Hey Todd, Bill made better heads at Xtreme for me! Cooling of the last génération machining is way better for température ontrol at high boost . No problem for few 200deg peaks on RR350 Xtreme heads . But the porting+valve size setup done on this heads you show looks great ..specially on exhaust D-shape work 👍 unfortunally i not see Oring seal on exhaust them we have to use old 3,2/3,3l turbo seals i suppose. Thank you for this Vidéo Todd❤
@@cyrilperroud1130 that's awesome to hear! Yes a conventional gasket is used on the exhaust side on these. I'm sure Pauter would be happy to machine an oring groove in the exhaust flange if we requested it. Be sure to watch the next video in this series. I go over the strength of the different alloys vs temperatures. There's some surprises in there for sure!
Bit scary when you hold the heads side by side and the OE heads have super thin fins and decent space by the chambers whereas the billet heads are super dense with no space either side of the combustion chamber?? The cooling airflow must be massively throttled... and diverted over the top??? I guess these are just for drag racing?? Short bursts only.
Luckily the heads are a bit narrower than the bore spacing so there's nearly a 3/16" or 5mm gap between them. So even where the fins are solid, there's still an air channel to help cool them down. It'd be interesting to 3D print these instead where you could route cooling between the back side of the combustion chamber and studs for even better cooling than oem. You might even get away with a 4 valve air cooled turbo head that way too. Stuff conventional casting / machining is not capable of doing.
@@protomotiveindeed. I've seen similar billet heads where we measured about 20% drop in cooling airflow. We did cost up a printed head but the amount of machine time meant they were $6000 each before we even got to machining. I was also looking at ways to manufacture new exhaust port heat shields to help replace the missing ceramic liner.. meanwhile, 4v heads will always be extremely limited on power. I can't imagine those Swindon heads will support continuous power above 300hp.... water cooing ala 935 /956/959 is the answer now we can buy 200W water pumps cheaply there's no reason not to....
@@robertcorbishley1712 no doubt 3d printing them would be 3x cost. But does have interesting advantages :). I did reach out to Swindon on the 4v stuff since we had many inquiries for using them on turbos. Like you I knew they'd be limited as Porsche already did the research and fixed it with water cooling on the 956. Swindon rates theirs at a max 500hp which may work na on a nicely built 4L. I personally wouldn't turbo them though.
MODE Motorsport Design started making the SS Niresist rings back in the 80s. The stepped version are for the 964 993 applications. Patrick MS is knocking off these and many other products originally created by Bob Holcombe of MODE.
Thanks for the correction. I didn't know Bob had come up with that design. I have tremendous respect for him. He's been quite the innovator in this industry!
All good and we got a few more sets of flame rings here if need them. Also setup sheet specs. Done many sets of these heads with Brian, including the 1st 993 set. All turned out excellent. More than a few won many races. Few sets ran with Jim Higgs JB Racing steel lined cylinders / CP X forged pistons, excellent results. Nice works. Very informative vid, love it, thanks for sharing. @EuroPartsWest @protomotive
@@bmday77 Good to know. Shoot me an email with the spect/setup sheet and pricing/availability on the flame rings you have there to sales@protomotive.com. Be sure to check out part 2 coming up this weekend, I hope. It covers all the thermal expansion rates and strength of materials. We found a few surprises in the data that was fun to share :)
Corrections. The stroker crank is 82.4 in the engine these are going on. I'm told that the Xtreme heads are now made of the better RR350 alloy vs A356
These are very nice. Can be made for 911, 930, 964, 993 and turbos. Any valve and port configuration as well. Very fun!
Sweet!
Hey Todd, Bill made better heads at Xtreme for me! Cooling of the last génération machining is way better for température ontrol at high boost . No problem for few 200deg peaks on RR350 Xtreme heads . But the porting+valve size setup done on this heads you show looks great ..specially on exhaust D-shape work 👍 unfortunally i not see Oring seal on exhaust them we have to use old 3,2/3,3l turbo seals i suppose. Thank you for this Vidéo Todd❤
@@cyrilperroud1130 that's awesome to hear! Yes a conventional gasket is used on the exhaust side on these. I'm sure Pauter would be happy to machine an oring groove in the exhaust flange if we requested it. Be sure to watch the next video in this series. I go over the strength of the different alloys vs temperatures. There's some surprises in there for sure!
Bit scary when you hold the heads side by side and the OE heads have super thin fins and decent space by the chambers whereas the billet heads are super dense with no space either side of the combustion chamber?? The cooling airflow must be massively throttled... and diverted over the top??? I guess these are just for drag racing?? Short bursts only.
Luckily the heads are a bit narrower than the bore spacing so there's nearly a 3/16" or 5mm gap between them. So even where the fins are solid, there's still an air channel to help cool them down. It'd be interesting to 3D print these instead where you could route cooling between the back side of the combustion chamber and studs for even better cooling than oem. You might even get away with a 4 valve air cooled turbo head that way too. Stuff conventional casting / machining is not capable of doing.
@@protomotiveindeed. I've seen similar billet heads where we measured about 20% drop in cooling airflow. We did cost up a printed head but the amount of machine time meant they were $6000 each before we even got to machining. I was also looking at ways to manufacture new exhaust port heat shields to help replace the missing ceramic liner.. meanwhile, 4v heads will always be extremely limited on power. I can't imagine those Swindon heads will support continuous power above 300hp.... water cooing ala 935 /956/959 is the answer now we can buy 200W water pumps cheaply there's no reason not to....
@@robertcorbishley1712 no doubt 3d printing them would be 3x cost. But does have interesting advantages :).
I did reach out to Swindon on the 4v stuff since we had many inquiries for using them on turbos. Like you I knew they'd be limited as Porsche already did the research and fixed it with water cooling on the 956. Swindon rates theirs at a max 500hp which may work na on a nicely built 4L. I personally wouldn't turbo them though.
MODE Motorsport Design started making the SS Niresist rings back in the 80s. The stepped version are for the 964 993 applications. Patrick MS is knocking off these and many other products originally created by Bob Holcombe of MODE.
Thanks for the correction. I didn't know Bob had come up with that design. I have tremendous respect for him. He's been quite the innovator in this industry!
All good and we got a few more sets of flame rings here if need them. Also setup sheet specs. Done many sets of these heads with Brian, including the 1st 993 set. All turned out excellent. More than a few won many races. Few sets ran with Jim Higgs JB Racing steel lined cylinders / CP X forged pistons, excellent results. Nice works. Very informative vid, love it, thanks for sharing. @EuroPartsWest @protomotive
@@bmday77 Good to know. Shoot me an email with the spect/setup sheet and pricing/availability on the flame rings you have there to sales@protomotive.com. Be sure to check out part 2 coming up this weekend, I hope. It covers all the thermal expansion rates and strength of materials. We found a few surprises in the data that was fun to share :)
Great vid Todd, thanks for taking the time to do this.
You're very welcome :)