Ive had the new engine up and running for a couple of weeks. Its interesting that even with the larger valves and ports, the power is very similar(at the same boost and rpm) to the standard head engine. The new valve springs have certainly helped tho.
Im turning this engine a little faster, up from about 7400rpm with the last engine, to 7800rpm. A few of you would have seen the videos that ive posted from Sandown.

Ive changed from the coil on plug ignition to ordinary bosch coils and leads. Just makes it a little easier to read plugs quickly. I have to build another inlet manifold as the runners are too small at the flange for the ported head. It will still be fairly long, probably around 500mm. I might make a new exhaust manifold with slightly larger tubing while im at it. I have a feeling this is the next bottle neck. Im using very small tube on the current one.

Ive going to put a third motor together in the next few weeks with a few more changes. I`ll probably go forged pistons on this one. The standard pistons must be getting close to their limits.

I`ll put some bits up for sale in the classified section.

A couple of pics.







Im making new manifolds as the old ones dont match the ports on the new engine.
The new turbo manifold is 1.5mm larger on the tube ID, and made of stainless. It might crack up being stainless, but should retain the heat better.

Using a filler with more nickel might help prevent cracking unless it's in the weld effected zone of the parent metal. Annealing would help or at least a stress relieve but I don't know anyone with a furnace that can help with that. I got a good reference on materials if you're worried about it and want to try something.

I like what you've done with the water pump delete! Neat.

Interesting, Ive nearly got it welded now. The tube is 304 and the filler rod is 316. I would have prefered to match the rod but none was available locally. I believe 321 stainless is the material of choice. It`s available from Burns Stainless in the US but not cheap.

To do the electric water pump conversion, I tapped the water bypass hole in the top of the block and fitted a 1/4 NPT plug. Then just cut off the standard radiator hose tube from the block to give more room for the turbo. I might even cut the extra cast iron off the side the block to save weight on the next engine.

it'll be fine, being thick buttweld joins. (professional opinion) one thing to consider is that stainless manifolds can grow quite a bit when red hot so good clearance is probably important.

nice work sirat

May as well just see how it goes. It's true, SS grows more when it heats up than mild steel, also conducts less heat.

Finished welding the manifold. Still have to machine the flange surfaces.

That is some tidy work right there! What've you coated/ painted them with?

No coatings, just garnet blasted. I dont want to spend the money on coatings.
I may just wrap them where they are close to the inlet runners. The wrap that is available now is suposed to be better than the old fiberglass stuff.

They have done an article on the car in this months RACE mag. It should be out soon.