Head Gasket

[DougF]

I bought a new Payen gasket and will use sealer on it. I'm hoping there isn't a problem with the head as I have many hours of work into it.
I installed ARP studs when the engine was new last year, so I should be okay there. It'll get ugly if one breaks as they get snugged in.
You were fortunate with your head stud breaking where it did.

 

[Brosky]

You'll be fine with the ARP studs. Just follow the sequential torquing either with their lube or oil to the proper settings. Retorque after 800-1000 miles.

 

[KVH]

BTW, I had quite a difficult time cleaning the thread bores before installing the new studs. I didn't want to ruin the threads in the block, but they kept binding. I used a gun barrel wire brush and some oil, and tried to abide by the "finger tight" rule, but had to violate that on three of the stud bores. There, I needed a light touch of a wrench.

 

[Brosky]

TR6's are notorious for getting studs and threads fowled up with rust on the right side of the block due to the cooling jacket running through that area. I had a heck of a time getting mine out and we used an engine lift and torches to get the head to break loose and I only had 54,000 miles on it.

Thread bores that are closed in should always be cleaned with a bottoming tap or thread cleaner to insure getting everything out. A blast of air in there will clear the remaining debris and every stud or bolt should fit in to the bottom finger tight.

Keep in mind that the studs or bolts never really go to the bottom, or you would be torquing against a solid block. They are a prescribed length that will allow enough clearance to fit in, but not bottom out too soon.

If you need to force them in, you will be working against that restriction when you torque them. In most cases, unless you were using a wrench from the third thread down from the top, you will probably be OK.

 

[DougF]

Another issue with the head...there was a fairly heavy carbon build up on the piston tops and in the combustion chambers, but the exhaust valves were all white except for #5 that was affected by the head gasket. Colortuning, the best I could achieve was a mixture of blue and yellow. The exhaust never showed evidence of running rich. The plugs were tan/gray.

 

[poolboy]

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It doesn't take long for a deposit of carbon to build on the piston tops even with a perfect mixture. but the white exhaust valves may be indicating a lean and consequently hot engine.

Can you post a picture ?

 

[Brosky]

I agree with Ken, White usually always is lean and hot. That could even come from timing advanced too far, along with a slightly lean mixture.

 

[DougF]

Finally got the head to the machine shop this morning. He is going to install Viton seals after magnafluxing and checking for warpage. I also need to use a shorter shouldered spark plug. Been using stock NGK plugs that have a 3/4" shoulder and need to change to a 3/8" one due to combustion chamber alterations.

 

[DougF]

Just got the head back this evening. Everything checked out well. He found the valve seals and made an installation tool for me to use. He said, "Guess what these seals are for? A Detroit Diesel!" I found this pretty funny.

So, a night of work in a warm basement and back to the cold garage.

 

[DanB]

I just put a new head gasket on my Toyota van. It was a composite gasket and the manufacturer recommended putting it together dry. No sealant of any kind. You will probably want to check with Payden or Fel Pro to make sure you follow their guidelines. Call their tech line.

I have had a Fel Pro composite copper gasket on my TR4A for about 20 years. I even removed the head once and reused the gasket, which you are not supposed to be able to do, and it still is sealing.

Dan Blackwood
South Charleston, WV
66 TR4A IRS EFI
80 TR7 DHC

 

[TR3driver]

That's been pretty much my experience with all head gaskets. If the mechanical stuff is right (especially liner protrusion on the TR2-4 motor), the gasket seals with or without any goop. If it's not right, no goop in the world will keep it sealed for long.

But then I'm not a big believer in valve seals either. The guides need just a bit of oil for long life, and the stock oiling system delivers just a bit of oil to them.

 

[DougF]

Thanks, the head gasket will go on dry.

I was getting oil into the combustion chamber, more than likely due to the side oil pipe.

I will install an oil cooler; a fan thermostat sensor into the thermostat housing; a fan override switch and an indictor light on the dash support. These things along with the new spark plugs and radiator cap will hopefully solve the overheating problem.

Stay tuned for the next episode of "As The Engine Turns."