4age 20v head vs 16v head... Big cams and serious flow

[Delazy]

I believe the new Ferrera valves Anthony (250hp 5.5ag) developed exclusively are longer and drastically improve flow rates while being the same size due to redesigned shape .. Shall point him this way to contribute also ..

A topic I am quite interested in and will intend to add more in relation to prime86s last post, but being at work and stuck on iPhone doesn't help atm

[Prime86]

For the guys who don't know Hasselgrens 20V engine made 240hp on a standard stroke bottom end and the spark plug tubes weren't modified so that's a pretty impressive figure considering they would have been limited on the rpm to around or just over 9000. Yes it's short on power compaired to the later style 16V with Gandry fuel system and barrel throttles that makes 300hp.

Delazy is correct as far as the valves play a huge part in making the extra power in the topend Atlantic engines. Valve design and how far they are recessed in the head, seat design all play a part in extracting the extra hp. I believe Atlantic engines with a rebuilt head or what they call a used up head can loose as much 30hp from the valves and seats alone. Hasselgren does a 7 way valve grind on the top spec engines, which goes to show just how far they go to extract that power.

[Delazy]

to further this thread again...




hasselgren ported atlantic 16v head...




hasselgren ported 20v head

[Prime86]

Thanks for posting up the pics. The 16V head above is a head that Billy Andrea (Edmonds) had for sale a while ago. Billy is a personal friend of Paul Hasselgren and I believe he has a guy from his shop work after hours to build these heads. This head is ported to suit the TRD Atlantic throttle bodies and is rated for approx 245hp@10,000rpm.

[Delazy]

nice work spotting the head mate...the 20v head is billys personal head...which made 210hp

[Prime86]

Thanks mate, I have looked into these heads a lot...Lol.

What I found interesting is how nice and clean the entrance of the intake port is and yet the blending down the back is probably what most would call average. All Hasselgren heads are like this and I have seen discussions on how disappointed some people who have purchased these heads have been. Hasselgren obviously know the main points of how to get the head to flow and concentrate on them the rest is just a quick tidy up.

I know a guy here in OZ who purchased a 20V head from Tony with the HKS 20V stroker that Quicksilver race engines had done exactly the same as his head. This head came over bare and he has since got it built buy a head shop here. The first thing the guys said to him is they weren't happy with the quality of the port job and they would like to blend and clean it up before building the head even though it performed very well on the flow bench at Quicksilver.

[Delazy]

this is the Ledwith racing CNC head from ireland...



this is anthonys 5.5ag 20v head as prepared by quicksilver

[Prime86]

Those guys in Ireland know how to do it well. I remember seeing an AE86 rally car over there that would of been the most modified rally car I have ever seen it was a work of art with IRS, dogbox and the works done it was such an impressive car. The engine was a 20V that I'm sure was built by these guys and it was claimed at the time to be 280hp and had the dyno sheet with it.

[Delazy]

speaking to one of the irish boys and anthony earlier, the ledwith head has only ever made 230....so still trailing anthony somewhat....he has had a glance over the thread but hasnt had the time to contribute as yet

trying to find a pic of my head...its nothing compared to the others ive posted...but the more the merrier i figure

[johl]

its on your shoulders mate^^^^
thank you, thank you. try the veal