porting

[cummins king]

anybody want to give me a quick crash cource on porting and polishing, and what type of tools you use
thanks

[DTanklage]

i use a dumore motor

series 35

they are as good as it gets

be careful - this thing will remove material like no tomorrow

http://www.dumorecorp.com/grinder.htm#10

kinda spendy but they are the best for porting

if all you are doing is a cummins head there is hardly any material to remove

you could just use a 1/4" air grinder (hard on the air compressor tho)

contact joe at mondellos for your arbors cartridge rolls and such

he is the man

http://www.mondello.com/Catalog/SA_Video.htm

leave the swirl affect in the intake port of you will lose power - no kiddin

most important area is from the valve seat 1/4" into the bowl

that and the guide area

supercharged engines do not see hp gains from porting like gas motors do

unfortunately

[seeker1056]

I use a makita long nose electric grinder and tree shaped grind stones as they produce a nice finish and remove material quickly. The grey stones are really aggressive and the pink stones leave a nice finish surface

The PDR site shows some good pix of a ported head although I would do considerably more work around the valve guide areas than they show.

For our purposes meaning pressurized flow, smoothing out the casting flash and corners and blending works a world of good

Larger passages are not necessarily what you are looking for but you are looking to equalize the sizing of the passages so there is less bottlenecking to the valve, especially at the valve guide areas

A five angle valve job would also make a huge difference.

On the exhaust side, port matching of the exhaust manifold it self should show a lot of benefit.

If you have never ported a head before, do a lot of research first - its an expensive "OOPS" when you break through the casting into the waterjacket

When we were doing race porting we always bought a junk head for the motor type to be used and removed the valves and got out a 1/4" drill and swiss cheezed the entire port. Just slicing a port in half does not give you a clear enough view.

This allows you to see exactly where the casting is thick and thin, and it shows where the most gains can be made as you open the port behind the valve and valve pocket.

Then you port this swiss cheezed port and when your happy you make cardboard templates of the entire port in various places.
These templates then become yuor guide in the good head ie you only grind till the template fits.

Even still with all of this information, it would take a book(s) to describe where and how much material to remove and why.

And then, no two heads or ports (different engines and layouts) are the same so then to really do it right you need a flow bench

And no matter how much you read it still takes a good eye as well as a "feel" for the work.

Do yoursellf a favour and get a good pair of anti-vibration gloves cuz by the time your done even one port your fingers will be numb which isnt a good thing longterm. Good motorcycle glove swill do in a pinch.

Its a terrible job at the best of times but it is also really rewarding if ya get it done n done right - good luck

[DTanklage]

ps - porting is like welding - it is an art

just because someone has a tig machine does not mean they can heli arc

i suggest you get some cracked junk heads and practice A LOT before you start removing material from your head

there are water jackets in cyl heads too

[DTanklage]

opps, sorry, wrote this (*and a bunch more...lol) but didnt hit submit right away and didnt know that someone else already touched on these thoughts

stones?

i didnt know anyone still uses stones to port

do you finish with cartridge rolls or pink stone?

check out mondello's site, he has all sorts of bits n stuff

don

[cummins king]

thanks for the info, how long does it take to do a head proporly

[seeker1056]

how long??? thats a relative term? Are you doing an allout port job or just a casting smooth job?

In my heyday once all of the prelim research was done and the templates made - I could do an entire port in about 50 minutes

then my hands needed a rest.

How long will it take you ?? no idea

Yes I use stones on cast iron they are faster than burrs - and those carbide burrs are dangerous in the extreme - especially if they grab and try to rip the grinder outa yur hands and especially so workin in aluminum - however a burr is all that will work in aluminum ;o(

[DTanklage]

a dumore will spin a carbide 20,000 and there is not a iron cast that will slow it down

was suprised to see joe sell the makita on his site

templates are great

another big plus is to scribe out all your final sizes (at the openings) BEFORE you start the job

[seeker1056]

dumore or makita - at 20,000 when that carbide grabs it walks that bit in a circle about a dozen times before u can get off the trigger

I have seen cast iron so work hardened that a carbide just bounced on it barely scratchin the surface.

I really liek the look of that dumore - I may look into buyin one if my makita burns down again someday, as in worn out.

;o)

[DTanklage]

you wont regret it

get the 35 series

and i am tellin ya - with a carbide it will take 3/8 deep swipes at alum

and spins so fast it doesnt dig in to cast iron

don

ps - they do not even have a trigger! (cuz they have so much torque they know they wont dig in) they have a toggle sw

for real...

[cummins king]

maby seeker i will take you up on your somtime soon, one thing i wasnt blessed with was pacients

[DTanklage]

like i said, it takes more than just patience...

"owning a heli acr machine does not make you a tig welder"

did you check out mondello's site?

he does list some kits for beginners

as in first time porters

and porting one of these things is a lot easier than doing a all out n/a motor

you could do it if you really wanted to

the practice suggestion is a good one

[cummins king]

sorry i doin an all out motor is easyer, bolt this to that weld this, no real guess work

[DValentine]

I can vouch for being a NOOB and trying to port a head. I found the water jacket in the number 6 exhaust port. Called PDR and ordered one of theirs....stage one....happy camper.

You can have my old one to play with if you want.



Dave

[ford69557ci]

depends on how much you want to do on the time i my porting guy has like 12 hours on the in take and exuahst sides but thats with milling of the factory intake and tappin the heads for the new bolts