Why does everyone hate the E303 cam?

[ba123]

I just did a search as I don’t remember why I installed my cam at 4° advanced and all I can find is people who hated the cam I have.

I’ve never run it, but I planned it working with all the other things I did but just curious why all the hate. Did this that tried it do so on a relatively stock engine?

I really don’t remember all that went into my planning so many years ago but I had to pick this for a reason.

Thanks!

 

[House]

I thought everybody loved the E303? haha

 

[ared77]

Yeah, I thought it was very popular.

 

[ba123]

The more I search, the more I find both ends of it. I guess it doesn’t really matter since, like I said, I planned the whole build together, engine and lots of mods, tranny, stall converter, gears…

It’s just been so many years since I planned it that I don’t remember it all. I decided to install the cam straight up and no advance added unless someone really has a good reason for advance.

Thanks!

 

[jamesroney]

The more I search, the more I find both ends of it. I guess it doesn’t really matter since, like I said, I planned the whole build together, engine and lots of mods, tranny, stall converter, gears…

It’s just been so many years since I planned it that I don’t remember it all. I decided to install the cam straight up and no advance added unless someone really has a good reason for advance.

Thanks!

E303 is a POS. Nobody that has ever bought one and run it with a EEC-4 computer has ever liked it. I threw mine away in my 347 SEFI build. It’s junk.

It can be made to produce good power at the top end, but driveability is poor. There are just so many better choices out there. All of the Ford alphabet cams are junk.

A dog can be made to pull a wagon too. But it still isn’t a horse.

 

[Gsxr7000]

I can tell you that the E 303 cam is very desirable to the mustang community. They actually bring good money today.

 

[ba123]

E303 is a POS. Nobody that has ever bought one and run it with a EEC-4 computer has ever liked it. I threw mine away in my 347 SEFI build. It’s junk.

It can be made to produce good power at the top end, but driveability is poor. There are just so many better choices out there. All of the Ford alphabet cams are junk.

A dog can be made to pull a wagon too. But it still isn’t a horse.

Ok, we’ll, I’m not running a normal computer so keep your fingers crossed for me. I’ll either prove you wrong, or change my cam.

 

[lars]

It has a narrow lobe separation angle (110°). Rule of thumb for EEC-IV computers (yes, I saw that you don't have one) is that they aren't idle friendly with much less than 114°. It's an even, as opposed to split duration cam. General thinking in the small block Ford community is that, due to the shape of the exhaust port and location of the valve, that it's inefficient and needs more exhaust duration. I'm merely the messenger here- I don't have enough direct experience messing with cams and heads to weigh in.

Back when I was paying attention, split duration cams were just coming into vogue and the alphabet even duration Ford cams were being panned. There are a lot of options these days, but hey, if you have it, run it. Cams aren't that difficult to change. I've changed a few with my engine in place, despite being told that it wasn't possible.

 

[904Bronco]

Ran an E303 cam for years in a 312 V8 Fox body mustang Opentrack car. Wants to idle at 900-950 rpm, Great at 3500 rpm in 3rd gear.
Not much past 5200 rpm running Edelbrock heads, a little slow out of the hole.
I have never heard a Bronco guy say that he was happy with it in his rig, just not the right Cam for Bronco needs. You asked...

 

[ba123]

Thanks, yeah, hoping I have better luck running an MS3 setup.

Also hoping that I get more out of it with my heads and intake than others have, as well as the prob higher stall converter than other tried it with? I set that for the cam, but don’t remember where. Maybe 2200? Idk. Been too long.

I did plan and buy this stuff 30 years ago, but pretty sure I planned it well. I did, though, plan it more like a Mustang than a Bronco, so time will tell.

 

[56f100bbw]

I can tell you that the E 303 cam is very desirable to the mustang community. They actually bring good money today.

I got one in my 66 fastback mustang but I haven’t got it started yet

 

[Quick & Dirty]

Advancing the cam increases torque at lower rpm by a few ft-lb at the expense of torque(and HP) at higher rpm. Many aftermarket street cams are ground with 4° advance built in, E303 is not.
Advancing closes the intake valve earlier which increases dynamic compression/cylinder pressure at low rpm, but doesn't allow the cylinder to fill as well when intake velocity increases at higher rpm.

 

[ba123]

Advancing the cam increases torque at lower rpm by a few ft-lb at the expense of torque(and HP) at higher rpm. Many aftermarket street cams are ground with 4° advance built in, E303 is not.
Advancing closes the intake valve earlier which increases dynamic compression/cylinder pressure at low rpm, but doesn't allow the cylinder to fill as well when intake velocity increases at higher rpm.

Yes, agreed, and perhaps normally in a Bronco it might be good at 4° advanced, but I’m feeling that since I also have the ability to change from low torque to high rpm power with my BXR intake plenums that I would just put the low torque plenums on and it would be the ideal scenario.

 

[kman67]

I installed an E303 cam when I did my mustang fuel injection 15 years ago. It doesn’t have good take off power. The power kicks in after 2000 rpms. I had trouble with rough idle when I came to a stop. I had to have EFI guy tune it and it helped, but still have a rough idle when I start it when its warm. I’m finally going to change it out when I do my Explorer serp conversion. I have a stock stall torque converter. 5.8 with Edelbrock performer heads and intake, 9:1 compression.


Sent from my iPhone using Tapatalk

 

[ba123]

Yeah, I'm thinking that's why I got the custom converter with a higher stall.

I wouldn't even know at this point what cam to go with for this if I did change. For those anti-E303 guys, what would you say is best for my setup?

30 over bore
Trick Flow Twisted Wedge Heads
BXR Intake
30 LB injectors
MS3 Ecu

 

[Timmy390]

My advice....first, match your cam characteristics to how you plan to use your rig. Second, match it to the rest of your combo. Not just motor. You have to consider gears and transmission. You will get 100's of cam suggestions as everyone (including myself) will tell you they picked the "best" cam.

For example, if you plan to cruse around at 2100rpm and you can don't make power till 2500rpm, it's not going to be optimal. IMO the goal is the be in the power band when crusing. My cam makes power from 1500-5500rpm and is more of a torque cam. So when I'm in 5th and bumping 2400rpm's I have good response and climbs hills without downshifting.

Having a 351W also helps the torque.....

Tim

 

[bigjhoov]

E-303 seems to be a high rpm cam. I have one in a '96 explorer motor that I bought, I'm planning to pull it and put an explorer cam back in. I may even retard it a few degrees for better low end power. Or I might go the Comp Cams 35-349-8.

 

[Timmy390]

I might go the Comp Cams 35-349-8.

That's my cam..... I noticed a difference over the Explorer F4TE-6250-BA. The 35-349-8 didn't play well with my SN95 EFI which was tuned for the F4TE but I got it running right with an idle air bypass. It just needed more air at idle than the IAC could give

Tim

 

[MarsChariot]

I am using the E303 in the '71 with Mustang EFI. Since I have 4.11 gears in the rear and do a lot of high-speed highway travel to wheeling locations, it seems to be a happy cam even with a NV3550 5th gear. Around town it is fine, and on the trail I use 4-Lo, so the power seems fine for me.

 

[ba123]

I am using the E303 in the '71 with Mustang EFI. Since I have 4.11 gears in the rear and do a lot of high-speed highway travel to wheeling locations, it seems to be a happy cam even with a NV3550 5th gear. Around town it is fine, and on the trail I use 4-Lo, so the power seems fine for me.

Thanks, that's nice to hear. That's kinda similar for me. I've got 4.57 but my AOD top gear is 0.67 vs yours at 0.78 I think. I also have all the upgraded internals for it and wide ratio kit. Planning on 35's with that.