A little cam help please.

[66gt350]

I've heard that but never tried it. I guess I might on my build. My 94 Cobra short block has an E303 roller cam which everyone says is too mild so I may be swapping in something a bit more radical and keep the lifters. What specs are you using on the Clay Smith cam?

I'm not sure which cam I'm gonna go with. I've talked with George at Clay Smith a couple of times. I'm not gonna go too much more radical than the ford cam. I just want to get away from the e303 and the dreaded idle surge, even though I've got most of that tuned out.

The retro lifters are over $400. They have an H bar to keep the lifters from rotating.

With those retro fit lifters, do you need to run a small base circle cam? I think I heard that somewhere, but I don't recall.

Sort of.

An early 302 has a different firing order. A later 5.0 and all 351 windsors have the same firing order. You can use a cam for an older 302 but must use that firing order. I don't recommend it however.

Normal 5.0 motors have the older style firing order, it's the HO motors that have the different firing order. but most cams that manufacturers grind have the HO firing order.

289 1-5-4-2-6-3-7-8
302 (Pre-82) 1-5-4-2-6-3-7-8
5.0 1-5-4-2-6-3-7-8
5.0 HO 1-3-7-2-6-5-4-8
5.0 Truck 1-5-4-2-6-3-7-8
351 1-3-7-2-6-5-4-8

Over the years, I've run both firing orders in my car. I've never had any issues with either one.

 

[tarafied1]

quick history lesson. In 1982 Ford reintroduced the GT (Mustang GT that is). It was a tried and true smog motor 302 but they put a marine application 351W cam in it and a bigger 2 barrel carb. Ever since then the HO motor's have been using 351W firing order. It was just some off-the-shelf stuff in the beginning.

As for the smaller base circle roller cam, I'm no expert but I believe it is needed to keep the cylinder part of the lifters in the bore of the older block as the newer block has a different casting.

Since I'm on a budget, I'm going to start with the E303 but once I am comfortable with my driving and the car set-up, I plan to play with cams, intake, heads and maybe some day a turbo. This car is going to seriously beat on!

 

[gotstang]

As for the smaller base circle roller cam, I'm no expert but I believe it is needed to keep the cylinder part of the lifters in the bore of the older block as the newer block has a different casting.

Yeah. There is another option; a 5.0L type cam with linkbar lifters will work to retrofit an older block. The small base circle cams are just one big compromise and $$$. When you can pick up a used performance 5.0L cam for $100, the retrofit cam really isn't a great option, IMHO...the linkbar lifters are not too expensive, so it can be done for reasonable $$.

As for cam reccomendations, I'd probably stick with a hyd. flat tappet for simplicity. A Lunati 61002 would probably be my top choice, followed by a Comp XE268H...but, cam selection depends on the rest of the engine specs, especially heads and compression ratio.

 

[panteramatt]

Great. So any of the used cams made for HO 82-93 5.0 will drop right into my 351 right? And as long as it a hydro flat tappet all I would need is new lifters?

 

[Sluggo]

Great. So any of the used cams made for HO 82-93 5.0 will drop right into my 351 right? And as long as it a hydro flat tappet all I would need is new lifters?

As long as it is a roller. Flat tappet cams can not be reused.

 

[tarafied1]

yeah, technically you could put in a used cam but if you are going to all the work to put a cam in and get it all adjusted and stuff I wouldn't put a used cam in. It's way to risky IMO. New flat tappet cams are not that expensive from PAW, Jegs, Summit, etc.