Head Gasket Failure/Issue Survey

[Barrykearley]

11 hours ago, EXCEL V8 said:

The Goetze gasket is no longer being made.  I've recently found it impossible to find one on this side of the pond.  There is a replacement available from Lotus but not much feedback about it yet.  Gary Kemp stocks a steel MLS style that is slightly thinner so has implications for compression ratio - if that is a factor.  I'm about to build my engine using one of the new Lotus gaskets so we'll see!

Pete

Based on the crap supplied by some of these suppliers - both uk and usa - I’d proceed with lots of caution. They have form in supplying anything they can - and form is clear all over the Internet of failures of these gaskets which are all similar in failure mode.

Goetze gaskets we’re available when I did mine over the first covid lockdown - a new batch had not long been made.

[drdoom]

Very much appreciated chaps. So Barry, to whom did you turn for the Goetze?

Seems the uprated studs are regarded as the way to go? Must admit I'm challenged to understand how it is the steel fasteners ( fixed in aluminium ) which are the fail point, though I will defer always to the wisdom of those who've gone before.

Cheers

[Barrykearley]

I’m pretty sure from memory it was from SJ sportscars. If it wasn’t them then it would have been PNM engineering.

[Barrykearley]

it was definately SJ Sportscars for the head gasket

[drdoom]

So to conclude, one must be particular on the choice of head gasket. What have we to conclude on the importance of the uprated studs?

[Chillidoggy]

The original Lotus head studs are a high-quality item, with rolled threads. When I rebuilt my engine I reused them, with a Kemp-supplied head gasket. 5,000 miles on, and no problems thus far.

[snowrx]

I've read that there were two styles of studs, later engines had supposedly better items with a dimpled end.

With regard to my above postings, actual measured CR was 8.39:1 with thin (blown) gaskets, 8.11:1 with the thicker one (still working) when I calculate with actual head volume and compressed gasket thickness. This with JE aftermarket pistons in an LC block.

[Chillidoggy]

These are the S4s engine studs. Definitely dimpled on the ends.

[EXCEL V8]

Gary Kemp also sells uprated studs - I've bought some for my build.

Pete

[snowrx]

I think this is the OE stud from my '85 910 LC engine.

[drdoom]

Right. The dimpled studs are regarded as upgrade over early type, noted perhaps in the Lotus Service Bulletin recently circulated somewhere hereabouts. Thomas, the difference in CR's you report surely cannot be a matter for concern in and of itself. What I have learned in regard to forced aspiration engines is above all to mind in cylinder conditions under load. Timing never over advanced, mixture always comfortably fat, intake air temps as low as feasible, plugs on the cold side, all cylinders in balance and octane as high as is practical. That well sorted and one is good for the sort of boost levels you're running. Moving further on to truly great increases in power output raises the stakes in terms of gasket integrity and whatever structural limitations are native to the engine.

Cheers

[GavinT]

From what I’ve learnt….the original non dimpled studs are fine for the old metal type head gasket but not for the later Goetze ones. The Goetze gaskets require a much higher torque load to seat and seal correctly. The original studs are not up to the task. Upgrade the studs and use the later torque specifications.

 

Lotus Service bulletin 1993/07

TITLE:            Introduction of revised cylinder block, head & gasket

REASON:       Quality improvement.

                      The cylinder block and cylinder head of the Lotus 910/920 engine have been re-cast and upgraded in respect to stiffness, lightness, cooling efficiency and dimensional control. In addition, a new type of cylinder head gasket has an increased tolerance to severe thermo-cycling, and improved durability.

ACTION:        The new components have been introduced on engine serial number: 28096 (last 5 digits of engine number) - January 1993.

With the exception of the block deck height and various core and blanking plugs, the new block and head share all functional dimensions with the old type, and when service stocks of the older components are exhausted, the new parts will replace them. 
New heads may be fitted to old blocks and vice versa, but the new head gasket should be used in both cases.

The new block and head may be readily identified by cast Lotus logos on the front and rear faces of the cylinder head and at the top right hand rear of the block.
 

Cylinder Head Gasket

The steel and asbestos laminated gasket, B907EO026Z (Coopers - silver incolour) has been replaced by a reinforced fibre-composite gasket A912E7029Z (Goetze - grey/brown in colour) 
This uses a built-in silicone sealing bead around the periphery and a Viton seal around the oil feed hole. 
The compressed thickness of the new gasket is approx. 0.5 mm (0.020") greater than the old gasket and the deck face and liner seats of the new cylinder block have been lowered by a corresponding amount.

Service Replacement

i)   New engines must be fitted only with the new type gasket. Fitment of an old type gasket to these engines may result in piston foul and/or detonation due to the raised compression. 

ii)   When stocks of the old gaskets are exhausted, old engines should be fitted with the now gasket, which will also replace the 'extra laminate' thicker gaskets (A911E1292, B911E1292) used on some low compression 912 N.A. engines.

Note that the extra thickness of the Goetze gasket will result in a slight reduction in compression ratio (typically about - 0.5 numerically) when used on old engines. 
This may be advantageous to fuel octane tolerance, especially if the head face has been machined to correct distortion or erosion.


Goetze Gasket Fitting Procedure   

There are two points to note when fitting the new type gasket to new or old type engines:

a)       New engines must be fitted only with the new type gasket.

b)      The cylinder head nut tightening procedure has been amended and requires the use of an angle gauge. A Sykes Pickavant tool under Lotus Part No. TOOOT1235 will be despatched and invoiced to all dealers shortly.

Use the latest type cylinder head studs (B907E0224Z) identified by the dimple machined in the top end. Tighten into the block (with oiled threads) to 37 - 41 Nm (27 - 30 lbs.ft).

Fit head gasket (dry) and cylinder head. Fit washers, oil head stud threads and fit nuts.

Using the existing tightening sequence (from the centre outwards; see Service Notes EB.7),

Tighten the head nuts in the following stages:

i)        20 Nm (15 lbs.ft).

ii)                   + 75 degrees

iii)                  + 40 degrees

iv)                 Wait 5 minutes 

v)                   + 20 degrees

 
Cylinder Liner Adhesive

The sealant used between the base of the cylinder liners and the block (formerly Hylomar) has been changed to Loctite 572 adhesive/sealant (A912E7030V) in order to reduce fretting and noise; improve sealing durability; reduce the risk of liner disturbance with the cylinder head removed. The use of Loctite 572 has been introduced together with the new block and head castings, but may be used on all Lotus 900 series engines. Loctite 572 Application Procedure:

Thoroughly clean the liner spigot and seat, and the corres­ponding areas in the block.

Dry fit the liners and check that there is a nominal clearance between the top ends of the liners. 
Check the stand-out of the liners above the block deck face (liner 'nip') which is unchanged at: - 0.03 mm to + 0.05 mm (- 0.001 to + 0.002 in);

Maximum variation between adjacent liners: 0.03 mm (0.001 in)
Apply a small bead of Loctite around the seating face of the liner.
Apply a thin smear of Loctite around the outside of the liner spigot.
Apply a thin smear of Loctite around the top edge of the liner spigot bore in the block.
Slide the liners into the block and fit the cylinder head within 4 hours to ensure that the liners are seated correctly before the adhesive cures.
If this procedure is used on an “old” engine, apply a red paint mark for reference to the cylinder block at the end of the engine number stamping.

Note that when assembled as above, the liners will subsequently require the use of a liner puller tool (TOOOT0012A - existing part of the dealer special tool kit) in order to extract a liner from the block. 
The improved security of the liners also means that if care is taken, there is no necessity to reseal the liners in the normal course of cylinder head removal/refit

Cylinder head layout and orientation

Lotus Esprit cylinder head tightening sequence                 
 
Summary
Vehicle manufacturers specify torque values for certain fasteners such as cylinder head studs and nuts. 
This is to make sure that fasteners are not over-tightened or under-tightened. 
The torque wrench is used to apply a specified amount of torque to a fastener. 
The torque angle gauge is used to make sure there is equal tightness across all fasteners on a particular component.

 

 

Just looking at the ARP head stud kit supplied by JAE, instructions say to torque to 110 ft lbs using the ARP Ultra Torque lube. Also when installing the studs in the block, only hand tighten them. The final seating of the stud happens as you torque down the head.

 

[Invictus005]

1991 Lotus Esprit Turbo SE. According to my service records, this head gasket was installed by the previous owner in 2017, at an approximate mileage of 38K. I’ve experienced a gradual, but noticeable and progressive engine power loss during the past 1K miles. It finally blew at cylinder 4 and filled it with water at 62K miles. 

Has anyone seen a head gasket look like this, especially after only 6 years of use and 24K miles? It looks absolutely trashed. Fire ring at cylinder 4 is also cracked. Car in my possession has never been tracked or abused. Running S4s chip. 

Any ideas on who the manufacturer for this gasket is? If anyone has for sale a new original German made Goetze gasket, please contact me privately, I’m interested in buying one. 

[Barrykearley]

Looks the same nasty specimen that I had on my S4s. A couple of the “specialists” were flogging these gaskets in the USA and UK. They were simply not fit for purpose.

[Invictus005]

10 hours ago, Barrykearley said:

Looks the same nasty specimen that I had on my S4s. A couple of the “specialists” were flogging these gaskets in the USA and UK. They were simply not fit for purpose.

From what I understand, head gaskets sold by JAE, Kemp, and currently by even Lotus themselves, are all the same and one gasket? I conclude this from pictures, thickness measurements, and serial/model markings. If this is not the case, I would love to learn further info. 

[Barrykearley]

There was a period when OEM gaskets were not available. One of the said specialists had a batch of gaskets made which were then distributed. There’s no shortage of images of these gasket failures all over the internet - more so in the USA where boost cranking is popular. They will and do fail if boosted over time even at standard levels. 
 

The difference between these and Goetze are massive and very obvious 

[GavinT]

There is a theory that keeping the heater on all the time aids coolant circulation around #4 cylinder. Helping to reduce the hot spot around that cylinder and reducing the possibility of gasket failure.  True or not, I don’t know. But since the rebuild of my Stevens turbo I’ve been following that practice.

[ChrisJ]

Yes, I have the heater on the Esprit on at all times, and when coming into traffic, I always start the fan as well.

The Excel, it isn't always set to heat, but again, in stationary traffic, on goes the heater and fans. Have noticed a distinct drop in the temp gauge on the Excel when doing this.