griff851
Well I just thought I'd post my theoretical solution to a bevel issue and see if anybody could see flaws.
The bevel manifold sits on the head with a 7mm rubber gasket. The manifold has a lip protruding from its mating surface that is 1.5 wide and 4mm high. This lip sits inside the gaskets intake hole and locates the gasket on the manifold. When you assemble the manifold the gasket compresses down to about 6mm. Thus leaving 2mm. This 2 mm forms a grove effectively even thought the gasket bulges a bit in compression and makes port matching difficult, and is plain bad Juju in the flow department.
My solution. Machine off the lip and go a further 4mm into the manifold forming a 1.5x4mm step inside the throat. Then make up a 1.5 wall and 10mm wide ring. Insert it in the manifold, assemble the manifold less the gasket, then port match. Then assemble. Wah-la.
851 tricolore
sounds like the lip does have a function, but my Hailwood always sucked the rubbers into the inlet tract, originals (read, old chewed up, with aluminium reinforcements that cut through the outter surface and slide around) or patterns (floppy rubber sheet).
So I bought a Malossi kit with a sandwich plate and O rings either side- unfortunately you have to machine (file) the lip off the inlet manifold, but it has been leak and distortion free for years now- and you could probably match the sandwich plate to the head and manifold so long as you don't need to go too big.
In fact you could probably copy this system- made from ali plate, if you need bigger ports.
good luck
Ian
griff851
I did look in to those, Brook Henry was selling them for bevels, and bevel heaven has them in black as well. They are based on the Pantah manifold, except the Pantah has rubber bushes around the studs. That way it still limits the vibration reaching the fuel bowl. I guess heat as well.
I don't really see any way other than the sleeve approach. I'm trying to get the best of both worlds on the go. My old dinosaur is getting some upgrades and because there is not much you can do to the head other than stick in a 42mm inlet valve (done years ago), the only place to recover some flow is that joint I feel.
I did just happen to come across in the bottom of my magic box, a pair of Gowenloch high comp pistons. Good thing too as my skirts after 80-85,000km are ted. Things internally are also beginning to have holes drilled in them. The clutch basket went on a massive weight loss campaign last week. 😄 The poor fly wheel is already just a shadow of original self.
