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Cracked Cylinderhead?
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baklys View Drop Down
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Points: 520 		Post Options Post Options   Thanks (0) Thanks(0)   Quote baklys Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2017 at 4:00pm
Originally posted by azfletch azfletch wrote:

It is imperative that you use sealant on some of the head bolts (lower ones by the Exhaust).  If you install them dry they will weep coolant and also allow air into the cooling system causing overheating.  Before you condemn the heads check these bolts and also that your two freeze plugs in the head behind the exhaust are not leaking.

So you think that using sealant will prevent cooling water entering the exhaust port?
Baklys



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baklys View Drop Down
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Originally posted by wantajav wantajav wrote:

Hello

What do all the spark plugs on that side of the engine look like?

Can you do a compression test?

Does the car have bubbling in the radiator while idling?

Can you do a leak down test?

Maybe it is just a head gasket or intake manifold gasket, not the head itself.

Well, I just can not understand that it is the head gasket as long as there are really pooring out water of the header while the plug is remowed..   As I wrote, I ported the heads, but that was not much that I removed so it is a bit strange that I entered the water jacket..  I can not see any exhaust in the radiator, no bubbles..
Baklys



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-76 Gremlin X V8

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-70 Gremlin Race

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baklys View Drop Down
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Points: 520 		Post Options Post Options   Thanks (0) Thanks(0)   Quote baklys Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2017 at 4:07pm
Originally posted by bvpotash1 bvpotash1 wrote:

If you ported the exhaust roof that's your problem. Ask me how I know. You need another head. Might as well upgrade to dog leg. It made a big difference for me.

Yes.. I think that is what will happen.  I have many dog leg heads, but no square port. And I just like to have the original heads on the 390 to keep the car a bit original. But I am sure it will help on the performance, yes. :)
Baklys



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mstrcrftr View Drop Down
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i have a set of square port heads but i am in texas.
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baklys View Drop Down
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Points: 520 		Post Options Post Options   Thanks (0) Thanks(0)   Quote baklys Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2017 at 5:23pm
Originally posted by mstrcrftr mstrcrftr wrote:

i have a set of square port heads but i am in texas.

PM sendt...
Baklys



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-76 Gremlin X V8

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-70 Gremlin Race

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Boris Badanov View Drop Down
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Points: 4209 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2017 at 6:16pm
Dog leg heads will not help performance
and may hurt it by cutting compression.
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Boris Badanov View Drop Down
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Points: 4209 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2017 at 9:27am
I agree it is very unlikely that the head gasket is the cause.

If you made a "water letter outerer" in the exhaust port
gasses may or may not enter the water jacket.

BUT water may enter the combustion chamber during valve over lap
and this problem can do serious damage to the cylinder (s).

Time for a new set of heads.

Truth is that even the stock iron heads are excellent and there
is no reason to port a set of street heads.

Get a set of Eddys or ask here on the forum.

343 heads are common and cheap. Shipping will cost more than the heads.
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Points: 2837 		Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2017 at 10:17am
Agreed get the head replaced if that is the problem and stop worrying about it.

I had two 4.3 Astro vans leaking into the back left cylinder. The first one I replaced the head gasket without checking the head for cracks. Guess what, it still leaked and in went the bars leak. Next one I used bars leak right away and got almost 300k kms on it putting that crap in about once a year. Once during that time the hub came off the water pump and the fan went through the rad. Surprise, it was not plugged at all. Other products I have used plugged the rad but did a better job of sealing the engine leak.
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990V8 View Drop Down
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Over here in the UK, K-Seal is the best leak stopper. Little ceramic beads.
But it certainly is hard to get out of the system once it's been put in.

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baklys View Drop Down
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Originally posted by 990V8 990V8 wrote:

Over here in the UK, K-Seal is the best leak stopper. Little ceramic beads.
But it certainly is hard to get out of the system once it's been put in.

Ivor

Yes, in last desperation I think I will try to use some high tec leak seal..  But anyway the plan now is to buy a new set of heads so I can have the car running again.   And after reading all your answers thank you everyone for helping me. And next time I will pressuretest the heads after porting. Just can not understand that I took that much out of that port, it was just a mild porting and polishing job.  Maby it is the head itself that has got a crack in the corner.

Again thanks alot :) 
Baklys



Live in Norway!







-76 Gremlin X V8

-69 AMX 390 4 spd

-70 Gremlin Race

-63 Classic

-and 4 more gremlins..
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