Calling on head porters advice

Bruceynz

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How much of the push rod hole can I remove?

and

How do you pocket port, what is pocket port?

Thanks
Bruce

PS - Never ported heads before :)

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Justwondering

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Bruce,
I was quickly glancing at the pictures and the
second (bottom) one looks like an evil spirit face.

Perhaps your problems with the car are related to the upcoming Halloween holiday and things will clear up in November?

bekasu
 

BudW

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It has been over 30 years sense I ported some cylinder heads. What fun (note: I’ve not missed it, one bit).

Most cylinder heads have about the same casting thickness everywhere. Knowing how thick that casting is, and staying under that, is the big part.
Going too far can be = to having a new expensive boat anchor.
Porting close to the cooling jacket is an area to keep in mind – for those mistakes are deadly to cylinder heads. Coolant is always under pressure and will always look for a leak.
Going too far to the oil area can be fixed with epoxy, sometimes.

Some porters say to get an intake (and exhaust) gasket and port to the size of the gasket. You will find porting that much material off will take forever.
Even this picture of yours shows how much material needs to be removed – if a person was porting to match the gasket.
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My opinion (which you take however you want), if doing yourself, port to clean up the roughness in all of the intake/exhaust ports, then stop.
If going serious (full time racing, for example), then send heads out to a professional to have done. That way, if they break it, they pay for it.


I have in my garage, a pair of 340/360 “J” cylinder heads that came off of one the very first 360 2 bbls made. These cylinder heads are the good ones - but the intake ports look like some sort of a Halloween maze in a corn field. The roughest intake port castings I have ever seen. I got some sanding cones and spent a weekend and got 2/3rds of one cylinder head done – and then I gave up (just from removing the roughness).
They sit on a shelf by the door as a reminder- so if I go into the garage wanting something to do . . .

BudW
 

Badasspen

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OK, on the other hand I myself ported a set of leftover 273 closed chamber heads and found the process rather soothing and therapeutic. Once I became comfortable with my tools and technique I proceeded onto a set of 360 heads. Gasket matching, opening the intake and exhaust ports, smoothing and polishing the chamber surfaces. I opened up the intake bowls as well as the exhaust. Did a valve job and put in new stem seals. I was able to get under 13 secs. on a set of stock heads with 1.88/1.60 valves. I would consider this a success and am not one bit afraid to do it again. A long shaft die grinder with a lot of available air is the best along with the egg shaped spiral bit. The stones were good for polishing large surfaces, but little else. Just take the time to read up on it first, second, and third. Then grind away, you may find your Zen like I did. Completely dismantle your heads first, number your valves, and clean them well before you reassemble. Good luck.​
 
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BudW

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I like to use cardboard to stick my valves into - that way I can mark what and where.
Now they make plastic trays that are handy to use to keep all valve train components in order.

Note: the iron you are removing from heads as well as the abrasive from sanding pucks and/or grinding bits are very abrasive to the engine, once assembled.
Be sure to clean heads thoroughly before assembling engine!
I have seen WAY to many engines damaged from abrasive material from what can only be from incomplete cleaning.

BudW
 

80mirada

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An electric die grinder or two will make life easier for most since having enough air is problematic for most DIYers. The push rod pinch has been discussed by many head porters over the years and it is a general consensus to smooth the transition over it rather than removing a bunch of material. General consensus was to remove about half of the total wall thickness and match all of them.
 
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80mirada

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You need to make sure to wear good protective gear. Goggle, dust mask, face shield, heavy apron, and ear plugs. A good scribe and some layout blue ( a large blue permanent marker works too) the biggest thing is to take your time and don't rush it!
 

76VolareRR360

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I just got done doing this to a pair of J heads with 2.02 intake valves. A good carbide bit and dye grinder help, but still plan on a few hours per port. Personally I wouldn't mess with sand paper cones, as you don't want perfectly smooth texture and they're pretty slow. I did a basic gasket match, and then removed the hump and straightened the tail where the valve stem enters the port. There are plenty of homemade tools for gauging wall thickness on the pushrod pinch, and you can always epoxy a copper tube in there if you break through.
 

F body Deconstructor Jim

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Carbide bits and electric die grinder with a variable speed control.
Ear and eye protection are a must. So is tons of lighting. I used both incandescent and flourescent lights.
Gasket match and general clean-up nets the best gain for the time spent.
You can easily go too far if your not careful. Best to test on a "scrap" head to get a feel.
Dont count on any two being the same due to casting core shift.
I used a /6 rocker shaft to build a simple head porting stand.
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Badasspen

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Starting another set of 596 heads today. Looks like they are very fresh from a build that used an unbalanced TC. Traded for a set of 318 heads I had under the bench. Dad put the 596s on a 318 and the results were terrible. Compression just ain't there on a 318. So I plan to finish the gasket matching, pull the valves and install the set of double springs I have. The valves and seals are new minus about 25 miles. I plan to do a little bowl work and clean them up really nice while I'm in there. I'll keep you posted.
 

F body Deconstructor Jim

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Its so simple and works very well. Excellent use for the old slant rocker shaft!
A long bolt threaded into the end of the head acts as a stop to keep it from swinging freely would hold it in several positions.
I did make an adjustable piece that screwed into an exhaust bolt hole to hold it in place to work on the bowls. Keeps it up off the work surface and steady.

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