a good decoke, but the inside of the ports also have quite a lot of carbon on them, does this need cleaning right back like the combustion chambers or will it be ok with these deposits on them? (See Image 2 - sorry for poor quality pic)

And lastly, how can I ascertain whether or not hardened/unleaded exhaust valve seats have been fitted? (Will be taking valves out when I get my hands on a spring compressor) - see pic of valves in Image 3.

Thanks in advance,
George

Image 1 - Thermostat:<br><br>

Port<br><br>

Combustion Chamber<br><br>

[Kevin]

Hi George, it wont do any harm to get of as much of the rust as possible although its quite common if a decent antifreeze solution hasnt been used, you could try some kettle descaler or similar.
It would be a good idea to clean the ports up as it all helps with getting a better airflow.
When you pull the valves you should be able to see the inserts if unleaded seats have been put in although you may have to look very close to see them.

If you want your photo's in one posting the way to do it is after loading the first one hit the preview button and then repeat until you have loaded all the pictures and they will be together. I have adjusted your post to show this.

[cormorant]

A useful article about fitting this head is here:

http://www.morrisminoroc.co.uk/index.ph ... highlight=

but maybe you saw it already....

[bmcecosse]

Clean off as much gunge as you can - if it has a bypass hose connection - it won't be 'unleaded' - don't worry about it!

[GeorgeHurst]

Aha! Thanks for that Kevin, I've never worked out how to post multiple pics in one go!

Thanks all for the advice. I have indeed seen that cormorant, thanks for pointing it out though. Will do my best to clean as much as poss when the valves are out.

BM, do you mean that is doesn't matter whether unleaded seats are fitted or not?

Something I meant to post with this earlier... could someone tell me what level one should fill the dashpot damper of an HIF 38 to? I will be using 3in1 oil, but am unsure how high to fill...

[bmcecosse]

Correct - unleaded is not important unless planning many hard miles of very hard driving! Just set exhausts to 15 thou gap (inlets 12) - and check/reset every 3000 miles. Just fill the carb up - excess will spill over into the inlet.

[GeorgeHurst]

Thanks BM

[bmcecosse]

In your pic - you can see ragged edge of combustion chamber. Worth just taking the edge off with a needle file - these rags can glow red hot - and cause pre-ignition and 'running on' .

[billlobban]

One of the Mini sites has an excellent article in which it is suggested that you 'pickle' engine parts in molasses
http://www.minimania.com/ArticleV.cfm?DisplayID=1881

[bmcecosse]

Crikey - Graham Russell again!

[billlobban]

Do I detect an anti-colonial bias Roy

[bmcecosse]

Not at all - just the ramblings of the infamous Russell!
He who swears by heavily modifying a 202 head - instead of simply bolting on a 940 head. Why does he say this ? Because where he is there are a great number of 1098 engines (with 202 heads) - and not so many 1275 engines with 940 heads! So - he has many 202 heads - and wants to sell them!

[billlobban]

Seriously since one of the original questions was about cleaning up the head has anyone tried the 'molasses' trick. Molasses appears to be reasonably cheap from farm feed suppliers

[GeorgeHurst]

Thanks for the additional comments on this. I was wondering about the raggy edges of the combustion chambers, so will definitely file those down.

I've also head soaking in diesel is a good way to clean up a head, any comments? Presumably one would need to soak the head in Gunk or Marine Clean or similar afterwards to degrease for painting?

[bmcecosse]

Diesel would be fine - wire brush in leccy drill is best way (wear goggles) to remove the gunge. Just wash with carb cleaner spray (toluene) to degrease it! Flash over with the gas blow torch also works well - keep the toluene away!

[GeorgeHurst]

Great, thanks, I think I prefer the idea of diesel to molasses!

[billlobban]

I've never tried it since I recon I'm sweet enough as it is but the article does say that it really cleans off any rust in the block or head

[bmcecosse]

Cola probably does the same job as molasses - both contain acid!

[billlobban]

Tried cheap cola myself recently following your advice - really not much of an effect - think you'd have to steep it in coke (other brands are available) for about a year to make any difference.
On the subject of grease removal I have a glass fronted log burning fire which gets coated in tar. Tried most things to get it clean over the years - almost impossible to get clean - but commercial dish washing fluid works instantly - also takes your fingerprints off. Dont know the chemical composition since the label has fallen off the container but it works wonders.

[GeorgeHurst]

Well, I guess I might try both, if one doesn't do the job then I'll try the other. thanks again