Performer 318/360 intake

[cudabob]

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

 

[rumblefish360]

As in a power gain?
Making it more efficient?
It would be small, but it is free power.

Practice porting, it won’t hurt any.

 

[Professor Fate]

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]

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.

 

[cudamark]

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.

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.

 

[AJ/FormS]

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

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.

 

[rumblefish360]

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.

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.

 

[rumblefish360]

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.

Heck yea! The original poster should get a cam with as much lift as possible to take advantage of the heads air flow capability.

 

[cudabob]

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.

 

[rumblefish360]

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.

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.

 

[MopaR&D]

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.

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.

 

[cudabob]

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.

 

[Professor Fate]

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.

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.

 

[junkyardhero]

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.

 

[crackedback]

For all the 318/360 performer haters.

A couple of things I was around... port matched 318/360 with a 1" open spacer was only 5-7 hp behind a RPM AG/1" spacer on a 425hp 360 engine.

Port match it... it will do good things! Plus if you step up a little it's already done.

 

[TT5.9mag]

I’m not sure for a cruiser the juice will be worth the squeeze. The amount of time you’ll need to spend on it to gain really anything on a mild combo is not worth it. Leave it alone and go drive the crap out of it. You’ll never miss the 4-5 hp you coulda had.

 

[Kern Dog]

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.

195 cranking PSI ?

That is horrible advice, man.
Who wants to be restricted to premium gas all the time? I've ran several cars with cranking compression in the 140-160 range and they all ran fine on 87 or 89. High compression is great for race engines, single purpose cars and such but for a dude that just wants to improve on what he has, your suggestion costs too much, is too much work and will result in fewer options for fuel when out on road trips.

 

[crackedback]

JMO. it's only time. If you already have the tools to do it. Go for it. If you have to buy a bunch of stuff to accomplish it. PASS
Would I tear apart an already running engine for this one process. No.

For those that want that intake shootout link.
Dyno-Testing Small-Block Intakes - Induction Extravaganza - Hardcore Tech: Dyno Blast

 

[alpha13]

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

The low rise Performer intake has small runners designed for the 318 heads. They won't flow alot of air. It works alright on a 360 if you aren't turning alot of RPM and any intake that is port matched will definitely make a difference. However, I wouldn't spend alot of time with a Performer on a 360 unless you didn't have another option. There are much better intake manifolds on the market for the 360 that don't give up any bottom end. The the Edelbrock Performer RPM intake is basically the best intake manifold you can buy. Works great at all engine speeds and is good on stock engines all the way to a more serious race engine. It's a great design.

 

[MopaR&D]

The low rise Performer intake has small runners designed for the 318 heads. They won't flow alot of air. It works alright on a 360 if you aren't turning alot of RPM and any intake that is port matched will definitely make a difference. However, I wouldn't spend alot of time with a Performer on a 360 unless you didn't have another option. There are much better intake manifolds on the market for the 360 that don't give up any bottom end. The the Edelbrock Performer RPM intake is basically the best intake manifold you can buy. Works great at all engine speeds and is good on stock engines all the way to a more serious race engine. It's a great design.

Well he said right there "low compression 360 with stock heads and stockish cam" and he's trying to spend the least amount of money needed so dropping $400+ for an extra 5-10 hp sounds silly to me.

 

[junkyardhero]

Well he said right there "low compression 360 with stock heads and stockish cam" and he's trying to spend the least amount of money needed so dropping $400+ for an extra 5-10 hp sounds silly to me.

especially when that 5~10 is more than likely above the operating range he's planning on running in.

you hit the nail on the head. the performer is the right piece for the job in this instance.

 

[TT5.9mag]

especially when that 5~10 is more than likely above the operating range he's planning on running in.

you hit the nail on the head. the performer is the right piece for the job in this instance.

And facts are facts. The performer, in the test Dulcich did for hot rod, made more torque down low than the rpm air gap did. They started the runs at 3000 for all the tests and the performer was ahead there in torque and horsepower, even on a 10:1 solid cammed 360 with ported heads. For a cruiser that’s never going to see 4000 rpm the performer gets the job done, dare I say better than anything else.

 

[junkyardhero]

And facts are facts. The performer, in the test Dulcich did for hot rod, made more torque down low than the rpm air gap did. They started the runs at 3000 for all the tests and the performer was ahead there in torque and horsepower, even on a 10:1 solid cammed 360 with ported heads. For a cruiser that’s never going to see 4000 rpm the performer gets the job done, dare I say better than anything else.

i demand at once you stop being reasonable, this is FABO after all.

 

[AJ/FormS]

195 cranking PSI ?

View attachment 1716487061

That is horrible advice, man.
Who wants to be restricted to premium gas all the time? I've ran several cars with cranking compression in the 140-160 range and they all ran fine on 87 or 89. High compression is great for race engines, single purpose cars and such but for a dude that just wants to improve on what he has, your suggestion costs too much, is too much work and will result in fewer options for fuel when out on road trips.

Like I said, mine runs on 87E10 and has since 1999.
The question is, why put a new roof on a building with a crumbling foundation?
OP already has alloy heads; but his pressure is just 145psi, indicating either
1) that his pistons are way down in the holes, or
2) that his stockish cam, ain't so stock.

145 psi is fast approaching a lazy-dog bottom-end, and with nearly always a sluggish throttle response, when the carb is correctly sized; and the 600 is too small for the cam and heads.
And; since we're NOT in the racing forum, and since, I have a lifetime of experience as a streeter, and since, the OP is asking for an opinion, here it is again;

for me, my opinion is, that porting is NOT the next thing to spend money on.
The next thing is to get the pressure out of the basement.

Kern Dog; you are free to state your opinion as to the OP's request.
You are not free to downplay anyone else's opinion.
Let the OP make that decision.

 

[MopaR&D]

Like I said, mine runs on 87E10 and has since 1999.
The question is, why put a new roof on a building with a crumbling foundation?
OP already has alloy heads; but his pressure is just 145psi, indicating either
1) that his pistons are way down in the holes, or
2) that his stockish cam, ain't so stock.

145 psi is fast approaching a lazy-dog bottom-end, and with nearly always a sluggish throttle response, when the carb is correctly sized; and the 600 is too small for the cam and heads.
And; since we're NOT in the racing forum, and since, I have a lifetime of experience as a streeter, and since, the OP is asking for an opinion, here it is again;

for me, my opinion is, that porting is NOT the next thing to spend money on.
The next thing is to get the pressure out of the basement.

Kern Dog; you are free to state your opinion as to the OP's request.
You are not free to downplay anyone else's opinion.
Let the OP make that decision.

He's not spending money on porting, he's doing it himself. It's just a quick-and-cheap overhaul. There's a big difference between

"hey I have my engine apart to fix some leaks that just happens to have Edelbrock heads, anything I can do for cheap/free before I put it back together to make it better?"

And

"I'm doing a full rebuild of my 360 with Edelbrock heads, help me select the best parts"