head porting
- Thread starter mluck
- Start date
plastic-idol
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simon
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Nothing beats a FoMoCo shop manual. Same goes for the Schjeldahl bros´ Falcon Performance Handbook... and this forum of course.
For valve removal, you need a valvespring compressor. There are several types available, manual or compressed-air operated thread-type and lever-type spring compressors.
following the directions of the manufacturer, compress the valvespring, remove the valve keepers, remove the spring compressor again and remove the two-piece valvesrping retainer, valvespring, valve and umbrella seal. Ideally, the head should have been taken off the block before attempting to remove the valve assembly, as the valve would fall into the cylinder once the valve keepers are removed.
The pic below shows my budget KDtools compressor at work
I also highly recommend slade´s (cobrasix) Kastang webpage
For valve removal, you need a valvespring compressor. There are several types available, manual or compressed-air operated thread-type and lever-type spring compressors.
following the directions of the manufacturer, compress the valvespring, remove the valve keepers, remove the spring compressor again and remove the two-piece valvesrping retainer, valvespring, valve and umbrella seal. Ideally, the head should have been taken off the block before attempting to remove the valve assembly, as the valve would fall into the cylinder once the valve keepers are removed.
The pic below shows my budget KDtools compressor at work
I also highly recommend slade´s (cobrasix) Kastang webpage
The "old fogey's" approach... (I say that because it calls for planning!)
If you're going to change the valves up to the larger size, order them in. If you're changing the cam, order the other stuff, too. Buy a spare head gasket, carb gasket, exhaust gasket.
Compression test the motor before dismantling, and record the results.
Remove the head. Remove the valves and stuff, labelling clearly each one as you go. Stick the head in a plastic crate full of caustic soda for a few days, with occasional prodding and sloshing. Remove and hose off. Remember your gloves and goggles with caustic (trust me; I learned the hard way). Any remaining lumps or grease or grunge can be scraped when dry, then removed with methylene chloride paint stripper (hose off again).
Pop out all the freeze plugs, and the log end plugs. Take the head for garnet or silicon carbide grit blasting and make sure they rip into the water jacket everywhere. It should be the same colour inside these areas as outside. Ask for a protective phosphating clearcoat to be applied immediately after blasting. Put the head on a plastic bag, on a shelf for a week. Any cracking will show up as weep lines in the matt grey surface.
Spend a half hour with the die grinder deburring all the nasty edges that will tear your fingers - they're all over a bare head.
Next, equalise the exhaust ports. Scribe a level line top and bottom and make sure the gasket is a neatly cut one. Use it to define the sides and corner radiuses. You'll get further faster with single cut carbide bits in an air die grinder. Failing that the Dremel 7360 dedicated flex shaft tool looks pretty good to me.
Following task is to maximise the intake hole. Ensure it's a good 1/64" behind the gasket lip, and larger than the carb base hole. With a ball-end bit, round the edges where the mixture tumbles into the log.
The stuff that Doug covers well, can be your next project - the cc'ing, port and chamber polishing/equalising. Leave the final finish/adjusting until after the valve work is done, and any skimming completed. Reassemble with the new seals when all is to spec.
A cosmetic smoothing, degrease and careful paint follows. Install it, and have some fun.
Cheers, Adam.
If you're going to change the valves up to the larger size, order them in. If you're changing the cam, order the other stuff, too. Buy a spare head gasket, carb gasket, exhaust gasket.
Compression test the motor before dismantling, and record the results.
Remove the head. Remove the valves and stuff, labelling clearly each one as you go. Stick the head in a plastic crate full of caustic soda for a few days, with occasional prodding and sloshing. Remove and hose off. Remember your gloves and goggles with caustic (trust me; I learned the hard way). Any remaining lumps or grease or grunge can be scraped when dry, then removed with methylene chloride paint stripper (hose off again).
Pop out all the freeze plugs, and the log end plugs. Take the head for garnet or silicon carbide grit blasting and make sure they rip into the water jacket everywhere. It should be the same colour inside these areas as outside. Ask for a protective phosphating clearcoat to be applied immediately after blasting. Put the head on a plastic bag, on a shelf for a week. Any cracking will show up as weep lines in the matt grey surface.
Spend a half hour with the die grinder deburring all the nasty edges that will tear your fingers - they're all over a bare head.
Next, equalise the exhaust ports. Scribe a level line top and bottom and make sure the gasket is a neatly cut one. Use it to define the sides and corner radiuses. You'll get further faster with single cut carbide bits in an air die grinder. Failing that the Dremel 7360 dedicated flex shaft tool looks pretty good to me.
Following task is to maximise the intake hole. Ensure it's a good 1/64" behind the gasket lip, and larger than the carb base hole. With a ball-end bit, round the edges where the mixture tumbles into the log.
The stuff that Doug covers well, can be your next project - the cc'ing, port and chamber polishing/equalising. Leave the final finish/adjusting until after the valve work is done, and any skimming completed. Reassemble with the new seals when all is to spec.
A cosmetic smoothing, degrease and careful paint follows. Install it, and have some fun.
Cheers, Adam.
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