SAIC MLS head gasket

[jonaf]

Anybody fitted the latest version of the MLS head gasket (without headsaver shim)? http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... TQ:GB:1123

[Mykel]

This sounds interesting indeed. Lots of "enthusiastic talk", but maybe there's a point to it if you get to the core.

Maybe we should ask our favourite meccies about it? Russell, for example.

[Rob Bell]

The NAC/SAIC engine is the N-series derivative of the K-series. They may have made some re-designs of the water/oil ways in the cylinder head (that's what I've heard) - and I'd like to be able to compare the two engines in a side by side comparison. So yes, it should fit. But I'd want to check to ensure that none of the galleries are obscured.

I was particularly interested in this bit on re-tightening the stretch bolts: "New torque settings are 20Nm, then 180 degrees then 135 degrees (For information purposes only)"

Not sure how you can easily do 135 degrees - a quarter turn and then an eighth turn... Anyone heard of this before? K-series has always been 180 then 180 degrees.

Might have to do some asking around.

[Rich in Vancouver]

Not to try to change the subject but this is closely related...I recently changed the HG on my 1996 MPi and used an MLS gasket.
The car now runs like a champion but there is a very slight weep of coolant from the head gasket (coolant alarm goes off monthly-ish)
This isn't a big issue other than the coolant drips on the exhaust so it smells worse than it is-very annoying!
I have been wondering if it would be worth tightening the head bolts an additional 15 degrees or so to increase the clamping force a bit.
The last thing I want is to feel the head bolt strip the bolt ladder in the sump!

Opinions?

[jonaf]

Not to try to change the subject but this is closely related...I recently changed the HG on my 1996 MPi and used an MLS gasket.
The car now runs like a champion but there is a very slight weep of coolant from the head gasket (coolant alarm goes off monthly-ish)
This isn't a big issue other than the coolant drips on the exhaust so it smells worse than it is-very annoying!
I have been wondering if it would be worth tightening the head bolts an additional 15 degrees or so to increase the clamping force a bit.
The last thing I want is to feel the head bolt strip the bolt ladder in the sump!

Opinions?

I have the same experience with the MLS gasket. It will not seal perfectly unless sealant is applied to both sides of it. The shim is coated so it can be left alone.http://www.vhtpaint.com/products/coppergasketcement/

[Rob Bell]

Hmm. I guess you used new stretch bolts on replacing the head gasket Rich?

Given that your only other option is to change the gasket again (and interesting to read Jon's comment of needing to use a sealant, which I've not heard of being required before), I don't think you have much to loose by adding an extra 15 degrees of torque to the stretch-bolts. My gut feeling is that it won't work though.

Interestingly, Payen OE gaskets seem a little more tolerant to things like liner stand proud than the MLS?

[jonaf]

The elastomeric seal on the OE gasket is pliable. The MLS is flexible but not sufficiently soft to make a perfect seal. It has happened to me twice after I fitted MLS gaskets that they bled slightly.
Omega 101 http://www.sovereign-omega.co.uk/Omega- ... alant.html will cure the leak but the narrow passages (the jiggle valves) in the system may become blocked.

[Rob Bell]

I agree with you Jon - I wouldn't want to add one of these sealants to the cooling system for exactly this reason. I fear that Rich is going to have to replace the gasket again.

Rich, the head didn't warp did it? Check the diagonals with an engineer's straight edge and a feeler gauge, and if any suspicion, get it machined. Fingers crossed the head is fine (I think you probably caught it before any overheating occurred)

[Rich in Vancouver]

Thanks for your input gents!
I did check the head for flatness and it was excellent. Mine is an early engine and the liners do stand proud (Don't recall 100% but I think it was about .004")
I didn`t use sealant, did use new bolts and did not replace the rail for the uprated one. Over here, on standard head gaskets the general practice is to avoid using sealants on head gaskets although some racers do use them. The MLS gasket is a new one on me so I installed it dry as per instructions.
I have been wondering how the Payen gaskets compare as Payen has been the preferred gasket for the B-Series engine for many years and even stood up to the supercharged 1960 motor in my ZA Magnette. I haven`t read much about their use on the MGF as everyone seems to talk about the MLS gasket. I do like the way the Payen stick to the metal surfaces.
I will have a go at cranking the head down a bit as I am sure that a thou in the right spot would stop the leak. I know odds aren`t good that this will work but I really don`t want to change the gasket again as I have months of work lined up on my other MGF and I am hoping to have some time to drive it this summer!

[Rob Bell]

Sounds like a problem with the gasket sealing them. The stand proud sounds about right - and certainly it doesn't sound as though you are getting any leakage past the fire rings Rich.

Thing is about stretch bolts is that they yield at a specific stretch load, so the clamping force is probably unlikely to change much by turning the bolts a further few degrees. But nothing ventured, nothing gained - do let us know how you get on.

Bringing this back to the SAIC gasket - I have no idea whether this would offer any advantage over the "LR" MLS. The SAIC gasket looks very similar - but coated on both sides to generate a seal???

Has anyone here ever used this gasket?

[jonaf]

Sounds like a problem with the gasket sealing them. The stand proud sounds about right - and certainly it doesn't sound as though you are getting any leakage past the fire rings Rich.

Thing is about stretch bolts is that they yield at a specific stretch load, so the clamping force is probably unlikely to change much by turning the bolts a further few degrees. But nothing ventured, nothing gained - do let us know how you get on.

Bringing this back to the SAIC gasket - I have no idea whether this would offer any advantage over the "LR" MLS. The SAIC gasket looks very similar - but coated on both sides to generate a seal???

Has anyone here ever used this gasket?

I bought one from South Lake Minis yesterday. I expect to to receive it next week. I just bought an LR Freelander with the old style gasket that weeps coolant on the front of the engine and I will share my experiences once I get it fitted.

[sworks]

There are a few variants of head gasket, the original which is still the best one to use if the liner height isn't as good as it should be, the MLS version that was developed for land rover and the later ones with the modified torque setting. Non should need any sealant or extra torque to seal. I have however screen a few FAI MLS gaskets fail for no apparent reason so I prefer to use Payen ones. Just my opinion of course

[Rob Bell]

Unless the liner heights have the prerequisite stand proud, I wouldn't risk an MLS either. I'd probably linish the block to get the necessary stand-proud first! But that would really only be countenanced in the context of a major engine build.

Jon, look forward to hearing your experience with the SAIC gasket

[Steve White]

The original engine from my car suffered two separate gasket failures after is was rebuilt with MLS gaskets, and on both occasions no obvious cause could be found.
I have since fitted another low mileage engine, but the original engine has been re-built using the latest Elastomer gasket (BW750) and uprated oil rail so I now have a spare

DVA's also recommends having heads hardness checked (anything below 90 Brinell is considered scrap).

[Rob Bell]

For anyone interested in what a Brinell hardness test involves:

[alanrt]

When I bought my 2001 F in May 2011 I checked to ensure that the head gasket had been done. I had 2 receipts for head gasket replacements. They were from different MG specialists. The first in 2005 and the second in 2009. In September or October 2011 I started to lose coolant but could find no sign of a leak. The garage I use which is not an MG specialist but do a large amount of work on K Series engines including competition preparation of MG ZR rally cars confirmed that it was HGF.

When they removed the head they found a delaminated 3 layer MLS and the liners were not proud of the block at all. It was as though they had been machined level with the block. After the block was skimmed to give the correct liner height they fitted the later revised MGR head gasket. When I asked about the gasket they said that provided the job had been done properly with the correct liner height then the MGR gasket is as reliable as any other and that they had never had an HGF on any of the competition cars. They did concede that the ZRs are fully warmed up before being driven.

[Rob Bell]

If you read the K-series workshop manual, it says that the liners should be flush with the deck height of the block. However, engine builders have subsequently found that some stand-proud is preferable, particularly where it comes to integrity of the fire-rings. However, you can't go back and edit the original text!

Unsurprisingly, there will be those who still maintain a low stand-proud of the liners. In fact I recall advice printed in Safety Fast by Ron Gammons regarding exactly this point: he quoted the original text.

[jonaf]

I found traces of oil in the header tank in my 'F so I fitted an SAIC to this one as well. Both the Freelander and the 'F seem to work well with their new gaskets so I trust this will be a lasting solution.
I fitted the old elastomer gasket in the 'F in 2001 after i bought the car with HGF. No steel dowels were available then and I think this may be the reason I now got oil in the coolant. A slight leak through the oil passage to the oil gallery in the head into the water jacket was about to ruin the elastomeric seal and it was about time I got it sorted.

[Rich in Vancouver]

Here's an update from me.
A month or so ago I got back from a long-ish drive to find the expansion tank full to the top with a good layer of oil on top, so Rob it looks like you were correct about needing to redo the gasket. I ordered a SAIC gasket from South Lakes Minis and was impressed with their quick service. They are enthusiastic about this gasket and were able to provide advice as to whether sealant was needed (NO!) The gasket inspires more confidence than the MLS gasket fitted previously. It is at least 4 layers and is riveted together with 4 rivets outside of the head perimeter so it will be easy to tell if an engine has one of these fitted. When torquing up the head this gasket certainly seems to have more compressible volume than the MLS. It really felt like it was compressing. Doing the 180+135 was no problem. After torquing to the stated 20NM I drew a register line on each head bolt, all facing the same direction and used these as a guide. I then rotated each head bolt in order 90, 90, 90, 45 ensuring all of the register lines pointed the same direction at the end. After doing all the ancillaries the car started right up with no problems to date. No more leak! (knock on wood!)
Pics to follow.
SAIC Gasket




Note the register marks on the head bolts

[Mykel]

Very interesting report, Rich, thanks a lot!

Whilst checking for availability, I noticed that both the southlakesminis.co.uk web site is down and their ebay shop is empty. Does anybody have any information about what's happened to them?