head saver shims

[Dieter H. Marschall]

Good morning everybody,

Yesterday I talked to the German Stag owner Klaus Schlüter. He is very fond of the head saver shims, which he has built into his car.

As my Stag engine shows some "pinking" when accelerating after some head skimming, I assume that the compression is too high now.

So I am thinking of building in some shims, too.

May I ask you some questions.

Where should the sealant be applied?

Do I need to worry about corrosion of the waterways, as I will have alloy, steel and stainless steel combined?

Any help is highly appreciated.

Kind regards,
Dieter - from Germany.

[nib]

Hi Dieter
Firstly are you sure it is down to the head skimming work that is making it pink because its a lot of unnecessary work putting the h/s shims on.
Regarding the shims some recommend to put it(h/s/s) onto the block under the head gasket and some on top of the head gasket.The company where I bought my head saver shims recommended on top of the head gasket so thats the way I went.
I applied Wellseal to both sides of the shim,it is like syrup very sticky.
I dont think corrosion will be an issue concerning the shim to be honest.
Mark

[arthurg]

hi

pinking can be a combination of thing like ignition timing or the heads just double check everything because removal of the heads can be lengthly job but on the otherhand my experance with saver shims is good if you follow the guidelines given companys called gosnays should be able to help

[wilf]

Burning oil can also cause "pinking" - does the engine use any?

Also, have you checked the advance curve on your distributor?

[Dieter H. Marschall]

Hello,

I have taken the ignition "back" as far as possible. There is no significant use of oil.

Then again I have no clue how to check the advance curve on my distributor. Can you please advise?

Kind regards,
Dieter.

[Klaus Schlueter]

Hi Dieter, we enjoyed the evening with you and Gaby very much and hope you did find some sleep besides speculating about the saver shim.
For me it was really a saver as the block was skimmed too much on one side. It was installed 10 years ago with Well Seal on both sides and placed onto the block surface under the gasket. Still working fine.

Best regards
Klaus

[Klaus Schlueter]

Dieter, do you use Super 95 or Super Plus with 98 Octane? When we go to Italy with the Stag and only get 95 I can hear some pinking with the ignition on standard setting of 12 deg. BTDC

Klaus

[wilf]

Dieter - I was musing that maybe your distributor advance/retard mechansim could be seized. You could easily see that with a stroboscopic ignition timing light. The actual advance curve "should" be OK if the mechanism is working correctly, and really needs to be put onto a distributor curving machine to check (not too many mechanics would have one of those these days, might need to find a specialist if you have to).

[flying farmer]

When you say you have taken the ignition timing back as far as possible do you just mean you have run out of adjustment on the slots of the distributor mounting bolts?
If this is what you mean, what is your current ignition timing?
If you can't get to less than the standard timing you need to remove the distributor and turn it one tooth round before replacing it, this will give you more adjustment, turn the oil pump drive shaft a little to help refitting the distributor.
Be carefull about running the engine too retarded as this can make it run hot making pinking worse. A favorite for this is a non functioning vacuum advance capsule
Neil

[Dieter H. Marschall]

Hello all,

Thank you very much again for your help and advice.

@ Klaus: I use 98 octane petrol. The ignition is set at 11°.

@ Neil: I will try this. Thank you for the hints.

Kind regards,
Dieter.

[flying farmer]

Dieter, is your engine fitted with the dished pistons or the domed pistons?
One of my engines was running with domed pistons, standard thickness head gaskets, and the heads skimmed down to the valves and could still run on ordinary unleaded at the standard ignition timing unless I picked up a dodgy tank of fuel.
If you have the domed pistons make sure you are using a mk2 distributor as the mk1 gives too much advance.
It is also worth checking that the advance weights are returning properly at low revs, I recently had a spring go weak and it would sometimes stick with three or four degrees of unwanted advance at low revs. Fortunately I found a spare spring in my spares supply
Neil

[Dieter H. Marschall]

Dieter, is your engine fitted with the dished pistons or the domed pistons?
One of my engines was running with domed pistons, standard thickness head gaskets, and the heads skimmed down to the valves and could still run on ordinary unleaded at the standard ignition timing unless I picked up a dodgy tank of fuel.
If you have the domed pistons make sure you are using a mk2 distributor as the mk1 gives too much advance.
It is also worth checking that the advance weights are returning properly at low revs, I recently had a spring go weak and it would sometimes stick with three or four degrees of unwanted advance at low revs. Fortunately I found a spare spring in my spares supply
Neil

Hello Neil,

I wish I knew what type of engine, distributor and pistons I have in the Stag. The Stag itself is a 1971 Mk1. The engine is obviously a Mk2 factory replacement with the following engine number: LF804 ESS

As far as I can see from the intake manifold etc., it shows all the characteristics of a Mk2 engine. What number should a Mk2 distributor have?

I tried to find out through the plug holes whether the pistons are domed or not - to no avail.

Kind regards,
Dieter.

[flying farmer]

From one of V MADs earlier posts there are at least three different distributors, plus some USA market ones.
The numbers he posted were 41276, 41336, and finally 41525 which was fitted from engine no LF2001 onwards so I would presume you have one of the earlier ones
I know the 41525 has 7 degrees of mechanical advance as I have a couple of these fitted. I also know I have an earlier distributor fitted to one engine that has 13 degrees of mechanical advance. Unfortunately I don't know what number this distributor has on it, but it works OK as it is on a mk2 engine that has been fitted with dished (county) pistons
The amount of advance is stamped into the stop above the advance weights and can be seen if the distributor base plate is removed. It would give you a chance to check the operation of the weights and springs, and give everything a clean and oil.
There is always the possibility that when the factory recon mk2 engine was fitted to your car it came without a distributor and they fitted the large advance mk1 distributor to the high compression mk2 engine that needed the smaller advance range
Neil

[V Mad]

Dieter, I am sure the solution to your pinking is to get your ignition timing right. Race engines can run at very high compressions and they will not be pinking because they set the ignition timing curve to get the best power; (pinking results in lower power).

To start with a quick check of dwell is worth doing if you have a dwell meter (try Gunsons Testune, cheap on ebay).

The static timing setting is only approximate, since the pulley can rotate from its original position (so I hear) so your static timing might be wrong.

There are two advance mechanisms, 1, Centrifugal 2. Vacuum. Both can suffer from faults like loose or broken springs, parts which dont move as they should, etc. You can look for gross errors by using a timing lamp on the pulley: check the advance vs revs and compare to the tables in the ROM, Engine Tuning Data page 05-3. Disable the vacuum advance first. Its worth removing the small calibration plate and cleaning it up, then painting on some bright marks to highlight the main points 10deg 20 deg 30 deg. Mk1 timing advance is about 24 crank degrees max, Mk2 is about 14 deg max both, at around 5000 rpm. These figues are of course added to the static figure. Vacuum advance is a little more difficult, as it needs a calibrated vacuum source.

As Neil says the early 41336 had nearly twice the advance of the later 41525.

Its a pity you are not in the UK as I have a distributor tester, and I could check the operation out for you (no charge) although you still can if you want to pay the postage. But I dont have the facility/parts to fix everything that might be needed although I can do the basiscs. If you need any distributor services like repair, recal, recon etc you could contact Lee at H&H in the UK, he is very helpful, or there is the Distributor Doctor as well.

[Dieter H. Marschall]

Good morning all,

Thank you all very much for your precious hints! I will have to wait for my friend to return from his holidays. He has all the equipment to check the timing etc.

All the very best and Happy Easter!

Dieter.