[Mr.Mazza]

You need to get some bloody great channel-lock pliers and bend that big stiff bracket into a place that forces the header tight into the head. Straight in, nice and flush and tight. Any side gaps can be filled with a wrap of beer can metal cut about 1" wide, and wrapped around the end of the header pipe where it fits into the head. That fills the gap nicely.

Get the header where it needs to be to fit right, and then bend the bracket to where it holds it right.

Well the header bracket is actually two parts at the rubber mount attempt before didnt work, so I'll move the angles around until its happy, bolt it down. Shim if I need too THEN line the muffler up.

[ace.cafe]

Correct!

Get the header on right, then work on the muffler fit.

[Mr.Mazza]

Correct!

Get the header on right, then work on the muffler fit.

Sweet.
And soonish I will have to take the head off, it didnt get retorqed soon enough and the head gasket is weeping.
But I wanted stronger head studs anyways so Ill get some and put them in, with hardended head washers and a new copper gasket and keep the old one as a spare.
How tight does a stud have to be? These studs have a square end for installtion.

[ace.cafe]

Do not tighten the studs.
They should not go to the bottom.  Put them almost all the way in, but not all the way,  and then tighten the nuts to 20 ft-lbs. No tighter.

Copper head gaskets leak if it is not sprayed with gasket sealer. The head gasket gap should only be about .003" thinner than the copper gasket, so it seals.

[Mr.Mazza]

Do not tighten the studs.
They should not go to the bottom.  Put them almost all the way in, but not all the way,  and then tighten the nuts to 20 ft-lbs. No tighter.

Copper head gaskets leak if it is not sprayed with gasket sealer. The head gasket gap should only be about .003" thinner than the copper gasket, so it seals.

Okay, only 20 with better studs?
I think the gasket wasnt sealed, I will seal it.
You can leave the rocker gear bolted up when pulling the head correct?

[ace.cafe]

Okay, only 20 with better studs?
I think the gasket wasnt sealed, I will seal it.
You can leave the rocker gear bolted up when pulling the head correct?

The studs are not the weak point. The threads in the aluminum engine case and in the aluminum head are the weak point. No more than 20 ft-lbs. It doesn't matter what the studs are.

Yes, you can leave the rockers on when taking the head off, as long as you can get a socket over that head nut that's next to the rocker block.

Also, no more than 5 ft-lbs torque on the rocker block nuts, and the same on the rocker cover nuts.
These little threads pull out of the aluminum head very easy, and 5 ft-lbs is well tested and works with no problems arising. I know it seems like very little, but just go with it.

[Mr.Mazza]

The studs are not the weak point. The threads in the aluminum engine case and in the aluminum head are the weak point. No more than 20 ft-lbs. It doesn't matter what the studs are.

Yes, you can leave the rockers on when taking the head off, as long as you can get a socket over that head nut that's next to the rocker block.

Also, no more than 5 ft-lbs torque on the rocker block nuts, and the same on the rocker cover nuts.
These little threads pull out of the aluminum head very easy, and 5 ft-lbs is well tested and works with no problems arising. I know it seems like very little, but just go with it.

Righto!

[Arizoni]

A few numbers for folks worried that 5 lb/ft of torque on their rocker arm block nuts might not be enough to hold the block down, here's a formula for calculating the compressive force created by one bolt or stud/nut after torquing it.

F = T/(d x .20) (see below)**, where F = compressive force measured in pounds, T = torque in lb/in***, d = major diameter of thread.

For 5 lb/ft of torque we have 5 X 12 = 60 lb/in

If the thread size is 1/4 inch then d = .250

That gives us 60/(.250) .2 = 60/.050 = 1,200 pounds.

With 4 nuts per block that equals 4 X 1200 = 4,800 pounds.

** The .20 value is for dry, steel threads. For lubricated steel threads use .15

*** Note, the torque must be in lb/in.  If you are using pound/foot values, you must multiply the value by 12 to get pound/inch values.

[Mr.Mazza]

Righto!
Pulled the header pipe off, turns out the cooling ring was stopping it sitting flush so moved that, modifyed me little bracket so it was good, maniseal the cylinder head. Put it together, gave it 20 mins to set, then fired it up for 5 mins to heat the pipe. (Maniseal sets when warmed) and a perfect seal!

[ace.cafe]

Sounds good!

BTW, if the "cooling ring"  gets in the way, just take it off. They never had those things on there originally anyway, and they don't "cool" anything, nor do they do anything else of value. They are just visual baubles.

[Mr.Mazza]

Sounds good!

BTW, if the "cooling ring"  gets in the way, just take it off. They never had those things on there originally anyway, and they don't "cool" anything, nor do they do anything else of value. They are just visual baubles.

I like the look
But I thought they drew a little heat from the start of the pipe?

[ace.cafe]

I like the look
But I thought they drew a little heat from the start of the pipe?

It's okay to like the look.

Drawing heat from the start of the pipe is not a desirable attribute. First, the hotter the pipe, the more power the engine will make. Second, any heat dissipated from the pipe by large alloy fins that sit right in front of the cylinder head fins cause extreme heat to be transferred to the air that flows into the cooling fins, interfering with the cooling of the cylinder head.
IMO, everything about the "cooling ring" is bad. I never use them.

The ONLY thing that can be said in its favor is some people like the look. IMO, the look is not worth the downsides.

[Mr.Mazza]

It's okay to like the look.
Drawing heat from the start of the pipe is not a desirable attribute. First, the hotter the pipe, the more power the engine will make. Second, any heat dissipated from the pipe by large alloy fins that sit right in front of the cylinder head fins cause extremely hot air to be the air that flows into the cooling fins, preventing cooling of the cylinder head from taking place.
Everything about the "cooling ring" is bad. I never use them.
The ONLY thing that can be said in its favor is some people like the look. IMO, the look is not worth the damage.

So more harm than good?
And Ive noticed the engine is running much much cooler now it has about 250 miles on it.

[ace.cafe]

So more harm than good?
And Ive noticed the engine is running much much cooler now it has about 250 miles on it.

Yes, it's ALL harm.
There is no good. Except for the looks, if you like it.

After 250 miles the engine should be running considerably cooler. You are a good measure of the way though the critical phases of your break in. The rest is just adding miles to continue smoothing of the surfaces that rub against each other.

[Adrian II]

The AVL models never had cooling rings, just the securing flange - those engines were intended to run hot, though.

A.