Thread: Cam or not to cam

how do you know if you have a cam or not from the prvious owner??.....just thought id add that....

cheers

good question? Vehicle only has 185000 k's on it. I know the previous owner never touched it, but don't know before him. LOL

Number 1, that thing needs to see a jenny craig workshop for a bit of weightloss, all those accessories add up, and weight equals fuel consumption. Number 2, and this is probably the biggest factor is that at 185,000km the cam and valves will need attention. The 3.9 is already a low comp engine so I would say the 350K isn't going to be much improved without the power to weight ratio shifted around a little, in the vehicles favour Gearing with the 265 tyres is a little high too, which makes the engine work a little harder on even the slightest gradient or headwind.

You could find yourself spending over 2K to add another 80 to 100km to the range.

My 4.6 RR had a High comp very well set up engine, and the reason it had a 130litre tank is because it would only get 550km from it

JC

I'm a mechanic by trade so it will only cost me parts. Any idea what cam profile I should be looking at?
Thanks RAD

Originally Posted by Rad

I'm a mechanic by trade so it will only cost me parts. Any idea what cam profile I should be looking at?
Thanks RAD

if your a machanic...i wasnt being cheeky i was actually asking ..is there a way that you can tell if you have one or not ???

cheers

Originally Posted by Rad

I'm a mechanic by trade so it will only cost me parts. Any idea what cam profile I should be looking at?
Thanks RAD

Rad,

I'm guessing about 2100Rpm at 100km/h with those tyres and standard Disco transfer gears, so as you can see the poor little 3.9 is way below its good orque band here I would suggets if you are keeping the 265's to fit a 1.410 transfer case from a Defender, then you will have 20% lower gearing in high range, adds about 350rpm at those speeds.

Cam selection with the auto is limited to a new standard EFI cam, or a Dynotec PC215. (Only slightly more exhaust lift)due to poor vacuum at idle.

Take off the extractors and port match, and port match inlet manifold to heads also. This will make heaps of difference. I would definately give it a valve job, and refit heads using the thinner steel shim gaskets as they will give you a little more compression. Try a little more ignition advance (Up to 12 degrees on ULP) and ensure the vac and mechanical advance is in good nick. A big fat blue spark is also important, and aftermarket distributors like scorcher etc make some high output ones. But as I said be careful spending and spending to save only a little bit. It is a big help if you don't have to pay someone to do it though

JC

The defender transfer case make any difference to the low range gearing?? Also you read about the piper cam kits on the net lately offering better low down torque? I don't want any lower vacuum the brakes suffer enough as it is. Would love to be able to upgrade to the larger Defender brakes while i'm going. Might have to try and find a cheap wreck somewhere.
Thanks RAD

To check if a cam is worn you can drop off the rocker covers and check valve lift with dial indicator. I haven't done it myself on the beast but will need to find some time to check it
RAD