85 replies to this topic

[JustSteve]

I think this is great that you've built this... HOWEVER, I really don't like the idea of having that central exhaust port and I think that's going to put a lot of people off too.7


Well done on coming this far though Cant wait to see power figures

Edited by JustSteve, 03 February 2013 - 06:51 PM.

[steven]

sounds lovely !

[Elmtech]

The head is for sale now here
It's not exactly a fully automated shop, but it will have to do for now.

edit: We will add more options soon, such as complete kits and other customisations.

Edited by Elmtech, 09 February 2013 - 07:50 PM.

[brum,brum,mike]

Nice!

Keep us posted on power figures

[Elmtech]

We had the head off last week to check everything after the running we've been doing. The valves had leaked slightly, to fix this we machined the valves down a bit(diameter) so that they fit better in the seats. The original problem was that the valve seats were designed for 33/29mm valves, but the actual valves were about 33.3mm and 29.3mm so they weren't really seating properly.
We did some more testing/mapping on the road and it seems to be running much better now. It also idles nicely at about 3000rpm :



We're trying to find a dyno place that will allow you to drive the car yourself so we can get some mapping done, we also want to get the new intake manifold installed before we do some pulls.

There are also some new pictures on our site showing the center exhaust port and the splitter as there seems to be some confusion as to how it is done.

[Elmtech]

After many failed attempts at printing the remaining part of the intake manifold we finally managed to get it done. It is now more or less installed and seems to fit pretty nicely, we should even be able to get an air filter on it if we want to. We might do some quick tests this weekend with it.

[Elmtech]

On the dyno yesterday:


And the power curve:

That converts to about 103hp. It's not as much as we were hoping for, but based on the power curve and our calculations it seems like the intake side isn't working at all. The engine now has a BP320 cam and 1.5:1 rockers. We're going to try 1.3:1 rockers next to see if that makes any difference. One issue now is that we can't advance the cam as much as we'd like because the valves start hitting the pistons, the 1.3 rockers will at least fix that.

We'll also try some different plenum sizes and other tweaks to see if we can get the intake ramming.

The cooling and everything else seems good though, we had no problems doing multiple pulls, no leaks and no over-heating issues whatsoever.

[Miniac86]

Looks amazing and I like the fact that you retained the standard mini tappet cover, pity it didn't give you a nice, smooth graph straight off the bat but that's the fun part of developing something new and fron scratch. Good luck with the future developments.

[mini13]

how much damn advance are you putting on the cam to be getting valve contact!

do you have flow figures for the head?

[Gremlin]

Can't you just have the opposite of the exhaust 4 - 1 but the edges smoothed over instead of that big ball?

[dan187]

an interesting read. I like the intake plenum. Is that an aluminium filled composite? We had something similar printed at university for our intake.

[Elmtech]

how much damn advance are you putting on the cam to be getting valve contact!

do you have flow figures for the head?

We were running stock timing on the cam when we were getting valve-piston contact. It's now a few degrees later. We did lose a bit of power though in doing that. With the 1.3 rockers we'll be able to put it back. We haven't had the head to a flow bench or ran cfd on it yet, so no flow figures.

an interesting read. I like the intake plenum. Is that an aluminium filled composite? We had something similar printed at university for our intake.

The black/yellow intake manifold in some pics is printed from ABS plastic, no metal or fiber reinforcements. The intake in the dyno video is just for testing purposes to see if the printed intake was restricting the flow(doesn't really seem like it was restricting at this point).

[giacomo]

any more news on this guys?

[crazirob]

What is the life expectancy of a 998 with 130hp ? Sounds like a 1500 mile rebuilder ?! If there is serious longevity in this I would seriously look at talk to u guys

[cradley-heathen]

well this is pretty impressive isnt it!

 

credit where its due, they got a 998 over 100 bhp at its first outing on the rollers, i have seen plenty big bore engines make less, even when fully fetled.

 

i wonder what it would be like with a more " friendly" cam in it? i wonder if it would make usefull gains in real life driveabilty with a less wild cam in it too?

 

i will be watching this closely