Now that my 2001 Boxster S is having great suspension and brakes (i.e.: PSS9, adjustable low arms, large Brembo rotors with 6 piston calipers).

The OEM engine is still doing good (sure, it has LN Dual Ceramic Pro IMS, low temp thermostat, 4” under drive pulley, new water pump, etc..) and performance (Afe) air filter followed by IPD intake tube, 74mm Tbox, IPD plenum, ..and then to a performance tuned tubes header going into 200 cell cats, followed to secondary 200 cells cat too. (Yes, you got it : all fine during 90 dB normal days in Laguna Seca)
All looks good, ..but, I would love to have some more juice !
Engine runs fine, ..after currently more then 1300 miles in Laguna Seca, ..and some other hundreds of miles in Sears Point.

Looking at the web site of Jake (Flat6innovations.com) I can find for a 3.2 Boxster S, the “Stage 2” solution is : 986 S (2000-2004) Boxster S 3.2L factory engines have increased displacement to 3.6L

If I read the web site of Charles (lnengineering.com ) I can find that a 3.2 to 3.8 Nickies inc. Boxster 101mm do exist and is available.

My big question is : Why Jake seems to not willing to use the 101mm bore option, available at LN to build 3.8 engines ????
OK, the truth with 101mm bore, you are at 3749 cc (3.749 liter), ..not exactly 3.8 !

I would love to understand that.
For my point of view, “nothing beats displacement !”, so why not going to “3.8”, and this simply by the choice of Nickies 101mm, instead of going to 3.6, using Nickies bored to 99mm (here the true number is 3.579 liter !) Btw, the prices of these Nickies (bore 99mm and bore 101mm are the same !)
(Being Swiss, I could add (joke), the Nickies should be like the cheese: if the holes inside are larger, you have less cheese, ..and it is cheeper, because cheese is sold by weight !)

Back to serious:
All the above taking in account that the crank stay as original, i.e.: in the case of the Boxster S 3.2, the stroke is 7.8 cm.

We may add that an S 3.2 has a bore of 9.3, or, the exact displacement is 3.179 liter !
I was thinking that the reason could be that Jake may not like so much to have 101mm of bore, leaving “little meat” between the cylinders, ..but if I’m right, the 2014 GT3 had (sure, it is a different engine : Mr. Hans Mezger, ..not a M96 !!) 102mm bore, ..with a stroke a little bit smaller (7.75cm instead of 7.8 !), ..that gives a displacement of 3.799 Liter !

Who can explain to me why moving up from a 3.2 into 3.6 would be better than 3.8 ?
Thanks in advance.

 

From a thread here:

http://pedrosboard.com/read.php?7,15110,15110

A cut/paste from Jake's comments regarding bigger engines:

"The majority of these engines have gone into 996 platforms primarily because we must base them from the 3.6 liter 996 or larger foundations to achieve this level of performance. We do not carry out "engine conversions" and require that the reconstructed engine thats being installed also be the customer's engine (unless it was wasted due to a huge catastrophe). For instance a 2001 Boxster S came equipped with a 3.2 liter, 5 chain engine. The engine we have developed for that application is 3.6 liters and has three stages of tune, the least making 290HP and the most making 345HP. As we see more and more of the 06 and later cars we are working with more highly developed factory engines that are also larger @ 3.4 liters. With these we can easily perform some magic to see a 400HP number (because of the crankcase used) and the engine can be installed with no conversion required.
To answer the question, what has limited the number of 400+ HP engines we have created has been my desire to take them on and the fact that I refuse to work with engine conversions as applications for them. We have produced 10 of these engines since 2009 when the technology that allowed an engine this large to be created was completed. Some have gone to the 996 application and others to the Boxster for later cars. My engine program levels the playing field between Boxster and 996 and my version of the engine as a "big bore" is the same for either one internally.

We have spent the majority of our time developing and applying our medium displacement 3.2>>3.6 and 3.4>>3.6 engines along with the 3.6>>>3.8 packages in stage I and Stage II where ECU flashes and other bolt ons are not required. A truly developed 4 liter engine starts at a figure that cost more than most any older Boxster can be purchased for today, but that doesn't stop most of our purchasers that have developed vehicles that can actually use this sort of power. Many of these engines have been sold to international purchasers.
I have a few purchasers who have gobbled up these exceptionally powerful engines for Boxsters but they are not posters. If you want to get in touch with them, just email us.
Bigger is not better."


And in reply to a post: "There's no substitute for cubic inches."

i.e. size matters"

Jake had this to say:

"Then why aren't all of us driving 10 liters?
I would much rather have a better built, more efficient medium displacement engine with a broad power band as most anything I can think of. Based on port flow and shape studies that we have carried out the M96 cylinder head cannot adequately feed an N/A 4 liter engine. The M97 cylinder head has dramatic changes that can sustain this on the 3.8 liter factory engines and these even outflow the new DFI port in a back to back comparison that we carried out a few weeks ago. I included the port characteristics in my most recent Flat 6 newsletter.

There is no better way to create a worthless engine than to make it so large that it's displacement exceeds the capability of the cylinder heads. That said, very few factory M97 base engines have the proper characteristics to sustain a 4 liter combination effectively."

 

well said.
it's not quite as simple as "bigger is better"

 

Thanks Macster,
I can see good sense in these answers, particularly in the one that says that the displacement has to have a "front end" (the head) that can serve it accordingly.
...but these answers have 7 years of age !
(I doubt at this time, LN had on the market 101mm Nickies available !)

About serving, it is interesting to note that an IPD (with 74mm t. box) brings a difference of air volume from the OEM intake (68mm t. box) that is quite substantial (18%), ..true, if the pressure remain the same !
I want to add from my observation that the OEM headers (exhaust from heads, to primary cats out) is probably the worst design that I ever seen (in term of air flow). You do not have to be a Nobel price in air flow to realize that this design is quite horrible. It is true that I read many time, that when Porsche did adapted the M96 3.2 liter engine from the 996 into the Boxster, one of the major change required by this mission, was to change the headers, (being in reverse direction, as the engine was in the center).

I heard few times that taking the engine “as is” from the 911 was the goal (economics) but marketing required that power had to be reduced, in order to not hurt the 911 market.
So, a bad exhaust with a “matching” ECU code ..did the work : To move down from 296hp (996 3.2) to 250hp (Boxster S 3.2).

After looking at the market, and not found what I was looking for, I worked, making a test to build a set of cat equipped headers from a balanced high performance direct (no cats, “competition”) header.
To do so, I played it “simple” : these high performance headers have 3 tubes, that comes down to one, and then after being on one, they go to the “joint” (a plate with 3 bolts) to go to the pipe that carry further “down” the secondary cat, ..before entering into the rear muffler.
I had the vision to use a 200 cell performance cat ..to do the 3 to one job, opening the intake of such cat up to a “circle” that would match an external circle that can include the 3 exhaust tubes before going into one !
Using steel laser cutter local facilities, I got a round steel pieces having internally 3 holes that matches positions and diameter of the incoming tubes, and with an external diameter that can be soldered directly to the cat.
The other side of the cat keeps having its “natural cone”, ..that can go to the “3 bolts” plate to join the OEM back tube, keeping dimensions and positions, ..to stay 100% compatible and would enable back to original or something else, ..if my idea would show to be wrong.

The result was more than I would expected ! First, noise was very close to original, no substantial noise addition ! (well, such idea would most probably not be successful commercially, as most of the people like noise ! (I’m the opposite : for me, making noise is just trying to attire attention, (..like babies does when they can not express their self), and also, loving to be in Laguna Seca, it is a must for me to be below the 90dB restriction too.)

Note that I also changed also the secondary cats against 200 cells performance ones, all to keep low noise, but the best possible flow.
Well, I can say that the feeling of the engine (I did not put it to a dyno yet) is extremely different, having a good intake line together with a good exhaust makes an important difference.
Not the noise. ..I’m talking about the “butt” sensor.
This is the “only” modification that I did on the engine side (except the classic “safety ones”, (that do not enhance any performance), like LN ISB, new water pump, low thermostat, 4” underdrive pulley, oil sump extension, metal “doors” oil baffle, magnetic oil plug, ..)

But, altogether, my engine did pass the “100’000 km” line (more than 65’000 miles), and, beside thinking on an eventual current engine “reflash”, I think that now, a good preventive rebuild would be great.
I even think of buying an additional engine, in order to get a rebuild, without loosing the use of the car while doing so !

Or, still the question open, going to 3.6 ..or 3.8 ?

..Keeping on mind that some of this engine architecture have been up to well over 4 liters, and also not forgetting that many had Turbos, ..that behave like having larger displacement !

 

There's a guy trying to sell a Boxster on Craigslist in Phoenix. Been for sale for awhile. Anyhow it's turbo charged. It would seem to me that this would be a good route to explore. Couldn't be as expensive as the $25 to $30 grand for a 3.8 (my estimate.) And as the power would come on at mid and high RPM, it would be less likely to twist half shafts and destroy gears. Still would require a rebuild, to detune and reduce CR to a point to reduce detonation.

I had an 85 Kawasaki GPz 750, it would lite up at 3000 rpm, and then take off. The engine was a stock 750, but way overbuilt to take the punishment of turbocharging. F***ing thing was a monster.

Here"s the Turbo 2000 S. https://phoenix.craigslist.org/nph/c...855202989.html

 

I own both a 996 and 986S. It’s utterly amazing to me how the Boxster engine dies at 5,000 rpm compared to the 996 engine. The exhaust and intake are awful in this application.

 

I used to think that there’s no replacement for displacement, which is true to a point. So I installed a 400 cubic inch engine instead of a 383 cubic inch because I wanted those extra cubes. It was a bad decision, as the 383 would have actually produced more power, more reliably.

Everything is a tradeoff at some point. I’d rather have slightly lower displacement and be able to rev the engine a bit higher.

 

@murphyslaw1978 : well, but in your example, between these 383 nd 400 :
Did the :
head,
valves,
cams,
compression
and etc..
where all correctly optimized on both cases ?

In my opinion, an IMPORTANT REASON why the displacement is limited in ALL racing categories, is simply because higher displacement makes an easy difference !
Or, easy rules to equalize power is to limit displacement.

 

Right, if all things are equal, then displacement should win.

But in my 400 vs. 383, the block design was slightly different where cooling in between the cylinders caused ovaling of the cylinders over time for the larger engine.

With these Porsche engines, I suspect there are trade offs that cannot easily be overcome, which is why keeping displacement a bit lower reduces those trade offs.

 

The responses from Jake may be 7 years old but the engines have not changed since he made his response. The 3.2l engine from the Boxster S or the 3.6l engine from the 996 hasn't magically developed better intake, heads, ports, etc, to accommodate the air and exhaust flow a larger displacement engine would require.

You can always reach out to Jake and ask about going big displacement and see if he feels the same way now as back then.

Kind of jumping around, sure one can go the turbo route. My 2003 996 Turbo 3.6l engine produced 420hp (with a 9.5:1 compression ratio). Had very large and intricate intake system, with air to air intercoolers which dropped the very hot intake temperature way down. (My Hellcat has a water cooled intercooler which also brings the hot intake air temperature way down.) (My Mini JCW 2.0l engine produces 228hp with its turbo charger setup. If one scaled that JCW engine up to 6.2l it would produce 706hp, just 1hp shy of what the Hellcat engine produces. Amazing power output from a 2.0l engine. (By way of comparison, the 2.7l engine in my Boxster made 217hp.) Don't know how much the JCW engine intercooler cools the intake air -- have not had the time to data log the engine's telemetry -- but as much HP (and torque) that engine makes the intercooler must be very efficient.)

Anyhow, the Turbo 3.6l produced more HP than my 2006 Pontiac GTO with its N/A 6.0l V8 (400hp). So one can get "big" HP from turbo-charging but that Turbo engine was markedly different from the N/A 996 engines. The basis of the Turbo engine is a race engine which with better rods could reliably produce 500hp+ in race trim.

Practically speaking with something like the 3.2l or 3.6l N/A engines with their high compression ratio one is limited to maybe 5 to 6psi of boost. The Turbo boost limit was nominally 0.7 bar (10psi) but under hard acceleration at higher elevations I saw 0.8 bar (11.6psi) even 0.9 bar (13psi) for some length of time, enough time to know the readings weren't spikes. Can't recall off hand how much boost the Hellcat supercharger supplies nor the turbo on the JCW.

I have no experience with the 3.2l N/A or 3.6l N/A engines (and just 4 months of experience with my 2008 Cayman S 3.4l N/A engine way back in April 2009) but with my 2002 Boxster 2.7l engine I had 15 years and 317K miles of experience and the engine pulled good right up to red line, 7200 RPMs if I recall. The engine's breathing wasn't too shabby. That was one sweet engine.

 

I fully agree that these engines and heads are older than 7 years, ..but the parts have evolved.
For example, 7 years ago, we did not had the IMSB ceramic double row pro !
And, the LN Nickies 101mm for M96 was not existing either !
New modern material for critical component like the connecting rods are existing now !
Think that now you can save a strategic amount of "unsprung" mass by using Titanium bolts on your wheels, 7 year ago, this was reserved for "rockets" !
To better illustrate this : To make my car lighter, I use (successfully) since few years a Lithium-Ion battery (about 4 pounds), ..instead of the OEM battery that weight 38 pounds !

We have to realize that in 7 years, a LOT of things have changed !

Sure, the heads are a limit in the flow "chain".
But today porting heads for m96 is "common !
And today, things like IPD plenum are also common !

I would just hope that Charles (from LN) would chime in, and tell about these 101mm Nickie form M96 !

Or somebody that bought and installed already a pair of these "wide" Nickies
I'm ready to bet that a few flew over here already, laugh a lot, ..and stayed silent !
If you play "this game", many keep the status of "sleeper". (By the way, I understand this more than very well )


Or : Yes, the core of the engine do remain the sames, but a LOT of other things have changed.

 

If you are interested in a larger displacement engine give Jake a call and ask him what he has to offer. I seem to recall he can supply a larger displacement engine -- which suggests he has solved all the issues associated with the larger bore size -- but requires the customer sign a waiver/release. But as you pointed out the quotes of his I posted are from 7 years ago. It could be he has come about 180 degrees and now big is where it is at.

Or check out a recent issue of Excellence for ads offering big bore Boxster/996 engines or big bore kits.

 

If you are really after displacement, why not a 6L GM V8?

 

with enough money you CAN turn your Boxster into a Camaro!

 

Wait, ..I'm not looking or thinking about going "extreme". Sure, I have even seen people putting a V8 into a Miata !
The person that "laser cut" parts and did solder my roll bar is a known specialist to put LS engines in any cars (his own car is a Datsun 510 with a BIG LS, see :
http://www.speedhunters.com/2019/02/...s-powered-510/
Being often at his place (Marcus Fry Racing), beside his Datsun 510, I saw LS's in RX7, in Mercedes 4doors (ex diesel), and etc..
This is not a plan for the Boxster.

I'm simply taking note that in the choices of Nickies for M96, ..there is a 101mm offering !
According to what I read above, it could be a stupid choice, ..but, I'm still surprised :
If Mr. Charles Navarro has this choice together with other M96 bore options, I can only think that there is a (good) reason !

I can also read this text on his site :
"LN Engineering recommends IPD Plenums paired with GT3 throttle bodies on all engines M96/M97 engines fitted with Nickies sleeves with displacement increases up to 4.2 liters to help take advantage of the increased displacement and performance Nickies offer."
(Here : https://lnengineering.com/products/ipd-plenums.html)

This is not 7 years old, this is today !
(Btw, I do not think IPD had plenums for M96 7 years ago !)