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PORTING aligning the gasket

OK so I’m trying to do a quick gasket port on the intake and the head on the intake side before I reassemble heads are gt40 irons (not p) and gt40 intake w/a felpro 1250 gasket not that this matters but if some wanted to know.

    My question is how do you align the gasket on both I was told to center it around the port. but I have a felling it should be centered best around the bolt holes and I back that because looking at the intake and the old marking from the old gasket it wasn’t near centered.

    My second question on the intake by where they injector sits on the bottom end of the intake where U s down off the rectangle port, is it ok to port away to the gasket or will I screw up the flow of the injector. I’m felling it might even improve injector flow.

    Last with the little porting experience I have, in the past I notice on iron a hard bit don’t ware out but is slow in removing material and softer bit removes material quite quick but ware out just as quick and I never had much luck w/ those stele bits maybe I’m not using them correctly.

Finally I recently read the post by ChuckW and was very impressed by his work porting those turbo heads.

Thank you in advance Billy

PORTING aligning the gasket

Reply #1 –
Don't gasket-match, especially if you're doing a "quick" port.  If you go too crazy, you'll wind up with a runner that opens up and then necks down again as the flow moves through it.

Clean-up the port on the head, using your gaskst to make sure you don't go too far.  Then using some thin cardboard and either a ball-peen hammer to mark the ports, or a razor blade to cut them out, transfer your port shape to the cardboard as well as a a couple bolt holes.  Transfer these to the intake and match to the port you just made in the head.  Make the ports in the intake slightly smaller than those you made in the head.  Do the same between the upper and lower, starting with the lower and them transfering the port shape to the upper.

Unless you're really hogging things out, or can get in and enlarge the entire runner, you don't want to make the ports larger where they mate together.
Long live the 4-eyes!  - '83 Tbird Turbo

PORTING aligning the gasket

Reply #2 –
Chuck is right, on production heads you are best just squaring up the intakes as-is since there are more restrictive places in the port. To match ports on the heads and intake, I always glue the gasket on the heads with a couple of dots of silicone, install the intake bolts in the holes in the head and slide the gasket up as much as the bolts allow. Use some tape to hold it, and let it dry. Carefully remove tape and bolts. Now put a bead of 3M yellow or black weatherstrip adhesive on the intake and bolt it down. Let dry overnight, and when you remove the intake, the gasket will come with it.
If there is any slop, raising any port helps. My Yates heads are patterned after Cleveland heads, and the intake ports are raised 2" above where the stock Cleveland ports would be.
Having the intake manifold slightly smaller than the head port helps reduce any reversion. Most Ford heads really benefit from having work done on the exhaust port.
On all heads, the valve bowl is the most critical and affects flow the most.

best tool for the job

Reply #4 –
When porting or grinding iron castings in general I like a " double cut carbide burr", typically a pear shaped or elliptical. Just in case you don't know, double cut refers to the cross hatched looking cutters vs. the single cuts that have 1 set of parallel helical cutting edges. Double cuts don't load up with " sticky" or cloggy materials, such as iron aluminum, & copper. A slight drawback is they are slightly harder to control, but not enough to change my mind about them. Secondly, about the porting, mainly just blend the 2  surfaces with a slight champfer at each, & yes use the bolt holes for alignment. I like to take a big fat sharpie marker, trace the gasket on the exposed metal and just try for about a 30 - 45 degree champfer uniformly around the port of each ( 1/16" @ 30 -45/ 1/8" @ 30-45). Stay away from the inside of each component though 'cause it's really easy to make turbulance and create an imbalance of the air flow.

PORTING aligning the gasket

Reply #5 –
Check out tmossporting.com and diyporting.com for some good info.

 Mike
[SIGPIC][/SIGPIC]88 t-bird: 5.0ho, gt40y, crane 2031, fms 1.7, paxton@5#, aod wide ratio, tci stall, performer rpm upper, 70mm bbk, pro m 60, 42#s, 3.73 7.5" posi, jba shorties, borla, upr x. 13.4 @ 104mph. cbaza, moates, tuned by decipha

PORTING aligning the gasket

Reply #6 –
I like round nose cylinders, and elipticals mostly, either single or double cut for iron. For aluminum, I use burrs that have about 7 flutes and are very coarse, and can't be used on anything but aluminum. I use either wax or transmission fluid to keep the burr from loading-up on aluminum. I prefer a front exhaust diegrinder.
I have to disagree with Jamezilla about port blending though. His advice will create a shape the opposite of an hourglass, and will cause port turbulance and could cause the fuel droplets to separate from the airflow and settle on the port walls. At the very least it  will do nothing but waste your time.

PORTING aligning the gasket

Reply #7 –
your biggest challenge is ports 1,4,5,8.  Its hard to get at the real problem up in the hole due to the angle the runner goes.

I use a conical (sp) or cone shaped bit in various sizes cause i know it leaves a flat surface behind when done.  Using an oval shaped bit might be good for corners or to achieve rounded flow paterns to knock off too sharp of runner angles,, but not really good for the floor or walls imho.
 

PORTING aligning the gasket

Reply #8 –
I don't have a problem using an oval burr to leave flat walls, but then few ports have walls that are flat for more than short distances. I use cartridge rolls to finish and blend.