So poking around couldn't find anything that kinda rolled through it,,,

2003 996 C4, 3.6 in good shape,, but has 112K on it.
generally well serviced, but thinking ahead, if I were to drive the car to RND
to get the engine refreshed. The big step is what all do I do to it.
Obviously a shiny set of nickeys.. IMS solution,, Baffle & pan
What displacement?? is there a downside to going 3.8 or 4.0?
I would assume that if everything else were stock(ish) that a 3.8 bump is likely a no brainer.

Goal, I want this motor to LAST. I am not looking for super gee wiz power..
Basically at my age (56) I figure if we rebuild the motor with good parts and its well
tuned and freshed,, It should last till I switch to something that doesn't require reflexes or vision..
I wanna be "that" old guy in the Porsche....

 

What are you looking to use the car for? If just a fun car for use on the public roads, the 3.8L will most likely be the better choice.

If you're planning for an elective rebuild, please PM me.

 

Subscribed as im curious about the answer.

Would have thought if you're there go the 4.0? Why not?

 

At age 68(69 next month) I went with the 3.8 Street Performer choice from F6I because I don't plan to AutoX or track it. I have a Civic Type R if I get that itch. I also wanted to keep the car "stock appearing" i.e.: stock intake and stock exhaust. Although not sure if a mild 4.0 absolutely requires those changes.

At my age I guess I AM that old guy in a Porsche...and loving every minute of it!

BTW vision, of some sort is always important in driving regardless of how fast the car is!

 

Having gone from 3.4 to 3.8 on an elective build, I can only add my 2 cents to your question by saying that the increased torque, drivability and power throughout the rpm range is absolutely
intoxicating. I can only imagine that a 4.0 would be even a little bit better !
This is the way the car should have come from the factory. It's also a lot of fun to surprise newer 911's when they can't quite pull away that easily from me.

 

I'm fairly confident, when it comes to the M96, bigger isn't always better. Seems like the 3.8L displacement is the best configuration before needing to upgrade other supporting parts to maximize the increased displacement. Just isn't worth it to do it right financially.

 

This is a great question. Hopefully Jake will interject.

 

^^ This ^^ I just did the same. I'm planning on doing a comprehensive post of my impressions of the entire experience, but suffice it to say in the meantime, I'm mighty impressed.

 

Good thoughts,, I was kinda "assuming" that 3.8 not a big deal, 33 CC's per jug. a 4.0 is about 66CC's per jug
(Approximately)
3.6 = 600CC cylinder
3.8 = 633CC cylinder
4.0 = 666CC cylinder

I have to believe at some point ,, a new Throttle body may be mandatory,
in checking the main players that rebuild these engines, I notice a couple
of the really top shelf ones don't offer the 4.0 as a standard setup.. they max at 3.7 to 3.8.

As much fun as the car is at 3.6 the economical side says don't over do it,,
the right foot side says there is no such thing.. LOL

 

What is the cost difference between the different increased displacements? If it is nominal, I don't see the downside to going as large as the builder recommends... is it an issue of the other systems (transmission, axles, brakes, etc?) that need to be upgraded to handle the increased power?

 

You know what Enzo would say. There is no replacement for displacement.

 

How is that on the track?

 

Mostly head work & camshafts.

 

The LN nickies are the same price for all 3 sizes.. That's what started me thinking..
I've been thinking that if the motor runs out to 150K a proactive refresh might be long term less $$.

I just have to decide if I want to do it myself or pay the freight ..
Since I'm a west coaster its non trivial to get a car or engine to the right place.

 

The “bigger is better” mindset doesn’t work. Often people see a bore size and go for the biggest one, just because it may not appear to cost any more... BUT, it does.

To feed the larger bore efficiently requires optimized port work, which then leads to other changes, that must then lead to other changes. If you simply throw a bore size change at these engines, efficiency drops really fast..

I can build a 4.3, or even 4.4L engine, but those makes up about 10% of what we build, because they require the most amount of other work to optimize the displacement increase. Even when we developed the very first 4.0, and built the first one with Nickies, I seldom went to that combination. In fact, my most efficient engine, making the most power per cylinder is a 3.7L. It makes more power per liter than my 4.0, until we apply Stage 3 tricks to the 4.0

Building an engine means more than making it bigger. The “bigger is better crowd” has always been the easiest to beat. Why? Because they beat themselves.