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DIY - Cylinder Head Porting

13K views 20 replies 15 participants last post by  rangerdoc 
#1 · (Edited)
After some extensive thought, I decided to hand port my existing 289 cast iron cylinder heads. Before someone reminds me that any aluminum head on the market, including the cheapest, will probably out flow even the best ported factory iron 289 head I'll explain my rationale. Quite simply, I don't intend to put much money into this existing engine. Hopefully by this time next year I'll have a fully prepped 347 stroker with a Weber induction, so I took the opportunity to do some cheap mods to my existing engine to run around this year. I bought a slightly used Holley 600cfm and Wieand Streetfighter intake on Craigslist, both for $150. I plan on installing a mild cam and lifters from Howards and have already purchased JBA's Tri-Y headers, which brings me to the desire to port my existing heads. I also looked forward to learning something new and if a little bit of power comes from it so much the better.

I read as much as I could regarding the subject and made particular reference to Glazier Nolan's Mustang Barn article which stated to spend the most time on the ceiling of the exhaust port. So that is where I began. I first needed to buy a tool to remove the valves. I got the Lisle spring remover from Amazon for $30. It's a great little tool. Simply put the handle over the valve, hit it with a hammer, and a magnet in the handle captures the keepers and retainer. Pretty slick. I picked up 2 TEMO carbide burrs (7" 3/8" ball end cylinder and a 3" 3/8 acorn) for $15 and $12 respectively. I grabbed a sandpaper roll kit from HF for $6 and went home Friday night to begin my weekend of grinding and sanding.

I began by removing the thermactor bump. This little bump extends into the port approximately 3/8 inches and really blocks the port. I began using the carbide burrs in my die grinder but the speed at which the material was removed was a bit intimidating and i felt I didn't have much control. I transferred the bit to a regular drill and it worked great. Not too slow and I could really control it well. After removing the bumps I went back and used my header gasket to draw a line were the manifold would lie. I tried to go approximately 1/16" inside the perimeter of the gasket to ensure a proper seal and avoid creation of a step between the two. I used a medium sharpie marker for the task and the line it drew was a perfect width. The port floor only needed a slight grinding as GN directions said but a considerable amount of material and flashing was removed from the sides and ceiling of the port. This took the most time. You"ll want to use the small tip of the acorn burr to get into the port corners and then work the flat sections. This way the corners stay tight. Go a little in the corners and then a little on the flat sections. Keep alternating to avoid grinding grooves which are hard to work out. The drill allowed a really low speed and I had enough control that the final grinding was just a feather's touch to smooth the lines. They aren't perfect but they're okay for me and my first time doing this. I will say if you have a spare set of heads to practice because my last port was much better than the first initially until I went back and cleaned it up.

I finished by grinding the valve guide down a bit as explained in GN's directions. Just go a bit and keep "rolling" the 7" burr into the valve area to make a smooth radius. It would be hard to really mess this up though because the port ceiling is there for a guide. You're just aiming to remove the little 1/8 inch bump from the valve guide. I finished by sanding everything with 80 grit sandpaper and then 120 grit.

I think they came out pretty good. The way Ford cast these heads I'm sure anything you do to them will be an improvement. Hopefully I'll feel the difference but if not I've gained a valuable experience and it only cost me less than $60 and some hobby time.
 

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#5 ·
Very Nice ! :cheers:
 
#7 ·
Very nice job - especially if that was your first porting job! I once just hogged out the thermactor bumps and noticed better response and gained some RPM's! Once you add in a performance cam, 4 barrel intake/carb, and tr-y's, you will have a pretty good running 289 even if the bottom-end is a fairly stock build.
 
#8 ·
Thanks everyone for the kind comments. My current engine was given a standard rebuild many years ago prior to being parked, hence the reason to pull everything apart to change the gaskets and seals and make sure everything is up to specs. Thought I may as well take advantage of the situation and port the heads. This weekend I want to work on the bowl a bit and smooth the transition immediately after the valve seat. There's a noticeable amount of casting flash on the intake valve side. Quick question, if I polish the chamber will I change the compression? It's only 9:1 or so now and I wouldn't want to go any lower but there is a noticeable sand casted roughness to the bowl. I thought about leaving it alone but if there's any performance benefit I'd be willing to do the work to polish it. Not much information out there on the benefits of polishing the bowl other than reducing pre-ignition from reducing carbon build up. Finally, everything I've seen so far says there's no real benefit from porting the intake side and even the gasket I have is pretty close to the edge of the port. Most folks say that the roughness of the port helps atomization of the fuel. Has anyone seen any benefit to cleaning up the intake side of things?
 
#10 · (Edited)
Porting the intake runners in these heads will make little noticeable difference unless you go to more extremes. I would not polish the intake runners. Polishing the combustion chambers will have some benefits but probably not noticeable and you will gain a cc or two of volume which will lower compression. Just removing sharp or protruding castings will still be beneficial and shouldn't change the compression. However, you can easily make up any loss by shaving the heads up to 20 thousands - just be sure this hasn't already been done. You might even gain a little and you may want to true them up anyway.
 
#9 · (Edited)
Nice ! and the 1st photo in the Glasiers article is of a port on one of my heads before I did my first port matching job. I had to grind out the thermactor bumps as well. with my port matching, tri-y's, distributor recurve, pertronix, 4bbl carb, performer intake, C90Z HiPo cam, my 289 got 321HP on the dyno.
 
#11 · (Edited)
I agree, the only thing needed on the intake size is to remove anything like a big lumpy defect. Ditto the chambers. Exhaust is the weakness on these, and you have cured that very nicely. Now that it can breathe out, what are you planning to help it breathe in? Howard's equivalent to the C9OZ-C is a pretty good choice.
 
#12 ·
Nothing too hot, what we used to call a 3/4 cam.

Howards Cams CL210031-12 Street Force 2 1963 - 1995 Ford 221-302 Hydraulic Flat Tappet 1500 to 5400 Camshaft & Lifter Kit
More Details »
Item #: CL210031-12
Lift: .475 / .496, Duration @ .050: 215 / 223, Centerline: 108, Street Force 2, Good idle & throttle response, Needs 4-barrel & good exhaust.

OR

Howards Cams MC210031-12 Max Certified 1963 - 1995 Ford 221-302 Hydraulic Flat Tappet 1500 to 5400 Camshaft
More Details »
Item #: MC210031-12
Lift: .475 / .496, Duration @ .050: 213 / 233, Centerline: 108, Max Certified, Broad power band, Excellent in hot street & marine.
 
#15 ·
ex ports and more

Brian, your exhausts look great. Of the two cam choices, I think the first one would be better, you don't need all of the extra exhaust the 2nd cam has, because your ports are much nicer than stock. What is a Streetfighter intake ? Do you mean a Weiand 8124 ? And what kind of 600 do you have ? Not all Holleys are created equal. LSG
 
#16 ·
Brian, your exhausts look great. Of the two cam choices, I think the first one would be better, you don't need all of the extra exhaust the 2nd cam has, because your ports are much nicer than stock. What is a Streetfighter intake ? Do you mean a Weiand 8124 ? And what kind of 600 do you have ? Not all Holleys are created equal. LSG
Thank you. Yes it's the 8124. I had to look it up. Just grabbed it off Craigslist and didn't pay much attention. Simply wanted a 4 barrel to replace my stock 2 barrel. I'll have to look at the carb to get a number off it in the morning. I agree with your opinion on the camshaft choice. Thanks again.
 
#19 ·
You did a good job raising the roof on those exhaust ports. So your not going to touch the intakes? There are a few low risk things you can do easily to help them out and since your at it i'd recommend doing it. Raising the roof, cleaning up the throat and cleaning up around the valve guide. Even some smoothing around the pushrod hump without going crazy and risking breaking into the pushrod hole. You can use a Felpro 1250 as a template offset upwards to raise the roof of the intakes

Are you going to port match the header exhaust inlets? Port matching the chambers to the cylinders is a simple trick to reduce turbulence especially on the exhaust cycle.

I live in Anaheim Hills. Where are you located?
 
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#21 ·
Thanks for this. I was going to replace my heads but now I can't afford to. Since I already have my cam kit I planned to do this same port work. This is my first time ever doing more than an intake and carb swap so I'm a bit nervous. Could you please list the part numbers to all the pieces you purchased?
 
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