80 replies to this topic

[Miniman Sam]

Hi, if the head studs and nuts are old or have been re used many times, they may have lost there strength, so although tourqued up correctly when cold, they maybe stretching when hot, this is why you maybe able to keep re tourquing some of the nuts after the engine has cooled down again to the correct tourque figure, if this is the case I would fit new studs and nuts.
I have only ever loosened the 4 head nuts on the rockers without removing the other nuts or head and have not had any issues although this was on a dry deck engine and 11 stud.

[mini_pooper]

If changing the nuts and studs anyway, is it worth the extra outlay for an ARP set? :)

[sonikk4]

Sounds good - is it a Payen Copper gasket you recommend or do they also make a composite one?

If you have an exact part no. that is always best :)

 

Now i was given this as a replacement and i believe it may have been this one

http://www.minispare...21.aspx|Back to

 

However this was over four years ago. I do remember it was Black but trawling through my emails i cannot confirm it was this exact item. And it was defo not a Payen Copper HG. Sorry its a bit vague but as i said it was sometime ago.

 

Maybe worth giving [email protected] on here a shout to see what he can do for you.

[Miniman Sam]

Hi, yes it would be worth spending the extra to get an arp set, they are brilliant quality and give you the proper feeling that they have torqued up, instead of giving you a feeling that you could keep torquing the nuts up, the arp nuts and studs basically give you feeling that they are as tight as possible as the material they are made of is far stronger, so they dont stretch, also if you get an arp nut and stud set it also comes with the 4 5/16 studs and nuts for the rocker posts as well.
Reading one of your other replies to regards the performance head gasket sold by mini spares that is out of stock, this type of gasket is composite and is made by ACL under the name MONORORQUE, they are no longer available as ACL went bust, but has recently re started so are currently only making engine bearings, although the engine parts surpplier were we get our engine parts from is listing an ACL performance a-series 998cc head gasket, so they maybe starting to make the gaskets aswell again.

[mini_pooper]

Great tips, thank you. Will very likely go with ARP studs and nuts when it's all apart anyway.

With regards to the gasket, I'm still not sure if copper or composite is the way to go (although I can't find a composite in stock anywhere). My worry is that since a copper one is currently fitted and leaking, I'll end up in the same place, although it don't know if it's a Payen or cheapo one that's in there now.

Are the Payen ones more forgiving than other copper gaskets and easier to seal? :)

[mini_pooper]

Ok, have gone ahead and ordered the Payen Copper head gasket, along with the Competition head stud kit from Minispares (I spoke to them, they said the ARP would probably be overkill and standard replacements would in this case suffice, so have gone with the middle ground, safety without going overboard!) 

 

Part no. C-AHT280 for the studs.

 

Spoke to the guys that built the engine, they used a gasket kit for the engine, but were very helpful and agreed I should replace studs too since they might be failing with each retorque. Minispares said they do not know of a kit that includes a Payen copper head gasket, so most likely the one fitted now is a cheaper one, with some kind of tolerance issue (hit and miss QC)!

 

Breather piping and Y piece for the crankcase to carbs also ordered, along with some new studs for the thermostat (and gaskets), heater tap gasket, rocker cover cork gasket and exhaust gaskets. Gaskets are not worth (or advisable) reusing! 

 

Thanks for all the help so far, will report back once I have done the work (hopefully this weekend) so others in the same situation can get advise 

 

Forgot to ask - will fitting the crankcase breather to the carb require any adjustment to the fuel mixture to compensate? Carbs have been on the rolling road, but with the filter venting to atmosphere at the time. Would the oil fumes / gasses make the mix a little richer?   

Edited by mini_pooper, 19 April 2018 - 10:13 AM.

[cal844]

Ok, have gone ahead and ordered the Payen Copper head gasket, along with the Competition head stud kit from Minispares (I spoke to them, they said the ARP would probably be overkill and standard replacements would in this case suffice, so have gone with the middle ground, safety without going overboard!) 
 
Part no. C-AHT280 for the studs.
 
Spoke to the guys that built the engine, they used a gasket kit for the engine, but were very helpful and agreed I should replace studs too since they might be failing with each retorque. Minispares said they do not know of a kit that includes a Payen copper head gasket, so most likely the one fitted now is a cheaper one, with some kind of tolerance issue (hit and miss QC)!
 
Breather piping and Y piece for the crankcase to carbs also ordered, along with some new studs for the thermostat (and gaskets), heater tap gasket, rocker cover cork gasket and exhaust gaskets. Gaskets are not worth (or advisable) reusing! 
 
Thanks for all the help so far, will report back once I have done the work (hopefully this weekend) so others in the same situation can get advise 
 
Forgot to ask - will fitting the crankcase breather to the carb require any adjustment to the fuel mixture to compensate? Carbs have been on the rolling road, but with the filter venting to atmosphere at the time. Would the oil fumes / gasses make the mix a little richer?   

The carb shouldn't run any different, you may get a smelly exhaust though?

[mini_pooper]

 

The carb shouldn't run any different, you may get a smelly exhaust though?

 

 

Thanks for the tip!

 

Probably wouldn't notice the smell change anyway, no catalyst was ever fitted to this car (1981) so it's more than enough to get you high, especially with a lumpy cam sending a bit of unburnt fuel though on idle   

[cal844]

 The carb shouldn't run any different, you may get a smelly exhaust though?
 

 
Thanks for the tip!
 
Probably wouldn't notice the smell change anyway, no catalyst was ever fitted to this car (1981) so it's more than enough to get you high, especially with a lumpy cam sending a bit of unburnt fuel though on idle   

Sounds good 😁

[Retroman]

You are going the right way the Payen copper gasket and the better head studs, they can can be torqued a bit more too.

 

That combination will take pretty much anything you can throw at it 13.2:1 compression and 60 lbft stud torque, no head gasket issues revving to valve bounce. (small bores 11 stud)

 

A tip to help the gasket settle in is to start the engine without coolant first time and run it for about 1 minute, then re-torque the head / set tappets.

 

Let it go cold, fill with coolant check torque / tappets again after 100/150 miles then at 500.

[mini_pooper]

You are going the right way the Payen copper gasket and the better head studs, they can can be torqued a bit more too.

 

That combination will take pretty much anything you can throw at it 13.2:1 compression and 60 lbft stud torque, no head gasket issues revving to valve bounce. (small bores 11 stud)

 

A tip to help the gasket settle in is to start the engine without coolant first time and run it for about 1 minute, then re-torque the head / set tappets.

 

Let it go cold, fill with coolant check torque / tappets again after 100/150 miles then at 500.

 

Good news and thank you for the advice! I was doing some searching now to find out if I should start without coolant first time or if this is more applicable when the whole engine is new. Will do as you say (makes sense!). Minispares however recommend only 45lbft torque (if I remember correctly) for these studs with a Payen copper gasket so will stick to that - that way I can always speak to them if it doesn't work ;)

 

One question though - the procedure is 'head on, torque + adjust tappets, run the engine for 1 minute, then cool, then fill with coolant'.

 

But do I then check tappets and torque studs again immediately after filling the coolant (when it's cold), or should I not torque and adjust tappets until after I have driven 100, then 500 miles?

 

How clean do the faces need to be for the gasket to seal completely?

[Retroman]

Sorry should have made it clearer;

 

Head on, torque + tappets, Run, Cold, Check studs + tappets, Fill with coolant, then after 100 and 500 Miles...Check torque + tappets

 

Its a bit of a faff but it always pays to check, its not a fit and forget item until after the 500 mile check

 

The faces should be clean and dry, I use brake cleaner, on every one, from standard 850 through to 12.9 litre 500 diesel horses with each pot over 2litre and a compression ratio of about 19:1

[mini_pooper]

Great, thank you! It's a faff, but less so than doing all the work again if it blows a head gasket or burns a valve.

 

And 12.9 litres with 500 horsepower in an Mini, would like to see that! (I assume that was not a mini, ha ha) 

[Retroman]

I think Harry Radcliff's old Buick Mini had 7.5 litres...

 

 

and the white Pickup....well....hahahha  bagsie not changing the head gasket on that

[mini_pooper]

 

and the white Pickup....well....hahahha  bagsie not changing the head gasket on that

 

 

Would be faster and cheaper to replace the whole unit  

Edited by mini_pooper, 20 April 2018 - 02:53 PM.