5.0 Build Up

[97 Expy 302]

As mentioned in another thread, I'm planning to make my explorer into something a little more serious for offroading. I've got what feels like a solid 5.0 under the hood (97 with about 170K on it) and would like to find the best improvements for torque that don't limit my ability to pass Cali smog tests.

I've read about:
-cobra cam
-cobra roller rockers
-96 Intake manifold

but not much else. Any advice on this or places I should look?

Thanks!

 

[kevinspann]

The only real differences in the early and late intakes is that the earlier ones had internal EGR, the later ones had external. Your 97 might still have the early intake anyways.

Rockers - not sure they'll fit under the stock valve covers. The cam - probably good for more top end power, but likely to lose low end that the Ex. lacks. The Explorer exhaust manifolds are just crap.

 

[97 Expy 302]

The only real differences in the early and late intakes is that the earlier ones had internal EGR, the later ones had external. Your 97 might still have the early intake anyways.

Rockers - not sure they'll fit under the stock valve covers. The cam - probably good for more top end power, but likely to lose low end that the Ex. lacks. The Explorer exhaust manifolds are just crap.

Thanks Kevin. Are there replacement headers that are worth the expense? I found some for the mustang but I need to make sure the CARB sticker is good on explorers and not just mustangs.

 

[Turdle]

You need to find "explorer" headers, and yes they are CARB certified.
Torquemonster headers are the only ones which will fit, unless you fabricate your own. Al's Headers is now making them. You will need to google the phone number and talk to them directly if you want a set. Be prepared to wait a minute for them.


Rocker arms will not help low end torque, nor will the cobra cam. Both are designed to bring the torque curve in higher RPM's

 

[97 Expy 302]

You need to find "explorer" headers, and yes they are CARB certified.
Torquemonster headers are the only ones which will fit, unless you fabricate your own. Al's Headers is now making them. You will need to google the phone number and talk to them directly if you want a set. Be prepared to wait a minute for them.


Rocker arms will not help low end torque, nor will the cobra cam. Both are designed to bring the torque curve in higher RPM's

They are a little spendy but very nice looking. I sent them an email checking availability. We will see when they get back to me.

On another note, are there roller rockers that will work with the explorer?

 

[BKennedy]

Have you done any suspension modifications? If not, that is where you should spend your money to make your Explorer more off-road worthy. The engine has plenty of power and would be last on my list if I wanted to make a capable off road vehicle.

 

[97 Expy 302]

Have you done any suspension modifications? If not, that is where you should spend your money to make your Explorer more off-road worthy. The engine has plenty of power and would be last on my list if I wanted to make a capable off road vehicle.

Spring over and solid front axle.

 

[boominXplorer]

To make roller rockers work you will need aftermarket valve covers + intake saper + modified EGR tube. You need 1.6 pedestal mount 5/16 roller rockers

 

[97 Expy 302]

To make roller rockers work you will need aftermarket valve covers + intake saper + modified EGR tube. You need 1.6 pedestal mount 5/16 roller rockers

I'll have to get past the referee and smog first I think. I don't know what they would do with aftermarket valve covers here.

 

[boominXplorer]

You can also use stock aluminum pre 93 year valve covers and trim the baffle back so the rockers clear.

If your lucky to find a good deal you can use 93 or 94-95 cobra stamped steel valve covers. They tend to go for $250 for a pair used

 

[Turdle]

Most "mustang" style valve covers have the oil fill and pcv holes right where you do not want them. Notice you will have a hole to the rear of the passenger side cover and a hole to the front of the driver side cover. You do not want the oil fill to be on the driver side.

I think the Ford Performance "truck efi" valve covers will have a hole in the front of the right side cover. This will retain the stock oil fill location. The driver side cover should be solid with no hole, or a solid grommet to fill the hole if there is one. Even with these you will need to trim the baffle for roller rocker clearance.

Truth being told, the pedestal rockers are weak. I see no reason to upgrade to rollers as the valve train will still be unstable above 5500 RPM's and a 5/16 pedestal will snap if you go there often. Unless you shave the pedestal ridge off and install 7/16 stud rockers, you should stay below 5500 RPM's, so, why have the roller rockers?

I believe stock rockers re 1.6:1 ratio.

 

[Scott B.]

I have Comp roller rockers on mine. I am using Ford aluminum aftermarket valve covers with a modified baffle and a custom oil fill tube. (I have the Mustang upper intake, not the Explorer intake.)

I had to use a 1" spacer to raise the upper intake to clear the valve covers.

As long as you don't look to close, you can't really tell the difference. But, if the inspector knows what he is looking at, he will see the spacer - which I believe is not smog legal.

As for the rollers, yes I went a little overboard building my 5.0. Are they needed? No. Do they hurt anything? No. Do they help? Yes, even at lower RPMs. Is it a big help? Probably not. The engine will spin up a little faster, there is less drag on the rotating assembly, resulting in (at least on paper) more power and better efficiency.

Unfortunately for me, the theoretical improvements don't really help at the gas station...

But it's fun to drive!!!!!!!!

 

[97 Expy 302]

I have Comp roller rockers on mine. I am using Ford aluminum aftermarket valve covers with a modified baffle and a custom oil fill tube. (I have the Mustang upper intake, not the Explorer intake.)

I had to use a 1" spacer to raise the upper intake to clear the valve covers.

As long as you don't look to close, you can't really tell the difference. But, if the inspector knows what he is looking at, he will see the spacer - which I believe is not smog legal.

As for the rollers, yes I went a little overboard building my 5.0. Are they needed? No. Do they hurt anything? No. Do they help? Yes, even at lower RPMs. Is it a big help? Probably not. The engine will spin up a little faster, there is less drag on the rotating assembly, resulting in (at least on paper) more power and better efficiency.

Unfortunately for me, the theoretical improvements don't really help at the gas station...

But it's fun to drive!!!!!!!!

Good to know. I think then that I will just rebuild my 302 and add a good set of headers and a cat back system. As I read the California smog requirements I can't change from stock exhaust from headers to the cat. I was hoping there were large gains to be made but it sounds pretty straight forward unless someone has a torque specific cam or something else to add while I'm rebuilding.

Thanks for the help with this!