Porting prices.

[HLS30]

What are cylinder head porting prices going for theese day ? I am talking a good job not a hack job by a want-to-be racer. With out replacing seats and installing larger vlaves on like an early square port L20B

[banzai510(hainz)]

matchport to a 1.5 inch(SSS intake gasket Or Felpro Gasket) is about 100-150$ a few years ago.

 

if you want tru MAGICAL HP porting your going to pay alot.

[Skib]

depends on who you know and how much porting you want done, the type of head ect., filling out a location helps us too ;)

 

for me I do the porting myself and can get the rest of the work (cutting valve seats, decking the head ect.) done at or close too cost

Edited October 26, 2009 by Skib

[Phlebmaster]

Just swap in an RB.. :D

[datzenmike]

I bought a $50 dremel like thingie with a hang up motor and cable drive somewhat like a speedometer cable with a head that you can chuck bits into. I also bought a carbide rasp? that I chuck into my electric drill for major chip removal. I bought a few 'tips' and sanding attachments and did my own. USE EYE PROTECTION! I found the work strangely satisfying to do and spent 16-20+ hrs on a head. You can't do it if you are in a hurry, pay someone if that is the case, I had the time and really liked working with my hands.

 

Z24 head ported.

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/IMG_0119.jpg[/img]"]

 

Made my own injector ports

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/00770024.jpg[/img]"]

 

The equipment used. Including 80 grit strips to seesaw through the open port to smooth and round the close radius.

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/00770013.jpg[/img]"]

 

I highly recommend doing it yourself. Once you have the equipment you can port and polish all the heads you want.

[zed]

I found the work strangely satisfying to do and spent 16-20+ hrs on a head.

I highly recommend doing it yourself. Once you have the equipment you can port and polish all the heads you want.

 

what Mike says. Porting/polishing is the best fun you can have with a motor. Can even be done with a hand drill and die grinder tips - but it's easier with an air tool driven off a compressor. Even an amateur like me can do it - if you're careful, and do some research. Best porting advice I got is rather remove less than more metal.

Honsowetz says not to remove the spark plug bosses from L heads. Also don't cut off the valve guide. Remember that removing metal from the combustion chamber lowers compression. He says unshrouding brings the best flow gains on L motors.

[Skib]

and do some research.

 

and lots of it :D

 

a poorly done head can hurt more than it helps.

and remember bigger isnt always better, its all about flow, not size ;)

[datzenmike]

... and remember bigger isnt always better, its all about flow, not size ;)

 

That's what she said.

[paradoxx]

That's what she said.

 

:lol::lol::lol::lol::lol::lol: I saw that one coming!

[hang_510]

With out replacing seats and installing larger vlaves

:blink:

impossible!

larger valve = new seats.

 

 

w/o going too crazy, DIY unless you have access to check flow after each step.

open em up a bit and smooth the angles.

[MAG58]

+1 for doing your own. But if you do, make sure you research your head and intake combination. To do a good port job you really need to know what type of induction you're running and where the flow should be directed on your particular head.

 

Like everyone says, it's not how much it flows, but where it flows it. Some of the most efficient heads don't flow 300+cfm and even if they did, the amount of time a cam spends with a port open at the amount to flow 300cfm is very small. Making sure that the head flows as efficiently as possible in the .300 range where the port will spend a good chunk of time open at will make for a much better port design.

[HLS30]

I have been getting quotes all over the place. From 300.00 to 500.00.

I think I found an early L20B square exhaust that is ported and polished with 280z valves for 450.00 has springs and retainers. This guy also has a stroker crank and J&E pistons for the stroker but I am only interested in the cylinder head. I have to look at my old books To see the diameter difference on the valves. I remember in the 240z it was common to do the 280z valves when building up.

I have to do some reading and researching.

[RoadRace]

Hi - i have been doing my own heads for 20 years. i own the equipment and have made a flow bench. its fun learning. the funny thing is the more i learn, the more i realize i don't know. here are a couple basic rules i've picked up along the way.

 

Rule 1: know your goal, n/a or turbo? .620" lift 300 degree cam running 9000 rpm with 50 mm carbs or 6000 rpm, 32/36 DGV and a 470 lift cam? the port configuration and valve criteria is significantly different.

 

Rule 2: Less is more. the actual amount of material that needs to be removed in order to yield the perfomenace gains expected is smaller than you want it to be.

 

Rule 3: the further away from the actual valve seat you go, the effect on the port decreases exponentially. for the most part, in the beginning, the valve itself is more important that the shape of the port. Port matching is a waste of time if the valve seats are too wide, on different angles, edge margin varies too much, etc.

 

Rule 4: Remember where it all starts! the combustion chamber is very important. Flame travel and combustion wall is critical - so DON'T change the basic shape of the chamber. Removing sharp edges eliminates a potential source of detonation - that includes the 'other side' of the combustion chamber - the top of the piston! make sure the valves have room for the gases to flow around them - 'unshround' the valves in the head - use the head gasket as a template to expand the chamber.

 

Rule 5: Short side radius. the short side radius in the port is the 'ugly stepsister' of the head porter. you look at it the wrong way and port flow drops like crazy - and you can't get it back, your screwed. leave the short side radius alone.

 

there are few guys i would trust with a Datsun head. The head porting philosophies are different from a typical 'chevy' head to a datsun head. apples and oranges - square port vs round. and i say this because every machine will tell you they can do it. be careful.

 

talk to Jeff Winter in CO. if you are going to pay somebody to do it. Super guy, he'll help you out. http://www.rallye-sport.com is his site. phone number is (303) 427-0510. the email addy on the site isn't current.

Edited October 29, 2009 by RoadRace
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