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Junior Charter Member
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Discussion Starter · #1 ·
OK - here's a couple of real basic questions...

I've got a 2000 Explorer 5.0 with less than 100 miles on it that I will be converting to Mustang specs for the roadster. It's got GT40p heads. I'm planning on using the M-6670-A50 Oil Pan Conversion kit which covers the oil pan/pump, serpentine water pump, timing cover, etc. This is what I want - right?

Next: I'm looking at replacing the cam with either a "B" or "E". I've got a 3.55 rear end - so I've got low end grunt. Which cam sounds right?

Then: With the cam, I have to replace the rockers - correct? If so, would I go for the M-6564-B351 or -E351 rockers?

Is the GT40p head using "bolt-on" or "stud-mounted" rockers? What's the difference? Here's a picture of my current rockers:



And, if I replace the rockers, do I need to replace the valve springs? If so, what type is required?

What else should I be concerned with?

When replacing the cam, I can do that without popping off the heads - right?

Thanks!
Darrell
 

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Junior Charter Member
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Discussion Starter · #2 ·
PS: The part numbers are out of the Ford Racing 2007 Performance Parts catalogue - courtesy of Max @ 5-Star (page 102-103).
 

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A Bor E cam swap will not create the need for new rockers, it "CAN" cause need for different valve springs.

You have bolt on rockers_they use a bolt in the center/stud uses a stud and are readily adjustable

Without the right tool, you will have to pull the heads to do a cam swap.
 

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Cobra Builder
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Darrell,

'01 Explorer here! You'll need to change the springs and retainers because the higher lift cam will cause the valves to float at higher RPM's. I used FRPP Springs M-6513-A50 & Retainers M-6514-B50.

I used FRPP "B" cam, and the cam will slide out after removing the push rods. I also used the same Fox conversion kit from Max at Five Star



Good Luck,
Pat
 

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section 8
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I would use the ford X cam especially with a light car like the FFR it'll move the power up in t he rpm band and save you some money on tires. Your rockers will work you may need a shim kit or 2 Also listed in Ford Racing catalog. Get a set of springs locks and retainers from comp or crane. Bob
 

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My GT-40p heads used pedistal mount rockers and they were not readily adjustable. They looked like yours. I replaced them with double roller rockers. Check your needed pushrod lengths before you button everything up. I do not know the base circle size of the cams you mention so you pushrods may or may not be the correct length already. These are some great info pages at the crane cams site.

I used a set of crane cams conical springs on my buildup. I used a crower cam with just under 0.5" lift. If you look at your exhaust valves they seem to have the stock keepers that rotate that valve. I have heard stories of those failing in high lift applications. I have never seen one fail, just heard enough stories to replace mine with crane keepers. Also note that on stock FORD valves the locks are at a different height on the exhaust and intake valves so get keepers made for a FORD.

Just info I remember from my GT-40p buildup. There are a couple of websites devoted to the GT-40p. Google should still find them


Bobby
 

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just another builder
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I really don't consider the b or e to be a "high lift cam" the b is a 3/4 cam for all intents and purpose...you can go 530 total lift before interference problems...(that's an e w/1.7 rockers...529)..otherwise you gotta fly cut or replace the pistons for valve relief
 

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Discussion Starter · #9 ·
Hey Pat - what are you using for the front pulleys, brackets, etc.? Not to mention that alternator? Looks fantastic. That's what I want!
 

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Cobra Builder
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FFCobra Fanatic
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I have a little over 5,000 miles on my setup. Its described below.

You do not need to replace the springs. My valves will float at 6250 rpm and I don't need to go there. At that rpm the engine is past making power.

With the E cam you do not have to replace the push rods.

I have the 1.7 roller rockers and they work with the E cam and stock push rods.

All in all the E cam has been a good cam it sounds right, its good at low speeds (parades and getting into the driveway). I have a B cam but have not installed it. Yes, you can replace the cam without pulling the heads.
 

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section 8
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The xfits with no mods and stock rockers but I used an 88 gt engine . Bob
 

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Discussion Starter · #14 ·
Thanks for the replies and suggestions.

Now another couple of related questions.

What is a “roller cam”? I’m assuming that is a cam that requires roller lifters and rockers – right? Is this due to the friction that the more advanced grind generates?

If I go to an “E” or “B” cam – do I need to get roller lifters? How do I tell (without taking the head off) if I’ve got them? Or does the fact that I’ve got bolt-on rockers imply that I don’t have roller lifters? Can you get the lifters out without removing the head?

If I go for either of these cams – do I need the Roller Cam Conversion Kit (FRPP M-6253-A50 page 94 in the 2007 catalogue)?

Thanks again for indulging in a little education for a novice.

Darrell
 

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You don't need to get roller lifters if you go with either cam. The stock lifters will work, but you'll realize more of a benefit with a different ratio lifter, as stated above. A roller cam is one that works with roller lifters. To tell if you have roller lifters, take one rocker off, pull the pushrod out, and turn the crank until one of the lifters comes out of it's hole. Pull it out with your fingers (assuming you've removed the dogbone, as well), and look at the end that touches the cam. If it's got a "wheel" on that end, it's a roller lifter. Roller rockers also have a wheel at the end that touches the spring. This reduces friction and has some power gain.
 

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A 2000 Explorer motor will have Roller lifters. Do you need Roller Rockers??? NO. The advantages to replacing your rockers is that due to the design of your stock rockers they create friction, and because of the stamped design they are prone to deflection. Deflection has the same effect as reducing your cam profile. When trying to get the most out a combination both are bad. A Roller Rocker will have a bearing at the rocker tip, and at the fulcrum. You can get replacment ROLLER TIPPED ROCKERS, but IMO just get a true Roller Rocker. I had a "E" cam (with GT40P heads)in a previous combo in my FFR. I installed it straight up with 1.7 roller rockers and liked it. As for the "X" cam. I am running one now. I dont think I would recommend an "X"...by the time you get up to an "X" cam there are far better grinds out there. A cam is described as a "Roller Cam" when it is used in conjuction with Roller rockers. NOTE: IMHO when running an "E" cam with 1.7 rockers you need to check for valve/piston clearance. You also have to check for correct pushrod length. I needed longer pushrods when I installed my "E" cam with 1.7 rocker. You will also need to change the stock valve springs...not so much because of valve float (with a E or a B cam valve float is normally a result of just plain tired valve springs, which should be replace anyway), but becauses coil bind of the stock valve springs at those lifts is very possible. FWI you can buy a tool from Anderson Ford Motorsports call a "AMF Tappet Tool". With this tool you can not only do a cam change with the heads on...you dont even have to remove the lower intake.
 

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With only 100 miles on the engine, the springs do not need to be changed, nor do the stock 1.6 ratio rockers. Just put in the E or B cam. Why not just leave it bone stock?

Be careful on this site. People love to spend your money.
 

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Discussion Starter · #18 ·
Great info! Thanks again!
 
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