I was wondering about the roller cam used in the 5.0 in the late model explorer/mountaineer... I'm looking to replace the tired 300/6 in my f150.. I picked up a motor from a 98 Mountaineer that has a burned up piston.... I haven't measured the cylinders yet but I am planning a stock rebuild possibly with forged pistons... I got the whole motor from throttle body to oil pan, and the whole engine harness, the only thing I'm missing is the maf and the computer.. Is the cam worth keeping or should I go with an aftermarket roller cam? I'm not looking for serious hp just something a little more powerful than the 300 and almost as good on gas... Also was there any application that used this 5.0 with a manual trans? this motor has the 2 coil packs and a cam sensor in the distributor hole.. or should I just get a distributer from a later 5.0 mustang and use the computer from that as well? I have no problem making a harness because I have all the sensor connectors on the present harness to work with..
Any input would be helpful..
Thanks,
Jason

 

I would keep the cam, I believe it's an E303, it's a good mix between low end power and high end hp, but an aftermarket cam would make an improvement. Call up comp cams and see what they have to say about the situation.

You'll have to get the right flywheel for that 5.0 to bolt up to your M5OD, but don't expect that M5OD to hold up to a lot of upgraded 5.0 power. As that motor is, it will easily out-power the 300. I hope you have the exhaust manifolds off it though, they use GT-40P heads which require a special header or manifold because of the spark plug location. If i am not mistaken, you should basically tear down the explorer 5.0 and make it more like the F-150's EFI system (using the distributor, one coil instead of coil packs, etc etc)...but I've never done the explorer swap or even really looked at one, so someone else will have to chip in here. We also have a motor swaps forum here that could help you.

 

I agree that the stock cam would probably be a good choice here. It's certianly not an E303. The E303 is way too radical for an Explorer anyway. It makes peak HP at 6000, and peak tourqe at 4500. E303's are notorious for a rough idle with mass air EFI too. The Explorer motor should be able to make about 300Hp with a E303 though. The stock Explorer roller cam is actually rather mild. Much milder than a stock 5.0 Mustang roller cam.

A good choice for a cam upgrade in the Explorer 5.0 motor, would be the comp cams XE264HR.

 

Ive been told in a few spots that the E303 is the stock cam....so I don't know which of us is correct...

According to Ford Racing's 04 catalog, you're not correct regarding the RPMs.

The cam has a spec of max torque of 2500 rpm, max hp at 5500 rpm from the catalog....and ford advertises it as a smooth idling cam. You're not gettin' crossed up with the B303 cam are you? Sounds jus like you're describing the B cam.

 

Hi Justin,

I know the characteristics of the E303 (aka..Crane 2040, part number 444231) by experiance, and I've seen several dyno charts of 5.0's using the E303 with various heads and intakes over the years. I'm also familar with, and have experiance with the B303. I know the old Motorsport catolog specs for the E cam that your refering to, but they are simply wrong. The E303 is really close to the B303 in duration, and in some ways actually more agressive. It only has 4 degrees less duration, at both .050 and overall, and it has a tighter lobe seperation. Moreover the lift of the E303 (using 1.6 rockers) is higher than the B303 at .498".

I have used the E303 in both mass air EFI 5.0 applications, and in carbed 5.0 applications. The idle is rather rough with EFI, but not so rough with a carb. It would be true that it has relatively smooth idle with a carb'd induction. If you set the idle at about 750, it's pretty darn lopey! It smooths out some up around 1000.

The Explorer 5.0, given the GT40P heads and the GT40 induction, would have been putting out at least 280-290HP with a actual E303, I'm quite certain.

The E303 goes back to at least the early 90's, and may be as old as the B303. I was reading dyno sheets for the E303 and using it by 92. The B303 was developed as a more EFI friendly version of the B302 in about 86. The B303 failed emissions cerification, so Ford began stocking the CARB certified Crane 2040, dubbing it the E303, for "emissions" legal. That's were the "E" designation comes from.

Regards,

 

OK I think I am going to use the cam that the motor has in it for now, I can always change it later... I drove the truck that the motor came out of after the replacement motor went in(125k junkyard motor) and it pulled pretty strong right up till the trans shifted (about 5500).. I have the exhaust manifolds but they look pretty restricted where the tubes are welded to the flange.. The flow path is about half the size of the exhaust ports.. maybe I can grind down the welds to open it up a little. The EFI that's on it looks just like a mustang EFI with the exception of the coil packs.. My plan is to find a dizzy and a computer from a late model mustang, preferably one with a roller cam so I don't have to get a new drive gear... If I have any trouble with the harness, summit sells the painless harness for the mustang 5.0.. I think they sell shorty headers that'll fit these heads too...

 

Sounds like a plan...


I was reading the E cam specs off ford's catalog, but the intake and other engine parts also determine the max torque/hp RPM levels....you put a truck intake (meant for low end instead of high end) on that engine w/ a E cam and it would move the peaks down the RPM scale, wouldn't it....?

 

ok I got a little itch and pulled the cam out... the number I found on it is- F4TZ6250B. I measured the lobe lift and got .263 on the intake and .280 on the exhaust.... with 1.6 rockers that would make about .421 intake and about .448 exhaust... no clue as to the duration... Also does it matter what year I get the flywheel from?

 

Good point. Most of the dyno charts w/ the tourqe peak coming at 4500, have been with aluminum heads or worked iron heads. With E7's it would probably shift it downward. One of the characteristics of relatively tight lobe seperation cams (The E is 110* lobe separtion), is a flattening of the power curves, were the tourqe peak can come lower, and at the same time, the HP peak comes much higher. The actual tourqe output from 2500 to 4500 may be rather close, so a change in head flow velocity or intakes..ect.. could change the actual peak tourqe rpm point quite a bit. The 110* lobe seperation also cleans up hydro carbon emissions, but it's nonetheless responsible for the seaching, lopey, low idle with EFI, too. The B cam and the stock cam ect.. average 112*, to 114* lobe seperation.

The idea that the E303 was the stock Explorer cam, probably comes from a Ford Motorsport dealer upgrade kit(M9000-E50) for the Explorer, offered in 1997. This kit included an E303 cam, and a set of Motorsport shorty headers. It claimed a significant Horse power improvement, without a significant loss of low to mid RPM tourqe.

 

That's not an E303. It does closely resemble the stock 94 Mustang Cobra cam, though. F4 also indicates that the cam was a 94 design. The 93 Mustang Cobra got criticized for being soft on low end tourqe, so the cam was redesigned to get more tourqe in 94. The 93 Mustang Cobra had a tourqe rating of only 270 ft-lbs, compared to the regular 93 5.0L HO's 300 ft-lbs. The 94 Cobra did had more low end grunt than the 93, although they didn't bother to change the official ratings.

I used a 95 Cobra cam in an HO with 1.7 rockers for awhile. It behaved much like the Mustang HO cam with 1.7 rockers. Decent low end, strong mid-range, but not much happening above about 5000 rpm. It didn't rev quite like the E cam does. The E cam makes 302's spin up fast, even with iron GT40 heads. The tach just jumps. You can bang the rev limiter.

The Mustang Cobra cam used 1.73 ratio roller rockers for .484 lift. This would give about .448 lift with 1.6's. Doesn't the Explorer use 1.7 roller rockers though?

The flywheel needs to come from a post 82 engine because they changed the imbalance that year. I think it was changed from 28 oz, to 50 oz, or was it the other way around?

 

This one doesn't have roller rockers , is it possible that they're 1.7 anyways? I was just assuming that they were 1.6... The stock hp rating according to alldata is 210hp@4500 and 280tq@3500, that's for a 97 4X4, which is what this one came from..
How do you think the fuel economy would be with the E cam? If it's not too much worse than stock I'll probably use that one with the mustang EFI. I'm gonna end up using the Mustang EFI anyway cause I have just about everything I need for it.. I'm also a little concerned with the durability of the M5OD so I know I can't go with too much horsepower.. I think I'd be pretty content with something around 275.. I think the 300/6 that's in there now is only 140 so even 210 is a pretty good jump.

I think my only issue will be with the flywheel and clutch for the M5OD, I think I need the 50 oz imbalance but I want to be 100% sure because I really, really don't want to change the flywheel in the truck..

 

Fuel economy shouldn't be the determining factor in selecting a cam...but the most fuel efficient would be if you made the torque peak RPM at an RPM level where you drive the most. If your average RPM was 1800-2000, than if you had the torque peak there, it would get the most gas mileage. Obviously, most engines are not this way.

The heads on the xplorer are GT-40P's which are considered a performance aluminum head. They'd shift the torque peak higher in the RPM over the E7s but would provide better flow for more hp. I think a torque peak at about 3k is perfect for this application, but everyone is different. An engine's power feels totally different if the torque is at 3k vs 4500...so it's all in what the user prefers.

 

I thought GT40P's were iron heads

 

Yes, the Gt40P as used on the Explorer are iron. The GT40Y or GT40X Tubro Swirl heads are the aluminum ones. The Gt40P is similar to the GT40 Cobra, but it has different exaust ports to make room for a unique spark plug entry. The GT40P requires different headers.

82 and newer 302's use the 50oz imbalance(SVO Motorsport catolog pg. 85)

If the rockers arn't roller, then most likely they are 1.6.

The 210HP figure is indeed the official rating, and it's well below what virtually identical engines, such as the Cobra motor make. The main difference must surely be the cam, or at least the lift at the valve. The HO made 225 HP and 300ft-lbs of tourqe with more restrictive E7 heads, and the considerably more restrictive HO intake and throttlebody, compared the Explorers GT40 peices.

To get an idea of how these cams compare, here's the duration at .050, and the lift, with 1.6's:

B303 -224* 480 lift, 112* average lobe sep.
E303 -220* 498 lift, 110* lobe sep.
Mustang HO -214* .444 lift, 114 lobe sep. (the Cobra cam is similar)
Comp Cams XE265 -212/218* .512 lift, 114 lobe sep.

The Comp cams XE265HR represents a nice middle ground between the stock Ford cams, and the more radical 5.0 Mustang aftermarket cams, like the B303, and E303. It would probably make a better cam choice for an truck, with more low end grunt. The operating range is claimed to be 1500-5500RPM.

I estimate that a GT40 parts equiped 5.0L engine (as the Explorer 5.0 is) would make about 255 HP and about 320 ft-lb's using the Mustang HO cam.

The B or E cam would pump it up to about 290HP, but both the tourqe and HP peaks would be higher up the RPM scale.

The Comp Cam would probably give around 275HP, and 300 ft-lbs, but at comparitively lower RPMs.

High RPM power is indeed harder on manual transmissions. I remember talking to a tranny tech once, about 5.0 Mustangs breaking World class T-5's fairly ofton. It was puzzling why 350 Chevy's in Z28's rarely broke the same tranny. He said: "The Chevy LT motors just don't have the HP up above 5 grand, like the typical street Ford 5.0L does."

 

Well, fuel economy is one of my main concerns with this motor.. I'm not going through all this trouble to swap motors just to get 11mpg.... to me it's not worth it.... I'm getting 21-22mpg with my 300.. I'll be happy with 15mpg from this 5.0.. If I can't get 15 or better, I'll just rebuild the 6.. This truck is pretty much my daily driver, 42 miles each direction to work 6 days per week... Although I would like to have a 300hp truck, I just don't see that happening while keeping any kind of decent fuel economy.. I'll probably just keep the stock cam and use a set of roller rockers and see if I like it... If not I can always swap the cam later.. My main concern is getting this motor ready to go into the truck before this 300 gives up...