Advice on porting and tools needed

Continued from thread viewtopic.php?f=1&t=58407

I've got the head off my 200 I-6, but am having a hard time finding the tools to port with. Have called all of the tool towns, as well as Harbor Freight with no luck. I found this on the Summit website but it looks like a bit more than I need - or is it typical? I've never done this before so don't know what porting tools are supposed to look like.

http://www.summitracing.com/parts/SU...0/?image=large

These appear to be some sort of grit like paper wrapped around the bit - I was thinking you'd be using some kind of grinding stone. Well, not stone but you know what I mean - like in dremel kits.

Any suggestions where to look for the individual pieces (hardware stores, used for and/or called something else?), and what they are actually called would be appreciated.

As for the actual porting/grinding is concerned; I'm pretty clear on what to do on the exhaust side, and don't plan to remove the valves. My question is regarding unshrouding. I'm going to to have the head milled .050, and don't want to lose too much of that gain. So how much should I grind away that will be beneficial but not lower comp. too much - half way out to the gasket line, 1/3, or should I just round the edge a bit and then leave as is for a fairly stock engine?

Here's a photo I took of the head - I don't see too much in the way of casting material in the comb. chamber itself to remove, just at the (lower) edge-

http://www.flickr.com/photos/sedanman/3819947512/

For those who didn't see the previous thread, I've only got the head off due to broken exh. manifold bolts, and figured I'd put the port divider in and do some porting/have it milled while it's apart. Engine is stock except for 2inch single exhaust, and a Pony blueprinted big bore/venturi 1101 carb from a 250.


Thanks.

You've got safety glasses, right? Don't start without them. Ear protection's a good idea, too.

Bulk removal of cast iron is best done with a double cut carbide burr. It takes some practice to maintain a smooth cut, but is possible. There's no need for a cutting lubricant like with some other metals.

Final shaping is done using "cartridge rolls" which are basically emery paper strips wound tightly around a spindle or shaft so that it constantly presents an abrasive surface as it wears. Not to be confused with sanding drums, which merely have a replaceable sleeve of abrasive.

I'd suggest checking the exhaust gasket against the manifold before attacking your head.

Be warned that the carbide bits can "jump" around in a small port and cause a little more damage than anticipated. Choose an ergonomic working position where you can control the tool with both hands.

Unshrouding the valves is the far more important issue instead of the scant compression you might lose by doing so. Also important is achieving a desireable quench, moreso than overall compression #'s. Using the head gasket as a guide wont be the best method for unshrouding the chamber. The best method would be to place the head on the block, and flip it over and look down the cylinders to see how far the chamber is from the edge of the cylinders, and then scribe each chamber to conform to the actual cylinder it will be mating to. The bores in the head gaskets are usually bigger in diameter than the cylinder bores are, and using the gasket to open the chambers up to can often make the unsuspecting hotrodder make the chamber too wide and overhang the edge of the cylinders. This would go unnoticed if you didn't put the head on the block and turn it upside down to see that you have ground too much of the chamber away, then its too late, you end up with a worse shrouding problem than when you started. Another common error is when port matching an intake or exhaust port, many people assume that you take the intake or exhaust gasket and center the bolt holes to line the gasket up, when in reality, when these components are bolted up, they rarely center up that way with the gasket. The more accurate way is to bolt the intake to the head with the gasket in place, then take a small 1/16" drill bit and drill thru the intake flange at each end of the intake, and on thru the head into the port mating surface. Don't go so deep as to hit water or anything, but deep enough so you can insert the bit back into the holes when you take the intake back off of the head. Make sure to mark the gasket to indentify which side goes faces toward the head and intake surfaces. Once you unbolt the intake from the head, take two of the drill bits and insert them at each end of the intake where you drilled the holes and then place the gasket onto the intake, using the drill bits as alignment pins. Then you can scribe the intake ports, and repeat the same procedure for the head, and scribe it. You can see that if you don't use this method, you might actually create more of a port misalignment than you had to start with. When your ready to install the intake, put a bolt at each end to hang the intake, similar to how you put a header on, and insert the drill bits thru the intake, thru the gasket and into the head. This will keep the port alignment in the same relationship as when you port matched it. This will help insure that you don't end up making a lot of grinding dust and not having anything beneficial to show for it.

Electric die grinder: http://www.harborfreightusa.com/usa...o?itemid=44141&CategoryName=&SubCategoryName=

I have this one: [urlhttp://cgi.ebay.com/LOT-OF-2-NEW-ELECTRIC-DIE-GRINDERS-w-wheel-tools-cut_W0QQitemZ360178323828QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item53dc4d1174&_trksid=p3286.c0.m14 [/url]

It is cheap but works. Does 28,000rpm only which is too hard to control.

I added this to control speed:http://cgi.ebay.com/2-STEP-AC-POWER...in_0?hash=item3354d6ec61&_trksid=p3286.c0.m14

Sanding cone set:http://www.harborfreightusa.com/usa...arch.keyword=sanding+cartridge&submit=find+it

Carbide Burrs: http://cgi.ebay.com/4-PC-DOUBLE-CUT...in_0?hash=item33519c9591&_trksid=p3286.c0.m14

Flapper wheels: http://cgi.ebay.com/11PC-240-GRIT-F...0?hash=item518bc0bac1&_trksid=p3286.m20.l1116

http://www.popularhotrodding.com/en...core/0412em_porting_cylinder_heads/index.html

I will be porting my own head. My dad's back when out and he had to have emergency surgery and is currently immobilized and on pain killers.

I have access to four 2.3L four cylinder heads and two 3.3L heads so I have plenty of willing victims to butcher..er, experiment on.

Ditto on the eye protection. I'm a pretty careful guy and wear glasses, but I still got to go to the Eye-Doc and get a piece of rusting cast iron out of my eye because I wasn't wearing goggles. :nono:

It's not nearly as much fun as it may seem.

Wow - thanks for all the great info, guys. I forgot to click "notify when people post" and thought I had no responses. At this point with the more info I'm getting about how much work needs to be done, and the car show on the 30th, I'm running way behind schedule and may just have to get the head milled and broken bolt extracted, and put it back on. Also, a friend suggested that porting the exhaust won't do a lot of good without doing the intake area under the valves, and chambers (?)

I haven't enjoyed the car for about 4 summers, and want some driving time before the weather turns. What I really need is a second cruiser so I can work on one and drive on - the Escort doesn't cut it at car shows

However, for the sake of conversation, since I will eventually do all of this;

Addo - regarding the gasket against the exhaust manifold, I was surprised to see no flange on the inside of the manifold, and a bit concerned the casting is too thin to enlarge. Ford six book says to "enlarge slightly larger than manifold opening", but not by how much. 1/16, 1/32, ???

Anlushac11- Hey, man, long time! Thanks for the links - I was going to use a drill motor as that's what I have but am having second thoughts about that now. Hope your dad is feeling better soon...

jamyers - indeed, I always wear eye, ear, and lung protection. I've yet to find safety glasses yet that fit well with my respirator though.

CNC dude - I've got a '68 log head, so won't be doing any intake port work. Thanks for the thorough info though - I'd never thought about the gaskets not lining up. On the exhaust, could I just "hang" the gasket on the bolts since it will rest on the top of the holes? I'm a little confused as to how I will be able to compare the size of the cylinders with the head sitting up on side on the block just by eyeballing them though - please clarify if you can. It was the Ford Six book that said to use the gasket as a template on the cylinder head...

First I was going to do my front end and then the engine this winter, but the good engine test results got me all excited. I'll have to tear it down again next summer when I'm detailing the engine bay to do the porting, I think :roll:

Sedanman, hanging the exhaust gaskets on the bolts to scribe the outline is more than adequate. The intake gaskets on engines that are not a log-style, are usually pretty sloppy fitting, as far as having a lot of front to back movement of the intake manifold to the cylinder head, so drilling a hole for an alignment pin at each end becomes more needful to insure you can more closely re-align these two components when the time comes to bolt them together. As for the head gasket trick, that was obviously an issue the person writing the book wasn't aware of apparently. You can place the head gasket onto the block and see that the bores in the gasket are going to be quite a bit larger than the bores in the block. So tranferring that outline that you now see is too large onto the cylinder head will make the chambers also larger than the bore in the block as well. By having the chamber overhang the edge of the bores, even by a fraction, will tend to cause the supersonic air/fuel flow to do funny things. Even trying to redirect a portion of it back toward to intake valves, and possibly back into the intake, instead of keeping it in the cylinders where it belongs. Im porting a log head for one of the guys on here, and am going to be accessing the intake ports inside the log, and enhancing and making the entries into each port more consistant and better flowing. I will be posting some flow #'s as it progresses, if any are interested. There is a good chance that one of the larger car mags will be featuring a head porting series in the near future that will reveal a lot of tricks and ideas like I have mentioned above, and will show the Chevy, Ford and Chrysler 6's for their often overlooked potential. And since the cylinder head is a major component that affects the outcome of most engine builds, it will be something you want to stay on the lookout for when it comes out....

I understand what you're saying about the inadequacies of this method, CNC dude, but am still unclear as to how to determine accurately how far to unshroud the valves. But again, this will have to happen later.

One thing I would like to do though is work the intake opening, but am not sure how much extra metal is there. These two front to back photos of the intake show how the side of the inside of the log curves to the top, and then there's a sharp angle. Is there enough material to remove to make it a more even curve on the top to get better flow to the far ends of the log, or is there not (or is it even worth it?) This log does not have fins on the top of the inside of the log that I believe I've seen in earlier heads; (click on photos to enlarge and see my notes/questions)

http://www.flickr.com/photos/sedanman/3819140941/

http://www.flickr.com/photos/sedanman/3819140841/

First, you will need to put the head on the block and scribe around all the cylinders to see the relationship between the edge of the bores to the chambers. On a typical race engine, you need at least .125 clearance minimum as a starting point around the diameter of the valves to effectively unshroud them. However, on many stock cylinder heads, the chamber design doesn't always allow this before you go beyond the edge of the cylinder bores, so that is also another reason to use the head itself as the template. Now in a perfect world, the unshrouding should be done at the time of the valve job with a cutter designed to locate off of the centerline of the valve. This way the radius formed by the cutter, clearances the chamber with a consistant arc and depth, as opposed to doing it with a hand held grinder that might not give you the same consistant radius around the OD of the valve. In extreme cases of very bad shrouding, the cylinder head(s) are often offset in one direction away from the cylinder bore to help when the valves crowd the cylinder bores. It helps when the heads are the symetrical port style when doing this also, like most V8 Fords are and the BBC. Anyway hope this helps give you some direction with your project. As for the log head, I have several cutaway sections of a head that the Fordsix member gave me to use for laying out his cylinder head, he has previously posted the pics of these cutaway on here, so maybe you can do a search to find them, or I can take some pics to send you or post them. Thanks

This photo shows how the chambers were just barely shaved to accomodate the larger 1.75 and 1.5 valves:


Exhaust porting:


Ported pockets w/3 angles:

Stay away from "stones" cutters they blow up!!!!
Looking at your chamber pic exhaust valve looks good no need to unshroud. Sketch coming by "PM" about unshrouding actaully for 300 but principle is the same.
love air grinders , speed ajustable and exhaust air blows on work. Suggest along with goggles dust mask also if you have shop vac attach it to the backside of your work so iron dust / filing are sucked away from you.

Thanks again, guys. I am down to just one week now to get this back together, so the only thing I'll be doing is the milling at this point. Cleaned a lot of crap out of the exhaust manifold today, and cut out the burst choke tube and it's being welded up. I'm still curious about the intake carb hole (see my last post) - may have time to work that thursday before dropping the head off to the machinist Friday.

CNC - I STILL don't understand how you can scribe the cylinder bore diameters on the head - the only way I can see to do it is drop the crank and pistons, and reach up inside :roll:

Sedanman":1qwuhrq3 said:

....

CNC - I STILL don't understand how you can scribe the cylinder bore diameters on the head - the only way I can see to do it is drop the crank and pistons, and reach up inside :roll:

Click to expand...

Yup. Pistons gotta come out to do do that. The crank could stay in place but it would be easier with it removed as well.

Oh, my bad, I was assuming you were doing a complete teardown. Yes, the pistons will need to be removed as Lazy JW said and would be much easier if completely disassembled. You can however, place the head gasket on the block and see how much larger than the cylinder bore it is, and then place the gasket on the head and move your scribe line inward the same amount to compensate for the over bore of the gasket. Its a little more tedious but still fairly effective and accurate. You might need to place some dowels(or drill bits,etc..) in the head where the dowels index to locate the gasket more accurately.

Thanks - I guess that will have to happen another time - like when I build my other block and get a 2-V head..... But the INTAKE - I only have one more day to work on this before taking to the machine shop - what about the bottom of the opening of the carb hole in the INTAKE

Is there enough material to radius this to a more even, curved shape, or are the risks of opening too far not worth it? Click on photos to enlarge.

http://www.flickr.com/photos/sedanman/3819140941/

http://www.flickr.com/photos/sedanman/3819140841/