Head gasket problems!!!!!!!!!!!!!!

[saska]

Hold on a second, you are saying the heads are differant between the turbo and N/A engine?

Parts manual lists only one head for all models -- AlOOE6186S

[CRAMBURY RS]

Hold on a second, you are saying the heads are differant between the turbo and N/A engine? I've never
seen that on the Isuzu's over here, the differance was in the pistons not the head.


Also the only differance I see besides the 2 extra rubber seals is on the upper right. One gasket has a rubber seal
and a seperate hole from the head bolt hole. The other has no seal and the holes are simonized.


Steve

don't think so, just that the gaskets are. the water journals are obvious, but if the thickness is different that would impact/explain the size of the combustion chamber.

i don't mind a thicker gasket and dropping .2 in the overall CR ratio given than mine is nearly 9.5 as is. i guess i'll just ask now and on the zone, but would it be an option to add a 4th layer to the MLS? not for all gaskets, just those interested.

[Specky]

Just comparing them now....

Intresting...

There are a few differences, just off to do some dimension checks.

TTFN

[Specky]

Here's the pic of the Turbo gasket,

I've marked the differences.

As for the dimensions,

I require a micrometer to be more acurate...(they are different, but only just)

Also a bore guage...



TTFN

[Specky]

Here's a few more pictures...

Specky's top tip for telling which is which..... without trying to orientate yourself around the gasket....Tab=Turbo

Pic 1 side by side (Top)
Pic 2 size differece
pic 3 size difference and seal
pic 4 one on top of the other
Pic 5 Side by side (Bottom)

[Specky]

Here's the vernier measurements until I can do the Micrometer.

Had a look at the Zone, no update as such.

Turbo Gasket:-

Bore Ø 81.17mm
cylinder ring 1.32mm OR 1.33mm
Gasket aspect 1.20mm

N/A Gasket:-

Bore Ø 81.19mm
cylinder ring 1.27mm OR 1.28mm
Gasket aspect 1.27mm

TTFN

[CRAMBURY RS]

all of a sudden i feel really proud of my CAD

[infinity13x]

Here's the vernier measurements until I can do the Micrometer.

Turbo Gasket:-
Gasket aspect 1.20mm

N/A Gasket:-
Gasket aspect 1.27mm

What is the gasket aspect? Is that compressed thickness?

[Specky]

If you were to take the gasket as an assembly, you'd have the metal bits, the rubber bits and the gasket bit. It's the gasket bit. Uncompressed gasket as it's new.

TTFN

[bobbrown]

I would think the gasket material on a composite gasket to compress by about 0.05 to 0.075mm (0.002" to 0.003") so the NA gasket is slightly thicker but reducing its thickness by 0.07mm is only going to increase the CR very slightly.
A MLS gasket I would think is going to compress less.

[CRAMBURY RS]

I would think the gasket material on a composite gasket to compress by about 0.05 to 0.075mm (0.002" to 0.003") so the NA gasket is slightly thicker but reducing its thickness by 0.07mm is only going to increase the CR very slightly.
A MLS gasket I would think is going to compress less.

i don't think the MLS will compress enough to bother measuring. and that's assuming the 1.3mm isn't a compressed measurement already by the product manufacturer. the OEM is fiber, this is flat steel.

[CRAMBURY RS]

assuming the CAD is good and these MLS HG's are a go...IS ANYONE ACTUALLY INTERESTED?

[Dico]

Did I read somewhere that someone suggested the head AND block 'may' need skimming or is that definately not necessary? (assuming the head is relatively true to begin with)

If this isn't necessary then I'll jump on board.
Did we get a final price? Any more in the UK care to share postage costs?

UK list

1- Dico

[CRAMBURY RS]

Did I read somewhere that someone suggested the head AND block 'may' need skimming or is that definately not necessary? (assuming the head is relatively true to begin with)

If this isn't necessary then I'll jump on board.
Did we get a final price? Any more in the UK care to share postage costs?

UK list

1- Dico

i believe that was from Ferriday for the fire-ring type (copper and fiber). the MLS will require at least the head to be resurfaced and the block to be true. i plan to wet sand the face of the block a little as gently and evenly as possible to remove any old gasket material. i had the block resurfaced less than 12k miles ago. the head will get an inspection, fine resurface and maybe a wet sanding as well. the MLS is much more pliable than a copper fire ring type and the embossments will secure a seal.

[Ade]

Good News,

head gaskets avaliable from SJ sports cars, he says he has hundreds.

Ade.

[bobbrown]

With any head gasket replacement the head and block need to be flat, just how flat depends on the type of gasket being used and the type of engine.
Composite gaskets can take up a lot more than a MLS gasket so for a MLS gasket the head and block need to be as near flat as possible.
Also with MLS gaskets the surface finish is important and it is no good just scraping of the old gasket and fitting the new MLS gasket.
With a MLS gasket the head must be flat with less than 0.05mm across the head this also applies to the block, in this case less is better.
The surface finish requirement is also a consideration with a MLS gasket and it has to be better than a composite gasket.

When I have rebuilt race/rally engines I have always had the head refaced and the block checked and refaced if needed and have never had an issue with a head gasket failure on any event not like some others have had. It does not mean you have to take large amounts of material off the head, in a lot of cases only 0.02 to 0.05mm will produce the desired results but in our case the limit is 0.4mm so you can remove a lot of material. This limit can be increased with the use of a slightly thicker head gasket to compensate for the material removed.
Not the whole story but with any head gasket replacement flatness and surface finish are very important if you want the head gasket to last.

Bob

[bobbrown]

Good News,

head gaskets avaliable from SJ sports cars, he says he has hundreds.

Ade.

A pound to a pinch of salt they are not genuine gaskets, The question would be who's are they.

Bob

[Ade]

Hi,
I asked the question and was told they only supply genuine gaskets. I have ordered 2 so I will let you know what packaging they come in.

Ade

[CRAMBURY RS]

just think of it...never having to worry about the HG

[racerstev]

Chysler 2.0 and 2.4's need no more then .004" warp on there heads with MLS gaskets. The shop manual states that
the surface must be "scratch free".

When Chysler came out with the 2.0 in 1995 they had nothing but failures with there normal composite head gaskets.
This lasted till 1998 I think. In 98 they came out with the MLS gasket, they just swapped gaskets with no machine work,
this fixed there problems 100%. No machine work was done for the swap.

Of course a Chysler engine isn't a Isuzu engine so take it for what it's worth. I plan on getting both the head and block machined
just beacuse they will be out getting rebuilt anyway.

Steve