Whats the difference between 041 and 044 heads? As far as I can see the same casting (thicker sections and lon reach plug) is used and the only dif is the 041 uses stock size exhaust valves. Is this true?
I'm building a warm 2054 (74 x 94mm) using a scat C35 cam, will 041 rob significant power?

This is anecdotal but the Mexican 043 has the best port design out there. Also has very similar characteristics to a stock head as far as cooling is concerned. Some renowned headporters in the US are making a lot of power with these heads.
The 041s are good, if you change the seat and valve in the exhaust for a larger one (35.5). My understanding is that the 39 x 32 design was to create extra heat to lower emissions. It is a mismatch in valve sizes for a performance (or any) engine - they will work, but you could do better.
The 044 is the head that is used most extensively, and there are plenty of people making a lot of horsepower with them. Probably the CNCed 044s (round port) would be the best bang for your buck.
Its where you make or break the engine - pour as much money as you can afford to into them... Theres a good article in the tech section of http://www.cal-look.com  .

Just a reply to the above regarding the CNC'ed 044 heads (CB Perf). I had the opportunity to have a look at a set of these (over the weekend) with a head porter explaining the 'features' of these heads.
He was very critical of the porting carried out.
The valve-spring seating 'bump' in the intake port is totally removed weakening this critical part of the head. Where the CNCing stops and the raw casting begins in the seat there is poor transition and distinct roughness.
The CNC machine obviously duplicates the machinig process identically, however this requires the head to be perfectly positioned in the machine. Alot of the other holes(etc) that are machined at the same time (as the porting work) were shown to me to be poorly located on the casting. That is the head was not perfectly positioned - therefore neither was the porting of the intakes, combustion area ....etc.
The pocket shape around the valves was all wrong (in this porters view) having steep sides and too much material removed opposite the spark plug thereby slowing down the flame front and taking heat away from where it is required.
Running my fingers inside the ports of the CNC 044 and then doing the same with a bone stock VW casting clearly indicated to me that the VW head was better (off the shelf)!
Also he pointed out that alot of the head porters using these heads were complaining of uneven head chamber volumes!
In short he was not very positive about the CNCed heads. Apparently CB had alot of them CNC'ed and had no excess raw castings to supply (to the various head porters) for several months.

Kind regards,
Ali

There is no doubt that CNCed heads are not perfect, and there have been issues with ccs in combustion chambers. I am using a pair of the big oval ports, my chambers cced out close to perfect. The bump in the intake port is still there in my heads. The ports are too big and not a good design. I ran a 15.57 1/4 in the pouring rain with stock gears (3.88 r and p) with these heads.
With the new wedgeport design there have been engines making over 200 hp (2276 k8 combos) at the flywheel - for 700 US you arent going to do a lot better. Race heads by a porter are going to be 1200+ US.
Bang for your buck right !!!
They are a compromise but not a bad place to start, if you can operate a dremel with a flap wheel you can remove most of the machining flaws, I cleaned up the seat, port transition on mine, took off sharp edges in the combustion chamber.
Maybe 4 - 5 hours work.
If I could do it all again I wouldnt have bought the heads I have, saved a bit more and got some purpose built.

[Edited on 10-3-2004 by AdrianH]

Thanks for the info on CNC'd heads. I was really wondering however, whether the 041 (with smaller exhause ports -32mm) will rob much power on a street driven engine (i.e. RPM<5000) I guess I know my answer, but I'm only going on 'gut-feel'

Gene Berg called them bastard sized valves.
The engine will run, but it could be better, then again my wife could be a supermodel

Gulp -- well I guess that has answered my question.
No 041 heads for me.

Time to save up for some good 044 heads and out with the rotary file.

A.J Sims was the head porter I was talking to about the 044's. He has a web site:
http://lowbugget.com/ 
He seemed fairly well educated (although he can't spell the word 'budget'!) about heads, and was very interested in providing the correct heads for the application (ie. asking the combination of all other parts to be used and the cam profile and intended use of the engine....etc).
It may be worthwhile e-mailing him re your intentions and simply asking for his advice.

Kind regrds,
Ali

A mate of mine in Cali is running a set of his Level 7 heads

I believe Ryan has one of "those" 1916's

I have no reason to doubt Ryan but with those "serious" heads he is making BIG power

AJ certainly knows his heads