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Need advice on GEMS 4.0 rebuild for 98 Discovery (US model)

Posted: Sun Mar 15, 2009 5:07 pm
by juha_teuvonnen
Hi,

I have a 98 Discovery with a dead 4.0 GEMS motor (ran without oil, supposedly seized). I also have a factory new short block, missing camshaft, cam gear and chain. I am located in the US.

I was told that I should use 4.6 cam with the 4.0 motor, is this correct? Will the car pass emissions testing? Should I use a quality aftermarket cam instead? If so - information about US vendors will be appreciated.

I was told that instead of Rover stretch bolts I should use ARP non-stretch bolts because they are better. Is this actually true? If so, where should I buy them (in the US).

Are dynagear timing chains any good? They have 2 different kinds, a stiff and a floppy, what is the difference?

Are there any quality aftermarket cam chain sprockets that willl work with 4.0 GEMS engine (it has cam sensor, so I can't use 3.9 parts)?

Information on vendors of the following good quality aftermarket parts will be appreciated:
- top end gasket set
- bottom end gasket set
-head bolts
-camshaft
- timing chain
- camshaft gear (4.0 not 3.9)
- lifter set

Posted: Mon Mar 16, 2009 5:54 pm
by CastleMGBV8
Juha,

What do you intend using the vehicle for?

There are plenty of US vendors for parts for uipgrading the Rover V8 because of it's ancestry of originaly being a Buick 215 engine, and lots of parts for Buick 215 300 and 340 engines can be made to work in a Rover.

For standard parts gasket sets etc. I'm not sure if you have Land Rover dealers in the US but if you stuck D & D also known as the Aluminium V8 Co.

http://www.aluminumv8.com/

who can supply standard and tuning parts.

Kevin.

Re: Need advice on GEMS 4.0 rebuild for 98 Discovery (US mod

Posted: Mon May 18, 2009 12:57 pm
by TVRleigh
juha_teuvonnen wrote:Hi,


I was told that I should use 4.6 cam with the 4.0 motor, is this correct? Will the car pass emissions testing? Should I use a quality aftermarket cam instead? If so - information about US vendors will be appreciated.

I was told that instead of Rover stretch bolts I should use ARP non-stretch bolts because they are better. Is this actually true? If so, where should I buy them (in the US).


Are there any quality aftermarket cam chain sprockets that willl work with 4.0 GEMS engine (it has cam sensor, so I can't use 3.9 parts)?
The 4.0 and 4.6 blocks are from the same casts (but are graded and the better graded blocks was use for 4.6's) but there is no reason why a 4.0 blocks cant be used.

ARP studs are better, as they can be re-used. as said the rover studs are the same as Buick.

There is one company that do an adjustable Cam Chain and sprocket, but the stand 4.6 one is fine.

If you change camshaft it may not work well with the current ecu, you best keeping to standard also if you want to pass the US emissions