gkbikers

Hi folks.

I went on a little spending spree over Christmas and bought a 1997 Ford Explorer. It is a complete, running car. At first, I was somewhat unsure of the heads, although I "thought" they were the non-P GT40 version. Later, in the daylight, I was able to find the "III" (3 bar casting) in the right front head. So, I have a GT40 head 5.0. It runs pretty good, has a very slight, barely discernable stumble off idle, but otherwise just purrs right along like a good Explorer engine should. It has a "check engine" light that stays on, but I have not yet run it by someone with a code reader. That is one of my first goals, so I have some sort of idea about what is wrong. I plan to use the EEC-V stock computer with a TWeecER add on OR build/buy a DIYMegasquirt. I want to keep the coil packs vs. going backward with a distributor.

I plan to leave the engine pretty much stock except for a cam swap. I may swap heads DOWN THE ROAD to some aftermarket aluminum ones with bigger ports and better flow, but for now I want to live with the stockers.

One rebuild question is, "what cam to choose." I realize this is a really difficult question to answer because of personal goals, hardware, EEC-V software, etc. What do I want? I want the engine to run smoothly at all speeds, no stalling, sputtering, etc. I want decent mpg figures (20+ hwy). I want a power band that really starts coming on at about 3,000 rpm and goes to somewhere between 6,000 to 7,000. No more rpms that 7K and that should be beyond its power peak. I think the big challenge will be having the engine "happy" at low revs, i.e., no stumble, hesitation, etc., but very willing to go the the "ceiling", if you will.

I was thinking of either a TFS stage 2 OR Ford Racing F303. I know that the GT40 heads supposedly will not flow past .500 lift (which may be why so many people choose an E303 which has lift at .499ish). Please remember, I don't want to have to pull the engine if I take the plunge and buy something like AFR185s. Along with your cam recommendation, please tell me whether you recommend running it "straight up", advanced, or retarded and by how many degrees.

Also, I do not plan to go stroker (no 331 or 347). If anything, I would do a simple 30 over if I cannot use the stock pistons in my refresh.

By the way, the engine has 198,000 miles, it appears.

Thanks all.

Gary

tbone heller

I have been running the F303 cam since Ford introduced it in the mid 90's. It produces good power & idles well. I have used it without a supercharger, but it seems to perform much better with one. I am sure that there is something better available because the F303 is 20 year old technology.

tbone heller

I do not think that the parts from your Explorer will be able to reach your 7000rpm goal. You may want to install your Explored engine as-is while you save up & assemble your "desired engine". The rpm that you are seeking will most likely require larger injectors, throttle body, MAF, better flowing heads & intake, a solid roller cam, as well as a balanced bottom end with a certified balancer.

gkbikers

Mr. Tbone, I appreciate your input. A couple questions for you.

I live over in Buford, Georgia, so I have to meet our state's emissions requirements.

Is Canton inside the Georgia emissions "environment" and, if yes, do you have any problems meeting emissions checks?

Part of my plans involve using the EEC-V with some tuning either by Tweecer or replacement with a MegaSquirt. I'm hoping that if I choose a HiPo cam, I can still pass emissions with the modified EFI. I have a 1995 OBDI Miata.

Also, since I am keeping my GT40 setup for the present, is the F303 "too much" or will it pretty much match and max out the GT40 heads and intake on the Explorer engine?

I know there are better cams out there, but the "alphabet" cams seem like proven performers. However, if you have an idea for my goals above, I'd love to hear your suggestion.

tbone heller

I think that the F303 will work well with a GT40 set-up.

What year car are you planning on using? For emission purposes I would suggest you use a pre-OBDII car. Mine passed emissions with no problems for the past 4 years.

As far as which computer system to use, I would recommend that you find a good dyno shop that can tune the car for you. Call my friends at Injected Engineering http://www.injectedengineering.com/ & tell them what you are planning. Those guys know Ford tuning. I contacted them about my car, & they told me what was needed before they could tune it (plugs, fuel pump size, injector size, TB, MAF, ect.).

I also have a guy that is great & reasonable with the exhaust system. He is in Canton as well.

sebz

Don't forget that the explorer have flat piston... If you keep the stock explorer engine, i go with a stock mustang cam. And your sure on emission test... you can add 1.7 rocker later.

Also did you keep the explorer ignition?

gkbikers

Thanks sebz. I haven't taken a thing off the Explorer yet. I plan to keep most of what is under the hood, including antilock brakes, master cylinder, all wiring, etc. I can always throw it away later.

As for the pistons, I may have to replace them once I get into the engine. If I do, then I can pick the right parts for the job. Otherwise, I can have the pistons machined for additional valve clearance, right?

On the cam, I don't think a stock HO Mustang GT cam, even with 1.7 ratio rockers, will give me the powerband I'm looking for . . . soft on the bottom, then building from 3,000 to 6,000 Plus. I'm looking for more of a road-race power curve than a dragster power curve. The dragster would need more torque to launch. I just want enought smooth-running torque down low to idle around town.

We all have to remember one thing when talking about power down low: the Miata engine is no torque monster, but it lugs good then really comes on at 4,000 rpm and screams to 7,000 and more. That's the powerband I'm trying to achieve. With a custom mapped ECU, the right cam, etc., I should be able to achieve it. Finding that right combination will be the challenge.

Thanks guys. Please keep the suggestions coming.

Gary

MRM331

I've been pretty happy with the E303's I've used a few times. They can be degreed to move the power band up or down for street or track use but are also not to extreme. The next best route would be to have a custom cam ground for exactly the power and torque you want. This sounds a little over the top but I hear it can be done for around $400.

-Jason

gkbikers

Thanks Jason. Let me ask you, have you or your father had any experience with the "F" 303. I just wonder how it compares to the "E'. It looks a little hotter up top and a little softer down low.

tbone heller

Since Ford considers the E-cam as an emission friendly cam, I would not expect it to be much "hotter" than a stock H.O. cam.

MRM331

The E303 in my current car making me about 30 more rwhp than the car I built with a stock cam. The stock cam was a nicer daily drive though and much better on the wallet (25 mpg on a regular basis).

Offered for comparison:
(all rwhp numbers from the same Mustang Dyno)

-----
1990 White-
306 ci
9.5 compression
1992 Stock Mustang cam
GT40 intake, throttle, mass air and heads
stock a9l (no tuning)
19 pound injectors

240 rwhp, 19-24 mpg on 87 octane

-------

1994 Laguna-
331 ci
10.75 compression
E303 cam
GT40 intake, throttle, mass air and heads
stock a9 (no tuning)
19 pound injectors

270 rwhp, 14-20 mpg on 91 octane

-----

Another car we built:
93LE
306 ci.
9.5 compression
E303 cam
Edlebrock intake, 65mm throttle (same as GT40), 72mm mass air (same as GT40), AFR heads (slightly better than my father's "worked" GT40's)
stock a9l
19 pound injectors

270 rwhp, 16-22 mpg on 87 octane


-Jason

engineer

Hi All,

Old thread, but I thought I would post as its a common question Cam.
1. Cam upgrades on 200K mile engines with moderate compression (9;1) , poor flowing heads and a restrictive intake intakes don't make much more power than stock
2. My guidance on the short block: I would rebuild the bottom end.
3. GT40 heads dont flow anything special. As you will be rebuilding the heads (because after 200K miles they wont be great). I strongly recommend a set of Twisted wedge 170 or AFR 165 heads with the right chamber size to get you around 10:1 compression.
4. With that done a custom can with up to 224 deg @ 50 duration and up to 0.6 in lift will work great. If you want OTS CompCams XE264, XE270 and XE274 are good choices...XE274 is a decent cam
5. Use a 70 or 75mm Throttle body (Accufab)
6. For intake use Holley Systemax, Trickflow Track heat or R intake, Edlebrock equivalent. Just make sure you get min. 250cfm flow rating on the intake you use.
7. EECV ECU can be easily programmed to suit using the SCT tuner
This engine will pull hard and make a solid 350-370hp and will idle pretty well AND give you good gas mileage if tuned properly.

Enjoy