Blown Head Gasket

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3406pk

3406pk

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Had an unpleasant surprise a week ago. Checked the Duster 408 over to prep for drag races coming up. Checked the oil and it was way over full. Then checked radiator and it was below cores. OH OH, knew I had a problem. I had run it at drag races 2 weeks before and ran fine; just unloaded from trailer and parked in garage.
So pressurized the cooling system and could hear air leaking into #3 cylinder. Leakdown test was still ok for that cyl and really good for all the rest. Decided to pull that left head first and spotted the problem right away. The compression ring on gasket pushed out and caused water port to leak to lifter valley. Was hoping the gasket was only problem, so took head to machine shop to crack check and look at valves.
Cut oil filter and check for metal, was good. Whew that's a relief. Put in some oil and drove oil pump w drill to flush out water from passages and roller lifters. Cam and roller lifters still look good. Am glad I put in roller cam instead of flat tappet for this incident. Head checked out ok, he did skim cut on head surface and touched up one valve. Pistons look great so good to go.
Well I got lucky on that one. The head gasket was Felpro 1008 and had been in 3 years, and before that refresh was 10 years on same part number gasket. Is this gasket failure common or unusual?
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It is a 10.5:1 CR, running on 91 pump gas. Pistons and spark plugs all good.
I now realize that I had a warning as I found small amount of water in the oil separator in the PCV hose line.
 
Pretty common...small blocks have been doing that since they started to get modded...back in the day it was a pain with 13.5 comp...Milodon head studs and 3M glue...If a customer came in with it smoking out the breather you did not even have to take off the covers,you just told them Head gasket...
 
I had it happen to me with felpro gasket at 10:1. From that point on I have always torqued them and let it sit overnight. I would go back and re-torque them. They would always turn a bit more. Never happened again. Now I run studs and cometic’s, did the same thing with the cometic’s, they did NOT turn more when rechecked.
 
Piston still dirty, so it wasn’t leaking coolant into the cylinder or was not run much at all with it popped.
 
3406pk said:
Had an unpleasant surprise a week ago. Checked the Duster 408 over to prep for drag races coming up. Checked the oil and it was way over full. Then checked radiator and it was below cores. OH OH, knew I had a problem. I had run it at drag races 2 weeks before and ran fine; just unloaded from trailer and parked in garage.
So pressurized the cooling system and could hear air leaking into #3 cylinder. Leakdown test was still ok for that cyl and really good for all the rest. Decided to pull that left head first and spotted the problem right away. The compression ring on gasket pushed out and caused water port to leak to lifter valley. Was hoping the gasket was only problem, so took head to machine shop to crack check and look at valves.
Cut oil filter and check for metal, was good. Whew that's a relief. Put in some oil and drove oil pump w drill to flush out water from passages and roller lifters. Cam and roller lifters still look good. Am glad I put in roller cam instead of flat tappet for this incident. Head checked out ok, he did skim cut on head surface and touched up one valve. Pistons look great so good to go.
Well I got lucky on that one. The head gasket was Felpro 1008 and had been in 3 years, and before that refresh was 10 years on same part number gasket. Is this gasket failure common or unusual?
View attachment 1715783349 View attachment 1715783350 It is a 10.5:1 CR, running on 91 pump gas. Pistons and spark plugs all good.
I now realize that I had a warning as I found small amount of water in the oil separator in the PCV hose line.
Click to expand...
I've always had the head gasket blow between the cylinders, never like you had. Definitely looks like there was a weak spot there that finally gave out.
 
3406pk said:
Had an unpleasant surprise a week ago. Checked the Duster 408 over to prep for drag races coming up. Checked the oil and it was way over full. Then checked radiator and it was below cores. OH OH, knew I had a problem. I had run it at drag races 2 weeks before and ran fine; just unloaded from trailer and parked in garage.
So pressurized the cooling system and could hear air leaking into #3 cylinder. Leakdown test was still ok for that cyl and really good for all the rest. Decided to pull that left head first and spotted the problem right away. The compression ring on gasket pushed out and caused water port to leak to lifter valley. Was hoping the gasket was only problem, so took head to machine shop to crack check and look at valves.
Cut oil filter and check for metal, was good. Whew that's a relief. Put in some oil and drove oil pump w drill to flush out water from passages and roller lifters. Cam and roller lifters still look good. Am glad I put in roller cam instead of flat tappet for this incident. Head checked out ok, he did skim cut on head surface and touched up one valve. Pistons look great so good to go.
Well I got lucky on that one. The head gasket was Felpro 1008 and had been in 3 years, and before that refresh was 10 years on same part number gasket. Is this gasket failure common or unusual?
View attachment 1715783349 View attachment 1715783350 It is a 10.5:1 CR, running on 91 pump gas. Pistons and spark plugs all good.
I now realize that I had a warning as I found small amount of water in the oil separator in the PCV hose line.
Click to expand...
When you put the engine back together use new head bolts or studs.
I do not reuse critical fasteners
When you use new heads bolt apply them with a hardened washer under the head.
Chase all the threaded holes clean, clean, clean.
 
i've had the odd motor repeatedly blow head gaskets despite checking faces for straightness. an 'old guy' mechanic friend told me to torque the head bolts 20lb ish above book. i've not done a gasket on them since.
 
3406pk said:
Had an unpleasant surprise a week ago. Checked the Duster 408 over to prep for drag races coming up. Checked the oil and it was way over full. Then checked radiator and it was below cores. OH OH, knew I had a problem. I had run it at drag races 2 weeks before and ran fine; just unloaded from trailer and parked in garage.
So pressurized the cooling system and could hear air leaking into #3 cylinder. Leakdown test was still ok for that cyl and really good for all the rest. Decided to pull that left head first and spotted the problem right away. The compression ring on gasket pushed out and caused water port to leak to lifter valley. Was hoping the gasket was only problem, so took head to machine shop to crack check and look at valves.
Cut oil filter and check for metal, was good. Whew that's a relief. Put in some oil and drove oil pump w drill to flush out water from passages and roller lifters. Cam and roller lifters still look good. Am glad I put in roller cam instead of flat tappet for this incident. Head checked out ok, he did skim cut on head surface and touched up one valve. Pistons look great so good to go.
Well I got lucky on that one. The head gasket was Felpro 1008 and had been in 3 years, and before that refresh was 10 years on same part number gasket. Is this gasket failure common or unusual?
View attachment 1715783349 View attachment 1715783350 It is a 10.5:1 CR, running on 91 pump gas. Pistons and spark plugs all good.
I now realize that I had a warning as I found small amount of water in the oil separator in the PCV hose line.
Click to expand...

Did you deck the block when you went through the engine? I always say this is the stuff that burns a guy. It’s much cheaper to get a clean flat deck the first time through than to redo it later.
 
448Scamp said:
Did you deck the block when you went through the engine? I always say this is the stuff that burns a guy. It’s much cheaper to get a clean flat deck the first time through than to redo it later.
Click to expand...
Block was decked on original build. Checked now and was flat.
 
Thanks all for comments and suggestions. I have it together now and will start tomorrow.
 
After owning a billion Neons, I'm going to recommend MLS gaskets for anything and everything from now on.
 
I had a 340 that smoked bad out of 1 bank, the head gasket blew into the valley under the intake manifold. I had a 360 high compression engine do the same thing, but I think my dad detonated it, by the looks of the bearings and main caps. I have been retorqueing the 1008 head gaskets after break in.
 
After some comments about retorquing, I put torque wrench on bolts after sitting overnight & before start. No movement at all. Start up went good, and ran good at track. Thanks for comments.
 
3406pk said:
After some comments about retorquing, I put torque wrench on bolts after sitting overnight & before start. No movement at all. Start up went good, and ran good at track. Thanks for comments.
Click to expand...
Normally you would perform a retorque after the engine has gone through a few heat cycles.
 
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