Should I port my 351C 4V heads?

[Luc Feilla]

Hi everyone - I just bought a 1971 Mach 1 Mustang. It has 351C 4V and 4 speed, and 3.25 Trak-Loc gears. I will be putting a new cam, intake and headers on the engine.

I will have the heads off so I thought that I would get some mild porting done on the heads while they were off; some bowl work, a little short turn radius smoothing and slight shaping of the valve bosses. But the more I read about getting this work done the more leary I became of doing anything. I actually read one engine builder who did a back to back dyno test on a street/strip motor and made the exact same horsepower after porting the heads. I can't find any real before and after head porting dyno tests. Let me know what you guys think. Thanks!

BTW The cam going in is a solid flat tappet 288/292 advertised duration, 228/234 @ .050 duration and .535/.553 lift. 114 LSA. Pretty mild stuff, just a fun street cam.

 

[Q1SVT]

BTW The cam going in is a solid flat tappet 288/292 advertised duration, 228/234 @ .050 duration and .535/.553 lift. 114 LSA. Pretty mild stuff, just a fun street cam.

Seems you answered your question...

Here ia a real world non ported 4V headed motor:

https://7173mustangs.com/threads/sh...-very-good-dyno-conversation-on-tuning.45128/

 

[Cleveland Crush]

My opinion Luc: With your engine setup and your intended use, you will gain nothing worthwhile with porting. Apply your efforts on a good tune and a high quality valve train setup. Then enjoy those factory Cleveland ports!

 

[tony-muscle]

Depending on your end goal. If it is just for cruising, then don't waste your time. If you want more power because you have a use for it, like racing or simply going fast from light to light then it may be worth it. However, unless you really have a reason to keep the stock heads, I suggest you invest in a good set of aluminum heads like CHI heads. It may cost a bit more but at least you don't have to deal with the unknown results from whoever is doing the port job. If you really still want to port your heads then find a reputable Cleveland head porter. I have a need for power due to my racing hobby. I first went the direction of porting the heads with some small gains. After some time I bit the bullet and went all in with a set of CHI 4V heads and that's when the gains really made a huge difference.

 

[Luc Feilla]

Thanks guys for the replies. I think I won't port the heads. When I say port I really mean just smoothing out the exhaust short turn radius and the bowl areas a bit. But it really doesn't seem worth it given the generous amount of air these heads flow and my smallish solid flat tappet cam. Even my head porter send not to bother given that I just want to go fast light to light and do the occasional Historic auto course HPDE events.

tony-muscle - you are correct, of course. The aluminum heads are the way to go for power; the improved designs and technology of the past 50 years make them much better. However, I am nostalgic (anachronistic?) and can't part from the old iron slugs!! I know it doesn't make perfect sense but I am going to stick with them

 

[Stanglover]

I'm NO engine guy by a looong shot, but I didn't see mention of installing rocker studs if you're going with a solid flat tappet cam.
If I were redoing my motor, I'd go with a good set of roller cam and lifters and a very good timing chain set.
Just my 2 cents worth.