TheSamba.com :: View topic - New Revmaster DG063 10 fins cylinder heads

Wed Jul 16, 2025 6:57 pm

14 per hour, you forgot a zero :lol:

If the world was fair, but we always knew it isn't
But I'll do anything once, just to see, and I guess that's why I'm barely scraping by, but very few regrets.

Wed Jul 16, 2025 7:14 pm

$140/hr would probably make my hands feel better the morning after.

I really like building heads. I am always learning something new, and they are interesting. Building spring plates, IRS kits, and disk brake kits are the opposite, but I can actually make a living building suspension and brake parts. The suspension side buys me more tools for the non-profitable heads and engine side. :lol: :lol:

Brian

Wed Jul 16, 2025 7:36 pm

Wonder how practical it would be to come up with some sort of porting template (tutorial?) to sell so I can be cussing at heads and manifolds after 30 hours of grinding. :-k

Thu Jul 17, 2025 4:41 am

What Brian needs is a $250,000- $500,000 multi-axis CNC mill.

Then, once he's got his ports and chambers "just so" by hand, he can do a 3D scan of them and start churning them out by the hundred load. Then the market can complain that CNC heads by a guy in SD are "ridiculously overpriced" at $1500 a set. The payback will be measured in decades, if not centuries.

In keeping with the way things are done these days, we should start a GoFundMe page for him and harangue people to donate. The fund should top out at about $126, before we all peder out.

Thu Jul 17, 2025 5:36 am

94touring wrote: Wonder how practical it would be to come up with some sort of porting template (tutorial?) to sell so I can be cussing at heads and manifolds after 30 hours of grinding. :-k

Interesting idea, but they would have to be for specific heads.
Back in the day there were templates available for the SBC 461 & 462 double bump heads.
I used a set to port some 462 heads for a poor boy 331 that got my 67 Camaro streetcar into the mid 12's.

Thu Jul 17, 2025 5:47 am

Yeah, I've got templates in my shop I've used to port rotary engines, which got me thinking why not for something like this situation. Brian's already put out great info on correcting panchitos. I'd really like these heads for a specific build I'm working on, but they won't do me any good unless I get the flow numbers and ratios correctly done.

Thu Jul 17, 2025 8:50 am

58 Plastic Tub wrote: What Brian needs is a $250,000- $500,000 multi-axis CNC mill.

Then, once he's got his ports and chambers "just so" by hand, he can do a 3D scan of them and start churning them out by the hundred load.

Is that how CB's cnc ported 044 heads are created?

Thu Jul 17, 2025 9:15 am

chrisflstf wrote: 58 Plastic Tub wrote: What Brian needs is a $250,000- $500,000 multi-axis CNC mill.

Then, once he's got his ports and chambers "just so" by hand, he can do a 3D scan of them and start churning them out by the hundred load.

Is that how CB's cnc ported 044 heads are created?

That is how CBP 044s are ported, with Pat Downs' ports and programs.

Thu Jul 17, 2025 9:33 am

Brian

Thu Jul 17, 2025 9:34 am

Haas makes some "affordable" 5th-axis trunnion rotary attachments. Used starting at $10k. Depending on the size.
Might be able to fit a head on a TR210.

Fri Jul 18, 2025 6:51 pm

Alstrup wrote: Brian_e wrote:

I can email Roy, and Empi, and see if they want to loan me a head for a test as well.

Brian
Good luck with that. They don´t like to be humiliated in public. Me neither.

When VW Trends did a headflow shootout, in the early 2000's, we had a hell of a time getting folks to supply a head, that met the criteria that everyone had to adhere to. A couple of them were not tested, because they didn't follow the rules. I don't know if they were trying to cheat, or they just didn't understand the instructions.. I got min some trouble with all of that, but *I* ran the SuperFlo bench, and I dare ANYBODY to say I didn't report my findings fairly and accurately

Sat Jul 19, 2025 5:48 am

Well, yeah, Brian is right with the point that flow numbers are only 30% of the tale. So even though it can be a good read, a head flow comparison is not really much more than that. If you do not know at least the port volume of a given head you can´t really assume much. I myself focussed too much on flow numbers for many years. That got me in trouble a couple of times with engines not performing anywhere near what they were supposed to. Today, when "we" have much better tools and much more general knowledge we also look into avr port velocity and port denity energy and also where/how the fuel mix is distributed in the combustion chamber.
Then we need to decide,
which rpm band do we want the engine to work in.
What displacement.
Which induction system do we want.

Then when the moment of truth comes and the engine (hopefully) is put on a dyno or chassis dyno we can (again, - hopefully) rely on the dyno being properly calibrated after DIN, SAE60 or SAE 1349J corrections. Then we have a chance to know what that given combo actually does. If we could get that far the average home builder, and even us semi pro´s, would have a much greater chance of selecting the parts which suits his or her expectations.
Also, in almost any case except drag racing the focus should be more on APB compared to peak hp. - That said, the 2 hang together to a certain extent, but still. For instance, Back in 2018 (Before the world got on edge) I helped setting up a Porsche 993 for compeeting in the Moscow 500 You are only allowed to do so much in the stock class, but it is possible to find a little here and there and also to move the power around a bit. In the final tune we were 10-11 hp away from the highest peak pulls, but the car was 0,23 seconds FASTER on the 500m. That solely came from more torque in the midrange so the engine picked up better after gearshifts.

Anyway, back to this subject. - If you want to compare cylinderheads, you need more data than just flow numbers. BUT! Here is a little giveaway, which I believe Brian has also touched somewhere. If you compare flow numbers on 2 sets of heads you should pay attention to how well the heads flow BELOW 0,400" lift and ABOVE 0,400" as 2 separate comparisons. If one cylinderhead flows better below 400 thousands and still hangs on fair above, that head will 95% of the time perform better in a street configuration.

Sat Jul 19, 2025 11:23 am

I think a shorter version of what you are saying is you want the "highest average area under the curve." This would be true for both flow and velocity, if you can optimize both.

Sat Jul 19, 2025 11:42 am

Victor H wrote: I think a shorter version of what you are saying is you want the "highest average area under the curve." This would be true for both flow and velocity, if you can optimize both.

Yes, highest area under the curve for both, and that is why it’s hard, and why every head is different. Huge ports flow big CFM, but terrible ft/sec. Tiny ports have really high ft/sec, but they might not have the correct CSA to support the RPM.

The very fine line is keeping the port small as possible, while flowing as much as possible with the correct CSA. To do this, you need to be able to figure out what the air is doing in each part of the port, and how to change it. This very fine line is what most all of the “porting VW heads” videos on YouTube are completely missing.

Brian

Sat Jul 19, 2025 12:07 pm

You happen to have any ft/sec numbers to other street heads to show as a comparison to these 063s?

Sat Jul 19, 2025 1:46 pm

94touring wrote: You happen to have any ft/sec numbers to other street heads to show as a comparison to these 063s?

These are from my notes of heads I have tested on MY flow bench. These will probably not match advertised numbers from others.

Quick easy numbers all at .500” lift. All 40x35 heads. All tested with correct manifolds.
Ft/sec numbers and port volume.

Brother’s round port.
263.1
66.6cc

Aa502’s with only blended chambers and my valve job.
267.6
68cc

Panchito w/ blended bowls
271.0
64cc

Berg 040 from 2000ish. Ported by Mick Wooten
283.9
67cc

My aa500 40x35
279.0
66cc

Revmaster 063
265.8
67.6cc

Mofoco 042 with a slight oval port work
252.0
67.5cc

Tims S1
298.6
64.5cc

Other bigger valve heads.

Brothers Mid or Big D. 44x37 and huge ports. These heads were a dog.
236.6
83.2cc

New CB wedgeport 44x37
246.7
77cc

New CB ultramag 44x37
250.7
75.2cc

Remember…… the more ft/sec per CC, the more efficient the head is, and the more port energy it will make. The better the port energy, the better the cylinder filling, and the better the torque. BUT……..if the port volume is too small, and the CSA too small, the engine will not rev real high. This is all dependent on the displacement and the upper RPM you are hoping for.

Example, my 2332cc in my bus has a pair of 40x35 aa500’s I built. They are 278ft/sec at .500”, and 65cc ports. They run to 5200rpm, and they are done. No more, finished. Good bus engine. Boring hot rod bug engine. More port volume would get the ACSA up, and help it rev a little higher. Much higher after that, and would need a bigger valve.

Brian

Sat Jul 19, 2025 2:38 pm

One other advantage of high port velocity you didn't mention. The higher the port velocity the better the mixture and turbulence in the combustion chamber and the lower the risk of detonation for any given load/rpm/ throttle opening (again, within reason).

Sat Jul 19, 2025 3:25 pm

Tims really blasting air in there. Thanks for posting these. My backup plan I was leaning towards cb ultra mag, but this changes my mind a bit since I too am doing a 2300+ cc good bus motor/boring bug motor.

Sat Jul 19, 2025 5:16 pm

Those Tims S1 heads are kinda crazy. I had Greg do them with a smaller port volume on purpose. Those are the fastest airspeed heads I have had on my bench. I have used S1 heads on other engines and they always work fantastic.

If I was building another 2300+ bus engine, I think it would get Tims S2 heads with about a 72-73cc port volume, and something similar to a web 163.

Brian

Sat Jul 19, 2025 6:17 pm

You read my mind on the stage 2 Tims since he list them with 73 port volume, plus I've already committed to a w163.