tuna55
HalfDork
3/29/10 7:46 p.m.
Raze wrote:
MadScientistMatt wrote:
93celicaGT2 wrote:
Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside.
That may be flawed logic.
The gasket can still go from one cylinder to another...
That's why you'd have to get steel rings placed into grooves in both the head and block, least that's what I'm thinking, but then the need to weld it together diminishes...
I really need to think about how to accomplish what i'm going for here beyond machining the whole thing.
Why do you think steel rings would seal at all? They use soft metal for a reason, I suspect. If you were to do this, the best bet might be to carve away the cylinder head until you get to just the combustion chamber, and weld that.
Who really needs coolant, anyways? Weld on some fins.
Raze
HalfDork
3/29/10 8:07 p.m.
tuna55 wrote:
Raze wrote:
MadScientistMatt wrote:
93celicaGT2 wrote:
Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside.
That may be flawed logic.
The gasket can still go from one cylinder to another...
That's why you'd have to get steel rings placed into grooves in both the head and block, least that's what I'm thinking, but then the need to weld it together diminishes...
I really need to think about how to accomplish what i'm going for here beyond machining the whole thing.
Why do you think steel rings would seal at all? They use soft metal for a reason, I suspect. If you were to do this, the best bet might be to carve away the cylinder head until you get to just the combustion chamber, and weld that.
Who really needs coolant, anyways? Weld on some fins.
I guess I should have explained more fully instead of saying steel rings, basically take a headgasket have to be a decent quality one, take the rings out and then sink it into the block deck and head after having the head and block machine matched to a dang close tolerance. It should act to reinforce the HG by not allowing it to expand to the point of rupture, and basically reduce the cross section of the HG that actually sees load to whatever gap you have between the deck and the head. Ideally welding would be best, but I'm trying to find alternative methods of achieving similar results with tools and equipment laying around...
The original Bugatti engines (straight eights and fours) had the head and block cast as one. Very similar to the Offys. When a valve job was needed, the crankshaft (usually a roller) had to be removed......a complex job. Typical Bugattis were overhead cam with 3 valves per cylinder. Cars like the T35b used superchargers to get very high power back in late 1920s. With that setup, the headgasket was the weakest link so it was taken out of the equation.
By the way, the pipe on the upper right side of the Bugatti engine is the "backfire port". Most Bugs had them to relieve extra pressure in the manifold. The right side bonnet also had a hole to match. If you see a T35b entering a fast corner on overrun, you usually see flames exiting this port....glorious! 
Most aircooled aircraft engines (Lycoming, etc) have the head cast into each "jug", so the only leakage area is the cylinder base against the block.
tuna55
HalfDork
3/30/10 7:31 a.m.
Raze wrote:
tuna55 wrote:
Raze wrote:
MadScientistMatt wrote:
93celicaGT2 wrote:
Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside.
That may be flawed logic.
The gasket can still go from one cylinder to another...
That's why you'd have to get steel rings placed into grooves in both the head and block, least that's what I'm thinking, but then the need to weld it together diminishes...
I really need to think about how to accomplish what i'm going for here beyond machining the whole thing.
Why do you think steel rings would seal at all? They use soft metal for a reason, I suspect. If you were to do this, the best bet might be to carve away the cylinder head until you get to just the combustion chamber, and weld that.
Who really needs coolant, anyways? Weld on some fins.
I guess I should have explained more fully instead of saying steel rings, basically take a headgasket have to be a decent quality one, take the rings out and then sink it into the block deck and head after having the head and block machine matched to a dang close tolerance. It should act to reinforce the HG by not allowing it to expand to the point of rupture, and basically reduce the cross section of the HG that actually sees load to whatever gap you have between the deck and the head. Ideally welding would be best, but I'm trying to find alternative methods of achieving similar results with tools and equipment laying around...
I think that a good copper gasket would seal way better than what you described under high boost/no coolant conditions, but I've never done either.
