VW Cylinder Head Quick Reference Sheet

[AlteWagen]

I think I will make this a topic of its own

Trying to find this data in one place is frustrating when deciding what heads to use for a specific build or if heads have been modified significantly from as cast form.

Combustion chamber volume is ACTUAL chamber cc not including step volume if present. Step height is measurement is in the adjacent column with total advertised combustion volume listed under the miscellaneous column.

Retail listing is for TWO cylinder heads at current market prices as of Jan 2014



If product manufacturers/distributors have more accurate/updated data please let me know and I will update the listing immediately. Any new products will also be gladly added as they become available.

edit: updated sheet
edit: updated again
edit: still updating
edit: did I mention update?
edit: newb clarification
edit: update some more
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Cylinder Head Quick Reference Sheet

[Ian Godfrey]

It would be useful to have the available valve sizes in a separate column, as some CB heads are available in different combos
the JPM230 valve size is 48/38. no step
CB street elim 42/37.5, 44/37.5, 46/38 no step

the chart is a great idea

[66brm]

It would be also handy to add other shops specs too such as DRD's L3,5,6,7 etc
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[Quokka42]

Hmm, interesting - but you show the Los Panchitos as not having a step and the guys who have bought them say they do, even if bored to a larger cylinder size?
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[SBD]

Mofoco 042's have a step. Roy told me that the step is about .060" high and that on a head bored for 90.5/92 mm cylinders the 53cc volume includes the step. I haven't done the math but he said removing it would leave a chamber volume of about 43cc.

[AlteWagen]

[58 Plastic Tub]

Excellent information, and nice to see it coming together in one place. The trouble is, there are a lot of information holes that really need to be filled to make this super useful. This is a nice starting point for guys with the appropriate equipment to help fill in the blanks.

If somebody had a flow-bench, and could post observed (as opposed to reported) numbers at .5" of lift and 25" vacuum, as well as accurate cc measurements of the intakes and chambers, we wouldn't all stumble around in the dark when trying to put together combinations.

The same applies to camshafts. If somebody had a profiler and could digitize the various popular grinds, the combination of real flow data and real cam profiles would allow desk-top dyno simulations with real numbers.

We tend to worship in "air-cooled orthodox" chapels of one stripe or another, and there are guys that have observed a lot over many years of screwing engines together. But building combinations and trying them to see how they work is a hideously expensive way to experiment, and it's what keeps guys from coloring outside the lines. As software gets better and better, at least the first stages of experimentation can occur in the digital (as opposed to physical) world and weed out the combinations that look promising, but are fatally flawed in some way.

This is a fantastic step in the right direction. I appreciate the time and effort to share with the class.
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[AlteWagen]

[58 Plastic Tub]

[AlteWagen]

thats great info, i will update the table with that as it seems more standard and easier to compare. The data I had came from their ad in HVW so maybe the higher numbers were at higher lift.

The info on the panchito was directly from Pat Downs in one of the threads here. I still wish I could find the actual chamber and step measurement separate not combined as published.
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[modok]

Assume a .055 step of stock bore size and do the math, it won't be far off.

The super-pro heads sure ought to be killer eh? They look to make the mini-wedge obsolete! Man, I want some!

But what if you want a high velocity 60-65cc intake port to make big torque for a smaller CC engine???? many aftermarket heads are too big already!

[AlteWagen]

Im waiting for RM to respond with the port cc of an as cast head, the only problem is they dont have stock sized valves. Since it looks just like the old 041 Im guessing 59-61cc.

On a smaller engine (1679-1835) is there any downside to having 40x35 with no port work and an as cast 60cc port? To me the 049 in stock form looks to be the same as the ponchito
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[modok]

Depends. If single carb then it's not too big a deal to have a too big port, since the port is a much smaller section of the "intake system"
With IR carbs the port is very important!

The panchito could support a 1600cc to north of 7k rpm! if the port is bigger than needed all you get is less torque, that's all you get, less!

[AlteWagen]

Application wise what would you want for a performance street engine?

1679-1835
110-120 cam
8-9.5 to 1 compression
1 1/2 header
36 or 40 IR carbs

60cc port 35x32
60cc port 40x35
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[modok]

Some of the different castings have a little different port shape so the intake CC isn't exactly comparable, for instance the 040 and 041 have a HIGHER port compared to 311, 113, 043, if you compare them.

since this thread is about head castings I will say 043 or 113 or 311, maybe 311 mexicans.

Modified by someone who knows what they are doing, which is a point we don't always agree on, so maybe we open a new thread for that

Larger intake valves may be a good idea but only in moderation and probably only with larger bore, and depending on lift..... the 120 and 110 are medium lift; you could go either way

[58 Plastic Tub]

[AlteWagen]

updated chart above
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[vwracerdave]

You need to update the original chart in the first post of this thread.
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[bvilletom]

A great idea to make a VW cylinder head flow chart. I can help fill in some of the blanks on the chart.

The Fisher book on "How to Hot Rod the VW" lists the head flow numbers for single port and dual port 1600 VW heads but does not have the test pressures. I have a Super Flow bench and I tried all kinds of test pressures to duplicate the figures in the book and failed to match them. They all seem to be too high but the modifications they did all pretty much checked out as far as the gains and losses went. Even lowering the valve seats the large amount recommended by the book worked really well.

Here are some of the flow numbers for the vintage style heads.

Bvilletom (Tom Bruch)
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[AlteWagen]

THANK YOU SOOOOO MUCH!!!!!

By any chance did you save any of the data on the 1500/1600 SP/DP heads? I would love just to have the stock data so everyone knows what they have as a base line.

If not would you mind doing some more flow testing?
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Grapes of Wrath $200 Engine Rebuild
Official Dual Carb Thread
Cylinder Head Quick Reference Sheet