Dimensioning issues have the engine apart at this time. The cams have so much lift that and the valve are so big that we chose to increase valve to piston clearance. At the same time we are considering more compression. At 9000 rpm the last thing we need or want is internal conflict.
I'll keep you all posted with pictures of the new piston we are having made.
Cheers

any updates??? i was loving this thing!

Henry,

Beautiful build, as always.

How did you get the case so clean, soda blasting?

No news to report. This current economic situation he me scrambling much like so many of you.
I already build the corral for the pony that Obama promised, now I'm just waiting for my bailout money.
All kidding aside, this group of politicians couldn't be more wrong.:confused:
Whenever you medicate an injury solely to mask the pain you hamper the recovery.

Rant over, now back to engines and real would fantasies.

She's finished.

Titanium 2.5 Engine

Supertec has decided to build an "old school format with a modern twist". The base platform is a 2.5 liter, MFI, twin plug engine. The twist is this engine uses GT3 Gen 2 titanium rods and a new peanut shaped combustion chamber.
Why, we wanted to build an 8500 RPM high compression engine that would run on pump gas.
Twin plugging helps with low octane ratings but the new innovation is to replace the standard Porsche hemmi head with a more modern peanut shape chamber. This allows us to run a relatively flat top piston to generate high compression. This one will make a static compression of 10.25 to 1.
We start:
68 aluminum case
shuffle pins
piston squirters
boat tailed (I know, boating makes no measurable difference, but this case was boat tailed when I got it)
oil bypass modification
oil mod for cross drilled crank
Dry film Moly coating on main bearings
Distributor mount modified for late shaft
Mounts welded for MFI pump
Oil pump
Supertec flow modified Carrera pump
Crank 2.2 counter weighted
Cross drilled
Knife edged
Journals ground to 53 mm RSR with .100" fillets for strength (GT3 bearings, dry film moly coating)
GT3 Gen 2 titanium connecting rods (130mm center to center)
911 SC distributor gear (counter clockwise rotating)
Ion plasma surface hardened
Pistons and cylinders: Mahle 8.5:1, 90 mm RS
Supertec head studs
Heads:
2.4 heads with MFI injector ports
Peanut chamber (51cc)
Big valves 47 mm intake and 41 mm exhaust
38 mm Venti Port intake
37mm exhaust port
Heads have been shaved .040" and a .040" dimension shim added. This a shim placed between the head and cam tower to return a shaved head to proper thickness.
Supertec valve springs (90lb seat pressure and 220lb @ .500" lift)
Aasco titanium valve spring retainers


http://forums.pelicanparts.com/uploa...1264088839.jpg
http://forums.pelicanparts.com/uploa...1264088856.jpg

a couple of q's Henry:
1. are those your new slide valves for intake??
2. are you using cam line oil restrictors??
3. burns twin dizzy or cop??
4. what exhaust & muffler going to run??
5. how long will this engine be at your shop...I want to see it in February when I visit you... :-)
Look killer for sure... I would guess ~300hp at the crank...?
Bob

1) The slide valve system is a project I got in the middle of about 3 years ago. It was a little more than half done when I stepped in.
We completed three sets and that is the extent of my commitment to this project.
2) We use cam feed restrictors on every engine we build.
3) This engine is being sold without a distributor. If the customer wants my advise, he should install a Burn_Bros dist.
4) The engine is being sold with no exhaust. I'm not even sure what kind of car it's going in. 911 ? 914-6 ? VW ?
5) The project is being shipped to Florida as soon as the customer arranges shipping.

As you are running single ignition but the radical head geometry, what is the measured compression ratio? This will run on "91 octane gasoline" or what passes for it here in California?

This engine has twin plugs.
http://forums.pelicanparts.com/uploa...1264201894.jpg

Whoops, I guess I remembered the 3.5 engine posting.:confused:

So, what is the C/R?

Our goal or target number was 10.25. The final cr was revised 11.5:1

Hi Henry,

What coating is that on the fan and housing?

TIA

Henry-

Any idea how much power it will make? Ballpark figure is fine.

This is more of a process than a coating.
The fan and ring are bead blasted with Potters AD which leave them shiny silver.
Then they are washed in heated caustic soda. This brings back the wonderful dark oxide color.
Then we soak the parts in penetrating oil (I have to keep some secrets :) ) and then heat to allow the penetrating oil to flow into the magnesium pores and dry.
I have no idea how durable this process will be but adding more penetrating oil should bring back this look.


We built this engine with all the methodology we have developed over 30 years of building 911 engine. Max horse power was not the goal. The widest power band was. Because of the Venti-Port and high compression we believe this engine will produce exceptional power from 3500 rpm to 8500rpm. Ambitious? of course, but it's my fantasy, I can make it as cool as I want :)
Oh yes, horse power? 280 +

http://forums.pelicanparts.com/uploa...1264088856.jpg

Sweet mother of god:eek::eek:, that's a work of art (as usual) Henry! Thank you for taking the time to share your build with us. Truly edifying and inspirational.

11.5 to 1!! Holy Schmoly, those are water cooled numbers!!

I was thinking of selling my 68 2.0 AL motor, but i gotta save it now for a build like this one day.

awesome Henry just awesome

Henry,
Is there going to be some sort of knock sensing? Given that the heads are a new-ish design, and 11:1 is getting up there is there a plan if premium pump gas isn't enough?

The hemi chamber design of the early Porsche 911 is one of the reasons the 911 has detonation issues.
This new chamber and relativity flat top piston should minimize the propensity to detonate.
As for fuel: whatever it needs.

The hemi chamber design of the early Porsche 911 is one of the reasons the 911 has detonation issues.
This new chamber and relativity flat top piston should minimize the propensity to detonate.
As for fuel: whatever it needs.

Add on: Back in the IMSA days, rules limited 962 engines to run only one spark plug.
They also had fuel regulations. Porsche chose to redesign the chamber to accommodate the regulations. The head below was the result of their efforts. The heads in this little 2.5 take the concept one or two steps further.
http://forums.pelicanparts.com/uploa...1264285372.jpg

Henry:
Is there any more info to report on this super monster in its new home (track or street)?

I'd really be curious as to how it ended up on the dyno, where they actually run it at, and what kind of fuel it ended up using. It is uber wicked.

Personally, it is my absolute favorite of all your builds.

tadd

I don't really understand..