porting heads, worth it?

[Sonicaceman]

Okay i've been thinking about porting my roush 200 heads just because they're not that great and my numbers are crap. I don't want to do a full on port job, i just need the exhaust opened up because that is the part lacking on these heads and maybe a clean up of the rest of the heads to get some of the corners and edges smoother to flow more. I heard about 1800 dollars for a full port job, anyone know about how much to just do the exhausts ports and a very mild clean up of the heads to get rid of some of the crappy machining from the original cast. otherwise it's not worth keeping these, might as well buy better new aluminum ones. On a budget here too. Also i want to port my lower GT-40 intake. Just looking to get input on prices for both these and if it's worth it to do this besides buying new heads and a new intake.


347, gt-40 intake, roush 200 heads, 70mm tb, 24lb injectos, fender cai, 255 fuel pump, canton oil pan, electric fan, msd 6a, mac long tube w full exhaust 2.5", anderson cam n3 (must go not right for my combo), 3.73 axle, sct custom chip, dyno tune

all this = a poor 247rwhp/317tq mustang dyno machine #'s

 

[Bullitt347]

I would say you need a new intake manifold before you worry about porting cylinder heads. Also what size is the MAF? For a 347 you should also have a bigger T-body as well. That engine should be putting out a MINIMUM of 150 MORE RWHP. Porting the heads and a cam are not the answer............yet. And you should use at least a 30 lb/hr injector IMHO.

 

[85_SS_302_Coupe]

I agree with the above statement....but, as for porting...i'd say not unless you already have some super nice heads and you still need more flow.

Now...you'll have your people who are happy with Thumper heads (ported E7's), and that's great. Those people are likely not using those heads on a 347 either.

Then, you've got ME...i've got ported 351W heads on a 347, BUT i didn't pay a dime for the port work, i bought them already ported. I would still say that for the money you should just shoot for some nicer aluminum heads, because even with porting there are some aftermarket heads that are just plain old superior no matter how well you port a set of heads because it's not always about how hogged out the heads are, it's about port velocity which you eventually loose when you port them out enough. I paid $260 for my heads and had to put new valves in them which cost me another $450...that's $710...i see aftermarket aluminum heads on my local classifieds all the time for that much. If i could do it again i'd save up and go the aluminum route.

 

[strtrcr50]

Before he gets rid of his intake, here's an intake shootout on a 347.
Super Intake Shootout - Muscle Mustangs and Fast Fords
85 SS 302 coupe's logic is exactly why I have a set of tw heads. When it was all said and done, it didn't cost that much more to go aluminum.

 

[mavmavv]

Im currently doing some home-porting on a set of GT40s and a Typhoon intake.

I think simply doing the required research and learning about headflow is reward enough for me. I hope maybe to get about 10-15 more rwhp from cleaning up some of the harsh edges.

Also, your numbers are stupid low. Something is up with your combo.

 

[KamiKaziDK]

Before he gets rid of his intake, here's an intake shootout on a 347.
Super Intake Shootout - Muscle Mustangs and Fast Fords
85 SS 302 coupe's logic is exactly why I have a set of tw heads. When it was all said and done, it didn't cost that much more to go aluminum.

Thank you for finding that article!! I hate how everyone always says the gt-40 is good for 350 hp, it's insulting to that intake. Uprgrading from a gt40 to a tfs-r only nets you 25hp on a stroker.......and you loose that much torque? The gt40 is an awesome intake that deserves more credit that in gets. You might want to port your lower intake and port match it to your heads, and try opening up your exhaust ports and gasket matching them as well, but I still think a big part of your problem lies in your tune and your camshaft though

 

[85_SS_302_Coupe]

Im currently doing some home-porting on a set of GT40s and a Typhoon intake.

I think simply doing the required research and learning about headflow is reward enough for me. I hope maybe to get about 10-15 more rwhp from cleaning up some of the harsh edges.

Also, your numbers are stupid low. Something is up with your combo.

A friend of mine took some E7s and simply ground out and matched the intake and exhaust gaskets to the size of the ports on them and he picked up 11hp at the wheels. That's not too bad for not going into the bowls and under the valves.

 

[mavmavv]

A friend of mine took some E7s and simply ground out and matched the intake and exhaust gaskets to the size of the ports on them and he picked up 11hp at the wheels. That's not too bad for not going into the bowls and under the valves.

That may be the extent of my work. Simply cleaning up the ports and the walls for any bad castings. Im not sure if I want to get into the bowls or not seeing how this will be my first port job. Although Ive found a TON of reading material from TMoss

Porting GT40P Exhaust Port

So much info there

 

[clement]

nevermind

 

[Sonicaceman]

porting replies

good feedback from everyone. i have some things to think about now. i'm kind of partial to the gt-40 because i previously had a edelbrock performer that worked good but was given up for the gt-40. one switch is enough i hope. a lot of this is dependent on application, and i know my cam is a problem, not right for the car, i'm going to fix that but i'm not sure how good my heads are either. i'm really considering the AFR 185's but i've been told there can be clearance problems with them even if your pistons have valve notches. i can't notch mine anymore because they are hypertetic pistons (they do have notches) and it would weaken them too much. my mustang guy told me there could be a possibility of the valves not working right because the valves are a little offset on the AFR's. i'm not sure if i want to take the chance on spending the fifteen hundred on the heads then having to spend another 400 on pistons, i could just go out and buy the new Brodix heads that are a little more. Either way i'm considering The AFR's as a head, a new(custom grind or a comp cams version) cam and keeping the intake, and porting the bottom section.