TRP951

I think i heard 111mm bore was just about pushing the limits of the 968/s2 block and with the broadfoot stroker crank it would make a 3.5-3.6 engine which would be monstrous. Hmm with a vitesse turbo and software i wonder what numbers you could expect......

lleroyb

In '89 Jochen Freund (944 Senior Project Manager said "We talked about a 3.2 liter engine -- the block can actually go that far -- but I don't think you will ever see it."

On the other hand he didn't say 3.2 was as far as it COULD go.

Lou

inactiveuser92616

the chassis can handle it... Renegade Hybrids drops in the LS1 corvette engine.

Jakerx

i believe 107mm is the biggest mls cometic head gasket currently made. however, i would stick with 106 mm. 3.3 is not possible. i would go with 107 ONLY if you were utilizing darton wet sleeves. dry sleeving would be a big no-no there in my humble opinion

also, it's actually like 3.07 or something when you say the "3.1L" 951's.

Campeck

jake. i just finished saying perry had a 3.5L block.

and not only was it sleeved. it didnt crack or anything like most sleeved ones do.

Porsche-O-Phile

A properly sleeved block will not crack.

Anderson jobs excepted of course.

evil 944t

3.2 is very easy. Getting a crank stroked is very easy too. It just takes research and finding the right place. There are places that will do it that are not "Porsche tuners". I won't give out names as it might hurt some feelings of people on the board who make a living off this stuff.

hosrom_951

Tim: Boring to 111mm is not a good idea, it will not last long. Sleeved blocks bore out to 112mm before installing sleeves (look for Chris Whites posts on MID Sleeves).

BlueRiver86

Yeah, some pretty big engines have been shoehorned into 944s.

Scott M.

Weren't the DOOM motors a 3.6L block?? 1200ish hp.

Maybe someone can talk Norwood into making a few more.

jabbadeznuts

nine-44

I recall Hutley had 3.1 3.2 3.3 and 3.4 advertised on their site.

Robby

The Broadfoot cranks are the only way I know- this plus a 106mm bore for a 944- the 944 is 100mm bore already & 968 @ 104mm- JME has made many 3.1L 968s by boring to 106mm... I have been told that these are the practical limits though... Someone listed measurements a long time ago & said the 944 walls were only ~11mm & 968's were a little smaller- not sure how one could go to 111mm then, b/c, that would be all of the wall itself...? I don't know any of this myself, just quoting... I'm looking into the MID sleeves for 2.7L myself... Chris White seems to know this stuff very well...

As for chassis being able to handle this- well, that's a loaded question... Ask dif people how good our chassis are & you'll get plenty of dif responses... Chris Cervelli used to call them flexi-flyers... No 944/968 chassis will even compare to an E36 M3 chassis or higher (this includes MANY newer cars) in torsion or bending... Every few years, each new model of any given car will increase the stiffness of their chassis by a huge percentage... does this mean that we were driving cars made of Nerf before...? Does it mean that we have to always have the newest possible chassis to go up in HP? Ask Bob Norwood... His Doom II WAS just over 1000HP.... Gomes has been supposedly playing w/1400- not sure how these engines will do reliably on the street, but, it does show the limitations of development at this point... Personally, IF I hda the money to go to a monster engine in the ~700RWHP/TQ range, I would jump all over it- would increase spring rates, sways, & possibly brakes, etc, but, still... would not worry about the chassis until I had too.... Just be sure to keep us informed if you DO try something cool like this.. ;-)

evil 944t

A 3.1 is a very safe design. 3.2ltr is fine then you need to start getting into stroked cranks.

Of course all of these are $10k+ motors + turbo + EMS+suspension+ Brakes+ LSD+ Rims and tires.

One really needs to think if they really need this kind of power. Traction is a big deal over 400rwhp and 275's are probably the largest you can fit without mods to the fenders.

Robby

Evil- when you say 3.1 & 3.2L's are safe & "then you need to get into stroked cranks" are you saying you could do enough bore to get those #'s by themselves??? I mean, a 3.1L from a 944 block would need 112mm bore & 3.2L would need 114mm bore... I'm assuming you mean that 3.1 & 3.2 is from combining the 3.0L crank w/106 or 108mm bores...? 108mm sounds pretty extreme, but, I'm sure it's possible. Also, have you (or anyone) ever heard of a 3.0L block being taken from 104mm to 108mm before? I'm assuming it's possible, but, the cylinder walls in 3.0's is supposed to be a tiny bit thinner- I've seen 944's listed being just under 12mm & 968's as being ~10mm IIRC....???

The higher the Power to weight ratio you get, the more traction becomes an issue, for sure, but, there are many things you can do to help fix this prob, from suspension, to lower boost settings in lower gears, to tires (size & type), better LSD (Torsen maybe?), etc... This can all get expensive, of course... A fully-streetable 951 w/400RWHP/TQ means each pony would be carrying a little more than 8lbs- at the wheels... This is using test weight too... Viper GTSR is about that but at the crank... That's getting pretty strong. There are people who have gotten much larger than 275's on 944's though, but, like you said (evil), might need fender mods... Danno has some good info on how to get more fender clearance than even the Turbo S (which has factory rolled fenders) on his website...

As for 3.1 & 3.2L , etc... I'm very leary of anything above a 104mm bore for 944... I can't argue all of the various technical points, but, can only say to look around... I mean, how many street cars here have stood any length of time, reliably, w/anything more than 104mm bore? Hell, for that matter, w/ANY bore?? The tried & true way is still the 3.0L crank w/stock bore, giving 2.8L & getting more low-end. But, there are many on this list who have made quite a case for larger bore... Are the MID sleeves limited to 104mm or 106mm? Garrity Repta used to like 104mm + 3.0L crank = 3.0L, but, he had some serious HG prob's on Rob Langley's car, using copper HG's- Powerhaus & Cervelli said not to do this as far back as 1997... Anyway, I'd like to hear from some more guys w/overbored motors that have lasted awhile- I want to find the best method IF I'm going to do it... Seriously leaning towards MID's... I could go all day on this subject- so many variables & questions, etc...

Does anyone know how much one of those Broadfoot cranks would cost???