cam shaft advice

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cam shaft advice

November 21, 2005, 09:58:35 PM

I recently got GT-40 heads in nice shape off a 97' explorer. When I’m going to put them on, while the engine is apart I might as well do the cam shaft. The question I have is what kind off cam B303, E303, F303, X303, Z303.or another type. Any input on rockers too ex... 1.6 Or 1.7 or does that depend on the cam.

Just looking for advice. My motor is 5.0HO w/mass air. Tranny is AOD.

cam shaft advice

Reply #1 – November 21, 2005, 10:02:35 PM

i would go with the b303.

cam shaft advice

Reply #2 – November 21, 2005, 10:21:30 PM

I have the Stage1 Trick Flow cam in my Bird. It has a similar mild rumpy idle to the "B" but makes more mid/upper range power and is only $139 at Summit racing. With a performance cam, I'd replace the valve springs befor you inst the heads... With either cam, you'll need a 2400-3000 stall converter. A set of 3.73s won't hurt either

cam shaft advice

Reply #3 – November 21, 2005, 10:22:27 PM

Just got off the phone w/ jegs he said the biggest I could go is F303 cause of .512 lift and leave the 1.6 rockers. Or I will have to change my converter. I’m still confused.

A little more info is this car is my weekend warrior. Not an every day driver.

cam shaft advice

Reply #4 – November 21, 2005, 10:31:20 PM

So what's your setup now, and what mods are you planning???

cam shaft advice

Reply #5 – November 21, 2005, 10:35:34 PM

would a "B" not be as agressive as im looking for.
and i agree im going to change the valve springs.got gears already.this converter is a 'monkey wrench' i relealy dont want to dig that deep right now. but do want the bigger cam.

cam shaft advice

Reply #6 – November 21, 2005, 10:45:33 PM

Quote from: TurboCoupe50

So what's your setup now, and what mods are you planning???

It’s my 4th T-bird. Got it about a year ago just re-did the whole interior motor is a 92' mass air motor w/ HO firing order the previous owner don’t know what out of, I think an explorer because of looking at the top of the plenum (V8 5.0). It appears to be mostly stock. I picked up those heads and upper & lower GT-40 intake from the local bone yard.

just want to make a hotrod like i said its my weekend warrior want to make it go fast and slepper looking thats just one reson i like thunderbirds

cam shaft advice

Reply #7 – November 21, 2005, 10:48:25 PM

With any cam larger than a "E" you should get a higher stall converter. Actually a converter like I suggested would help a stock setup considerably...

cam shaft advice

Reply #8 – November 21, 2005, 10:51:35 PM

All the Explorer engines already have GT40 heads(most are GT40P), you think the present engine has stock heads???

cam shaft advice

Reply #9 – November 21, 2005, 11:01:00 PM

I would also suggest the TFS stage 1, the FMS alphabet cams were good in thier day, but that was 10 years ago. there are many cams equal price that produce as much and more than the FMS cams. The TFS is a great cam and with the 1.6's you should be fine, always do piston to valvle clearance check. and youll be ok with a stock stall for the time being but you will want to upgrade in the future.

cam shaft advice

Reply #10 – November 21, 2005, 11:17:53 PM

Quote from: TurboCoupe50

All the Explorer engines already have GT40 heads(most are GT40P), you think the present engine has stock heads???

there GT-40 not GTP i was told GT-40 were used from 96 to 97 1/4 & GTP were used 97 1/4 to 2000 something.

cam shaft advice

Reply #11 – November 22, 2005, 12:04:52 AM

For a car with the stock convertor I'd get the Comp Cams XE258HR which specs out at .533/.544 lift with 208/216 duration @ .050. If you use a 2400 to 3000 RPM convertor I'd use the XE266HR which specs out at .544/.555 lift with 216/224 duration @ .050. With the 266 cam they suggest using 3.27 to 3.73 gears. Both cams have 112 degree lobe separation which will work fine with the EEC-IV

I'd use 1.6 rockers and definitely check piston/valve clearance. When choosing a cam remember for a street car less is usually more. If you get a cam that has a powerband that starts at 3000 RPM and your stock converter flashes at 1600 to 1800 tops your car will feel alot stronger with the stock cam till 3000. I would at a minimum match my cam to my converter, gears, heads and intake (in that order). Just remember that the lower the stall speed the smaller the cam you need to run. Big cam with stock converter = dog:)

cam shaft advice

Reply #12 – November 22, 2005, 12:48:42 AM

either way, a converter will make a HUGE difference, and will help your track times considerably

a trick flow #1, and a 2800 stall converter would rock

cam shaft advice

Reply #13 – November 22, 2005, 08:14:39 AM

Another vote for TFS stage 1 here... good idle w/ a tiny lope to it...

cam shaft advice

Reply #14 – November 23, 2005, 11:21:15 PM

Get the head casting numbers...F77E is a GT-40P head. A "P" head will also have the letters "GTP" cast between the number 1 spark plug and head bolt, in a diagnal fashion. With the "P" heads, you will need specific headers. I also agree with the votes for the TFS stage 1 cam. I just bought one and can't wait to get that going, dual pattern cams will run better on mild 5.0's any day of the week(thanks to relatively small exhaust valves).