Anyone actually do the 3.8L engine rebuild?
#1
Anyone actually do the 3.8L engine rebuild?
Making a decision now on 3.6 engine rebuild vs. 3.8 upgrade. I did a search and it seems there are many folks that contemplated it but I didnt see anything with a post-rebuild update. The only downside I can see from doing the 3.8L is that my car would be hard to sell later (should I wish) to anyone who would race it. I suspect this car is a keeper so I'm heavily leaning toward the 3.8L for the torque. I believe the HP difference isn't that great. I assume the reliability is the same going forward. Thanks for any input.
Ramon
Ramon
#2
I definitely would. The additional cost is so small compared to all the labor. It would kind of be a shame If you didn’t at least benefit from some increased horsepower and torque. That is, unless the car is some collector piece you’re gonna try to sell at a premium at some point soon. Otherwise, I say go for it. Also, I think member luisGt3 did a 3.8 in his and likes it.
#3
Although it would be somewhat measurably "faster" with the 3.8...it seems that as of late many people appreciate the "character" of the 996.2 3.6 motor over its absolute output.
I've read comments on the forums and on BaT that the later 3.8s or 4.0s, although torquier and faster, don't have that "rush" of the 3.6.
No personal experience to verify but perhaps something to consider...
I've read comments on the forums and on BaT that the later 3.8s or 4.0s, although torquier and faster, don't have that "rush" of the 3.6.
No personal experience to verify but perhaps something to consider...
#4
Although it would be somewhat measurably "faster" with the 3.8...it seems that as of late many people appreciate the "character" of the 996.2 3.6 motor over its absolute output.
I've read comments on the forums and on BaT that the later 3.8s or 4.0s, although torquier and faster, don't have that "rush" of the 3.6.
No personal experience to verify but perhaps something to consider...
I've read comments on the forums and on BaT that the later 3.8s or 4.0s, although torquier and faster, don't have that "rush" of the 3.6.
No personal experience to verify but perhaps something to consider...
#5
Thanks for the comments thus far. Interesting. Would my R&P gear change the "feel" of the 3.8? I suspect it wouldn't as it would merely spend more time in the upper end of RPM spectrum. I didn't ask but I wonder if the rev limiter is reduced a bit?
#6
Do you already have a shorter R&P? 4.0? Or 997.2rs 3.89? I have the latter and love it, but truth be told, If I knew I was going to be doing a 3.9 I probably would have left the gearing alone. With the added power I don't feel like the shorter gearing was really necessary. With the stock 3.6 though, I freaking loved it and highly recommend it. Have you driven a 997.2 gt3 or rs? I drove a buddy's 997.2rs (with the 3.89 r&p) back to back with my 996 gt3 (which at the time had the rs flywheel, 3.89 r&p, and stock 3.6l engine), and the rs did not feel as "eager" to rev as my car. Hard to explain, but it was like you could feel the extra heft of the larger pistons (even though that sounds impossible). There is just something different about the character of the 3.8 cars. That's one reason I love the 3.6's (996 and 997) so much.
The following 2 users liked this post by ScottArizona:
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changster123 (08-28-2024)
#7
On my 996 I've had a 3.6 Mezger rebuilt into a 3.8 and later into a 4.0 with 106mm Mahle Motorsport pistons / liners. The 4.0 kit is much more trick from a tech standpoint. Having run both set ups under heavy track use for many hours at some high hp levels, I would 100% recommend the 4.0 Kit. There is simply no comparison in both power and smoothness over the 3.8 kit. The 4.0 kit uses the stock 76.4mm GT3 crank and does require minor machining of the case and water jackets but it's well worth it with the increased responsiveness of the engine with the larger displacement. The displacement actually works out to a 4.05L. Something to think about if considering an engine build. I was actually not very impressed with the 3.8 kit on my 996 and and my stock 7.2GT3 3.8L engine leaves a bit to be desired in smoothness as well compared to either a 3.6 or the 106mm 4.0.
Last edited by powdrhound; 12-08-2022 at 03:53 AM.
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changster123 (08-28-2024)
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#9
Edit: Got this from the sharkwerks site:
“ the character of the motor is amplified and even extended by an additional 400rpms. Utilizing our light-weight Piston kit we are also able to improve upon the already-quick throttle response and revs to an even more lively level”.
https://www.sharkwerks.com/engine/p4217-sharkwerks-3-9-liter-engine-upgrade-for-996-997-gt3-rs-SHAE230
Last edited by ScottArizona; 12-09-2022 at 07:35 PM.
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air993 (12-11-2022)
#10
Lots depends on the type of supporting hardware (i.e. MOI of the clutch assembly and the quality of tune more than just the small difference in displacement between a 3.8 or 3.9 which is relatively insignificant in the scheme of things.
Last edited by powdrhound; 12-10-2022 at 01:36 AM.
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air993 (12-11-2022)
#11
Great input from all. I seems to me that I need to evaluate the trade-off of a smooth revving 3.6L vs 3.8 with an additional 12 ft-lbs of torque. I may be leaning to keep the 3.6. A refreshed engine will already feel like I got a boost in performance. Although the 4.0 option sounds great, I'm not inclined to pursue such an expensive path.
#12
Great input from all. I seems to me that I need to evaluate the trade-off of a smooth revving 3.6L vs 3.8 with an additional 12 ft-lbs of torque. I may be leaning to keep the 3.6. A refreshed engine will already feel like I got a boost in performance. Although the 4.0 option sounds great, I'm not inclined to pursue such an expensive path.
can’t go wrong. And I think you are right that you’ll feel a nice improvement with everything new. Plus, now cool that you will essentially be the first owner of the new engine!
#13
-Scott
#14
Total out the door build cost on any build, a 3.6, 3.8, 3.9 or 4.0 will vary greatly depending on what all is done while the engine is out. To get an idea, speak with several builders and get quotes on what you are considering and that will give you a better picture of the final number depending on how crazy you want to go.
Last edited by powdrhound; 12-15-2022 at 02:43 PM.
#15
interesting info above. I recall being told years ago that the jump in price to make a 3.6 into a 4.0 was fairly significant as opposed to a 3.8. I guess it would be if you use the 4.0 crank!