Ford Muscle Cars Tech Forum banner

1 - 2 of 2 Posts

·
Premium Member
Joined
·
14,758 Posts
Discussion Starter #1
This is a consolidated listing of all porting related posts from the old forums.
<font color="red">Refer to http://www.fordmuscle.com/archives/2000/07/homeporting/index.shtml </font>
-----
--- Question Head porting / exhaust ports (E7)? --with pictures


--------------------------------------------------------------------------------

Dale302 - 1:35 am on Feb. 1, 2001


I am currently completing porting work on a set of E7 heads for my 302. My question is would it benefit to open up the exhaust ports even more for a performance street / occasional strip engine. I've been a little on the conservative side in my porting by not matching all the way to the gasket.


I've read in several places that the exhaust port should be smaller than the header to prevent backward flow of exhaust into the port. Supposedly the reverse flowing exhaust pulse encountered is reflected back by the flat surface at the opening of the exhaust port. Again supposedly opening the exhaust port to match the header is bad for performance.

My dilemma is how much step is enough and how much is too much. Here are pictures one of my exhaust port as they are now. I've had Chevy valves installed with a 3 angle job (Intake 1.94"/Exhaust 1.6"). I blended the bowls and smoothed the radius after the valve seat machining was done. The boss and bump were gounded smooth and the port was open up a little.




First is a picture with a template of the header opening. Second is the port with the exhaust gasket over it. My question is for my application would opening up the port more benefit me and if so how much more and on what sides should I open it up. If opening it up is the answer, should I keep a consistent port width all the way to the bowl. I've been told a venturi on the exhaust port is not need as is the case with the intake port.




Any information and experience is welcome.

Thanks,

Dale302


----------
1969 Mustang Fastback, 1970 Mustang Coupe, 2000 Ford Focus ZX3 (daily driver)
I design high performance computers for a living, cars for a hobby



--------------------------------------------------------------------------------

KarlJay - 4:27 am on Feb. 1, 2001

In my opinion, the exhaust port should be just a hair smaller than the header. The reason I say that is having the flow hit the edge of the header is much worse than having the port 1/64" smaller. That's what I did on mine and I ended up having to gind a little off the mouth of the header to get the proper match. I also had to raise the headers 1/8" and move one forward 1/8" to get the proper match. I oblonged the holes to get the header to adjust



--------------------------------------------------------------------------------

Dale302 - 10:36 am on Feb. 1, 2001

Karljay,

I cleaned up the header to match the oval gasket that came with the headers. You can see that in the first exhaust port photo. As you can see the port is still a fair amount smaller than the header opening. I agree with keeping the exhaust port at least a hair smaller than the header that only make sense.

I guess the real question is if having a more significant step in size is a good thing. I've read more than once, that having a step from the exhaust port to the header is important. That step acts as a dam to reverse flowing exhaust pulses. I assume that pressure from exhaust pulses from other cylinders could affect a cylinder that is currently expelling exhaust. Thus the need for the reverse dam. This reverse dam idea might be a bunch of bull, but I don't know. That's why I am here asking the question.


I am very tempted to open the port up more closely to the header size, but have fear of messing up this reverse dam effect and maybe hurting exhaust flow and velocity also. I guess if the reverse dam is important on engine like mine, what is good step size? Should the exhaust port a 1/64", 1/32",...1/4" smaller?

Again this is a high performance street engine not an all out race engine and I want to keep the low end rpm performance decent. So I assume a port that is a little to small is better than a little to big. It would be good to have a feel for what is just right.

By the way Karljay. What kind of engine do have? How did it responded to the opened up exhaust ports to near the size of the header opening. Is the low end rpm performance still acceptable?

Thanks,

Dale302


----------
1969 Mustang Fastback, 1970 Mustang Coupe, 2000 Ford Focus ZX3 (daily driver)
I design high performance computers for a living, cars for a hobby



--------------------------------------------------------------------------------

FasterDamnit - 12:18 pm on Feb. 1, 2001

Dale302,
If you are more interested in a flat torque curve and more useable power below 5000 rpm, then smaller ports are better (up to a point.) The smaller ports maintain a higher flow velocity, improving torque in the rpm range most used on the street. I bet what you have done will work very well for you. Choose a good set of Tri-Y headers (to also enhance street torque.) Did you read our head porting article on this site? I ported my heads with the intent of maximizing my ET- so I ported my ex. ports out to the gaskets and then ported my header flanges to fit. The mismatch will help reversion- but a well designed exhaust sytem will do the same thing. At the minumum use an H-pipe, an X is preferable- 2 1/4" or 2 1/2" pipe.
JimL.

----------
Technical Editor, Fordmuscle.com
65 GT, 289, T5. '92 LX, 5.0, AOD.



--------------------------------------------------------------------------------

Dale302 - 2:58 pm on Feb. 1, 2001

Thanks FasterDamnit,

Yes, I read your porting article and several others. Most of them including yours were aimed at high rpm and maximum E.T. Though I want good upper end power, I also want decent low end power to. That's why I didn't match the exhaust ports though I did opened them up a bit over stock.

I guess I basicly want all upperend power I can get while still having good street manners. I don't want it to be unpleasant on the street.

My exhaust system is 2.25 409 Stainless with Flowtech 1 5/8" primaries and 3" collector.
I will be adding either a H or X pipe. The flowtech header flanges were matched to the oval gasket you see in the photo. The second photo was a felpro gasket I plan to use. The felpro seems better qaulity than the oval one that came with the headers. Though the oval one gave me a good template to match the header flange ports.

From your response I gather you think my port size is good for what I want. I guess my question was how much is enough and how much is to much for a strong street engine?

One other question how big of a issue is reversion? Would you consider my exhaust system a good one?

On the intake side I only plan to open the port up enough to match the intake manifold. The manifold is a Edelbrock Performer RPM.

Thanks for your help. Any suggestion or comments are always welcomed.

Dale302

----------

--- Porting and polishing heads


--------------------------------------------------------------------------------

Ford Man - 8:24 am on Feb. 8, 2001

For those who have ported your heads by the article on this site, how long has it taken you to complete a set of heads? Also i have a dremel 5 speed rotary tool, will that be enough to do them if i go out and buy that flex shaft? Also will three or four carbide bits do the job fairly well if i get a variety of sanding cartrages to smooth everything back down? Should i have the heads machined first for larger valves before i port them? What all does a 3 angle valve job do? Will if benifit the heads alot? These are a few questions i have. I have started opening up the ports a little what what bits i have but i was just wondering should they visit the maching shop first? If i should take them to the shop first, should i go ahead and cut down the smog bumps and valve guides, ect? and polish them when they come back? Any input will be greatly appreciated. thanks



--------------------------------------------------------------------------------

FasterDamnit - 10:25 am on Feb. 8, 2001

First off, the article answers most of your questions. The Dremel will not be enough- unless you have months to do this. Get the flex shaft. Spend the money on a true carbide tip and use an air powered or electric die-grinder for the big work (as recommended.) Time? At least 40 hours- you will want to go slow at first to get the feel of the cutting tools. I had mine cut for bigger valves after the porting- just asked the machinist to blend the new seats into the bowl. You don't have to worry about protecting the valve seats. Same for the guides. Plan on new ones. Gotta run. Godd luck!
Jim L.

----------
Technical Editor, Fordmuscle.com
65 GT, 289, T5. '92 LX, 5.0, AOD.



--------------------------------------------------------------------------------

KIE - 1:35 pm on Feb. 8, 2001

To answer your question about the 3 angle valve job by a means spend the money. Straight angle valve jobs are all most unheard of in the performance world. You will improve the flow of air around the valve when it opens and also control the seat margin a lot nicer. Be aware when porting. Bigger is not better. If in doubt leave it alone. Work on unshrouding the nasty lip just under the factory valve seat machining area. Blend it right to the seat and then have the larger valves installed. As far as porting, stay with just matching the intake to the heads unless you feel you know what you are doing in the port floor/roof and guide area.
KIE

----------
Ken Imhoff




--------------------------------------------------------------------------------

460 Tom - 1:25 am on Feb. 9, 2001

Fordman, I purchased two carbide burs about $40 each, and two mandrels that hold the cartridge rolls about $5 each, and a bunch of cartridge rolls in #60 grit,#80 grit,and #120 grit,at a local industrial supply company.You will need a good air powered die grinder and a high output compressor,as the die grinder will consume more air than a paint spray gun! If you can't find these things locally,Summit Racing has all this stuff. Get some high quality dust masks and some ear muffs and do this work while your wife is away if you wanna keep peace at home!

----------
Nothing worth doing is easy...




--------------------------------------------------------------------------------

KIE - 1:34 pm on Feb. 9, 2001

Fordman, I bought a electric die grinder(the big one) at Sears for 89.99 last year. It had the hp but the duty cycle is a little low and would heat up if you didn't give it a rest once and awhile.It did my intake and heads in under 40 hrs. The unit comes with both 1/8 and 1/4 collets. It is a good buy.
KIE



--------------------------------------------------------------------------------

Dale302 - 9:24 pm on Feb. 10, 2001

40 hrs sound pretty reasonable if its your first porting job. I did mine with a air die grinder I got at Home Depot for about $25. I also used by Dremel tools for some of the finer work, but the dremel is probably optional. I also purchase the deluxe porting kit from Standard Abrasives. I believe it was about 30-35 buck. Go to their website they have a porting How-to. (www.standardabrasives.com).

I didn't use carbide burrs. I used just the kit a couple of extra grinding stones from Home Depot. The carbide burrs are probably worth it. I pretty much wore out the stones porting one set of heads.

Do everthing that can be done before the 3-angle valve. One slip of the grinder and bye-bye valve job.

I did do the blending myself after the larger valves and 3-angle valve job, but I was very very careful. I saved some money doing the blending myself, but one slip and I would have negated that saving. Its best to let the machine shop do the blending, but it your call.


Good luck,

Dale302

----------


--- Porting 5.0 heads


--------------------------------------------------------------------------------

MachMe - 11:09 pm on Mar. 13, 2001

I'm in the process of porting stock cast iron heads from an 87 Marquis for my 85 Ranger. My reference has been the article on this fine webzine. I have completed the exhaust side on one head and was about to start taking down the valve guide boss on the intake , but it does not appear to be as sharp and flat as I expected from the article. They are untouched still, but I am wondering if Ford adressed this since 1969 or should I continue grinding away half of the height of the boss in the bowl as the article suggests. Right now the intake and exhaust bosses are the same length and since the intake valve is larger I wonder if shortening the boss is a good idea? I'm liking the grinding but I don't want to have so much fun that it gets me into trouble. What do you think? Oh yeah, my intent for this motor is to be reliable, make good power down low and use Ford parts. Compared to the 302 2 barrel that's in there this one (efi) should be a major improvement both in performance and economy.



--------------------------------------------------------------------------------

Mr Torino - 3:07 am on Mar. 14, 2001

You can grind down the guide boss on the intake as long as the camshaft you are running does not have alot of lift with big spring pressure. Its the side loads of the high spring pressures that rapidly wear down a valve guide,so, as long as you're going with mild mannered stuff,it should work just fine without problems.



--------------------------------------------------------------------------------

MachMe - 8:48 am on Mar. 17, 2001

Thanks Mr. Torino. I am heading out into the garage this morning to finish the heads. I have confirmed your advice with a friend at work who has been a Ford mechanic forever. Till the dust settles...

--- Self-porting heads in UK


--------------------------------------------------------------------------------

simon - 7:13 am on Mar. 17, 2001

Hi there,

As you can probably imagine, there is very little information about ford small block engines over here in England, so I was very pleased to read the article on self-porting small block ford heads.
I'm building a Cobra with a 302 ford and when I start re-building the engine for fitting to the car I am going to port the heads myself. As you can appreciate, if I get it wrong I'm in trouble as small block ford heads are rarer than hens teeth over here !!
Firstly I would like to ask, what valves should I order to put in the heads if I want to improve the flow? I read something about Chevy valves would theses be ok? what part numbers would I want? keeping in mind I can't just wander down to the local shop, bits have to come across the Atlantic.
Also, how far can I go with the porting? as I really cant afford to get it wrong and it will be my first time porting a head?
Thanks for your help.
Simon
[email protected]



--------------------------------------------------------------------------------

MachMe - 8:38 am on Mar. 17, 2001

Simon,
I am in the middle of porting my first set of heads - although I have the luxury of a local boneyard if I mess up. I ported and polished the exhaust runners and bowls as the article recommended. No problems there. I got a little skiddish about cutting into the intake valve guide bosses. So I am about to go out this morning and cut away at them. I posted a question on this site earlier this week (porting 5.0 Heads) and need to check it this a.m - you may find these answers helpful. I also checked with a friend at work and he said there is plenty of meat on the bosses to grind away as the article recommends. The limiting factor is the selection of cam and springs. A
radical cam and strong springs may exert side loads significant enough to accelerate wear on the guides. You need to have the goals for power production in mind before preceding too far. You can always take more off......

I have read that Chevy 2.02 intake valves will work in 302 heads but try a mustang specific web site for a buildup and concerns about shrouding, etc.
Again where do you want your power, what tranny are you using, etc. should all be considered and carefully thought before you grind in to your rare heads. Have fun!!!




--------------------------------------------------------------------------------

michael - 7:18 pm on Mar. 17, 2001

someone stole my copy of ford high performance but i thought it said something about chev valves with longer stems.



--------------------------------------------------------------------------------

FasterDamnit - 7:41 pm on Mar. 17, 2001

Intake- 1.94" diameter, stock length with adjustable stud mount rockers- NON-Rail rockers! (rails are little flanges at the tip of the rocker Ford used instead of guide plates- they fit down over the valve tips- hence the tips were a little longer.) Don't go larger than that in diameter- the cylinder wall will shroud the valve.

Exhaust- 1.60" diameter, stock length with same caveat. "Stock" length means Chevrolet 350 c.i. V8.

If you have rail tip rockers and don't want to change the heads to screw-in studs and guide plates then Manley makes 1.94"/1.60" valves with the longer tips. Let me know if you would like part numbers.

Retailers-
Summit- 1-800-230-3030
PAW- 1-818-678-3000
JEGS- 1-800-345-4545

Most will send you a catalogue for free in the US- not sure about the UK or if the toll free numbers will work.. They also have websites.
JIm Langley

----------
Technical Editor, Fordmuscle.com
65 GT, 289, T5. '92 LX, 5.0, AOD.



--------------------------------------------------------------------------------

V8740 - 8:09 pm on Mar. 17, 2001

I've read that the 202 valve will not flow that much more than the 1.94 in stock heads.

--- Porting 302 Heads?


--------------------------------------------------------------------------------

Slasher306 - 8:15 pm on Mar. 18, 2001

I am porting a set ford 302 heads and i have been told that if the came doesn't have huge lift you can completly remove the valve guide boss from the intake and exhaust.
Cam=Comp cams .509intake .509 exhaust
What would you suggest?

Secondly, if i want to put in the chevey valves in can i use the stock rocker arms?

And last but not least i just purchased some dynomax headers and I noticed that the flanges are round and not square like on the head. So i was wondering if i should port the exhaust port openning the same shape as the on the headers.



--------------------------------------------------------------------------------

MachMe - 8:07 am on Mar. 19, 2001

I am heading out to the garage this morning to finish porting my 5.0 heads. Have you read the article on this website? I used that as a guideline and checked with a knowledgeable Ford mechanic. I know I can take more of the bosses than I did, but I chickened out. The tops of the valve guide bosses were 1 and 14/32 inches from the bottom of the combustion chamber (head gasket mounting surface) stock. I took them down to 1 and 20/32 and shaped the entry. Its gotta flow a lot better, but its still less than the article said I can do. My goals are to increase port velocity for low end, going into my Ranger 4wd, and low compression,etc. so I am gonna quit there.
Check the other postings on the techboard (one's mine) for more info - it seems to back up what you are told about spring pressure. As for matching to the header - that has to do with what do you want out of your engine - high RPM max flow(volume - match them) or low RPM (velocity - don't bother). I'm assuming you are looking for max volume if you are going ot larger valves. Maybe you'd do bwell to select a different cam than to grind your bosses away to nothing to get your flow you want? Good Luck.

--- Head-Porting_Question


--------------------------------------------------------------------------------

Robbi - 5:58 am on Nov. 27, 2001

Hallo,
Now I am porting my 289 heads and I see a problem.
One of the exhaust-ports has a complete other design .
It went to the header-side normaly and it went to the intake-side (egr ?, emission control ?).
I dont know how to port this exhaust-chanel.
Plese help !, or maybe some pictures .

Thanks
Robbi



--------------------------------------------------------------------------------

V8740 - 7:33 am on Nov. 27, 2001

Make believe it's not there. It's the crossover port that heats the intake. Whatever you did to the rest of your ports do to that one as well.



--------------------------------------------------------------------------------

Robbi - 8:41 am on Nov. 27, 2001

I think the crossover will increase the exhaust-gas-flow .
Are anywhere Pictures avalable?



--------------------------------------------------------------------------------

musthave302 - 12:50 pm on Nov. 27, 2001

Your gasket set will probably block off that passage anyway. As such, no exhaust will travel through that corridor, and porting it in any fashion will waste your time. Many NHRA stock eliminator cars actually fill that will aluminum so that the heat from the exhaust won't travel to the intake and rob horsepower.



--------------------------------------------------------------------------------

Pale Rider - 12:56 pm on Nov. 27, 2001

Robbi, just like v8740 says, make believe it's not there. I ported my heads and when I got to the port with the exh. gas crossover I did it just like the rest. That's all you can do short of filing it. For 99% of us shade tree types, filing the ports probably isn't worth the cost and effort. Good luck on your porting. It's actually pretty fulfilling. Looking at those smooth shiny ports will make you feel all warm and fuzzy inside.



--------------------------------------------------------------------------------

Pale Rider - 12:58 pm on Nov. 27, 2001

That should be "filling", not filing. I'm a moron.



--------------------------------------------------------------------------------

Robbi - 2:05 pm on Nov. 27, 2001

OK, I will port them the same type !

I am interisted in YOUR pictures also !
I have never seen that bowl-work for this chanel.
I will send pictures also.
I saw all pictures in the archives but found no one from this chanel with crossover.



--------------------------------------------------------------------------------

Pale Rider - 2:42 pm on Nov. 27, 2001

I wish I had some pictures for you Robbi. I took a little video of my "porting job" but I have no way of getting any pics on the internet. My feeling are basically this, take your time with the grinder and if it looks right, it probably is. Remember, velocity is more important that volume most times.
I wouldn't get too crazy in the bowls. I'd do a simple smoothing of casting ridges and leave it at that. The porting article on this site has some good pics for doing comparisons. Print the article off and keep it on your bench with you while your porting. Good luck.

----------
1976 Elite 460/C6
"Nothing like a good piece of hickory."



--------------------------------------------------------------------------------

Hottarod - 4:54 pm on Nov. 27, 2001

Take care on the sides of the exhaust ports that have the EGR channels. Don't grind much on the sides where the valve pocket turns into the runner. The casting is particularly thin in that area.

--- Headporting-Combustion-chamber


--------------------------------------------------------------------------------

Robbi - 10:30 am on Dec. 1, 2001

Hallo,
I have a problem with my 289 heads,
The Valve seat were teo times rebuild and they cut them deeper in the head.
now there are two steps between the comb.chamber to the valve-seat and
the Valves are plan to the chamber.
My question is:
Can I go the way to grind this two steps clear to make better flow?
I saw Aluminium Heads with good chamber cnc-build and they have the chamber I want to make.
I hope I can send you later today a pic.

This is a pic I found,
I want to grind my stock chambers that way .
Is there enough material to do that ?


Edited by: Robbi



--------------------------------------------------------------------------------

n2omike - 11:32 am on Dec. 1, 2001

Sunken valves don't flow very well. To fix the problem, just have larger valves installed. This will raise them up where they need to be. I dont' recommend having seats installed unless it's for a repair. After the larger valves are installed, you'll want to blend the valve seat into the bowl and unshroud the valves.

You CAN smooth out those ridges you are talking about of you aren't interested in larger valves.

Good Luck!

----------
Mike Burch, 66 mustang real street
302 4-speed 289 heads, 10.63 @ 129.3



--------------------------------------------------------------------------------

89 coupe - 12:03 pm on Dec. 1, 2001

There isn't nearly enough metal in the combustion chambers to reshape them that drastically on stock heads. Have larger valves put in your heads(1.84/1.54 if using 289 heads or 1.94/1.60 if using '69-'76 351W heads) and be sure to tell the machine shop you want the valves to sit high which will do 2 things. 1st you'll have better flow and 2nd you'll reduce the chamber volume which raises compression a little. 4-5 CCs worth can be eliminated with valves that sit high. Also you should put the heads on your bare freshly bored block and trace the exact bore on the head decks so you can unshroud the valves on the chamber sides to match perfectly with the bore for no turbulance in the incoming air/fuel mixture to encounter.

----------
--'65 Fairlane 500 wagon w/351W, '68 Falcon wagon w/289, '2000 SD F-250 V-10 crew cab off road 4X4, 01 Focus w/DOHC 2.0 4 valve, '78 Fairmont Wagon w/ fresh 10.5 to 1 302, & '76 Pinto wagon street/drag car .
MY WEBSITE



--------------------------------------------------------------------------------

RANDY - 7:40 pm on Dec. 1, 2001

Robbie,I'll sell you a set of 66 289 heads with big valves and fully ported!!These heads ran low 12's in my 66 mustang!! Mid elevens on 125 shot of nitrous!!! Give me 350 dollars and you pay shipping!!Email me at [email protected]

----------
RANDY




--------------------------------------------------------------------------------

Robbi - 7:33 am on Dec. 3, 2001

thanks for the informations.
Robbi


<font size=-1>[ This Message was edited by: admin on 12/28/01 1:20am ]</font>
 

·
Registered
Joined
·
6 Posts
Getting Ready to port the E7TE's off my 95' vert and have a few questions.

1. Will the 1.94 Int. and 1.60 Ext. stock height Chevy vavles fit these heads.
2. Will I have to convert to stud mounted rockers with guideplates or can I retain the pedestal mounts.
3. I plan to use these heads on a mild combo in my heavy vert AODE with 2200 stall converter and 3.73 tac loc rearend. Do you think they will flow ok with the bigger valves and following the guidelines from the porting article on this site.
4. Does anyone have flow numbers from a set of similar heads?

Thanks
 
1 - 2 of 2 Posts
Top