2.2ltr engine posibilitys?

[cully]

ive not found anything much on this conversion
looking for pros and cons is it a viable quest?

gti6 Block 86mm bore decked for correct compression
gti6 head
DW12TED4 crank 96mm stroke 60mm mains 50mm big-ends
S16 rods and pistons 152mm rod length 50mm big ends

what are the disadvantages of the Under-square engine compared to the square stroke of the STD Gti6

[powerandtorque]

At the very least you'll need custom rods and/or pistons to do it, as the combination you've listed will have the piston about 4mm proud of the block at TDC if I've done the maths correctly.

(or roughly translated, mashed into the head a few degrees before TDC and with enough compression it would run on diesel if the pistons did clear the head :p )

I dare say though that if you really want to go down the big-capacity 4-pot route then would starting with a 2.2 EW engine not be a better starting point?

There are a few large CC XU builds over on 205GTiDrivers that might be worth searching out - the largest I can think of is a 2.3 litre S16 engine that from memory is based on 88mm pistons and an offset ground 96mm crank with undersized bearing shells.... "Black_Mi16" is the username. There's numerous 2.1 builds, although most of them are 87x88 (2091cc) or 88x88 (2140cc) and the larger 92 and 96mm cranks aren't often used, I assume because of rod-angle or piston-speed related issues.

[Jonny81191]

/thread?

[Piggy]

Well by basic mental maths and thoughts...

It won't be so revvy but have more torque basically? No?

[Niall]

Square engines have a tendency to be very rev happy which is always a good thing if you ask me.
Anthony speaks sense. The XU is a great engine but the EW range is also bloody good, and hasn't been explored as much as the XU. If i was going to start again, it would be with a EW!

[welshpug]

square vs long stroke rule doesnt always work, renault use a 92x83 engine in the clios which go to 7,5k ad dont come near the pugs for torque, especially a mildly tuned 88x85 ew10.

a friend is going ew12 soon, as standard its a bit of a barge lugger making only 160 bhp at under 6k, but it'll be getting a complete standard 180 head and throttle bodies, not a clue what the numbers will be yet...

[Toms306]

Wouldn't it be easier/cheaper to supercharge a standard '6? Or am I missing the point of this?

[cully]

At the very least you'll need custom rods and/or pistons to do it, as the combination you've listed will have the piston about 4mm proud of the block at TDC if I've done the maths correctly.

hmm im guessing the gudgeon pin to piston crown is greater in the S16 pistons than the gti6 pistons then

as my hight stroke calculations show the S16 rods and DW crank combo near identical to the std GTI6


custom rods and pistons =£££ may as well buy a SC kit

[welshpug]

the square short block k20 honda also messes with the concept by being a square 86x86 that goes over 8k and has peak torque at 6k!

then look at the subaru world, 92mm bore 75mm stroke mostly peaking at 6k maybe more, wrc variants going to 5.5k if tgat but making 600nm O_o

[powerandtorque]

as my hight stroke calculations show the S16 rods and DW crank combo near identical to the std GTI6

custom rods and pistons =£££ may as well buy a SC kit

Standard S16 rods and pistons together with a standard 86mm crank results in pistons that sit approximately 1mm below the deck at TDC.

S16 rods and pistons together with an 88mm crank brings this up to zero deck height, 2044cc and compression into the 11's.

Love it or hate it, if you want more power from a '6 engine you can't really beat a SC conversion in terms of bang for buck.

As Welshpug says, you can't generalise on the characteristics of an engine by whether it's over or under square really. Good example is an DC2 Integra Type-R - an under-square engine at 81mm bore x 87.2mm stroke and yet it's an absolute screamer with peak power and torque at 7900 and 7300rpm respectively!

[bashbarnard]

Ohh this is interesting very interesting will be following with a close eye on this

[welshpug]

custom rods and pistons =£££ may as well buy a SC kit

not really comparing apples with apples there, rods n pistons £12-1300, JUST the Supercharger, £1500.

n-a builds are far simpler and cheaper to make reliable, much kinder on drivetrains, also much more fuel efficient if you are tuning old engines never intended for forced induction, look at the newest 911 engines, piss all over anything Peugeot have made for a road car, plus 40mpg.

[powerandtorque]

You talk about comparing not comparing apples with apples, and then in the next sentence are comparing a two decade old XU engine (itself based on a design drawn up in the 70's) to a brand new Porsche Turbo engine 

[welshpug]

I was highlighting the fact that an XU was never designed to be a forced induction engine and be fuel efficient, whereas even a high spec n-a build can be surprisingly good on fuel.

as long as its built and mapped right...


the SC conversions are terrible on fuel, cooling, drivetrain issues.

[Midnightclub]

I always thought if anything (providing they're built correctly, obviously) that an N/A engine that has been turned to forced induction would be better, airways etc.. would be flowed better because an N/A engine needs it more so to make good power than a FI engine. I can see why a S/C engine could be less efficient as it's causing more load on the engine, but a turbo motor should technically be even more efficient

[cully]

Standard S16 rods and pistons together with a standard 86mm crank results in pistons that sit approximately 1mm below the deck at TDC.

outside the box now!

would the above be an option for lowering the compresion for a turbo engine?

[powerandtorque]

What turbo engine? You've still got 10.4:1 compression with a matching S16 head and more with a GTi-6 one.

S16 pistons are flat topped and not slightly dished like GTi-6 (or with a shallow bowl like the detuned J4R engine) hence still fairly high compression despite sitting 1mm down the bore.

The 2.0 8v turbo (XU10J2TE) pistons have a sizeable dish in them and the chambers in the head are a fair volume as well, hence they're down in the 8's compression wise.

If you particularly want a low compression 16v for forced induction then I imagine that using a J4R bottom end with an S16 head would give lowish compression somewhere in the 9's (CBA to work it out)

[welshpug]

roughly 9.92 with 1.2mm gasket and no head skims.

[Lwilliams]

Not sure people that are building tb engines are to worried about economy mei?

[Piggy]

Just boost a jp4 cully

[welshpug]

Not sure people that are building tb engines are to worried about economy mei?

I'm not a trackday hero, so I don't want my mildly modified french heap to be drinking fuel....


a healthy engine lasts longer too, when you're racing if you can carry less fuel you go faster...

[Lwilliams]

Most people who put bodies on their 306 don't use it as a daily though...

I never said a healthy engine doesn't?

[welshpug]

You'll find most do far more miles off the track than they do on it!