Engine Performance Upgrades

[CAM II]

I am looking for some advice on performance upgrades to the 91-94 Explorer 4.0 L engine. I have been considering a slightly wilder grind for the cam and increasing the compression ratio to 9.5 to 10.5:1. Anyone have luck with this or have advice to increase low to mid range power without losing total focus on fuel economy? How about distributors that carry the parts to pull this off?

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[SteveVB]

search the site for cams the subject has been covered before.

Look for the book "How to build and modify the 60* Ford V-6 by Sven Pruitt from Vanir

As for myself I am rebuilding my engine with some mild porting, a Competition Cams 410-8, stock bottom end-so far.

Steve VB
91 Navajo 2.5" rancho,31" Goodyear AT/S and a bunch of parts for an engine.

 

[Cameron]

Welcome CAM II,

There is a lot you can do to the 4.0.


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Rock'n 97 Sport 4X4

 

[CAM II]

Steve VB

Will you have the heads milled to increase compression? How about the replacement of lifters etc.? Based on the input and sites provided...to go the route of forged pistons, rods and the whole shooting match is almost cost prohibitive. I might just leave the bottom as is and play with the top unless I stumble on some lower cost ways to replace bottom. Let me know how the cam works out.

thanks

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[SteveVB]

Cam,

I will mill the heads only if they need it. I am going to rebuild the bottom with stock parts, its been reliable for 150k and the cost is something also I considered. Most likely I am going to get new heads at this point. Mine are 91 heads and from what Ive read it would be safer to buy new than to work with the existing.
I am getting new lifters, pushrods,rocker shafts&arms,cam, timing chain/gears, and heads with the valves. Basically a new top end. With 150k on my engine im not going to save $200 in misc parts which if I dont replace them will probably fail. New cam needs the new lifters, and the pushrods need to be custom length for use with the new cam(I think). The rest is small change compared to the labor and time to pull it all apart if something "old" were to fail.

Basically Im saying about the same thing that you are- Im doing the work to the top end of the engine and leaving the bottom end alone. Im not looking for huge power increase - i think supercharging would be the way to go for that, but maybe get an increase of 20% with the cam,mild porting, headers,and TB. Well see.

Sorry for the long post

Steve VB
91 Navajo

 

[CAM II]

Steve VB--

When you start putting the package together for the Camshaft, lifters...all the requirements to fit a particular Cam into the engine, let me know the supplier you end up going with. I would rather purchase a package that supports 4.0L then end up having some guy pulling a cam and then a set of lifters and pushrods that supposedly go together.

Thanks