slydog 7,873 Posted September 18, 2018 It flows 26cfm better from 200th lift than the old one and carries that trend the whole way. It out flows the old heads total by 500lift. Share this post Link to post Share on other sites
ando76 4,354 Posted September 18, 2018 So 240-250 peak flow? All sounds good and the boost will make those low lift gains come on really strong. Good stuff. 1 79XD250 reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted September 18, 2018 Old head went as good as 260cfm after LHT re-cut the seats and valves and ported it to suit. Share this post Link to post Share on other sites
ando76 4,354 Posted September 18, 2018 So are you going to post figures of this one? 1 79XD250 reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted September 18, 2018 Nice. We will fill in the blanks ourselves. 3 CHESTNUTXE, 79XD250 and Valvebouncer reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted September 18, 2018 Nah thankyou. Entertaining as always. In reality the flow figures mean squat as you'll be blowing an atmosphere or better in there anyway. Can't wait to see the track numbers. Should be good. Hope you have the cage designed. 2 Valvebouncer and 79XD250 reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted September 19, 2018 Marshall Speed Shop will be doing the cage. 1 FORD_MAN reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted September 19, 2018 Nice. Moly or mild Share this post Link to post Share on other sites
ando76 4,354 Posted September 19, 2018 Cool. They look good all tig welded up. Share this post Link to post Share on other sites
79XD250 0 Posted September 19, 2018 How's the exhaust look? Share this post Link to post Share on other sites
deankxf 20,287 Posted September 19, 2018 12 hours ago, slydog said: It flows 26cfm better from 200th lift than the old one and carries that trend the whole way. It out flows the old heads total by 500lift. hey, just had a thought.. does the flow bench test with BOOST change the way the porting is done? or is flow same as flow regardless of NA or boost pressure? eg, going for the highest numbers without hitting water... or hitting water.. weld and repeat Share this post Link to post Share on other sites
ando76 4,354 Posted September 19, 2018 The flow bench just tests at a constant pressure. 28" is the industry standard. It can't account for boost as it relies on suction to get the cfm reading. Porting for boost will always draw different opinions, as with most aspects of engine building. It is generally accepted that if you can make the port flow more, then it will make boost quicker and therefor make more power at the same boost pressure of an unported engine. Ive spoken with Ray Hall at length about boost and porting for boost and he simply said - do what you are doing for aspo. Ray has been playing with boost for a damn long time. If your interested hit up his face book page and look at the Audi he is building g himself now. He is a champion bloke. Doesn't suffer fools. 3 79XD250, deankxf and Valvebouncer reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted September 19, 2018 19 hours ago, deankdx said: hey, just had a thought.. does the flow bench test with BOOST change the way the porting is done? or is flow same as flow regardless of NA or boost pressure? eg, going for the highest numbers without hitting water... or hitting water.. weld and repeat Look up Darrin Morgan of Rheer and Morrison. None better than Darrin. He still ports by hand every day. There's a awesome pod cast he did with Tom Martino and others that will blow your hair off. This is where most people fall over thinking they don't need a ported head on boost or even a cooler. You will make less boost but more hp becuase it's more efficient. 1 deankxf reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted September 20, 2018 If you like podcasts and want to learn this is it. Tom Martino and Darrin Morgan share soooooooo much knowledge its awesome. http://directory.libsyn.com/episode/index/show/readingtondigital/id/6783136 2 deankxf and Fingers reacted to this Share this post Link to post Share on other sites
deankxf 20,287 Posted September 20, 2018 will have a listen to that when i can make time. Share this post Link to post Share on other sites
slydog 7,873 Posted September 20, 2018 The real action starts from 20 odd minutes🤙 Share this post Link to post Share on other sites
Slow250XC 1,513 Posted September 20, 2018 When is someone gonna flow an ironhead!I wanna see figures. Standard port size looks similar to Sly's new ports.Are they too heavy for flow benchs to handle or are there no irons left anymore?Sent from my SM-J330G using Tapatalk Share this post Link to post Share on other sites
79XD250 0 Posted September 20, 2018 The trouble with iron head is the runner and chamber design are ordinary when compared to alloy heads and the iron takes more effort to port. I think they are the main reasons no ones puts the effort into them Share this post Link to post Share on other sites
deankxf 20,287 Posted September 20, 2018 the iron head is Bloody heavy! but they didn't seem to blow head gaskets back in the day? they'd need to have hardened valve seats or run a valve saver additive, they must be rare since they are 40yrs old also Share this post Link to post Share on other sites
slydog 7,873 Posted September 20, 2018 Measure the port opening and Ill tell you if there close. No lie's here. But as for using one get it flowed your self is the only way to really know. Share this post Link to post Share on other sites
slydog 7,873 Posted September 21, 2018 On 19/09/2018 at 10:10 AM, 79XD250 said: How's the exhaust look? Made room around the guide area as usual but nothing else really. Beyond popular belief theres no need to do anything special on any exhuast really. Needs to be a epically big cfm flowing head before you worry about big numbers on a exhuast. 1 79XD250 reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted September 21, 2018 the iron head is Bloody heavy! but they didn't seem to blow head gaskets back in the day? they'd need to have hardened valve seats or run a valve saver additive, they must be rare since they are 40yrs old alsoNo difference in expansion, warpage problems or bolts stretching, so head gaskets not a problem. Good engine in a boat too. Probably not too many around now because irons were only made for 4 years, alloys for 8.If Ford Oz's iron castings in the 70s were all like my 2V clevos, they're likely to be rough as guts. The sand gets rougher as it gets re-used each time.Alloys would have been cast at another plant using different techniques. First ones were made by Honda. They were also designed by them so would have been tweaked in the ports.Sent from my CPH1607 using Tapatalk 1 CHESTNUTXE reacted to this Share this post Link to post Share on other sites