Head gasket leak

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olei

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Hi,

I have a problem with my rebuilt '88 318 engine, head gaskets leak. Both of them has got a tiny leak of coolant creeping out between block and cylinder head below the headers. I also seem to get coolant in the engine oil. I have not re-torqued these head gaskets.

I am now using the P4120094 thin head gaskets, and OEM/untouched block deck surface and Edelbrock 60779 cylinder heads.

I have an average deck clearance at .012", but because of one of the cylinder banks not being level/square the deepest piston is .015" in the hole.

Now these thin head gaskets doesn't seem to seal very well?

I now have two options:
1) Replace with new set of thin head gaskets at .026" thickness (coated with Hylomar). .041" quench, 9.7 SCR and 8.88 DCR.
2) Use the Fel-Pro 1008 at .039" thickness. .054" quench, 9.37 SCR and 8.59 DCR.

This engine will use 91 octane pump fuel.

So what do you think? :)
 
The front and rear header bolts go into coolant, so if there's no sealer on the header bolt threads, it will often leak there, a little sealer should fix it up..

Why do you feel there is coolant in the engine oil?
 
If in fact you have coolant in the pan, then the gaskets need to come out.
I had troubles with the thin Orange gaskets as well. Many others do not have trouble with them. However, mine were blowing out the fire-rings. They were not leaking coolant. I was running 11.2Scr.
If you put the Fellpro-039s in, I have had zero issues with those, even reusing them. My current set is alive and well on the third install, and have over 100,000 miles on in total.
However, going to .054 quench will pretty much negate the quench benefit.Still, with aluminum heads and 8.59Dcr, you should be good to go.In fact it should run on 87E10,like mine does. I found my engine seems to be quite happy running 32 to 36 degrees of power timing on this gas and I don't notice any difference on the street. So I run a middle-of-the-road 34*.

Also, it is possible for coolant to get into the pan through other places.I highly recommend two tests; 1) the cylinder leakage test, and 2) the cooling system pressure test.
As a side note; I have had zero luck with Hylomar. Others have had success.
 
I had troubles with the thin Mopar gaskets leaking to the outside right in the middle on a 360 I had several yrs ago even though I checked the deck for warpage and had less than .002" and the heads were freshly resurfaced. I had open chambered heads so quench was not a consideration and I installed Fel-Pro 1008's and had no other issues. As long as the deck has no or very minimal warpage (less than .002") I don't see why a new set of thin gaskets coated with hylomar wouldn't work but I can almost guarantee you the Fel-Pro's will do the job, you'll just lose the quench affect
 
Thanks for all replies! :)

For calculating DCR i used this calculator:
https://www.uempistons.com/index.php?main_page=calculators&type=comp2
This one tells you to add 15 degrees to IVC. My intake valve is closing at 26 degrees.

From the beginning of I had planned on using the Fel-Pro 1008's, but I was afraid of using .054" quench and figured It would be better to have tighter quench and a bit higher DCR.


AJ/FormS;
Do you really think the .054" quench is good enough for the 8.59 DCR (I would consider this to be high DCR for 91 octane?)?


fishy68;
Do you have any experience with Hylomar coating on composite head gaskets?
I believe I checked for deck warpage, but I can't remember how much is was. I'll check this again when the cylinder heads come off.


Another thing is that this engine is in a '88 Dakota pickup truck (oops. This forum has some nice technical information!). I will do some light towing from time to time as well.
 

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Have you considered milling the heads and going with the thicker gasket?
 
olei said:
Thanks for all replies! :)


AJ/FormS;
Do you really think the .054" quench is good enough for the 8.59 DCR (I would consider this to be high DCR for 91 octane?)?



Another thing is that this engine is in a '88 Dakota pickup truck (oops. This forum has some nice technical information!). I will do some light towing from time to time as well.
Click to expand...

I don't understand the question. .054 is as good as no quench at all.
I have successfully run 8.7Dcr for 15 or more years on 87E10,with aluminum heads, and .034quench. Over 100,000 miles.
Some fellows on FABO, with alum heads, are successfully running a tic over 9Dcr. I cannot quote their exact Dcrs, or the quench, or the octane, they are running.I just recall they were; a tic over and a tic under.
 
olei said:
Hi,

I have a problem with my rebuilt '88 318 engine, head gaskets leak. Both of them has got a tiny leak of coolant creeping out between block and cylinder head below the headers. I also seem to get coolant in the engine oil. I have not re-torqued these head gaskets.

I am now using the P4120094 thin head gaskets, and OEM/untouched block deck surface and Edelbrock 60779 cylinder heads.

I have an average deck clearance at .012", but because of one of the cylinder banks not being level/square the deepest piston is .015" in the hole.

Now these thin head gaskets doesn't seem to seal very well?

I now have two options:
1) Replace with new set of thin head gaskets at .026" thickness (coated with Hylomar). .041" quench, 9.7 SCR and 8.88 DCR.
2) Use the Fel-Pro 1008 at .039" thickness. .054" quench, 9.37 SCR and 8.59 DCR.

This engine will use 91 octane pump fuel.

So what do you think? :)
Click to expand...

Edelbrock heads require the 1008's....
 
Using mp thin head gasket with eddy heads .no runs no drips no errors
 
To the OP, what is your advertised intake closing angle? (Not your .050" intake closing angle.) I like using a different calculator with advertised closing angle. The results are a bit different than the KB one.

I would go with the .026 hylomar coated gasket and keep the quench. If these gaskets come with no coating, then I would prefer a copper coating but that is just because I have used with with success before.

I am curious as to why you did not re-torque the present head gaskets or use a copper coating on them? Both of those are standard procedure for shim head gaskets, for me at least.
 
olei said:
Thanks for all replies! :)

fishy68;
Do you have any experience with Hylomar coating on composite head gaskets?
I believe I checked for deck warpage, but I can't remember how much is was. I'll check this again when the cylinder heads come off.


Another thing is that this engine is in a '88 Dakota pickup truck (oops. This forum has some nice technical information!). I will do some light towing from time to time as well.
Click to expand...

I haven't had a need to use it but I have known several reputable guys that claim it works real good. 12 yrs. ago when I had the 360 that leaked I didn't know about Hylomar or I would have tried it.
 
fishy68 said:
I haven't had a need to use it but I have known several reputable guys that claim it works real good. 12 yrs. ago when I had the 360 that leaked I didn't know about Hylomar or I would have tried it.
Click to expand...

where do u get it
 
I just use spray on copper seal on head gaskets. No leaks with thin gaskets.
 
Hey when using the copper spray, are you spraying both sides of the gasket and the block and head or just the gasket?
 
69_340_GTS said:
Exactly. Why do people not follow the manufacturer's instructions? And then wonder what went wrong?
Click to expand...

Spoken for truth Sir,
Someone, Anyone, show Me a factory (or aftermarket) instruction sequence
that stipulates sealant to be applied to a Head gasket ???

Through drilled head / manifold bolts (into water jacket) of course sealant is needed.

Head to Block surface ??? is sealant is needed, the machining is ca-ca,
or the components are miss matched ( read machining is ca-ca).

Of course one could argue sealant is needed for 'irregularities' (read custom build)
but that still= machine work is ca-ca.

Rant off, & apologies Sirs.
 
mech1nxh said:
Spoken for truth Sir,
Someone, Anyone, show Me a factory (or aftermarket) instruction sequence
that stipulates sealant to be applied to a Head gasket ???

Through drilled head / manifold bolts (into water jacket) of course sealant is needed.

Head to Block surface ??? is sealant is needed, the machining is ca-ca,
or the components are miss matched ( read machining is ca-ca).

Of course one could argue sealant is needed for 'irregularities' (read custom build)
but that still= machine work is ca-ca.

Rant off, & apologies Sirs.
Click to expand...

Those heads I ported, had a REAL FINE machined head surface.. I went Fel Pro blues, my quench was designed at .039 "on quench..I considered the Edelbrock machining too fine( grainwise ,on the head surface) for sealing steel shims.. The metallic coating does help,what fasteners are you using...?
 
mech1nxh said:
Spoken for truth Sir,
Someone, Anyone, show Me a factory (or aftermarket) instruction sequence
that stipulates sealant to be applied to a Head gasket ???

Through drilled head / manifold bolts (into water jacket) of course sealant is needed.

Head to Block surface ??? is sealant is needed, the machining is ca-ca,
or the components are miss matched ( read machining is ca-ca).

Of course one could argue sealant is needed for 'irregularities' (read custom build)
but that still= machine work is ca-ca.

Rant off, & apologies Sirs.
Click to expand...

When I was young and starting to work on cars (1980) I used to go up to Western Auto and buy steel shim gaskets and I'm nearly positive they recommended spraying them with sealer. They were only .020" or so thick so they wouldn't seal any irregularity at all by themselves. I don't know if they still make them today though
 
fishy68,
No lack of Respect Intended or Implied...
think about this, (with respects) Why ?? would a 'Fire Ring' need
sealant ??? Proper Machining is in & of itself an absolute.

Of course assembly could be an issue...

olei,

Update ????
 
Have you checked the deck and head surface to make sure they're square???
 
Hi all! Thanks for all replies.

I'm away for work so I haven't done anything yet. What I'm planning is to order a set of both the thin Mopar head gaskets (or the Mr. Gasket 1121G), and a set of 1008's. First I will try coated thin head gaskets, and if they still leak I will switch to the 1008's.

70aarcuda;
Is your block deck surface untouched?

nm9stheham;
I do not know the advertised intake closing angle, sorry. The camshaft I have is the Hughes Whiplash (roller).Why do you call this a shim head gaskets? These are "Flexible graphite core".

I also forgot to mention I use the ARP head bolts.
 
mech1nxh said:
fishy68,
No lack of Respect Intended or Implied...
think about this, (with respects) Why ?? would a 'Fire Ring' need
sealant ??? Proper Machining is in & of itself an absolute.

Of course assembly could be an issue...

olei,

Update ????
Click to expand...

None taken. A fire ring doesn't need sealed. What your sealing is the rest of the gasket that surrounds the water ports.
 
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