Jakerx

i just thought step it up a tiny notch with boring it a bit...

fast951

I agree with David, DO NOT SLEEVE a GOOD BLOCK!!!!! If you must sleeve, find a bad block and get someone familiar with the 944 sleeving process to do the job (Chris white is a good source).

David Floyd

Maybe I don't quite understand, you have a 3 ltr block, your going to bore and stroke it ??? How do you stroke a 3 ltr ?

pieball

And when they stroke the 3.0, why do they only go to a 3.1?

David Floyd

I thought 3.1 ltr was achieved from a bored and stroked 2.5 block ?

pieball

Hey wait a second, I'm asking the stupid questions here!

David Floyd

As I understand it, if you start with a 3 ltr block and crank, bore and sleeve to 107 mm = 3.2 ltr or bore and sleeve to 111 mm= 3.4 ltr.

Then you have to source piston/rings, headgaskets and so on.

450+ rwhp not enough with the 3ltr ?

Jakerx

omg i feel so stupid. i was thinking one thing and typing another because i got confused when someone p-med me.they were telling me to stroke my 2.5L block and since i was posting on this thread in another window things got messed up.

but actually, i have another question, can i just bore out the 2.5L block and stroke it with the 3.0 crank? are the cylinder walls very different with a 3.0 block?

NZ951

Yes you can bore and stroke the 2.5 for a variety of displacements. It really depends on your budget!

Jakerx

well another question really, is boring out a 2.5 block to 106 or 107 mm any different than boring a 3.0 block to 106 or 107? i'm thinking in regards to strength of the cylinder wall and running high levels of boost. any opinions appreciated...

David Floyd

3 ltr block is a much stronger than 2.5

Jakerx

so then who would be the best supplier regarding acquiring an mls head gasket for either a 106 or 107 mm bore application?

David Floyd

www.vitesseracing.com is where I bought my 106mm MLS headgasket

fast951

Just a suggestion here, and it's intended to save you all type of aggrevation and might save you a $ or 2.

Set your goals and your budget. Talk to someone that has been down this road before, do not start the project till you have the complete budget for it. Go to someone that has done the sleeving before, you will pay for their expertise but you will do it once and you will enjoy the car.

VERY few companies have sleeved the 2.5 or 3.0L blocks with success. It's not something you want to go cheap on as it'll cost you more later. Do not be surprised to spend $10-15K to get a good running engine (sleeves, rebuild, Turbo, engine control...).

Due to the Alusil wall thickness, it's not a good idea to bore them to a much larger size (0.5-1mm probably the max). To get larger bore you will have to sleeve. If you go "dry" sleeve the 3.0L is stronger as the cylinders a siamesed. If you go to MID sleeve (Cheris White had a thread on it not so long ago), the 2.5 or 3.0 will be "about" the same (strength wise) as the cylinders are removed for both.

David Floyd

Yep ! It all adds up quick....