996 3.4l M96/01 DIY upgrades

MisterCorn · 25 Dec 2017

I have a spare engine for my 1998 C2 which I intend to strip and rebuild with new chains/guides/bearings etc. When I have the heads stripped I would usually look at cleaning up and polishing inlet ports, matching exhaust ports to manifolds and getting 3 or 5 angle valve seats cut. I can hardly find any info on the M96/01 though. Any recommendations or suggestions?

I will be changing exhaust manifolds anyway as mine are shagged. Any good recommendations on those?

MC

Harv · 25 Dec 2017

I looked at options on the 3.6 heads recently during my 3.9 build and these were the observations.

The heads flow very well out of the box and are restricted by the intake manifolds, TB and valve shrouding due to the bore size (consider going to 100mm bore which will give you 3.7). I had a really through valve job done which put multiple angles on the seats and did a small amount of casting cleanup and radiusing where the gasses go over a sharpe edge into the port.

I've gone for a set of the 3 into 1 equal length stainless steel chinese equal headers which are a copy of the expensive FVD which PPBB on here swore by bolted on with stainless hardware and also gone with a decat to the existing PSE.

Hope this helps a little

MisterCorn · 25 Dec 2017

Thanks, unless I find bore issues I'm not looking to change liners and pistons, but could look at intakes. I don't want to go overboard. I'll check out manifolds on eBay.

MC

Harv · 25 Dec 2017

The manifolds are a good buy at about £125 on eBay when they are available.

Forgot to say I also had the heads skimmed to check for flatness (they were a little off) and along with the piston and liner change has resulted in a slightly higher compression ratio.

ragpicker · 26 Dec 2017

Didn't DynoMike put some interesting data up about the heads on the 'Bench Race 2000' thread?

I'd have a look at that initially.

Then there was PPBB's (I think) info on the different intake kits, where the K&N offering was worse than the standard airbox.

I would definitely go de-cat though, thats where you'll see most gains from anything you can do DIY IME.

Other than intake/exhaust there's not a lot else you can do without modifying the engine, unless you're looking at X51 intake manifolds :?:

MisterCorn · 26 Dec 2017

I have just reread Bench Race 2000. Great work and exachly what I love about this forum. This looks like the sort of manifold being discussed.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/400397511150

I'll start a thread on it when I start to strip the engine. A 3.7l conversion is the obvious answer, I'll have to look at costs.

MC

Dammit · 26 Dec 2017

The plan is for there to be a set of cams designed for a 3.7 M96, to be made in (likely) 2018, based on the research done so far, some of which has been presented in the Benchmark Race 2,000 thread.

I imagine* we could get two sets for only an incremental cost if you are interested?

*This is an assumption

infrasilver · 27 Dec 2017

The Chinese manifolds were dyno'd back to back with standard by Oz996 back in the day and found to produce less power and even though I've had my manifolds off a couple of times I have stuck with standard rather than go for aftermarket after his findings. Alex has also fitted a pair and said he felt a bit more low down torque.

Harv · 27 Dec 2017

I think that bhp test report had some inconsistencies in the testing :?:

I'll try and dig it back up for a re-read but in my mind an equal length system should be better, perhaps it makes more torque (not total bhp)

996 3.4l M96/01 DIY upgrades

MisterCorn

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Harv

Suzuka

MisterCorn

Fuji

Harv

Suzuka

ragpicker

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MisterCorn

Fuji

Dammit

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infrasilver

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Harv

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