3.4 to 3.8 bore

[Lyso]

I am going to have my 2000 996 re-sleeved from a 3.4 to a 3.8 L bore by LN. What are the disadvantages of going to the larger bore from stock??I understand you don't need to re-program the computer. I have new rods with ARP bolts. I am not going to track the car. Any additional things that need to be modified like cooling beyond low temp thermostat?

[Jeff Alton]

No disadvantage. You get a stronger more reliable cylinder, better piston and increased performance. We have build quite a few 3.4-3.8 and 3.6-4.0 and a couple 3.4-4.0 (with 3.6 crank/rods).

Get the largest of the M96/97 oil cooler options.

Talk to LN, they are very helpful with other things they recommend replacing, including Fuel Injectors.

[rfuerst911sc]

My 3.4 to 3.8 build starts in about two weeks. Only downside I can see is a lighter wallet 😁

[RStorbeck]

Brand new member here. Just out of a morbid curiosity, how much are we talking about here, ballpark. My 2001 has a lot of miles, mostly highway. There's a bit of a rattle until the oil pressure builds up when I start it after it's been sitting awhile so, I was thinking about doing the bearings anyhow.

[rfuerst911sc]

^^^ A 3.4-3.8 rebuild is 25-30k .

[RStorbeck]

Thank you for the reply.

[Lyso]

You mention "Get the largest of the M96/97 oil cooler options". The only thing I see is a stock OEM. Is the 997 oil cooler larger than the 996 ? Or is there a larger aftermarket that is not a remote oil cooler.

[rfuerst911sc]

Originally Posted by RStorbeck

Thank you for the reply.

I want to clarify , that cost is what a reputable shop will charge for quality work . That includes rework of the heads and using all new internal parts . And balancing all the rotating mass like the crankshaft, rods and pistons . Special coatings applied to bearings . And lots more .

[Jeff Alton]

Originally Posted by Lyso

You mention "Get the largest of the M96/97 oil cooler options". The only thing I see is a stock OEM. Is the 997 oil cooler larger than the 996 ? Or is there a larger aftermarket that is not a remote oil cooler.

997 S cooler. 997 107 025 02

Cheers

[Lyso]

Jeff
I checked out the 997 cooler and it is 15mm higher than the stock one and the rest of the footprint looks the same. As far as I can see the hight is not a problem. The only difference is the o rings. The larger 35mmx4mm o rings are the same but the smaller one for the stock is 26x3 and the 997 o ring is 28x3 . Which one do you use? is the water port larger on the 997 case?
Thanks
C

[Jeff Alton]

You use the O-rings from the motor the cooler is going on, in this case the smaller 26x3 will be used again.

Cheers

[syncroid]

I will second what Jeff said about replacing the fuel injectors.
I think you will like that motor once you get it going. I love the 4.0 in my wife's 2002 C4 Cab!

[Ob917]

Any recommendations in a Southern California shop to take my 997.2 3.6 to a 4.0ish engine? Especially San Diego area.

[syncroid]

Originally Posted by Ob917

Any recommendations in a Southern California shop to take my 997.2 3.6 to a 4.0ish engine? Especially San Diego area.

Call Callas Rennsport
They are in Torrence on Hawthorn.