I'm finally getting to build a 331 stroker, and need a recommendation for a cam. I have a set of AFR 165 heads and a set of GT40 tubular intake with lower ported by Tom Moss. I would like to get the biggest cam that I can adapt the EEC-IV to, and still pass smog. A couple that I'm looking at:

Ford E303: .498/.498 lift, 220/220 at 0.050, 110 separation. Seems most EEC-friendly, but seems to be much-derided for some reason.

Comp XE-270HR: .512/.512 lift, .218/.224 at .050, 114 separation. May be the most aggressive that EEC-IV can handle.

Other recommendations? TIA

 

A few months ago I reground a 5.0 HO core for a customer with a 92 Mustang that he restored. He wanted a cam that was similar to one of the 303 cams so I ground him 221/221 at .050 .525 lift on 114. 46.7 degrees of overlap at .006 cam lift. He runs it with the EEC-IV system but I think that he's upgraded the injectors and the mass air flow meter. It has a very healthy idle even on a 114 lobe sep. Later I did another cam for a customer using the same lobe on the same HO core but I pulled the lobe sep in to 110 giving it 54 degrees of overlap @.006. With a set of 1.7 rocker arms it has .555 lift. That guy is going to use it with a ported set of the X302 heads on a 5.0 in a street rod '42 Ford pickup. He isn't going to use the EEC-IV, he's going to run a carburetor.

It would be interesting to see how the tighter lobe sep cam with about 7 degrees more overlap would work with the stock system.

Also, these are both engines that are stock or nearly stock displacement. A 331 could tolerate more overlap with the factory computer system than only 302 cubic inches but I think that both of my examples are overcammed. I think that the 220 or so lobe is more appropriate for a 331 that's going to be driven on the street.

A lot of people feel that the E series of cams from Ford have lobes that are not aggressive enough. They do have very mild accelerations and moderate lifts for their durations. But I don't necessarily feel that this makes them a poor design. There are times when having duration is more important than some more lift at the top of the lobe. They were made to basically drop into an engine with an otherwise stock or mostly stock valvetrain.

A good example; I used an E303 lobe to regrind onto a factory Chrysler 318 roller core for a customer. It fit and worked great. The reason I used it was because finding a valve spring that'll fit and handle more than .460 lift takes a bit of doing on a 318 head.

 

Application? - I don't see a truck listed. Rear gearing, transmission type/stall speed, street or strip, etc...

Exhaust? Engines are air pumps. More air in/more air out will increase power. Helping the intake side won't do much if the exhaust is still a restriction! Headers - even shorties - will help over stock manifolds. Size of the primaries is dependent on application/rpms desired.

Compression? Not sure what 331 kit you're using, but going much above 9.5:1 will be tough to manage/pass emissions.

With a 331, you might want to consider 1.7 rockers as well since you're adding almost 10% to the displacement (again more air in/out needed from a '302'-spec cam.) The 1.7s will add about .~.030" lift to either cam you select, and duration will still stay the same (short) for emissions.

I had built an emissions-friendly 393W back in 2007 for my '89 daily driver that actually passed Ohio's emissions sniffer test. My 351W block was not a roller since those were harder to find back then... I used a Comp X4262H '4x4' torque-grind cam with 1.7 rockers. 3.55 gears, and a custom Wide-Ratio AOD. I daily-drove this for several years - even in Cleveland winters - and also used it to tow a 4000-pound trailer on occasion.

 

Thanks Gents,

More details:

This is going into my 1987 Mustang GT, which currently has the 5 speed T5 and 3.08 rear end. It will be mostly street driven, with road racing at Willow (Button and Springs) a couple times a year. I will not be doing drag racing, so ultimate power is not the goal.

Exhaust is currently Texas Turbo 1.5" shorty headers (smoother than stock), which I could upgrade to something like 1-5/8 if necessary. Stock catted H pipe, 2.5" cat-back.

I'm using this Scat 1-94055 kit: https://www.summitracing.com/parts/sca-1-94055 It has pistons with 5.2 cc volume.

Heads are AFR 165 Renegade 1472 heads with 58cc chamber volume. Yes, I wish I had gotten the 185s instead, but it's what I have.

Using Fel-Pro 1011-1 gaskets (4.1" diameter hole, .041" compressed). Other suggestions welcomed.

According to one source, the calculated CR is 9:1, while another claims 10.3:1.

But just based on all the measurements I can think of, I come up with 10:1. This is taking into account deck height (8.206), pin ht (1.165), gasket thickness and hole size, piston volume, bore (4.03), stroke (3.25), rod length (5.4), piston depth (.016). Did I miss anything?

I will be re-using a set of Crane/Cobra 1.7:1 rockers, so I don't need a cam with more than .32" lobe lift.

I read from various sources that 220 intake duration is about the max that a tuned EEC may be able to accommodate on a 302, so maybe a 331 will work better with it.

The E303 cam has a CARB exemption, so it's emissions legal, even though it only has 110 lobe separation.

The Comp XE270H is not CARB exempted, but has 114 lobe separation, so I expect it to be more emissions friendly.

The stock HO cam is hard to find; I would pull it out of my old engine if I didn't have future plans for it. The important thing is I need to keep it running, so I can't really raid it for parts.

I looked for a cam out of an Explorer or Mountaineer from my local scrap yard for regrinding, but even those are rare.

 

You're going to seriously limit output of that motor with a cam that cooperates with SD EFI and passes smog, to do that is has to produce a stable smooth idle with high vacuum. I have passed smog with a 35-349-8 in a 5.0 but that was a MAF motor, a good friend of mine had the Comp 35-351-8 in an '89 MAF 5.0 with Performer heads, GT40 intake, 24lb injectors that wouldn't pass a tailpipe sniffer test, some tuning I did may have helped but I never heard what the outcome was afterwords. That shows you where the line is between smog compliant and not with MAF but SD is even more limited.

All the Ford alphabet cams require MAF to run even half decent.
I think you're going to want/need a gear change, if you get that motor running to it's potential it'll make power out to 6000rpm, that puts you at 45-50mph in 1st gear depending on tire size which is just rediculous.

 

Thanks Paul,

I forgot to mention that I did a conversion to a stock MAF with an A9L EEC-IV a few years ago, and it's been running well, passing smog a couple times. This is on a mostly stock engine, in anticipation of the H/C/I upgrades. Other modifications are the aforementioned 1.7:1 rockers and the 1.5" headers, and the cat-backs that probably don't do anything for emissions. I also have a 70mm throttle body for the GT40 intake.

Tires are 245/45/17 from the 1996 Cobra brake conversion (M2300K). It's just a little taller (.052") than the stock 225/60/15, mathematically.

I'm estimating engine speed will be around 1900 rpm at 70 mph, a little below the advertised point at which the E303 starts make its influence, 2500 rpm. Would running the engine below this point be horrible for performance and emissions?

I figure if I want power at 70 mph, I can just shift it down to 4th, which should put the engine at just above 2500, and rev until the stock T5 blows up. It will be a good excuse to get a TKX.

I have the Moates Quarterhorse hooked up to the EEC-IV, using TunerPro RT to log data. I'm learning to use it to adapt the EEC to whatever larger injectors, MAF, and cam I end up with. (And I'm sure I'll be asking for help from people who are experienced with those tools.)

 

The thing is if you're going to road race the car you want more than 1 gear available to you for any given situation. For maximum performance the engine will spend all it's time between the torque peak to the HP peak.. that is the functional powerband and with a 5.0 that is typically 3000-6000rpm give or take. You might never exceed more than 100mph or so on the track(depends on the track of course), with 3.08 gears you effectively only have a 3spd transmission as you'll never get to the top 2 ratios. The correct axle ratio will put the engine at or close to peak HP at top speed in top gear.. or maybe 4th anyway.. lets reserve OD to retain a bit of street driving compatability, crunch the numbers to see what axle ratio is needed for that given your tire size. Hint... it's 3.73 to 4.10.

 

You're right Paul; running the numbers shows that 3.73 may be the best gear for road racing. That's going to be like the low ratio of what I now have in my Aerostar; first gear (3.4 in the M5OD, 3.35 in the T5) is almost useless, and second gear is far enough away that I can't really start there from a stand still. So I'm considering if it's worth that and the reduced fuel economy for something I may do just a couple times a year. The 8.8 rear is a lot more work to change out gears than an old 9" with the removable pumpkin, so whatever I decide will be like a long term commitment.

Let's say I go with the E303 (and all the other parts I listed), will the engine actually be making peak power at 6000 rpm?

Dave, I know you;re an advocate of tight LSA, which the E303 seems to have at 110. Most of what I read said that the narrower LSA tends to make the power and torque curves narrower, and allow more intake charge to exhaust out. So should I go with something a little wider, like 112 or 114? I would expect the wider separation to be more emission friendly.

 

To get the HP to peak at about 6000rpm in an engine of that size it would probably need around 240 degrees or so at .050 but I think that the all around performance would be better with it peaking lower with the ability to rev past the peak by 1000rpm more or less.

I think that a wider lobe separation does tend to be more emissions friendly but that really depends on the amount of duration. The stock Ford 5.0 non HO hydraulic roller is ground on a 107 lobe separation yet it only has 33 degrees of overlap at .006 lift. This is due to the cam being tiny. It only has 183/190 duration at .050. 241/251 @.006

The HO 5.0 cam is much larger: 210 @. 050 on both sides, 272 @ .006 but ground on a 115 lobe separation. According to the data from the cam that I plotted it has 38 degrees of overlap at .006.

I feel that if you have to compromise on the camshaft specs for emissions compliance or some sort of vacuum rule that compromising on the lobe separation yet giving the engine about the right amount of duration is probably the best way to go. Putting in the duration but then spreading it out to reduce overlap. For every degree that you widen the centerlines you lose 2 degrees of overlap so a little goes a long way.

A tighter lobe separation tends to make the torque curve shorter and at the same time taller, the engine makes more peak torque. This tends to improve acceleration through the power band. This is why most circle track camshafts tend to be ground using less duration and tighter lobe separations, 104,106, when compared to the same size engine used for other applications. In some special cases where compression and induction are rules limited this can get really tight. I've heard of 9:1 compression engines running cams ground on a 94 lobe sep in on 90!

 

The compromise gear would be 3.55, the only raises engine rpm at 70mph in OD 300rpm but that also reduces load on the engine which is actually more significant for fuel consumption with an EFI engine.at hwy cruise speeds. I can also speak from personal experience with doing the 3.08 to 3.55 change in these mustangs, overall the car ends up being a better driver all around.

It could be yes and it should also be making 350hp or so.

 

Thanks again Dave.

I went to a local-ish salvage yard today as they listed a 1990 Lincoln Mk VII LSC, which is supposed to have the same 5.0 HO as a Mustang GT of the same era. I thought if I could get its cam, it would make a good core to re-grind into something more aggressive. Alas, other folks with more time and keen eyes got to it before I could; they took the whole engine, and the EEC-IV computer.

There are a couple of other yards with Ford Explorer or Mercury Mountaineer that have the 5.0 engine. They should have the F4TE-6250-BA: .422/.448, 256/266 (guessing 201/211 at .05), 116 LSA.
Would these cams be good cores for regrinding to something like the E303 cam, but with 2 or 4 degrees more separation? (.498/.498 with 220/220 at .05, 112 or 114 LSA) I'm thinking base circle would have to be reduced by at least .076 to get the lift.

Or, it might be easier for me to get something like a TFS Stage 1 (.499/.510, 275/279, 221/225, 112 LSA). Will the durations be too much?

Paul, The 3.55:1 rear end sounds like a great compromise, but it will have to wait.

 

From what I've seen moving the centerline 2 degrees on each lobe to change the lobe separation 4 degrees shouldn't be a problem if you're using a lobe that's similar to the E303 which has.312 lift. It can be sort of hard to predict exactly how the size of the lobe will change when it is reground to change, lift, duration or both. The stock intake lobe on the F4TE cam is .264 lift so changing that to .312 is .048. That means that the minimum that would have to be removed would be .050 if the only change made was to the lift. It will take off more to make the changes in duration, lift and centerline so I think you're right that it could take off .075 or so from the base circle.

It is weird to watch the lobe as you regrind it. Usually with a change like this it'll start out on the base circle and then gradually climb up the flanks on both sides. If the centerline is being moved it will climb the one side more quickly than the other one and usually reach the nose before the other side catches up and the lobe cleans up. Sometimes it'll actually grind the base circle, then the nose radius and then clean up the flanks just depending on the design of the lobes.

On the regrind that I did using the HO cam where I moved the centerlines in 2.5 degrees on each side to reduce the LSA by 5 degrees the lobe I used had .326 lift. The base circle on that cam ended up at 1.330. On the HO cam that I reground using the same .326 height lobe and I didn't move the centerlines I ended up with a base circle of 1.335. It actually changed a surprisingly small amount. Now the intake and the exhaust lobe final sizes are probably slightly different from one another, I didn't put that in my notes but I do know that the one on the stock centerlines worked just fine in the engine with a set of stock pushrods and rockers. The only changes to the valvetrain was to the springs and retainers to accommodate the increased lift which ended up at .521

 

I'm not sure how I feel about buying a new E303 just to have it reground immediately.

So I'm looking on ebay for potential cam cores, and come across this:

https://www.ebay.com/itm/17553093741...Bk9SR7SfqK2pZA

It looks pretty beat up to me, and I'm a little amazed that the seller has such high expectations for it. Correct me if I'm wrong, but it looks to me that a lot of material has to be removed in order to make this core a usable cam again. How small can you cut the base circle before the oil passages no longer line up?

 

Most of the time any pitting goes away surprisingly quickly with a regrind but I would find a better core to start with if possible. I typed in "Ford TE cam" and found one that looks nice in the pictures. It just needs a trip to the hot tank. It is also too expensive at $143.33 with $39.19 shipping! They should be about $50-75

I bought a really nice stock HO core at the swap meet last winter for $20.

 

Thanks, I thought it was a bit pricy as well. Now that I know the market value, I'll keep looking.

Or I can go back to the local yard to pull one out.