Factory Five Racing Forum banner
1 - 11 of 11 Posts

· Junior Charter Member
Joined
·
1,009 Posts
Discussion Starter · #1 ·
This years winter upgrade will be porting my stock heads.

Hoping to tear in to the car this weekend and I’ll post my progress here.

Any advice is greatly appreciated!
 

· Junior Charter Member
Joined
·
1,009 Posts
Discussion Starter · #3 ·
Sorry, but if you're talking iron heads, unless you just want to do it for the experience, I think you're wasting time & money. What RPM's do you run? Porting is only going to help in the upper RPM's.
it’s a long cold boring winter, I don’t need anything for Christmas so I’m asking the wife for a porting kit.

the car runs consistent 13.10 with a best of 13.03 with the factory foxbody rev limiter. If porting gets me away from the tv this winter and gets the car to run 12.99 I’ll be a happy guy!
 

· Junior Charter Member
Joined
·
1,009 Posts
Discussion Starter · #4 ·
Here is my long term plan. I also have an ‘83 Mustang with an ‘89 engine converted to carburetor and as I upgrade the cobra the takeoff parts go on the mustang.

This winter is porting the stock heads on the cobra to see if I pickup any time on the 1/4. I’ve read a 20hp increase is possible.

Next step will be aluminum heads for more power and less weight, and the ported stock heads go on the mustang.

After that will be supercharger time.

Meanwhile I’m collecting parts for an FE build.
if I live long enough the mustang will have the aluminum head supercharged small block and the cobra will have an FE. 😉
 

· Registered
Joined
·
6 Posts
All of my information on porting cast iron heads is more than 25 years old. The single most important area is from the valve seat and the next 1/2 inch. On the intake side almost all the flow is at the top of the runner. On the exhaust improvement can be seen by changing the radius of the short side of the port. The most effective way is to buy one good long carbide cutting burr conical shaped. If you wear a thick wool glove on your left hand and support the bit with your thumb and fore finger you will have much better control. It’s the shape that makes the difference. Bigger is not always better. The best advice I can give you is to look closely at valve to port area on modern aluminum heads and try to make yours look like that. You will be working for hours, get a chair that is comfortable and good light it will be worth it. You should be able to get 25 horsepower.
 

· Junior Charter Member
Joined
·
1,009 Posts
Discussion Starter · #6 ·
All of my information on porting cast iron heads is more than 25 years old. The single most important area is from the valve seat and the next 1/2 inch. On the intake side almost all the flow is at the top of the runner. On the exhaust improvement can be seen by changing the radius of the short side of the port. The most effective way is to buy one good long carbide cutting burr conical shaped. If you wear a thick wool glove on your left hand and support the bit with your thumb and fore finger you will have much better control. It’s the shape that makes the difference. Bigger is not always better. The best advice I can give you is to look closely at valve to port area on modern aluminum heads and try to make yours look like that. You will be working for hours, get a chair that is comfortable and good light it will be worth it. You should be able to get 25 horsepower.
That’s very helpful! Thanks
 

· Registered
Joined
·
2,503 Posts
I had some "porting" satisfaction (but not on the heads) when installing an Eldelbrock Performer 289 intake on the Explorer engine I swapped into my Mustang. I did not port the heads at all, rather I ported the intake to match the intake gasket where the gasket was bigger, and trimmed any gasket edges that may have been obscuring the exit of the intake. For the most part the intake port on the head was larger - so no problem with the flow in as long as it is running downhill past the drop off.
Same theory on the exhaust - trimmed the exhaust gasket where it obscured the exhaust port, (the ports are kid of ovoid) then ported the entry of the cast iron replica 289 HiPo exhaust manifolds. It is a street cruiser so I want off idle response and it never sees over 4-5K rpm typically. It has a stock Mustang 5.0 Cam and I'm not sure it is any different than the stock Explorer cam. Running through stock Mustang dual exhaust with the tranverse muffler. It's a somewhat worn out old engine. With a 450CFM QuickFuel Carb it made 205HP/270TQ to the rear wheels through a C4 automatic.

Hope that helps!
 

· new member
Joined
·
451 Posts
rustyrim is on track with his suggestion port match the cylinder heads and intake manifold , the exhaust side has always been the small block fords head problem . every little bit helps any cylinder head from down low on the rpm scale to the top end the easier it is to take in and expel air the more power you make and more efficient it will be
 

· Junior Charter Member
Joined
·
1,009 Posts
Discussion Starter · #9 ·
The porting adventure is well underway. I’ve got the heads off. All good news looking at the engine, pistons and bites look like new.
The intake needs a lot of work, it’s a huge restriction.
 

Attachments

· Registered
Joined
·
1,619 Posts
awesome! how much more anticipated HP?

edit:
nevermind. I scrolled up and read the previous threads
 
1 - 11 of 11 Posts
Top