Copper head gaskets
Turbo Mini Forums

First topic as a member.

Right, I have been advised by a member of this forum to ask here for advice about the use and methods of use of copper head gaskets.

I am building a 74mm 1400 which is offset bored. This posess the problem of a standard gasket overhanging the bore promoting detonation and also fire ring burn out problems. I have been considering making up a copper gasket with laser cut, or water jet cut, which has beed suggested. The dilema I face is, after reading various things on the internet, there is about a 50/50 for these gaskets, the half against saying that they leak after a few hundred miles. I put this down to a few things but mainly people not folowing convention by not having perfectly flat surfaces and not re torquing after being brought up to working temp. Then the half for using these are again divided 50/50 with half for the use of the gasket 'Dry' with no sealants and the other for use with sealants such as Copper Cote and Hylomar Blue.

I have some one drawing up the gasket on CAD and getting some prototypes made in 1mm card. The sealing of the oil/water passages will be facilitated with 1.5mm section 'O' rings so the gasket can be installed 'Dry'

Again please remember that I would normaly use a Payen gasket if it werent for the overhang problems. This is also an option for my 16valve project requiring a totaly different hole pattern.

Your views, thoughts and recommendations on this would be much apreciated, but less of the negative as this will be happening whether it fails or not, its a suck it and see thing.

MS

Is the block 74mm already? or had you planned to take it to 74mm?

http://photobucket.com/albums/y139/Skinns46/

Its all ready 74mm

Ahh ok, Who's idea was it to use 74mm? Why couldn't they have been happy with 73.5mm. I must be honest and say i have never played around with a 74mm block but have you acctually tried a genuine gasket on the block face (metro turbo). There are quite a few of these engines about and they must get by some how. It won't be far off. As far as DIY gaskest go i've never seen one work with good effect.

http://photobucket.com/albums/y139/Skinns46/

i trust this is for turbo application????

i hate to sound negative but..... 74mm i doubt you would get the pistons to suite! with enough cc to bring your CR Ratio to a sane levell for Turbo application. 73.5 YES there are a range of pistons available

i have built 74mm bore N/A engines with no problems using Omega pistons 7cc dish. with NO inter bore blow bye on the head gasket.

the thing which takes out the gasket is called detonation or pinking. caused by too high a CR ratio or incorrect fueling
(too lean) or cooling problems.

the use of hylomar & the so called gasket goos! on a head gasket is insanity at its best and serves no purpose on a well built engineerd engine.

any of the well known gaskets say.. to name one a BK450 payne is more than up to the job even on a turbo engine running over 20+psi of Boost!

so for well built N/A engine its well over the top!!!

please dont wast your time, money & effort trying to solve a problem which isnt there in the first place.

the overhang problem isnt there on a 5 port head if the over bore has been done carefully.

the opinion i have given you the answers lie above.

good luck!

Edited by BENROSS on 23rd Mar, 2006.

Guys - His block is already at 74mm - lets answer the question eh

We kinda did Dave.
Like benross said there's no need wasting time and money on making a gasket when a standard one will probably do the job.

http://photobucket.com/albums/y139/Skinns46/

i dont want to sound negative dave i know where you are coming from, appoligies

his block is 74mm he has a problem!

in the gasket sense hes ok there IMO

would he be able to get a set of suitable pistons for 74mm or would there be a enough meat to have 74mm Omega pistons tops machined out? to get the CR down to a sane levell

mini sprocket did not mention he was turboing this engine?

these 74mm omegas are quite rare now!

Firstly the Pistons are 11cc Omegas and secondly We are talking N/A Cr set to 9.4 to reduce detonation issues but there is a deffinate overhang with a genuine Rover Payne gasket. I have spoken to MED and a friend has spoken to Bill Richards and they have confirmed this as well as speaking to Phill Hepworth, who also says the same. I also agree that gasket sealants should be left in the tube or can as the case may be when it comes to a composite gasket, but the copper gasket or the steel shims that MED have recommended, are a totaly different puppy. I am not talking about a layer spread on with your finger thick and gloopy, but rather a very very thin evenly sprayed on layer. I do not believe that Hylomar Blue is a bad thing when it is used in the correct maner. After all the only reason a gasket is used to mate components is to compensate for all the imperfections in the surfaces and inacuracies in machining as well as distortion due to uneaven loading caused by the clamping bolts. Composite gaskets form more readily to the mating surfaces where the use of any other sealant is undesireble. Anealed copper gaskets while being soft copper do not form well to severe imperfections and I suspect the use of sealant is more of a safety margin when the installer has not followed the convention I stated in my first post. Again going back to my first post I said I was 'o' ringing the gasket, sealant will not be used. Can any one give me one valid reason not to use this type of gasket in this maner I describe, and cost of manufacture or materials is not an issue. The only one I can think if is that it may leak oil/water, but if it doesn't, whats the problem. And what is with the negatives.

I say all this with respect and not to insult any one or offend. Just trying to get to the real reason that these do not work, and at the minute I dont see one.

In Light and Peace

MS

Edited by Sprocket on 23rd Mar, 2006.

I always just put a thin layer of LM grease on head and block never had a problem,think it helps the gasket spread under torquing

You could use a short stroke crank or trick short conrods and run tdc down the bore a bit if you wanted lower comp

Edited by Dangerous on 23rd Mar, 2006.

Metro turbo weekend driver,Mini turbo in the making again!

i have just take this pic of one of my 74 mm bored blocks i have had many years in storage.

you can see no over hang on the gasket
the center bores there is 3mm of meat between the bores exactley!

with an old compressed gasket i clocked up there was 0.3mm overhang, but this gasket came off a higley compressed turbo motor.
has the over bore wonderd ???

hope this helps you.

Ah, grease. Never thought of that.

So, Dangerous, you use these without problem. On what sort of engine/boost/power output is that on then :cool:

Head gasket info

http://www.babcox.com/editorial/us/us80222.htm

Metro turbo weekend driver,Mini turbo in the making again!

A friend of mine in Norway (http://www.ktv.no/~pjb-ktv/1399ccm.htm) ran a 1399 (74mm) engine with 11,2-11,5CR with BK450 years before it broke down. It NEVER had gasket problems. The reason why it broke down was due to the S block and 74mm bore. He revved the engine above 8000 regularly which I would believe made the thin flange S-block flex alot.

Not alot of help but will just say if it was me i would give the BK450 a go torqued down with ARP or similar hardware ( to cancel out varied clamping loads). I really do hope you have success with this motor as no one knows results until they have been tested, best of luck.

-MINI CLUBMAN 1380 TURBO-

Well 1071s its going to be SPI with a 44mm throttle body, ported manifold and bigger injector (theory being to reduce adaption by ECU), using the standard cam and CR to try and give the ECU as much of a chance, at least till I can fund the MS2. Im not looking for every last drop.

Its more of a test bed. Stage two head being fitted and 1.5 rockers (runs to a dark corner) to improve VE at least a little, breathing through a Maniflow LCB and decat pipe.

Nothing wild and wonderfull what so ever, but my eventual aim is to break the 90BHP barrier on the standard ECU without melting pistons. And yes Im sure some one has already tried and failed. But no one has mentioned bigger throttle body or injectors that I am aware of.

Lol

Yo going less with cc and me going with more cc on SPI

Was considering a Kent 286SP without 1.5 rockers. What do you think before I go and buy either. Never had a cam other than the MG, but always wanted the 286 since i was 16 for some reason and never even considered anything beyond that, I was led to believe they were race cams and this car is for the twisty windy roads and a 3.76 final drive.

Chav eater with a stealth look. Aiming to fit all that 16valve under standard bonnet with x member removed, maybe lifted at the back a little. Oh and I still have the Sprite transfers on the back, lol

Edited by Sprocket on 25th Mar, 2006.

Ah, the Kent 274sp, i did look at that. So you recon that is a good bet.

I was going big on the cam only for the increase in CC, my understanding of it was the more cc the less wild the bigger cams act ? but then there is the timing issue and , dam, that standard ECU, Doh.

A 286 cam is an absolute pig in a road car, even using a carb where you have some flexibility in setting it up.

Don't fall into the "bigger is better" trap with camshafts, I did once and it made idle non existant, and it wouldn't pull full throttle below 2500rpm.

I've seen the future and tbh its Pie

Im tempted to go for the 274SP. The scatter pattern sounds better when talking engines to people.

Lol, runs for dark corner again.

No thats it, settled, 274SP it is.

Just picked up the head today and it was as I thought, it had the bigger inlet valves than the one thats on the engine now so, not ideal but much better, just need to sort the gasket

found this http://www.ferriday.co.uk/copper/copper.shtml