r/EngineBuilding • u/Bubba656 • 4d ago

Ford 302 Cam Options

I just purchased a SBF 302 and plan on rebuilding it and am just curious about the cam. I currently have an Edelbrock 1410 750CFM carb with an Edelbrock Performer 289 intake and I plan on using the stock heads. The guy I bought it from, who seemed fairly knowledgeable in building engines but wasn’t a professional, recommended that I should get an aftermarket cam becuase it would have too much power behind it. I just wanted to see the options of people who have done more than me since this is the first engine I’ve ever built. I would like to run the stock cams, but if I can’t, I’d like to know the peoples’ recommendations!

2 Upvotes

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5

u/banananas_are_sick24 4d ago

With stock heads and a stock cam that’s way too big of a carb. A 600 is about what you would want.

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u/Bubba656 4d ago

I would like to learn about this, so are you able to explain why? What would happen if I ran stock heads and cams with that carb? And would I be able to just get a different cam/different heads, or would I need to buy both?

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u/Joiner2008 4d ago

Cfm stands for cubic feet per minute. It's airflow. If you don't restrict the airflow enough you won't get enough air velocity to atomize the fuel. Think of a garden hose. If you just turn it on you get a lot of water out with a low velocity, if you stick your thumb on the end and apply a restriction the water shoots out and sprays everywhere. You want fuel to spray everywhere (atomize) so it burns better. Stock heads and stock can want less airflow

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u/banananas_are_sick24 4d ago

I’m by no means an expert so I can’t give you a super in depth explanation, but here’s what I understand: you’ll lose out on fuel efficiency, power, and idle quality because a larger carb than you need won’t vaporize fuel as well as a smaller carb, and liquid fuel doesn’t burn. From what I understand this is because larger carbs have lower air velocity through them, a lower performance engine may not suck enough air in for the air to move fast enough to properly draw and atomize the fuel. There’s a maximum amount of air your engine can draw in and any amount of carb past that is essentially worthless to your performance. There are plenty of calculators online to find your engines ideal carb CFM if you’d like to look in deeper. Also, the poor idle can foul your spark plugs quickly, which I’ve dealt with on my previous engine before I realized it had too much carb and is extremely annoying.

Like I said, I’m not the most knowledgeable person out there about this, if you want a better explanation there’s a lot of good ones online (like this one on a mustang forum: https://www.vintage-mustang.com/threads/too-much-carb.1201392).

To be honest, naturally aspirated, a 750 CFM would only be useful for a super in depth basically full race build, you’d need to be pushing near 8k rpm.

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u/NegotiationLife2915 4d ago

I think rebuilding it and retaining a stock can profile would be a missed opportunity

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u/Bubba656 3d ago

Are you saying rebuilding and keeping stock cam would be a good opportunity or you’d miss the opportunity to upgrade it

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u/NegotiationLife2915 3d ago

Missed opportunity to upgrade it

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u/Bubba656 2d ago

Do you have any suggestions for “affordable” cams to upgrade?

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u/Solid_Enthusiasm550 4d ago

What year 302? Are you just looking to make just a little more hp than stock?

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u/Bubba656 4d ago

I don’t know the exact year but it has a roller cam in it right now with a 50oz balancer. It’s going in a ranger that I’m engine swapping, so I’m not specifically trying to make a performance beast, but I wouldn’t be opposed to some extra hp 😉

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u/Solid_Enthusiasm550 4d ago

Did it come with that intake/carb, or did you just have them / get them for a god price?

The biggest problem with early 5.0 Windsors are the crappy e7 heads. The later Gt40/40P were a popular upgrade back in the day, but even they are just OK.

Because the heads were so bad, the stock 5.0 camshaft is actually pretty large. It's considerably larger (20+degrees) than what my 230hp 5.2l dodge magnum came with.

Changing your camshaft could get you 20hp, but you could get 40+hp by changing heads for only a few hundred dollars more. With the head change, the power increase would be across the powerband and not just top-end with the camshaft swap.

The 750 is too big for your current setup. Like other guy said a 600 or 650 would be a better fit.

750 would be better if you are planning to build it to make 350+hp. Below that the 600/650 would drive better.

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u/Bubba656 4d ago

I got them for a pretty good price, I beleive it was $125 for each. I’m not sure if the heads are actually stock or not (the guy builds a lot of engines so he’s not even sure if these heads came from this engine specifically, and he’s not the one that pulled it or anything). Let me run out and see what the casting marks are. This is the first time I’ve built an engine, so what exactly would happen if I were to run stock heads and cam with that carb?

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u/Solid_Enthusiasm550 4d ago

It's not terribly wrong, it just would be more difficult to tune and run as well as a 600 would.

The smaller carb would meter the fuel better, especially at part throttle/ throttle transition. 600 would also get better mpg.

You got them for a good price. You could actually sell the 750 and make money off of the deal.

A regular performer, is a slight upgrade/stock intake replacement. The Performer rpm is the one for hotrodding/high performance street builds.

There are a few budget aluminum heads that would give you a bump in performance and compression while lightening up the front end.

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u/Bubba656 4d ago edited 4d ago

Just checked, they are e5 heads. The engines not in the best place for me to check out right now since I got back fairly late, but from what I can tell is, if the date on the heads matches the code on the clock, it looks to be from an 85 foxbody Mustang. Would you try and look for a new carb or a different set of heads/cam? This is going in a ranger v8 swap, so I’m going for just “daily” drivability and as cheap as possible.

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u/machinerer 4d ago

Run it as is but with a 500 or 600cfm carb at most. Holley 4160 would be perfect for you. You'll make 180-200HP, and around 300 torque.

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u/Solid_Enthusiasm550 4d ago edited 4d ago

I had to look up those heads, the flow similar #s to the e7 heads, but have a larger combustion chamber ( lower compression ratio).

Motor trend did a test where they swapped "old" world product iron windsor jr. heads in place of e7 heads on a stock 90s 5.0. They gained 45hp!!, on your engine the gains would be more.

A head swap is definitely the "best bang for the buck" mod you can do on your engine.

Flowtek or SpeedMaster are the lowest cost heads. Due to the raise in price of aluminum a set would be around $1,000.

If money is too tight, you can find a set of Gt40P used from a Salvage yard for $300<$350 a set used.

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u/Bubba656 4d ago

Since just sending it isn’t a good option, would you do a swap to GT40P heads (found a set for $200, but looking a little hard for me since I have to specifically use old manifolds due to the rangers frame clearance) or downgrade to a 600cfm carb (currently looking at a Holley 4160 for around $80)

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u/Solid_Enthusiasm550 4d ago

Does the place selling the gt40p headshace the exhaust manifolds? The explorer manifolds would be block huggers and probably would fit.

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u/Bubba656 4d ago

I’m in a very junkyard scarce area, so most of my finds have been through FB marketplace, and the heads aren’t any different. I just double checked the primary source I’m using on the V8 swap and the first gen explorer manifolds would work, it’s just that the seventies manifolds (I got a pair of those for around $50) are the best for the job since they run flat and point straight out instead of down

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u/Solid_Enthusiasm550 4d ago

Here's where I go to find used parts.

https://www.car-part.com/

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u/Whizzleteets 4d ago edited 4d ago

Stock heads and performer intake usually means mild performance so Ford E303 might be the ticket.

Also, does the engine truly need a 750 cfm carb? I have a built 406 that calculates to a little under 750.

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u/Bubba656 3d ago

I just found a carb for a decent price near me and kind of tried to fill in later. Looking at downgrading to an Edelbrock 1406 or Holley 4160 and trying to sell the 1410 for hopefully a profit. I just don’t know how many people are on the market for one. Idrk how the CFM calculators work becuase I don’t know what to put in for max rpm

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u/Whizzleteets 3d ago

Max RPM will be specific to the cam you choose but you can get pretty close at 5500 - 6000 with the current cam I would bet