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daveblank
Samba Member
Joined: November 07, 2024
Posts: 243
Location: Dallas, TX
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 Posted: Mon Nov 10, 2025 3:55 pm Post subject: Pat Downs cylinder head |
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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 |
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Brian_e 
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Mon Nov 10, 2025 4:24 pm Post subject: Re: Pat Downs cylinder head |
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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
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 80389
Location: Sneaking up behind you
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| Posted: Mon Nov 10, 2025 4:26 pm Post subject: Re: Pat Downs cylinder head |
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Who's gonna be the first and report back?
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
עַם יִשְׂרָאֵל חַי |
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daveblank
Samba Member
Joined: November 07, 2024
Posts: 243
Location: Dallas, TX
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| Posted: Mon Nov 10, 2025 4:39 pm Post subject: Re: Pat Downs cylinder head |
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| 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 $$ to get them & do back to back dyno sessions. |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Mon Nov 10, 2025 4:55 pm Post subject: Re: Pat Downs cylinder head |
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| Glenn wrote: |
| Who's gonna be the first and report back? |
I will buy a set and run them on MY flow bench, and do my measurements. Then post MY results.
His numbers are pretty stout for a 40mm valve. My bench has always read a little low compared to CB's advertised numbers. It will be interesting to see. Pat knows his stuff, and I know he has been working on these for a while.
I wish they had a slightly bigger chamber for keeping a tight deck on a big mild engine.
Brian
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Mon Nov 10, 2025 4:56 pm Post subject: Re: Pat Downs cylinder head |
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| daveblank wrote: |
| Glenn wrote: |
| Who's gonna be the first and report back? |
Tempting but my S2 Greg Tims heads shipped today. Too bad I don't have the $$ 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
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts |
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daveblank
Samba Member
Joined: November 07, 2024
Posts: 243
Location: Dallas, TX
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| Posted: Mon Nov 10, 2025 5:12 pm Post subject: Re: Pat Downs cylinder head |
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| 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. |
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chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 4220
Location: San Diego
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| Posted: Mon Nov 10, 2025 5:39 pm Post subject: Re: Pat Downs cylinder head |
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| The heads from Pat will be all cnc done? |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Mon Nov 10, 2025 5:42 pm Post subject: Re: Pat Downs cylinder head |
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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
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts |
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chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 4220
Location: San Diego
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| Posted: Mon Nov 10, 2025 7:18 pm Post subject: Re: Pat Downs cylinder head |
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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 |
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Prostockpat
Samba Member
Joined: April 13, 2023
Posts: 3
Location: Visalia
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| Posted: Tue Nov 11, 2025 11:05 am Post subject: Re: Pat Downs cylinder head |
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| 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. |
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74 Thing
Samba Member
Joined: September 02, 2004
Posts: 7672
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| Posted: Tue Nov 11, 2025 11:22 am Post subject: Re: Pat Downs cylinder head |
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| Is info avail on your website and will you offer bigger valved heads like 44x37? |
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fl59bug
Samba Member
Joined: November 23, 2005
Posts: 2075
Location: North Carolina
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| Posted: Tue Nov 11, 2025 11:43 am Post subject: Re: Pat Downs cylinder head |
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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 |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Tue Nov 11, 2025 12:04 pm Post subject: Re: Pat Downs cylinder head |
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| 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.  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
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts |
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Prostockpat
Samba Member
Joined: April 13, 2023
Posts: 3
Location: Visalia
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| Posted: Tue Nov 11, 2025 2:29 pm Post subject: Re: Pat Downs cylinder head |
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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. |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 4232
Location: Rapid City, South Dakota
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| Posted: Tue Nov 11, 2025 2:41 pm Post subject: Re: Pat Downs cylinder head |
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| 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
_________________
So more or less the lazier and stupider you want to be, the nicer quality parts you need to buy.
-Modok
Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
www.type-emotorsports.com
Type E Engine Parts and Supplies
https://type-emotorsports.com/collections/engine-parts |
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94touring
Samba Member
Joined: October 24, 2020
Posts: 645
Location: Tulsa - OK
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| Posted: Tue Nov 11, 2025 7:43 pm Post subject: Re: Pat Downs cylinder head |
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| Will there be room for a little more port volume and one size up on the valves? |
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sled
Samba Member
Joined: February 16, 2005
Posts: 6331
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| Posted: Tue Nov 11, 2025 10:24 pm Post subject: Re: Pat Downs cylinder head |
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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!
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drive your split. |
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jpaull
Samba Member
Joined: February 22, 2005
Posts: 3678
Location: Paradise, Ca
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| Posted: Tue Nov 11, 2025 11:04 pm Post subject: Re: Pat Downs cylinder head |
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| 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.
_________________
[email protected] MPH 1/4 Mile & 8.1 @ 83.7MPH in 1/8 Mile with Mild Type 1 VW Mag Case 2234cc commuter engine in stock weight bug w/only .491 total lift(CB2292 Cam), 42x37 heads, 48idf's, Street tires, Belt on, Mufflers, Pump gas, video of the run here: https://youtu.be/M3SPqMOKAOg
Transmission by MCMScott:
Rhino case, Klinkenberg 4.12, Superdiff, 002 mainshaft with 091 first idler. Weddle 1.48 Third & 1.14 Fourth. |
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Olli from NJ
Samba Member
Joined: May 10, 2007
Posts: 377
Location: Milton,DE
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| Posted: Wed Nov 12, 2025 6:23 am Post subject: Re: Pat Downs cylinder head |
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| 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. |
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