Performer 318/360 intake

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cudabob

cudabob

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I have a mild 360 (low/145 comp)stockish cam with edelbrock performer rpm heads with the performer 318/360 intake manifold with a 600 edelbrock carb on top.My question ,is there any point in porting the manifold to match the heads on such a mild build?thanks
 
Agreed- the gain would be miniscule, but still a gain.
If the engine is already apart, go ahead and port match it. Small gains can add up.
If it's together, and running? I doubt it would be worth tearing it apart, getting new gaskets, buying the burrs and grinder just to do that. Doubtful you'd notice much if anything on the seat-of-the-pants meter with a stockish build.
 
middleagecrisis said:
My question is why do you have Edelbrock RPM heads on such a stock motor? Personally, I’d changed the cam, intake and carburetor to take advantage of the heads that you have.
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Sometimes it's cheaper to get aftermarket heads than to rebuild the cast iron ones......especially if yours are cracked and you have buy another set. You get the added bonus of them being a good head if you want to warm up that engine in the future. The aluminum heads also allow you to run higher compression without detonation problems, and on a street motor, to run cheaper, lower octane fuel.
 
cudabob said:
I have a mild 360 (low/145 comp)stockish cam with edelbrock performer rpm heads with the performer 318/360 intake manifold with a 600 edelbrock carb on top.My question ,is there any point in porting the manifold to match the heads on such a mild build?thanks
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To really make those heads work, you gotta get that dismal 140psi up to at least 185, and 195 makes a killer street machine. Ask me how I know.
Until you fix the pressure issue, I wouldn't waste my time with anything else...... unless you have an auto-trans, then I'd order a performance convertor, one with a much higher than factory stall.
 
AJ/FormS said:
To really make those heads work, you gotta get that dismal 140psi up to at least 185, and 195 makes a killer street machine. Ask me how I know.
Until you fix the pressure issue, I wouldn't waste my time with anything else...... unless you have an auto-trans, then I'd order a performance convertor, one with a much higher than factory stall.
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Semi agree. While adding compression is a big factor, it’s not a 100% needed thing. More airflow over the stock heads is going to make more power.

Not taking advantage of the cylinder head the way the OE poster describes, is IMO, a terrible waste.

Even on a low compression engine, the added air flow will increase power. Leaving added compression and leaving a low lift cam inside is the horror. Even a modest increase of a camshaft would be great.
 
middleagecrisis said:
My question is why do you have Edelbrock RPM heads on such a stock motor? Personally, I’d changed the cam, intake and carburetor to take advantage of the heads that you have.
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Heck yea! The original poster should get a cam with as much lift as possible to take advantage of the heads air flow capability.
 
This is a bit of a different build for me.I have moved to a rural area and the good old days of 10 second street cars is 20+ years behind me.I need this car to cruise at decent speeds on the highway. I bought the car with this motor in it.Im trying to recycle as much as I can.The motor had to come apart because of multiple leaks.
 
cudabob said:
This is a bit of a different build for me.I have moved to a rural area and the good old days of 10 second street cars is 20+ years behind me.I need this car to cruise at decent speeds on the highway. I bought the car with this motor in it.Im trying to recycle as much as I can.The motor had to come apart because of multiple leaks.
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Port matching will allow the A/F charge to be a cleaner and easier flowing. This should help in easier breathing and increased fuel mileage. More Power vs the amount of throttle opening. Rejet as needed.

The easier it gets s to move the air and fuel out of the engine, the more potential power it can easily make. This requiring less open throttle area. More power with less fuel.

Sam’s would apply to the energy of the rotating mass and parasitic Greg on the front of the engine and the amount of power to rotat and move the parts behind the engine.

If it’s off the car, port it. If it’s on the car, leave it.
As said above.
 
cudabob said:
This is a bit of a different build for me.I have moved to a rural area and the good old days of 10 second street cars is 20+ years behind me.I need this car to cruise at decent speeds on the highway. I bought the car with this motor in it.Im trying to recycle as much as I can.The motor had to come apart because of multiple leaks.
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Totally understand your situation, lots of things my Duster "needs" to be optimal but right now I'm just thankful I still have it and can drive it.

It sounds like the engine is apart now then, correct? If so go ahead and open up the intake manifold ports to match the heads. You'll get a small increase in power and throttle response. Put it back together with good gaskets and run it. Of course higher-compression pistons, bigger cam and RPM intake would take advantage of the heads better but it will run fine without all that stuff.
 
If you go to YouTube "cudabob2" you can see some of my previous builds but I had to give up racing because of distance and financial commitments. This is more of a long distance cruiser for me and my wife to enjoy.
 
cudabob said:
This is a bit of a different build for me.I have moved to a rural area and the good old days of 10 second street cars is 20+ years behind me.I need this car to cruise at decent speeds on the highway. I bought the car with this motor in it.Im trying to recycle as much as I can.The motor had to come apart because of multiple leaks.
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Alright then, if the motor's apart go ahead and port match it- and the deeper you can go into the manifold the better.
The Performer manifold is kind of a compromise anyway; the ports are a bit bigger than 318 ports but not quite340/360 sized- that's how they get away with the 318-360 designation. Ideally, since it's apart, I'd be on the hunt for a dual plane intake with true 340/360 port sizes and a touch bigger carb to take advantage of those heads (you won't lose anything as far as drivability goes); but that's just me. A port matched Performer won't be bad, but if you can find something better, it will take less work.
The Eddy's 63cc combustion chamber (vs ~72 for stockers) is helping, but still I would reassemble with as thin of a head gasket as you can find (assuming a stock bottom end) to get as much squeeze as you can out of what you have.
 

there's a hot rod or car craft dyno shoot out from back in the day that pitted the new on the scene air gap against the performer, strip dom, six pack, and maybe torker?

anyway, the performer did admirably well in the lower RPM part not giving up much of anything in that "highway cruise" swath of testing.

granted, it was with eddy alum heads and a high lift cam but still...

point being, i think a gasket/port match and send it. low lift, and value for time invested is bang for the buck. any more than that you're picking fly **** out of pepper.

carb is a little small so there's room for improvement there. a QFT 680 VS would be choice on top of that.
 
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