retorque heads to solve issue?

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jcolman

jcolman

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I noticed some "soot" buildup on the front of the block, just below the aluminum heads. The heads overhang about 1" over the front of the block.

I'm wondering if I need to retorque the heads or just go ahead and change out the gaskets. This is a fresh engine with around 800 miles or so. 340 motor with edlebrock heads.

Thanks!
 
Check the torque by setting it just below torque spec and see if it clicks... if it does they are fine. It happens, more when the deck isnt milled. Sometimes painting it as a long block seals some of it in...or some gasketcinch along the outside edge of the deck/heads. One could come up with ideas...
 
I just went through this with Cometic. You have to back off each bolt or nut and retorque it. Make a mark on the bolt head and I’d bet you get another 1/4 turn out of it. You can’t just hit them with the torque wrench. You have to back them off first.
 
Rat Bastid said:
I just went through this with Cometic. You have to back off each bolt or nut and retorque it. Make a mark on the bolt head and I’d bet you get another 1/4 turn out of it. You can’t just hit them with the torque wrench. You have to back them off first.
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I read from his post he wanted to check the torque, not re torque it. So if you wanna back it off some 1st..is that in order or at random and are you draining the coolant.
Tell him entirely how .
 
Rat Bastid said:
I just went through this with Cometic. You have to back off each bolt or nut and retorque it. Make a mark on the bolt head and I’d bet you get another 1/4 turn out of it. You can’t just hit them with the torque wrench. You have to back them off first.
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And some of this is relative to materials used. At my age I have lived through reuse OEM head bolts and and the one use head bolts. The one use... once its stretched, it continues to stretch. Thus, one use.
I like to think quality hardware like ARP studs are capable of retorque. ARP might recommend new nuts to retorque on the same studs. I really dont know. What I do know is the difference in todays raw materials used to make hardware or anything else. So the gasket construction may be the issue or the hardware used to attach aftermarket heads may be the issue. good luck
 
MOPAROFFICIAL said:
I read from his post he wanted to check the torque, not re torque it. So if you wanna back it off some 1st..is that in order or at random and are you draining the coolant.
Tell him entirely how .
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Obviously something is amiss if I'm getting some soot on the block so my question really is: "I probably need to retorque the heads but should I simply remove them, replace the gaskets and re-install them"? I have to remove the headers in order to get to the head bolts so I'd rather do the job once, not twice.

I've read that you should retorque aluminum heads after break-in, but my motor already has some mile on it. I was wondering if simply retorquing them might solve the problem. I would obviously retorque them in the proper sequence.

Also, are you saying that I need to drain all the coolent out if I'm simply backing off the bolts a few pounds then retighting them?
 
MOPAROFFICIAL said:
I read from his post he wanted to check the torque, not re torque it. So if you wanna back it off some 1st..is that in order or at random and are you draining the coolant.
Tell him entirely how .
Click to expand...

I did tell him EXACTLY what to do. Back the bolt off (singular means one at a time) and retorque it. The carbon tracking says the heads need to be retorque. No need to drain the coolant or anything else.
 
jcolman said:
Obviously something is amiss if I'm getting some soot on the block so my question really is: "I probably need to retorque the heads but should I simply remove them, replace the gaskets and re-install them"? I have to remove the headers in order to get to the head bolts so I'd rather do the job once, not twice.

I've read that you should retorque aluminum heads after break-in, but my motor already has some mile on it. I was wondering if simply retorquing them might solve the problem. I would obviously retorque them in the proper sequence.

Also, are you saying that I need to drain all the coolent out if I'm simply backing off the bolts a few pounds then retighting them?
Click to expand...

See post 7
 
When ever using Tri-metal head gaskets such as Cometic or Mr Gasket. Both block and heads should be resurfaced using a CBN cutter. Most Machine shops don't use them because they are expensive. The surface when done correctly should look like chrome. If you don't have that done use Composite gaskets.

DSCN1104.JPG


DSCN1105.JPG
 
Define "soot". Soot to me would mean exhaust carbon "Chalk" which wouldn't be the head gasket unless something was really wrong.

Is the build up moving or growing?

Got a picture?
 
dano said:
Define "soot". Soot to me would mean exhaust carbon "Chalk" which wouldn't be the head gasket unless something was really wrong.

Is the build up moving or growing?

Got a picture?
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It's more like exhaust carbon. I wiped it more or less clean a couple weeks ago, then ran the car for about 80 miles. This is what it looks like now. You can barely see any deposits but there is a slight bit of carbon.
IMG_20211021_135128.jpg
 
Or dust from the road. Engines get an oil film on them, from them being an engine and when you combine dust and oil, they look dirty. I tried to find a very minor oil leak in a blown big block Chevy, using florescent dye. When I hit it with a black light after running for a few minutes, the whole outside of the engine glowed.
Did you use any sealer on your gaskets or put them on dry? What head bolts used or studs?
I retorked my trick flow heads, no I didn't back them off. Yeah, probably a pinch above torque specs, but so are most everyone's torque wrenches out of spec.
 
jcolman said:
It's more like exhaust carbon. I wiped it more or less clean a couple weeks ago, then ran the car for about 80 miles. This is what it looks like now. You can barely see any deposits but there is a slight bit of carbon.View attachment 1715808633
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IMO I would pull the heads and replace the gaskets with composite ones and use an ARP stud set with ARP thread lube. Anything else and your just guessing if it is going to work. I am like you I dont care to do it twice.
 
CRUZE 418 said:
Or dust from the road. Engines get an oil film on them, from them being an engine and when you combine dust and oil, they look dirty. I tried to find a very minor oil leak in a blown big block Chevy, using florescent dye. When I hit it with a black light after running for a few minutes, the whole outside of the engine glowed.
Did you use any sealer on your gaskets or put them on dry? What head bolts used or studs?
I retorked my trick flow heads, no I didn't back them off. Yeah, probably a pinch above torque specs, but so are most everyone's torque wrenches out of spec.
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Good point. The motor runs strong as it is but I'll keep an eye on it. I didn't build the engine so I can't answer your questions but I do know that ARP studs were used.
 
jcolman said:
Good point. The motor runs strong as it is but I'll keep an eye on it. I didn't build the engine so I can't answer your questions but I do know that ARP studs were used.
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This is typical of MLS gaskets. Doubt the surface finish is wrong because what you are seeing is SOP for those gaskets. Any bimetal engine requires a retorque. Even an all iron engine should have the fasteners retorqued before it gets off the dyno or after the first few hard heat cycles if you go straight to the car.
 
I used plan old .039" Fel-Pro gaskets and ARP head bolts with my Speedmasters and everything is dry/clean after many drives. I don't recall on this go around if the decks were cut.

It could be coming from the China walls, basically the seal between the intake and block. I had 1 leak there in the rear by the oil sender and had to redo the intake gaskets.

Honestly, unless its a major leak or your loosing a lot of oil making a giant mess I'd leave it and watch it.

One mistake people make with ARP bolt and studs is using the stock spec for toque. You need to know your fastener size and decide if you are going to use 30w oil or ARP lube and torque them to ARP's Specification.
 
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jcolman said:
Obviously something is amiss if I'm getting some soot on the block.
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Soot or oil residue with dust? Soot could mean more serious problems from where you say you see it...the other is seepage. The expansion rate is different between the 2... and I dont really see cometics NOT weeping oil. But that is just what I see after years of service with them.
jcolman said:
Also, are you saying that I need to drain all the coolent out if I'm simply backing off the bolts a few pounds then retighting them?
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Obviously not. Everyone's idea of re torque must be different than others though.
 
dano said:
I used plan old .039" Fel-Pro gaskets and ARP head bolts with my Speedmasters and everything is dry/clean after many drives. I don't recall on this go around if the decks were cut.

It could be coming from the China walls, basically the seal between the intake and block. I had 1 leak there in the rear by the oil sender and had to redo the intake gaskets.

Honestly, unless its a major leak or your loosing a lot of oil making a giant mess I'd leave it and watch it.

One mistake people make with ARP bolt and studs is using the stock spec for toque. You need to know your fastener size and decide if you are going to use 30w oil or ARP lube and torque them to ARP's Specification.
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I agree.
I also think the cometic is the common denominator with seepage.
 
MOPAROFFICIAL said:
Soot or oil residue with dust? Soot could mean more serious problems from where you say you see it...the other is seepage. The expansion rate is different between the 2... and I dont really see cometics NOT weeping oil. But that is just what I see after years of service with them.

Obviously not. Everyone's idea of re torque must be different than others though.
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More like the kind of soot you get in the exhaust tips but with a slight oily feel.
 
jcolman said:
More like the kind of soot you get in the exhaust tips. When I wiped it off, it didn't feel oily.
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It looks oily, it has that shine. Possibly oil from the china wall seeping and creeping as you drive then when you stop it flows down. The cooling fan and driving kicks dirt and grime on it. The think about china wall leaks is they are not overly prevalent until you drive, they won't leak much if at all until you drive. Speaking of oil leaks, what are you running for a PCV system?
 
dano said:
It looks oily, it has that shine. Possibly oil from the china wall seeping and creeping as you drive then when you stop it flows down. The cooling fan and driving kicks dirt and grime on it. The think about china wall leaks is they are not overly prevalent until you drive, they won't leak much if at all until you drive. Speaking of oil leaks, what are you running for a PCV system?
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I edited my post to say that the soot actually did have a slight oily feel to it after I wiped it with my finger. My PCV system was a breather on the passenger side, a PCV valve and another breather on the driver side. I just changed the breather on the driver side to an oil cap.
 
jcolman said:
I edited my post to say that the soot actually did have a slight oily feel to it after I wiped it with my finger. My PCV system was a breather on the passenger side, a PCV valve and another breather on the driver side. I just changed the breather on the driver side to an oil cap.
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Good, having the breather and PCV on the same side rendered it useless.

On the potential leak issue, I would get that area squeeky clean, go for a drive around he block and stop and take a paper towel and blot along from the header side to the intake and see where its coming from.
 
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