2.8 GT4 engine

[BK911]

I am doing some research to build a track beast. I am thinking of building a 2.8 for PCA events. What is a common bore and stroke for this engine? Right now I am considering using a 3.6 engine with a 2.2 crank and 98mm bore. Big bore/short stroke, twin plugged 2.8. Will a 2.2 crank fit in a 3.6 case? Can you bore a 3.6 to 98mm? I may need custom rods, anything else besides $$?

Thanks!
BK

[Wayne 962]

Case: 3.0 Turbo
Crank: 2.0/2.2(66mm)
Pistons: 95mm High Dome (Nikasil)
Cyl: 3.0L
Cam: RSR/GE80/906
Fuel: 46 Carbs / high butterfly
Heads: 3.0L (1978-79)
Disp: 2.8L
Comp Ratio: 11.0:1

Short Stroke 2.8L - This is a very rare and unusual engine. Because it uses the 3.0L Turbo case (Euro Carrera), you can use the short-stroke 2.0/2.2 crankshaft. The short stroke combined with the big pistons creates a very quick revving, high-RPM engine (8000-9000), with very little low-end torque. This would be an excellent engine for track use only. Use a high-lift, high-duration camshaft like the RSR, GE80, or 906.

This is one of the sample engines from the "Wayne's picks" table in the new engine book...

-Wayne

[Wayne 962]

By the way, using 98mm pistons would make it more of a 3.0 liter (2985cc).

-Wayne

[BK911]

Wow, I didn't expect a shopping list!

Thanks!
BK

[zuffenhausen]

BK,

Looks like Wayne has the path to a very nice (if difficult to source) 2.8. But to answer your two questions anyway:

Will a 2.2 crank fit in a 3.6 case?

No, the main bearing journal sizes are different.

Can you bore a 3.6 to 98mm?

The bore of the 3.6 is already at 100mm, so you'd likely have to sleeve cylinders to go smaller.

-zuff

[Wayne 962]

I forgot to mention that the 3.0L Turbo cases and 3.0L Euro Carrera cases (same case), are notoriously difficult to find, and highly sought after, specifically for this short-stroke motor combination...

-Wayne

[BK911]

I don't intend on building this anytime soon, more like a graduation present to myself! I'm still in the info gathering stage.

How about custom crank and rods in a 3.6 case? Does anybody make custom cranks?

Thanks!
BK

[HawgRyder]

Someone is reading my mind.
I was just looking at some 3.0 P&C's on Ebay...with the idea of putting them on my 2.0S.
OK...will the cylinders fit the block/case?
Are the studs at the same distance or are they further apart?
I realise that the MFI pump will have to be changed (larger) to give more fuel...and ignition might be a problem too (twin plugs)?
I already have "S" cams...and if the pistons clear the valves and everything else will fit....I just may try this.
Bob

[zuffenhausen]

Originally posted by HawgRyder
will the cylinders fit the block/case?

Nope.

Are the studs at the same distance or are they further apart?

Further apart. 86mm vs. 80mm.

I already have "S" cams...and if the pistons clear the valves and everything else will fit....I just may try this.

S cams won't agree with the CIS SC pistons either. In summary, don't try this. You can take your S to 2.2l, but that's about it.

-zuff

[Wayne 962]

Yup, get the engine rebuild book when it's released in final form - I have a table of engine recommendations in there that will basically give you a roadmap of what will work and what will not...

-Wayne

[poobala]

How much HP for 2.8, the combo you mentioned Wayne sounds like fun I wanna do it .

[Wayne 962]

I'm not sure - I'm offsite right now. Keep in mind that the 3.0 Turbo cases are very hard to find...

-Wayne