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Mon Nov 10, 2025 3:55 pm

I saw on Facebook that Pat is releasing his own cylinder heads soon. What does everyone think?

Release date mid 2026 from PDP.
The new as cast PDP 40x35.5 cylinder head. The first 40mm as cast head that flows 190cfm@25”. But even better, it has 310 Ft/Sec air speed.
This is the best flowing 40mm intake valve head I have ever been involved with and it’s my own, from my own company. 56cc chambers that will be available in 90.5,92,94mm bore.
This head cools like a stock casting so now you can make a ton of power without melting down your engine.
Keep an eye out on FB and IG for updates. Price will make everyone happy and so will the performance.

.100-48
.150-75
.200-101
.250-118
.300-137
.350-150
.400-162
.450-171
.500-179
.550-185
.600-190

69cc intake port volume
56cc chamber volume

https://www.facebook.com/share/p/1BZ8znv91n/?mibextid=wwXIfr

Mon Nov 10, 2025 4:24 pm

Great numbers, and the port volume isn't too huge. Should be an ideal head for a 2276, fk8, 9.5 street engine.

Should be exciting to see.

Brian

Mon Nov 10, 2025 4:26 pm

Who's gonna be the first and report back?

Mon Nov 10, 2025 4:39 pm

Glenn wrote: Who's gonna be the first and report back?
Tempting but my S2 Greg Tims heads shipped today. Too bad I don't have the $$ to get them & do back to back dyno sessions.

Mon Nov 10, 2025 4:55 pm

Glenn wrote: Who's gonna be the first and report back?

I will buy a set and run them on MY flow bench, and do my measurements. Then post MY results.

His numbers are pretty stout for a 40mm valve. My bench has always read a little low compared to CB's advertised numbers. It will be interesting to see. Pat knows his stuff, and I know he has been working on these for a while.

I wish they had a slightly bigger chamber for keeping a tight deck on a big mild engine.

Brian

Mon Nov 10, 2025 4:56 pm

daveblank wrote: Glenn wrote: Who's gonna be the first and report back?
Tempting but my S2 Greg Tims heads shipped today. Too bad I don't have the $$ to get them & do back to back dyno sessions.

His numbers on his heads are real similar to what I have measured on Tims S2 heads, and the port volume is just a bit lower.

Brian

Mon Nov 10, 2025 5:12 pm

Brian_e wrote: daveblank wrote: Glenn wrote: Who's gonna be the first and report back?
Tempting but my S2 Greg Tims heads shipped today. Too bad I don't have the $$ to get them & do back to back dyno sessions.

His numbers on his heads are real similar to what I have measured on Tims S2 heads, and the port volume is just a bit lower.

Brian

Either way I should be happy.

Mon Nov 10, 2025 5:39 pm

The heads from Pat will be all cnc done?

Mon Nov 10, 2025 5:42 pm

It says as cast, which will be the best way to do them for production. I would guess Pat will hand blend the bowls, and cut the seats, then send them out the door.

Brian

Mon Nov 10, 2025 7:18 pm

Are the 56 cc chambers for all 3 bore sizes? 90.5,92 and 94

With a 2180 and .040" deck with 56 chambers is 9.7 cr

2276 would be 10.0 cr

Tue Nov 11, 2025 11:05 am

Brian_e wrote: Glenn wrote: Who's gonna be the first and report back?

I will buy a set and run them on MY flow bench, and do my measurements. Then post MY results.

His numbers are pretty stout for a 40mm valve. My bench has always read a little low compared to CB's advertised numbers. It will be interesting to see. Pat knows his stuff, and I know he has been working on these for a while.

I wish they had a slightly bigger chamber for keeping a tight deck on a big mild engine.

Brian My bench is calibrated and uses a flow Com, it’s about as accurate as can be.It is possible that the as cast port could be slightly less flow but I’m not expecting less than 4-5 cfm at the higher lifts, possibly no loss at all.

Tue Nov 11, 2025 11:22 am

Is info avail on your website and will you offer bigger valved heads like 44x37?

Tue Nov 11, 2025 11:43 am

I think it is AWESOME that Pat himself is in here responding to comments on these upcoming heads. I highly respect him as well as his world-famous VW head expertise.

Ted

Tue Nov 11, 2025 12:04 pm

Prostockpat wrote: Brian_e wrote: Glenn wrote: Who's gonna be the first and report back?

I will buy a set and run them on MY flow bench, and do my measurements. Then post MY results.

His numbers are pretty stout for a 40mm valve. My bench has always read a little low compared to CB's advertised numbers. It will be interesting to see. Pat knows his stuff, and I know he has been working on these for a while.

I wish they had a slightly bigger chamber for keeping a tight deck on a big mild engine.

Brian My bench is calibrated and uses a flow Com, it’s about as accurate as can be.It is possible that the as cast port could be slightly less flow but I’m not expecting less than 4-5 cfm at the higher lifts, possibly no loss at all.

I wasn't doubting your numbers, I was just saying your numbers are impressive. I know how much work and testing it takes to get a 40mm valve up past the 175cfm @ .550" mark, and you are way beyond that!!

I use Audie Tech software and calibrate it before each use. :D It's interesting to compare numbers from different benches.

I am very excited to see them. I think there is a big hole in the market for a REALLY good production 40x35 street head. Something that can support a 2276/fk8 to 5800-6000rpm is what 80% of the street car guys on here really need. Big airspeed, and correctly sized ports should make a fantastic street head.

Any sneak peaks at chamber shape?

Brian

Tue Nov 11, 2025 2:29 pm

I do not want to post any chamber pics yet. I filled the lower side of the chamber with epoxy so I could shape it like I want. I will say that the chamber is not raised, more old school much like the Panchito. I know everyone wants their own chamber volume, I wanted to be in the middle of small vs big. 56cc is what I was shooting for.
The port velocity is spot on at a max of 310ft/sec with mid lift numbers in the 260/270 range. I worked the port cross section until I achieved the port velocity that I wanted. I’ve already tested this port and chamber on the dyno and it was impressive, the best power I’ve ever achieved from a 40mm intake valve. The exhaust port is small to moderate in size and has very high exit velocity.

Tue Nov 11, 2025 2:41 pm

Prostockpat wrote: I do not want to post any chamber pics yet. I filled the lower side of the chamber with epoxy so I could shape it like I want. I will say that the chamber is not raised, more old school much like the Panchito. I know everyone wants their own chamber volume, I wanted to be in the middle of small vs big. 56cc is what I was shooting for.
The port velocity is spot on at a max of 310ft/sec with mid lift numbers in the 260/270 range. I worked the port cross section until I achieved the port velocity that I wanted. I’ve already tested this port and chamber on the dyno and it was impressive, the best power I’ve ever achieved from a 40mm intake valve. The exhaust port is small to moderate in size and has very high exit velocity.

Sounds fantastic, especially the mid lift FPS and the small exhaust port!!

Are you taking names for the first batch yet? I suppose you are getting slammed with calls about them already.

Brian

Tue Nov 11, 2025 7:43 pm

Will there be room for a little more port volume and one size up on the valves?

Tue Nov 11, 2025 10:24 pm

that makes no sense from an as-cast head that's optimized for a certain valve size, IE the panchito. They do a wonderful job for what they are designed for, and it sounds like these new PDP heads are no different. Optimized for an as-cast *higher performance* 40x35.5 street head.

for larger port volume and bigger valves, a different CNC option on a different casting would be logical.

as-cast options are what keep prices down and cooling ability up. Check the cost and cooling difference between panchitos and CNC lines.

not to mention as-cast manifolds, which Pat is planning to offer for these heads as well!

Tue Nov 11, 2025 11:04 pm

sled wrote: that makes no sense from an as-cast head that's optimized for a certain valve size, IE the panchito. They do a wonderful job for what they are designed for, and it sounds like these new PDP heads are no different. Optimized for an as-cast *higher performance* 40x35.5 street head.

for larger port volume and bigger valves, a different CNC option on a different casting would be logical.

as-cast options are what keep prices down and cooling ability up. Check the cost and cooling difference between panchitos and CNC lines.

not to mention as-cast manifolds, which Pat is planning to offer for these heads as well!

Thats what I was thinking as well. I bet Pat comes up with a different casting and design for a 44x37 go really really fast set of heads.

Wed Nov 12, 2025 6:23 am

It's not on Pat's website but he does have both a 44x37 and a 42x37 CNC head. If you search his IG you will find some data on them.