Good Morning:

I have a 1998 DI 4.0L (HSE) and looking to boost the stock HP/Torque numbers by 15-20%, or so.

I've looked at toddco hedders, flow-through cats, and flowmaster muffler to open up the exhaust side of the beast a little.

Back in my machinest days, the limiting factor on most all "hot-air" engines is being able to enabling the things to breathe a little better"...so....

Is there a camshaft profile that is a direct "bolt-in" replacement (like a 4.6L possibly) and/or other modifiactions that could be accomplished which would still be within the parameters of the OBDII management system?

My power range is from "off-idle" to around 4000 RPMS.

If there are rover owners out there that have had success with these types of modifications, I would dearly love to hear from you, and/or, have you share the links for additional research.

Thanks in advance!

 

http://aluminumv8.com/ - call them.
Look under Engines & Components at the cams.

 

The 4.6 cam fits right in, but anything more will require a lot of head work and header to help the engine breath better other wise it is a waste, and you still won't get the % of increase you are looking for.

 

Thanks Mike...agreed (there was always a point of deminishing return trying to coax HP/torque from SB Chevrolets...I'm sure the "215 Buick" engine is no different).

Do you have, or could you point me in the direction of the specs (lift/duration/overlap) on the stock 4.6L camshaft?

The lift for the 4.0L camshaft is listed in the RAVE manual (valve lift .3913 I/E, duration 285 degrees I/E, overlap seems to be 142 degrees from I opening to E opening).

1. Were there any valve retainer to top of valve guide interference problems?
2. Were there any valve to piston clearance problems?
3. Would advancing the cam 2-4 degrees using an offset keyway to compensate for T-chain stretch help the lower end torque?

Another note: I noticed the inlet in the air filter box to be really small (1.5 inches) compared to the inlet on the throttle body (3.0 inches, or so). This seems to be a restriction in the intake side of the motor.

It appears to be easy enough to modify the inlet tube and open it up to approximately 3.0 inches...then using duct work to bring in air from the grill area of the vehicle...kind of a "ram effect" at highway speeds.

Modifying the intake side of the engine, opening up the mechanical side using the 4.6L camshaft, and reducing the exhaust restrictions using hedders/exhaust components seems like a financially viable alternative to a bunch of exotic machine work?

Again, I very much appreciate your thoughts!!!

Ron

 

https://landroverforums.com/forum/sh...ight=Poor+mans

feel free to laugh your *** off.

It was just an experiment, however it does work. Average temperature dropped tremendously, wether idling or driving. Not only that but when going from an idle to driving, temperature drops MUCH quicker than without. It seems like there is absolutely no air flow through the engine bay.

Im also reluctant to say this in fear of looking like a ricer or some teenager with a wooden 2x4 as a wing bolted to the hood of his trunk. It does SEEM faster. I understand air temperature isn't going to give a super boost, but it does seem a bit quicker than it was, with its limiting factor of and that the truck does not like to downshift at times when you want it to.

And finally I am seeing a 1mpg increase overall.

 

By the way, if your talking about the tube that protrudes from the air box, it simply pulls right off. Im not sure of its purpose. I know some vehicles have intake silencers [nothing resembling this at all] but I have heard no difference with or without it. Maybe its purpose is to move the intake closer to the headlight where hopefully cooler air will be. Who knows.

 

The tube on the airbox is a silencer. That is it. I can hear a difference, but I run a K&N. I got a spare airbox from a salvage and plan to open it up and do something similar with the intake. Probably wont run it down because I have seen too many people suck up rocks and water on the road with an intake that close to the ground.

The best cold air intake your can do is a snorkel on these things..

 

Hey Ok are u not worried about the k&n killing your maf. Everytime one is mentioned on here people start screaming to get it off before they kill their maf. I was just curious. Sorry about the highjack.