Has anybody had experiance porting & polishing the heads on an EFI 351w? I have done a number of carb engines & a diesel with good results. Since it is a port fuel injected engine, would you reccomend that I polish it about like the exhaust side, or just knock the rough off & concentrate on the bowl area, like on a TBI or carb engine? My thoughts are to polish it pretty good since fuel is sprayed into the port where the velocity is high & it wouldnt have time to seperate. Any thoughts or personal experiance?

 

I see what your saying about polishing the intake port. I also think that the extra disturbance from an un polished intake port might still aid in the atomization, if not enhance. From everything I have read be it efi or carb injection you will pretty much gain the same hp across the board. The same principal apply if you start taking material out of the intake/exhaust ports you will put the operating range higher and higher until you have a set of useless heads. Most I have seen from a street port / clean up what ever you wish to call it is maybe 15-20 hp. Keep in mind that would be using the same setup, if you change the cam etc. you should benefit more. Good luck with your van

 

JW, thanks for the advice! I dont get carried away when I do a port match & polish job. I am usually content to knock most of the rough off, but still leave enough enough on the intake side to promote atomization, and slick up the bowl pretty good. On the exhaust side, I slick it all pretty good. I dont do much grinding past knocking the rough cast off, unless there is a barb or something that I feel is in the way. Sounds like I should treat the EFI the same way as I have been doing the carb & diesel engines, and had good luck.

Seems a quick & dirty gains quite a bit on a street engine , and from experiance, going farther than that doesnt do much except waste time. I am looking for a good EFI cam, headers & perf. chip to help with all of this, and staying conservative.

 

Portwork on an EFI will be pretty much the same as a carbed or TBI engine...

because the EFI is a dry setup up until the lower intake....it is more forgiving......the best possible thing you can do is to port the intake....keeping the port size in a gradual reduction as you approach the riser on the intake port....(this should be the smallest area) then the transition area begins and the valve pocket or bowl is there....) This helps keep port velocity high thus keeping your intake and heads streetable....just keep the port sizes conservative. Lots of people say gasket match....but this is for muscle cars etc..... The Gas laws dictate that the smaller the volume, the higher the pressure.....and higher pressure means the gas moving through will have a higher velocity.

Then blend the fuel bowl smooth up under the valve seat taking care not to score it....the valve guide bosses should be ground to a funnel shape to add volume to the ports....the shape they should take on is a tear drop shape...

check this out:
http://www.replikamaschinen.com/Web_...%20chamber.jpg

Then get the intake ports bead blasted....to keep a semi rough texture..

the exhaust side should experience a removal of the EGR bump,smoothing of
guide boss, bowl areas and a mirror like polish with an enlarging of 1.5 mm on each side of the port, removing any cast flashing...(exh ports are where Ford heads suck)

There is a di it yourself kit out there....do lots of research on portwork....as ruining a good set of heads is easy to do.

 

Thanks Capone! Wow ! What a wealth of information you have just given me! That picture tells me alot! I am not new by any means to head porting & polishing, and this detail will really help me clean up things to flow better. I also noticed these heads have a nice "squish area", which I know helps the efficiency of this engine.

I have to change valve cover gaskets on this beast, and that is a good excuse to pull the heads & work some magic!

I noticed you are running a running a Diablo chip & Cam research cam. Are you running headers too? Did you remove the smog pump? How do you get along with the chip? How do you like the cam? Do you have the chip that you can change the settings on? I am really curious about a real world account of this setup, and you are running something very similar to my "People Hauler".

How hot a thermostat are you using? Stock?

 

capone if that is your port work then that is a nice job.

 

Notice in the picture of the intake port....right on the left side of the valve guide boss....the valve pocket size is gradually larger....while the right side of it remains the same size....this is done to promote swirl of the intake mixture...

So after the riser begins the transition to the valve pocket or bowl area....the
port expands and favors the upsizing to the left...(looking at the port from the
intake port entrance and comb chambers facing down) While the right side remains a straight shot down the combustion chambers.

Intake port size should remain about 1 mm smaller than the Felpro gasket size (at the entrance) gradually reducing in size as you approach the riser...

It is the exhaust side that needs all the help it can get.

I have a set of ported 351W heads that I can take pictures of....to help you in your adventure....they are complete and they are just sitting in my garage ...they are 1970 heads though 1.94/1.60...(they are the same except for the air injection passages)

I also noticed these heads have a nice "squish area", which I know helps the efficiency of this engine.
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Yes, the quench area is so important...because it alone can help or destroy your engine's ability to make good hp....by controlling pinging...

I have to change valve cover gaskets on this beast, and that is a good excuse to pull the heads & work some magic!
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Give yourself about a week to port and polish the heads.....it is labor intensive which is why it costs about $1200 to get them done right. There is a dit it yourself abrasive kit sold online....well worth it.

I noticed you are running a running a Diablo chip & Cam research cam. Are you running headers too? Did you remove the smog pump? How do you get along with the chip? How do you like the cam? Do you have the chip that you can change the settings on?
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I retained all of the smog equipment because it keeps the cat converters, O2 sensors and exhaust scavenging healthy, plus it keeps the CA smog ***** off my back. Today's smog equipment doesn't rob enough power to even think of taking it off....(less than .5 hp) and yes it helps clean emissions.

I have not ordered the Diablo chip yet....I recently dynoed the truck to get A/F readings throughout the powerband and was pleased by the results....I will order the two setting chip so that I can switch it back during smog tests.

The camresearch custom grind allowed me to increase duration and lift and reduced the Lobe angle separation a bit but it still passes smog and idle is smooth....the off the line torque now extends well into the high midrange.

I am running ceramakrome coated JBA shorties(these are bolt on and have plenty of room to work on changing plugs)...they are also coated inside with the higher temp black coating. The Bassani Y pipe was also coated to keep the exhaust gases moving fast....The truck also sounds more aggressive because of the coating....the flowmaster is a bit louder than before...

I am really curious about a real world account of this setup, and you are running something very similar to my "People Hauler".
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JW knows I have been raving about it...especially now that is is broken in...
Some heavy hills (grapevine enroute to L.A., climb to Reno, NV, Climb to Aspen, CO) that used to slow the truck down are now conquered with the Bronco full of people AND hauling a double axle trailer with a 280z on it...I can actually accelerate now!!

How hot a thermostat are you using? Stock?
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I went with the stock thermostat from Ford...to keep the ECU from guessing.

I also had the heads, intake, thermost housing, timing cover, water pump, finned alum trans oil pan, trans cooler and radiator heat dispersant coated
so it should help keep the ping at bay.....

 

JW, I get all my portwork done there....

takes forever and costs an arm and a leg.....airflow specialists are artists....
they can't be rushed and are a dying breed. People are even trying to mechanize the porting of heads and intakes....nothing matches the hand blended ports though....

 

Thank you again for your advice & time in helping shed some light on this project. I am printing out a copy of this & adding it to my service manual! I usually spend quite a bit of time studying things when I do a port match & polish job. This fuel injected job is a little new to me, but with your help & my past experiance, I think I can make this engine run strong, and still keep some green in my pocket !

I will be idle here for several weeks, as I am making my yearly trip into Mexico with a load of treasures for the poor, and open my shop to help get some crippled vehicles running again, and make some computers compute. January of next year, I will be driving my "People Hauler" from central Illinois down to central Mexico, tow-barring a small truck! Then, when it is in my shop, I am going to start to apply all this wonderful advice! I already have several pages of notes I have made from this forum - it is amazing what can be done when people pool their knowledge & information, and how many mistakes can be avoided!