85 replies to this topic

[Ethel]

It'd be interesting to see how a 7 & 8 porter compare. The Siamese exhaust port shouldn't be as bothersome as the shared inlets.

[Wil_h]

What is most interesting about this head is that compared to all other 8-ports that I can think of, it retains the same valve layout as the 5-port. this means you can use normal cams.

[Ethel]

A 7 porter would also let you retain the exhaust, so it's gonna be interesting to see the effect of the extra exit. Have to wonder how much you can do with the pushrods and head studs arranged as they are.

[giacomo]

any more updates on this :)?

[Elmtech]

Not quite yet, we've been really busy with some other work. But we will get the head machined asap(=hopefully sometime during next week).

[1994alex]

Any updates

[Elmtech]

Actually yes. The new head is now completely machined and just needs to be assembled. The exhaust ports were slightly tweaked for this version, but other than that it's pretty identical to the first version. We also got the custom valve seats. Of course we still have to make the intake and exhaust manifolds, so there is still a bit of work to do. We are also still really busy, so I can't really give any guarantees for when this will be done, asap is the goal though


Old head and new head


Intake port, you can also see the valve guide hole


Exhaust side


From the top




Valve seats

[Wil_h]

Sorry to be a pedant, but I only count 7 ports!

[Elmtech]

True, but if you look really closely at the exhaust pic, you'll see a 1mm groove in the center port. When you insert a steel plate there you get 8 ports.

[yeti21586]

nope will still only be 7 ports with a bit of metal disturbing air flow!

and 8 port needs 4 individual inlets and 4 individual out lets, meaning that you would need a 4 branch exhaust, were as by the looks of it you can use a standard 3 branch exhaust manifold meaning that the performance advantage of an 8port (while being only minimal over a 7port) is lost


YetI

[Elmtech]

An adapter with 2 outlets will bolt to the center exhaust port, so it will have 4 individual exhausts. Whether or not the port is too restrictive where the plate goes remains to be seen, but at least the area of the ports at that point is a bit larger than at the valve end.

[Artful Dodger]

looks flippin awsome whatever it is!!!



can i have one

[Carlos W]

It is absolutely gorgeous! Imagine opening the bonnet to be greated by that!

Just needs to be a 1275 head and it'll be perfect

Edited by Carlos W, 16 July 2012 - 09:15 PM.

[Wil_h]

Just needs to be a 1275 head and it'll be perfect

There is already a CNC machined head for the 1275 available. It has inbuilt injector bosses, fits a standard exhaust manifold and looks great too. You could buy one tomorrow.

[Elmtech]

We're still alive
We are still working on getting the head installed so that we can test it. It's starting to come along pretty nicely now and shouldn't be too long before there is smoke. We're going to run fuel injection on it so there is a lot of wiring that still needs to be done and we need to make an intake manifold.

Edit: I forgot to include some pictures of the fuel rail we machined so here that is.


This is what it looks like now


We needed a timing sensor for the cam and crank so we decided to make our own belt pulley from aluminum with some steel teeth for the timing.




We also machined the splitter for the center exhaust so that we get 4 primaries as well as a 4-1 collector that is now installed. Pics below show the splitter as well as the equal length primaries going to our 4-1 collector.





We also noticed while pressing in the intake valve guides that they didn't end up completely straight because of the shape of the port. So since we had to modify them anyway, we decided to make them more aerodynamic and better fitting while we were at it.




The plan was and is to 3D print the intake manifold from abs plastic, that way it's easier to get it to fit and it's relatively easy to get equal length runners. Printing such large parts however turned out the be a bit problematic so it's not quite finished yet. If it takes too long we'll just weld something simple together.



Some more pictures and other info can be found here

Edited by Elmtech, 02 January 2013 - 04:34 PM.