Whats your cam of choice?

[purpony]

I was wondering what everyone is using for a cam? Whats your combo?

I will be using a 97 Explorer 302 with NON "P" GT40 explorer heads.
and auto tranny.

I was something that will give decent power, have a nice lope, and be completely streetable.

Also, while you are ready, what kind of hp/tq would i gain from ditching the gt40 heads and going with aluminum aftermarkets?

[carcraft302]

I am using the E303. It is street legal and does a lot. That being said I am not very sophistacated in my understanding of flow dynamics, duration and all that. I am using heads that are stock with over sized valves and running 24 lb injectors. I figure around 300 HP.

[cgrey8]

The GT40 heads, will do ok...better than the E7 heads, but they are still production heads. The difference in performance between them and the GT40p is minimal, but enough that us with GT40p heads don't ever forget the "p". If they are ported out or at least port-matched, they can deliver a little bit more, but the restriction on either of the Explorer GT40 heads is the valves. For streeting around, they will still do a decent job and will get close to 300hp, but I'd expect 300hp is about the max you can expect from a 302 with these heads and that assumes an aftermarket intake, cam, valve springs, and headers. With stock Explorer components and ONLY a cam upgrade, don't expect more than about 260-275hp tops.

As for cams, slower ramp rates don't float valves as bad, but they aren't as good of performers as a cam that lifts the valves fast to get them open wide, holds them there, then slaps them shut. The catch is fast ramp rate cams need stronger springs. The E303 is one of the FEW performance cams with a slow ramp rate because it's designed to replace a stock cam with little to no other mods to the motor including reusing the stock springs. However if you go with a true aftermarket performance cam, expect to replace those springs or you'll likely float those stock Explorer valves if you get much over about 5000RPMs. I've been told the springs in Explorer motors are weaker than those in the GTs because weaker springs give the heads more longevity. Since Explorers weren't performance motors, longevity was far more important than performance...so weaker springs was a no-brainer.

There are quite a few good cams out there depending on what you are looking for. Unfortunately lope is going to be gotten with a fair amount of duration and overlap which won't do as good on the street as a milder cam but will scream at 5000+RPMs. With stock heads, I wouldn't bother with a high RPM cam. Match the capabilities of everything together and keep a mild, but high-lift cam to optimize the heads as much as possible. The higher the lift, the better as long as the heads can support it. I would recommend the RM Comp Special Grind cam. This cam was designed to replace stock cams in even Speed Density computers WITHOUT needing a tune. However when advanced 4-6 deg, it's a real performer in MAF-based systems or carbed systems. If you want more details on this cam, let me know and I'll get you some contact info for ordering that cam.

Another good cam is the Crane PowerMax 2020 (PN#444211). It has a HUGE amount of lift (.530"/.530") which is often more than stock heads can handle though. I think Crane said that with the combination of some minor machining to the spring seats and special valve springs, you can get the valve to travel the distance the cam is lifting without binding the spring. But the machining and springs are money. Is it worth it? You have to decide.

I think most people just go with the E303 just because it's a tried-n-true drop in cam. It may not be perfect, but it is the cheapest option and it isn't a bad cam, even if it isn't the best cam. But I personally think for street use on stock heads, the RM Comp cam is a far better choice AND it can also be installed without replacing the springs. But if you do replace the springs, you can get a higher rev from the motor.

As for aftermarket heads, a set of aluminum heads will get you into the 300hp range. Most H/C/I upgrades to a 302 will get you into the 325-350hp range. But there's a big difference between buying a cam to run stock heads and making in the 270ish hp range, and buying heads, cam, intake, and headers to get up into that 350hp range. You gotta decide what the budget is and what kind of HP you will be looking to make. It ALL comes down to money.

Another tidbit, if you replace the heads, you may run into trouble with the Explorer accessory brackets fitting on the aftermarket heads right. I've heard that even Trick Flow heads have some problems with interference with things like the alternator on GT motors that require Trick Flow valve covers for clearance. I have no clue what kind of problems would be involved with aftermarket heads and Explorer bracketry...hopefully nothing, but if something can go wrong, it will.

Personally, what I will be doing IF my house actually goes all the way to closing next month is to build a 331 with Explorer intake, heads, and that RM Comp cam. This way, the outer appearance and shape of the motor will be exactly as it is with a stock Explorer 302. The added cubes and longer stroke will increase low RPM torque. The higher lift of the RM Comp cam will extend that torque right to 5500RPMs. After that, the torque curve will taper off pretty quickly. I expect that combo to touch 300hp. If I'm lucky, it'll be in the 320s...but I'm not holding my breath on that one.

[87ranger]

comp cam xe274hr

[cgrey8]

comp cam xe274hr

That's a good street cam for a stroker motor with aftermarket heads, but would it work as well for a drop-in replacement on an otherwise stock motor with GT40 heads? I'd think the xe266 would be a better fit for that. But since I have never run either, I can't say that with any confidence.

Here are the specs on both:
xe266hr
-rpm operating range 1600-5600rpm
-duration @0.50, 216in and 224ex
-lift w/1.6 rocker, .544in and .555ex
- lobe sep angle, 112

xe274hr
-rpm operating range 2200-6200rpm
-duration @0.50, 224in and 232ex
-lift w/1.6 rocker, .555in and .565ex
- lobe sep angle, 112

Both cams have quite a bit of lift, which is otherwise a good thing...a very good thing. But I'm not sure if the GT40 heads can handle it. Thoughts?

[MalcolmV8]

I'm running the stock explorer cam

[cgrey8]

I'm running the stock explorer cam

You and me both. I remember back when I had the motor still on the stand and was faced with the decision to dig into the motor and replace that cam with something better. I didn't, but I often wonder how much different the motor would perform had I gotten rid of the ultra-mild Explorer cam. I think Plowboy34 did upgrade his Explorer motor with an E303 before installing his and seems to be quite pleased with the upgrade.