Thread: Porting Question.

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HI GROUP,MY QUESTION IS...IS IT WORTH THE TIME INVOLVED TO GASKET MATCH THE PORTS ON AN EDELBROCK RPM AIRGAP MANIFOLD WITH THE INTAKE PORTS ON A SET AFTERMARKET ALUMINUM HEADS? BOTH THE HEADS AND MANIFOLD ARE FACTORY,NEVER BEEN TOUCHED.WHEN I LINE UP A SET OF FELPRO 1205s,THERE IS A GOOD BIT OF ALUMINUM TO REMOVE,NOT ENOUGH THAT IT WOULD HURT EITHER.WOULD THE PERFORMANCE PICK UP ENOUGH TO WARRANT THIS JOB? IM ONLY GOING TO GRIND IN ABOUT A HALF INCH.ANY FURTHER WOULD PROBABLY BE A WASTE BECAUSE IM NOT GOING TO OUT PORT EDELBROCK OR THE HEAD MAKER.THANKS FOR ANY INPUT!!!

IMO I say hell yes, but others would disagree with the 3-7 horse power you will add.....

no it not worth any thing your much better if the intake is just a bit smaller then the intake port and a gastket match on the bench will not guaranty that it fits when pulled down with the bolts it takes abit of time to get the line up good somtimes the intake will need to be mill to get it right

^^^^What Pat Said^^^^


Smaller intake ports resist reversion.

Originally Posted by camaro_fever68

^^^^What Pat Said^^^^


Smaller intake ports resist reversion.

yep

I like to set the manifold on, then reach in and feel how it matches up. If the manifold is a bit smaller, like Pat sez, that's a good thing. Only if an edge is sticking out into the wind do you want to get out the Dremel. Doesn't happen very often, but worth checking. There's no advantage, and maybe even a loss, by having the port swell at the gasket and then choke back down.

Originally Posted by R Pope

I like to set the manifold on, then reach in and feel how it matches up. If the manifold is a bit smaller, like Pat sez, that's a good thing. Only if an edge is sticking out into the wind do you want to get out the Dremel. Doesn't happen very often, but worth checking. There's no advantage, and maybe even a loss, by having the port swell at the gasket and then choke back down.

WOW can we see a pic of your hand. Thats some pretty long fingers to be able to feel down the ports to see how they match up.

Originally Posted by BigTruckDriver

WOW can we see a pic of your hand. Thats some pretty long fingers to be able to feel down the ports to see how they match up.

I didn't know you were in Huntsville, for some reason I thought you were up North some where, not 70 miles north.

Originally Posted by camaro_fever68

^^^^What Pat Said^^^^


Smaller intake ports resist reversion.

Is this pretty much with a street engine ,daily driver, or is it also with a race engine??

Originally Posted by BigTruckDriver

Is this pretty much with a street engine ,daily driver, or is it also with a race engine??

That's with any engine. Of course, the bigger the cam the worst reversion will become an issue. An 1/8" lip on the bottom of the intake runner has the most anti-reversion benefit. It's also beneficial if the headers are about an 1/8" below the bottom of the exhaust port.

Originally Posted by camaro_fever68

That's with any engine. Of course, the bigger the cam the worst reversion will become an issue. An 1/8" lip on the bottom of the intake runner has the most anti-reversion benefit. It's also beneficial if the headers are about an 1/8" below the bottom of the exhaust port.

I apologize I was reading your post wrong . Makes perfect since once I read it slow
So your saying you should have a small lip on the bottom of the intake and exhaust ports. Sides and top should be smooth???

Originally Posted by BigTruckDriver

So your saying you should have a small lip on the bottom of the intake and exhaust ports. Sides and top should be smooth???

Yes. You never want the bottom smooth if you can help it.

Before any one here starts to port out a set of stock Chevy heads . Make sure you have a lot of extra time ! I have 7 Hours on one SB head and it's around 80% done . The heads that I am porting are the 305ci #601 55-58cc . I always hear how good they are when full ported . And how much power they make on the round and round 355 Claimer engines . Well good thing I have more time then money . I would say don't buy these 305 heads thinking you will port them easy and make Lots of power . When I am done they will work good . And this set of heads has screw in studs guide plates and S/S valves . Also a set of Z-28 LT-1 springs with HD retainers and Locks . Them old Fuelly heads never needed this much grinding

Originally Posted by tango

Before any one here starts to port out a set of stock Chevy heads . Make sure you have a lot of extra time ! I have 7 Hours on one SB head and it's around 80% done . The heads that I am porting are the 305ci #601 55-58cc . I always hear how good they are when full ported . And how much power they make on the round and round 355 Claimer engines . Well good thing I have more time then money . I would say don't buy these 305 heads thinking you will port them easy and make Lots of power . When I am done they will work good . And this set of heads has screw in studs guide plates and S/S valves . Also a set of Z-28 LT-1 springs with HD retainers and Locks . Them old Fuelly heads never needed this much grinding

The only 2 real reasons to port out a set stock heads is one if you going to be running with rules that specify "stock" heads. Two, if for some reason you just have to have your stock heads. There are so many better heads that you can get for a real decent price. Heck you can even find alum. heads real cheap.

Originally Posted by DennyW

1, I don't agree with that, cause the person may not have the money for any other heads. 2, They may want the experience of doing it, and seeing what the improvements are. 3, They may want to try another way of porting for testing their own theory. That's what I did on mine. It depends on a number of things though. Like where they want the performance at, at what rpm's. But, I will agree, if you have the money to get a pair all done, that would also be a good way to go, especially, if you didn't have the time, or tools to do them.

Ya , I guess thats another way of looking at it.... You would not have to try or test anything just by looking at a set of good heads everything is tested and proven on expensive flow benches, You can learn from those. You could buy a new set better flowing for the rpm you like for maybe 300 hundred more after selling these. If its just not in the budget ,well its just not there, port away...... Dunno maybe I am just steering clear of porting since I remember how much of a pain it was.