would never have figured that out...
but yeah, i've only ever heard good things of JMM too, if it wasn't for lack of funds, i'd be sporting their handywork under my bonnet.

That's gotten cheaper over the years. You can't beat the finish, i think they can even rough inlet ports with course media and mirror finish exhaust and chambers.

Like I said before, & pretty sure others have also, alot of people could cnc port a head. It's doing an effective job is the challenging part. If tickford_6 develops a good flowing head, which he already has, ultimately it's just a matter of digitising it (like xcabbi said) and mass producing. Thing is people have to run businesses and make profit & to be honest in my opinion, someone else doing the hard work is worth paying for! Some people, like a certain aforementioned company in previous posts, get a monopoly going and get greedy. That's unfortunate.

does anyone actually know what the price tag is for a machine that will digitize the head and machine it? the one ive herd about is worth upwards of 250,000 imported from america?

They would probably start at $200 000.

A friend of mine has a 3 axis machine at work that cost them $150 000. They can punch out some cool s**t, but a 3 axis machine can't do cylinder heads.
It's at separate machine to do the digitising.

http://www.romer.eu/products_512.htm

Portable coordinate measuring machines are developing to be a cost effective solution to a full sized scanner.

The University of Wollongong has the Romer multigage. Its a contact probe only device with a working sperical range of 1.2m so it would most probably need to be repositioned to properly do a falcon head. Each time you reposition the arm you lose about 0.045mm in accuracy. This arm is the baby version and it cost the uni $28,000 back in early 2010. The killer is the software. It comes pre packaged with delcam powerinspect which is rather limited in what it can do. You can only import IGES files and for you to import proper cad models you need a plugin for your chosen cad package. Just the solidworks plugin is $20,000. I spent most of this year trying to set up some welding jigs with this arm for my thesis but it was very limited in what it could do.

The best option for someone willing to use a portable cmm to scan a head would be the romer absolute arm with an integrated lazer scanner. The arm on its own is about $50,000. I don't know how much the laser scanner is but I do know it comes integrated with the new model of the absolute arm. In terms of software, Industrial measurement solutions can hook you up with some pretty cool reverse engineering software which directly integrates with soldworks. Might be worth checking out http://www.measure.com.au/

The only comparison available to JMM head is a VL head which u can buy RRP $1600.00 fully CNC, reco and ready to go...

Yeh it's not brand new cast but who cares as it's been fully reco and pressure tested...

I'm sure if his pricing was about the same for a reco head which has been CNC ported he would have a lot more interest...

A Similar comparison would be the CHI Hemi 265 Head $2,400

http://www.chiheads.com.au/6cyl_alloy_hemi.php

Am I missing something or is that $1600ish bare? And $2250 built? JMM want something over $2000 bare I thought?

Nah not missing anything - just saying VL comparison is high volume thus cheaper - the Ford OHC & Hemi 265 are low volume so its a better comparison

CHI Hemi 6cyl Head $2,250 Street Version complete
CHI Hemi 6cyl Head $2,400 Race Verison complete

Although you would buy a CHI Head bare @ $1,650 and add $2,000 for FULL Race Version by Dominator Engines who have the 11 sec NA 1970 VG Val Pacer TNT265

Or go extreme $3,300++ for Bare Custome CHI Hemi 6cyl Head from Rallis Racing

Those measuring arms are awesome xcabbi my brothers learning how to steer one at the moment,I think their only one of two companies in this town that have one. I know of a few different places with 5axis horizontal centres though.

have yuse ever had a cylinder head mob tell you that haveing ports really smooth and shiney like glass is bad for your car and that it's needs to be rough? my old man said the smoother the better and the bigger the better, he said that he used to use the intake valve on most round port heads and used it as a reference to the size of the ports used to do the same withthe exhaust ports. now when i mentioned this to the cylinder head mob here they said my father was an idiot and didnt know anything, mind you my old man has been a mechanic sience 1967 and he learnt from my pop who was heavily into drag raceing and he learnt from my great grandad who used to work for ford motor company in nsw. so can any of youse answer the original question, and whats your theory on it.

there is a point where its too big, the best person to talk to about this is tickford_6 hes very knowledgable on this kind of stuff, prety sure he started a head porting doco on the forum, do a search and have a read of that

yer i know too big can be bad but the whole idea of being really smooth being bad was something of a wtf to me, the head in my datto is ported out to match the size of the gasket something like 4mm between the rim of the gasket and edge of port was removed and it's smooth as silk and i have noticed that there was a massive response difference as well as the whole lose go after 150kmh issue, i founf even smoothing the inside of the carb on my bike made a massive difference, but with the datto i also had the manifold ported and smoothed out like glass my torque, power, response and fuel economy had all recieved a massive improvement.

They are a good investment, provided you have the right tuition on how to use them. I had to learn mine from scratch only to find out that it can't do what I want it to do. So for my use its a chuck in the bin type of item. However, for digitiisng heads. I reckon the absolute arm with laser scanning would be the ducks guts.

cozza
Smooth and shiny on the intake port is bad as the fuel sticks to the walls and you lose half of your air speed. Smooth and shiny in the combustion chambers is good as it locks the heat into the combustion chamber and helps the fuel burn. Also Smooth and shiny in the exhausts is also an ok idea as it helps with scavenging. The retained heat in the ports forces the hot exhaust air to go down the exhaust in order to find some cooler metal for it to pass its waste heat off to.

As for bigger is better, where did you lean that? The hans hartman school of race porting?

Think of a golf ball, If a golf ball has no dimples on it it wont travel very far. Machine dimples on it and it will travel much further than when it was smooth.

Thats how my machinist explained it to me when he ported my head and it came up mint.


http://i1198.photobucket.com/albums/aa452/hyperxr6/10122010031.jpg