ntgbrl

I called and emailed LNE asking the following question but didn't get a satisfactory answer (The person on the phone had no information other than prices, and the email response was a copy/paste of info on their website), so ill ask the community for their opinion.

I'm getting into the rebuild of my 1999 C4 with 150k miles on it (IMS paddle wearing out so a full rebuild is in order). LNE offers three options for resleeving the block, stick with the 3.4 or increase the bore to 3.6 or 3.8 liter displacement. The prices for all of the options are basically the same, so what are the advantages and disadvantages to each option? I wasn't planning on hot rodding the engine for this rebuild, I'm just looking for a reliable engine that'll last me for at least another 150k miles, but if the cost for upping the displacement is basically the same then why not?

Houtx996

another option is by a short block from Porsche, if all you are looking for is reliable and another 150k. https://rennlist.com/forums/996-foru...tallation.html

GC996

Comes down to if you want more power and more cylinder durability with the nickies versus small block without nickies and more power.

4Driver4

When I rebuilt my 3.6, I went 3.8.
4.0 was a consideration, but more than one reliable source told me that the factory ECU can adapt to about a 10% displacement change without needed a remap. 4.0 was pushing my luck, I felt, so I opted 3.8 to get a little more pull but to still be in the range.
I'm happy with the result.

Dr_Strangelove

What I was told during my engine rebuilding class (Knowledge Gruppe,) about the 3.6 M96 engine to a 3.8 is that the cams and everything in their stock form work very nicely, but with the 4.0 there are some adjustments should be made to achieve the ideal output from the engine and this is not something you will achieve "out of the box" with the components from a 3.6. It was explained to me that with the 3.8 you get the "out of the box" performance with the 3.6 components.

I have personally done a 3.4 to 3.6, as my home garage project after my class, and that was because some of the components had already been purchased for me by the PO of my project car who had bailed on his own "project" of a car. I would love to have it confirmed by a pro, however, that a similar scenario with the 3.4 would occur moving to 3.8 as a 3.6 would moving to 4.0. Perhaps some of the stock cams, etc, are not going to be timed ideally for the job of achieving maximum output, even if it is possible to use the stock components to complete the job.

TexSquirrel

I'm wondering if the DME in the 99 could handle even a bump to 3.6.
A 2000 or 2001 probably wouldn't have any problem, but the 1999 DME might have problems, and finding someone to tune it might be troublesome.
At least with a 2000 or 2001 should you run into ARF issues, you could find a tuner.

158Sierra

If I remember correctly, if you change a 3.4 to a 3.8 by using the 101mm pistons you should also upgrade to the forged rods too.

jobyt

DME on a '99 3.4L has no issues with a bump to 3.8L. OP has a C4, so with the e-gas, it will have a wider range of options (bigger throttle body, software optimization tunes) than the C2 with the cable throttle.

Type65

The PO of my 3/98 had the engine rebuilt to a 3.6 with LN Nickies after suffering from D chunking. I have all of the documentation and there is nothing that suggests any ECU tuning and the car runs and drives great. No issues what so ever.

Edit: My car is a cable-throttle C2

Sam-Son

VERY Interesting

This all makes sense now. A friend has a 99 C2 which received a later 3.6 engine. Bolted it in, reused the cable throttle, just plugged it in and everything just worked.

I've always wondered how that could be and now it makes sense. If I recall Jake doesn't tune the ECU on this less extreme builds.

996C438

I am in the process of building a 3.8 Stage II for my 99 C4 ......... small world 😁. Talking with Jake and Jud at FSI we decided to go the 3.8 for a variety of reasons . The most important to me is they have built so many 3.8's and it is a rock solid build . Reliability and great performance that is hard to beat .

I am also going with big valve heads with custom port work via Len Hoffman . I am not trying to build a race car , just solid street performance . I hope to have the engine built in June but my pacing item is the billet rods . Good luck to the OP regardless of what direction you go .

Flat6 Innovations

Make the decision based on what you can afford for head work. Bigger isn't better unless the entire engine combination, and subsystems are coefficiently altered.
Its all in the combination, displacement doesn't make the power. The combination is what separates these efforts, and the combination is what takes years to perfect. The combination goes right down to camshaft timing, and stock timing that is set with jigs and etc from the factory is only adequate for "stockish" engines.

Any time I add bore, I add port work. Finding the balance is what's tough.
I cover this in my M9X Performance Classes, to the letter.

BossAngeles

I have a 1999 and had L&N bore and nickel me to 3.6 and I'm a passionate, but daily driver. LOVE how it all runs and nor regrets and that was 40K miles ago! Otto's European in Venice, Ca did the final and updated parts to 04. Love the results.

Emefef

I did 3.6 to 3.8. As noted above, that didn't require any other significant upgrades or remapping.

wildbilly32

"My" engine guy reconstructed mine from a 3.6 to a 3.8. When he turned it over to me he said, in essence, "Go drive it..."

It doesn't matter to me how he did it because it turned out so well. I have never been more happy with an engine/car.