Any suggestions on how I am porting these heads?

Dont gasket match the exhaust ports!!! (sorry paul)You want a step between the head and header/manifold,or you get reversion.The expanding exhaust gases are (expanding) you dont want them expanding into the port creating a pressure front that the exhaust coming out of the cylender cant get past.Exhaust flow pulses from the other adjacent ports will also cause this to happen.Its not a good thing.Hence tuned/equal length tube headers to smooth these pulses out.That step between the port and header/manifold acts as a wall stopping the spent gasses from going back into the port.Unless you are building a max rpm,supercharged/turbo engine with an open large dia pipe it will only hurt head flow/performance.

 

I don't think I can gasket match the exhaust on these heads. They are oval ports and the gaskets and headers have rectangular ports. But I DID open them up a little.

 

Don't match the exhaust? Want to explain that better? If opening it up was bad, then I guess all those aftermarket heads with their larger exhaust ports, need to be tossed in the dumpster.

 

The exhaust ports on the 40s and Ps is 1-1/4 X 1-1/2 oval shape where the header and exhaust gasket is 1-1/2 X 1-3/4 rectangle shape. that is a LOT of material to cut away to gasket match. I thought I took too much on the floor and ate into the water passage. I am afraid if I took that much off the port exit I don't know WHAT I would hit...

The ports from valve to exit are much bigger and have better flow, but at the exit, it is an oval shape, not rectangular.

What I am doing is making the exit more of a circular shape to open the flow up, but not so much as to make them rectangular.

 

If your working on trying to port 40p heads and matching the header gasket, you don't need to do that.
The 40p heads exhaust port is quite special in design as the reason they flow so well untouched with smaller valves..
If you get wild in the port, the flow and back flow is upset from the factory design.
Not knowing about this gets you into trouble.
Flow mapping at the output of the ex port shows were the active and inactive point are. Porting without this knowledge is a shot in the dark.
These heads are not like the run of the mill heads where you can grind out and usually get an improvement but it's your call.
I'm just alerting you that this is a special case.

 

He's doing E7's, not gt40P's

 

Having a header with an opening larger than the port is not a problem at all and does help by interfereing with any reversion that take place thru the rpm band, in a motor that has a cam with some valve overlap timing.
Ford motor sports headers for these heads are a great deal larger.
In my installation, I actually installed more reversion control in the low flow path area of the headers outlet tubes to block even more reverse flow.
This greatly assists blocking spent gas from re-entering the cylinder and polluting the new charge. This means more power over letting it happen any more than can be helped.
I know this may be new or doubted by some, but the science is well known.
I have years ago done it on a single cylinder race motors and picked up an unbelivable amount to power both on the track and on the dyno where it was found originally by port mapping , then appling the right shaped contol plate.

 

Thats whats so good about this sport (hot rodding). we all have our own experiences. Every place there is a junction there is a pressure wave that is generated back towards the valve. Those pulses travel back and forth in the moving air column at the speed of sound. If they hit the valve at the right time they cause a vacuum pulse that adds to the filling of the cylinder but if they hit at the wrong time then they can cause problems and upset the cylinder filling. Street headers are not tuned - they aren't even equal length. If they were you would have to have one tube from each bank running into the opposite sides collector. The header's tubes are typically too big for the engine to which they are connected. They do provide less back pressure and greater flow than the factory exhausts and that is why they provide a horsepower increase. If they provide any tuning effect to an engine it is purely accidental. There is a pressure pulse generated where the head and header meet whether they are matched or not - there is an edge. There is also a reversion every time the valve closes and the pressure in the tube is higher than the pressure in the head. It generates a pressure pulse. The same thing happens where the primary tubes meet the collectors, at the collector flange, in the reducing cone and at each joint in the exhaust system.
You are right, the step from a smaller port into a larger header won't hurt the flow. (as long as the port is not restrictive) Either will increasing the flow through the port to match the header. Ford has always used exhaust ports that are too small - even for the small valve that they use. The Ford exhaust ports are restrictive. I open them up as big as I can to aid in getting that exhaust out of the cylinder and through the exhaust - short of tuning the intake and exhaust systems to make it work. I have my way - I don't say anyone has to do it my way. When someone asks for input I share - just like everyone else. I don't mind when you disagree - I may share my reasons and the theory behind it but I might not. This time I did. I don't expect it to change any minds. Try it if you feel like it- don't if you think it won't work for you. It means nothing to me either way. I have been wrong a number of times and still make mistakes - sometimes the mistakes work out OK - other times I fix it the next time around. I don't feel attacked and don't want anyone else to feel that way.

 

First off, these are non-P GT40 heads, not that this makes much of a difference.

Second, I don't race, but I do like to take it to the track to beat my own times, so I am not trying to scrounge up every last bit of horsepower. If I was, I wouldn't waste my time and money on second-hand parts, and be scrounging junkyards.

What I AM doing is having fun and experimenting with other people's trash This car was someone's throw-away, the engine block was someone else's mistake, the heads are junkyard, every part of this car is second hand.

I have never had the opportunity until recently to have a "hot rod" and now that I do, I am having a great time messing with stuff. I have always wanted to "port and polish" some heads, so these GT40s are the victims. I may screw them up, I may reduce their efficiency, or maybe, on accident, they may work very well. Won't know until after I am finished with them and get this engine back in.

I find all of this to be very fun, even though many people may think that I am ruining the car, heads, or whatever. Like I say on my signature below..."If you don't like it, I don't care"...I have having a great time with it

Lastly, thanks for all of the input. I am learning alot from all of your knowledge, wisdom, and experiences, and I hope that some of it works when I put this bit and that bit into my projects. If not, I will get the chance to try it again with some other parts

 

I'm glad your enjoying all! Cause as longs as you keep enjoying, you keep on sharing! I like reading your post an have learned on this as well!

I think your doing a great job and have come a long way! Don't care who you are,, someone will always have a better, ain't yours so is it better?

Keep doing what your doing the way you do it. I like how you do ask an learn an it shows on your learning. You are doing a great job in it all!

Sometimes you just gotta say,,, Yea yea whatever

 

Aftermarket heads are generally optimised in the exhaust port area allready and therefore dont need much help or tossing in the dumpster.Stock heads are a total compromise on every front so porting is done to improve them.The gt 40 heads allready have a good port designe for a street head and need very little to wake them up.As I stated before,unless you are running a flat out race motor its not necessary and since scoop is just playing I thought I would throw a toy in the sand box for him to use "If he felt like it" sorry if I sounded preachey but I have seen many a head get ruined with a simple (porting)and only wanted to spare scoop some of the agony(which he summarily discovered on his own)If you noticed I tend to throw info out there when I feel I have something to contribute or may be able to steer someone in a useful direction Or simply offer a different perspective.I only want to help and do so when I think I can so take it for what its worth,Info nothing more good or bad more info is better than none.Peace out.Pete.

 

Yeah, I am having a great time. And learning...

I agree that Ford did the best they could on these GT heads (40 and 40P). They didn't leave much to work out. What they DID leave and what I will be removing is the casting "bumps" around the valve stem and on the inner radius, and that "smog bump". Other than that, I will just be cleaning up and smoothing out.

Oh, yeah, and smoothing out that oddly positioned welded spot

Here is the ported (but not polished) 1st port with the casting removed from around the valve guide. It is the flat raised "tab" at the base of the valve guide that you can see in the intake port. The valve is in upside down just to keep it in the correct place while i work on the other port, I don't plan on running it like that

 

Looks good,if you are feeling adventureous you could try teardrop shaping the casting around the guides.

 

Any pictures of examples of that? I am just blending them into the walls around them....

 

Sorry wish I did for yah,(Im pic illiterate with the puter anywhoo)I will try to describe it for you.I am shure you know what the tear drop shape looks like so assuming that: you would cut the guide boss standing up in the port around its circumference rounding and tapering its sides to a point facing the port entrance on the intake and facing the port exit on the exhaust.Its done to aid flow around the guide boss and create a little extra velocity at the port roof.How much it actually adds is another matter,I am shure a pro could quantify it.Hope this helps you,good luck.Oh and watch those water jackets