Thread: 3.9 performance

A piece of string is thiiiiis long.
Just a couple of points. You state"

long weekend off road near cooma

In my experience you rarely need more power off road. It's on road the 3.9 is gutless.First question is "how many ks" There is no use trying to spice up an engine with 200K plus. Maybe your problem is that the cam is worn out. So first make sure the engine is in peak condition.
The cheapest and best bang for the buck is to have an interceptor fitted and dyno tuned. You can gain about 20% across the board. You may find when it goes on the dyno that there are numerous wear items that need replacing /adjusting
Of course the best fix for gutless is a 4.6 block and retrofit the 3.9 stuff , but you also need to have the interceptor to get the best out of it.

Next is a 308 /350 transplant. An old ZF and BW will not take this power for long.
How fast do you want to go? How much money do you want to spend?
Regards Philip A

Agree with above, spend the $$ on a 4.6 with high comp and fit gas and good torque cam.

If you have a auto which most RRC's are than it will be fine.
Just get a tranny cooler and get it serviced regularly.

You be looking at some $$ though. I would say $6-8K.
Good luck.

The cheapest and best bang for the buck is to have an interceptor fitted


stupid question probably but whats an interceptor and what does it do? zacc

engine health seems very good, compression equal across all cylinders, yet to lift tappet cover and check cam lift, yes its fine off road i'm just over the constant kick down at the slightest uphill. maybe lobe wear will know more after checking if lift is ok. chris

Things that can be done are ...

... Advance the Dizzy to 9 degrees ...



Low cost improvement is to buy some bosh 19lb GEN111 (ford mustang) injectors from the Ebay USA

Replace the CAM chain ... as it will be stretched


The motor is a slug ... and will always be, unless you start spending some serious bucks

Cheers
Mike

As someone has asked - what is a Interceptor?

Interceptor is a piggyback ecu that plugs in with the factory ECU. It then tells porkies to the fuel management and some control the dizzy.

My 3.9 had hit 190,00 km about a week ago and i thought it still went ok.I was getting a valley gasket replaced when the mechanic rang me and said that my cam was worn.And when i had a look at it he was right.The lobes were very rounded and on there way out.I had new lifters,timing chain put in along with the new cam and it goes really well now.I was quite surprised.Not to bad at all.Low down torque was heaps better and revved quicker.All up cost me $1400 to get new cam,cam chain,lifters and have it fitted.I wasnt going to get it done but im more then happy with the reults.