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CobraEarl
I have a 1997-1/2 Mountaineer motor that is stock except I changed out the cam to a trick flow stage one, sold the gt-40 intake and put a edelbrock performer rpm with a 600 vac secondary holley. I would think this intake and carb is similar to the flow of the stock GT-40 fuel injection setup. I put a Mallory unilight in with no ignition box(the unilight can fire without one). The headers are a set of 4 into one from Hunter's Kit car(Not a FFR cobra). I am running the stock valvetrain including the stamped steel rockers.

A couple of weeks ago I had it on a chassis dyno and it put 267 rear wheel hp and 285 ft pounds to the rear wheels. If you divide by .85 for driveline loss that is 314 hp at the flywheel. The stock rating for this motor is 215 flywheel so a cam and headers made almost 100 more HP.
There were a lot of 347 strokers with ported GT-40 irons and various aluminum heads and they were in the 300 to 313 rear wheel hp range. One 289 with aluminum heads and a pretty radical cam put 275 rear wheel hp. One thing that hurts the explorer/mountaineer motors is the exhaust headers which are small and full of crimps. I doubt they would flow enough for a briggs and stratton engine. Like you said the stock cam is tuned for low end torque and has no grunt over 4000. The cam really helps.

[ December 20, 2002, 09:32 AM: Message edited by: aumoore ]
 

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This is great news for all the budget minded folks! 300HP with a just cam and headers...no brainer.
 

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FFCobra Fanatic
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Wow! I've got an earlier (early 96) explorer motor with the GT-40 (non-P)heads and the wife bought me an E303 cam for Christmas.

jack
 

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The P heads flow a little more on the exhaust side than the standard GT-40 heads but not by much. I would say in a mild application both will have the same HP. The P's have a better combustion chamber and relocated spark plug.

Everything I have read is the explorer motors are basically the same as the 1993 Cobra mustang motor with a crappy cam and really crappy headers.
 

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I have a 96 explorer engine that I found on-line($1,500 -new from dealer). I changed the cam to a Trick Flow and everthing else is stock. Added a RPM manifold and BG 625cfm carb, It runs great right up to 6000 redline (MSD chip). I was also told that the short block is the same as a 93 Cobra Mustang ( I had one and sold it to get the FFR). The explorer engine is a great deal if your trying to save some cash, but still want plenty of performance. Chris
 

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FFCobra Craftsman
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Hey Aumoore those are great numbers, I have a p headed explorer motor with the same cam, but with EFI do you have a copy of the graph you can post, and if not do you know what the rpms were at the peaks, and one last thing, did you replace the valvesprings when you put the cam in or just leave the stock ones in?
 

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Gary
I am out of town but when I get back home I will try to scan and post the graph. The Valve Springs are stock and the tech guy at trick flow said the stock springs would work. I think I will change them one day as I think I get a little float(someone once described as a false rev limiter)above 5500rpm.

I think the HP peaked around 5500rpm and the torque was over 250 by 2500rpm.
 
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