SHORT STROKE MOTOR Build

[CamBiscuit]

A very big part of this build will be determined by budget - how much do you have to play with?
What sort of revs do you want to pull?

[Cairns888]

$$$$$$$'s that what it is all about. Bang for your buck.
Nothing worse than building an engine and not frightening yourself to death on the first corner. What do you have to look forward too?

Maybe look at car weight first?

If it is super light go for high revving short stroke.
If med weight go for torque like Chris.
If stocko go for a shorter diff ratio/ reliable as possible and light spruce up.

Or just bit the bullet go go for John's option @240hp.

Or chat to Paul about his fire breathing turbo monster.

Oh to be rich.

Good luck

[Terminator]

Porsche built short stroke (66mm) engines for the 2.5ST but changed to LS as there were vibrational issues that caused lots of failures

[CamBiscuit]

I think you'll find the issue was with the long stroke crank, not the short stroke crank...

[9er]

Yeah good on ya Cam..... now let's move on to the C/W crankshaft debate

[reedminor]

Build a 2.7 motor - torque, top end, and not ruinously expensive.... the best of both worlds.

Give me relatively, simple, well proven, drivable power over a motor that revs to 10K....

JR

[CamBiscuit]

Justin, some of us like to go the extra mile just because... ;-)

I looked up my old engine specs which were as follows:

• 2.4 litre 7R case, shuffle pinned, oil bypass mod, turbo pump, case savers, resurface & line bore
• 66mm ‘S’ counterweighted crank , cross drilled, magnafluxed + micro polished
• Pauter rods – balanced & sized
• 10.5:1 JE pistons & Nickies cylinders
• DC 44 Cams
• JB Racing Twin plug distributor
• Supertec head studs
• Heads ported by Rennsport Systems US, racing valve springs & retainers for safety.
• Webers with 36mm main venturis,140 main jets, 160 air jets, 60 idles,F3 emulsions, tall secondary venturis, double phenolic spacers to give extra manifold height. Port matched manifolds
• ‘Cairns’ muffler

I accumulated the parts over time because of cost. The heads alone were $6K..... but they were art. I think the total cost of the engine was circa $40k......but it was bullet proof and would pull like a stream train.

[reedminor]

Yes Cam,

Because you want to and because you can! Reason doesn't come into it.

It's a very fun process.

JrQUOTE=CamBiscuit;72754]Justin, some of us like to go the extra mile just because... ;-)

I looked up my old engine specs which were as follows:

• 2.4 litre 7R case, shuffle pinned, oil bypass mod, turbo pump, case savers, resurface & line bore
• 66mm ‘S’ counterweighted crank , cross drilled, magnafluxed + micro polished
• Pauter rods – balanced & sized
• 10.5:1 JE pistons & Nickies cylinders
• DC 44 Cams
• JB Racing Twin plug distributor
• Supertec head studs
• Heads ported by Rennsport Systems US, racing valve springs & retainers for safety.
• Webers with 36mm main venturis,140 main jets, 160 air jets, 60 idles,F3 emulsions, tall secondary venturis, double phenolic spacers to give extra manifold height. Port matched manifolds
• ‘Cairns’ muffler

I accumulated the parts over time because of cost. The heads alone were $6K..... but they were art. I think the total cost of the engine was circa $40k......but it was bullet proof and would pull like a stream train.[/QUOTE]

[Merv]

My 2.0L list reads quite like that with many of those mods and procedures (not twin plug), and the LN Eng Nickies and JE P's ($6000 for those alone now). It ain't cheap and the specialist engineering is hard to source. But boy does it spin up!

[Cairns888]

Hello Paul

Well sorry to drive you crazy ! I have looked at Dempsey's book witch opened up all sorts of options, hence my interest in what the consensus was. .

Dempsey's book mentioned something about a 2.7 with 964 cams etc etc didn't he?
Is this true or was it something else I read.
I have a 2.7 and very interested in which way you go forward on this build.

[Cairns888]

Justin, some of us like to go the extra mile just because... ;-)

I looked up my old engine specs which were as follows:

• 2.4 litre 7R case, shuffle pinned, oil bypass mod, turbo pump, case savers, resurface & line bore
• 66mm ‘S’ counterweighted crank , cross drilled, magnafluxed + micro polished
• Pauter rods – balanced & sized
• 10.5:1 JE pistons & Nickies cylinders
• DC 44 Cams
• JB Racing Twin plug distributor
• Supertec head studs
• Heads ported by Rennsport Systems US, racing valve springs & retainers for safety.
• Webers with 36mm main venturis,140 main jets, 160 air jets, 60 idles,F3 emulsions, tall secondary venturis, double phenolic spacers to give extra manifold height. Port matched manifolds
• ‘Cairns’ muffler

I accumulated the parts over time because of cost. The heads alone were $6K..... but they were art. I think the total cost of the engine was circa $40k......but it was bullet proof and would pull like a stream train.

Nice Cam. Very, very nice.