evoderby

Dave,

A less costly option than the approach Colin has suggested is to use a Cargraphic 3.8L kit (including Motronic hotfilm conversion and matching chip).

This way you can at least be sure you have a matched set of components, backed up by extensive development and the dyno sheets to prove.

Although this approach doesn't yield the same results that 9M gets from these engines, at least you can be sure that fueling and ignition is safe and you won't wreck your new engine due to injectors maxxing out etc.

http://www.cargraphic.de/stepone/dat...t_P64_3.8L.pdf

http://www.cargraphic.de/index.php?/...,1049/&start=3

When looking at the power graph this kit -only- yields 10Nm/13HP more than their 3.6L hotfilm conversion. When adding their GT exhaust/header (3.8L kit II) an additional 10Nm is yielded with an additional 15 HP (325HP total).

Biggest difference in price in this approach comes through using Motronic (€ 2.5K hotfilm/chip/injectors) rather than Motec (about £5-5.5K all in ???).

dave964diver

Thanks Colin, yeah of course all of that stuff you said - What does 'properly ported mean?' and the 993 vr valves are bigger? will I need to check that the piston have enough clearance etc.

NineMeister

Harald,
Don't get me started on Hot Film & MAF kits. At best the ones that I have seen yielded around 3-5hp more than a custom remapped standard Motronic; at worst they made less power than stock and the engine would not idle correctly. I should probably mention that I had an email from a potential customer in Spain recently who bought a complete 3.8 MAF package from Europe and now has the engine in pieces due to a melted piston....

Dave,
Properly ported means exactly what I said - the ports are reprofiled to maximise air flow without increasing port area. 993VR valves are lighter, 50/43mm dia with 8mm stems against the 964 49/42.5mm with 9mm stems; you need to fit 993 valve guides into the heads to run them. With a sports cam the lower weight reduces valve train loading (increasing reliability) and the larger valve has a greater curtain area which flows more air for any given lift. Optimise the cam events to take advantage of the increased c.a. and you can get more power & torque.

dave964diver

Thanks for the replies, that cargraphic package looks like a nice deal.

Opinions are very divided on the MAF or hot film option- seems a lot of cash for not much return. Colin, do you need to further machine the heads to accept the 50/43mm valves? And what about clearance for the pistons?

Cheers,

Dave

dave964diver

Well,

It's been longer than I expected but here it is ready to go in.



3.8 slip fit Mahle cylinders

Je pistons

Dc21 cams

Arp rod bolts

996 turbo oil pump

New exhaust valves and new valve springs.

Ps delete

Clewet single belt pulley conversion

Plastic intake manifold

Rs clutch and fly wheel

New tin

Plenty more bits and while you're in there stuff but I'm glad it's back together.

Now to see if it works.

garrett1021

Keep us updated

dave964diver

dave964diver

FeralComprehension

Niiiiiiice!

STUARTQ

Keep that rebuild info coming!

dave964diver

dave964diver

kos11-12

As for the 9m 4.0 litre, the 1000-2000rpm issues were eventually pinpointed to a pair of poorly machined prototype high lift race camshafts which had dissimilar timing between the left & right banks. Just goes to show that even if you think you know what you are ordering, you can still be sold a pup....[/QUOTE]

The Alpha -N mode tuning (TPS based mapping) probably did not help...!?

kos11-12

Hi there , very nice project , love to see your Dino result, with all my respect I think you may miss out some performance if not fine tune with a proper aftermarket ECU (and few others bits INC bigger capacity injectors )...and find to have to do things twice,
From experience owning a few different race engines, when you mod a few things you need to remap to get full advantage , event with a simple, single cylinder motor run with a carburetor ...nice pictures
Keep sending more,

NineMeister

Dave,
Hopefully this catches your build before it is too late. Unfortunately you will have a major problem with the heads you have machined because the machine shop has machined the heads totally flat and removed the essential cylinder location lugs on the corners. If you fit these they will shuffle across the tops of the cylinders and at best cause leaks. The only solution I can see is to use an aluminium L-profile "le mans" style sealing rings that locates into the groove of the cylinder and in a freshly machined groove in the heads.

Photo of 9m billet head shows the necessary location lugs.