Can anyone shed light on this? It was recently mentioned that angle cutting the head mating surface on the plenum would increase flow.

This used to be done on the old Datsun 510's to get a better shot at the intake valves. Does it also work on the B-18's?
Any details on the angle and an additional porting?

Thank you,
John

 

sounds like an interesting idea.......if you can remove just enough material so that it will still fit onto the head and the support braket on the back of the engine, it might accualy help a little............

i wonder if the mounting studs and bolts would still hold it securily though?

 

I really don't understand that because the port entrance from the intake manifold is pretty much flat leading to the valves before the ports start to turn downwards, unlike the GSR head. So I can't really see any benefit cutting the manifold flange to a different angle, would sure like to see if it makes any difference. Matt J. - Dropspeed - is attempting this I believe as we speak - would be interesting to see if it works for him.

Joey

 

SS works in Japan does this to their Bseries motors. They have the intake shot blasting almost straight down into the valves.....

I think it required welding more aluminum into the port and then reshaping it.... I believe it also necessitated running SS works intake manifold.....

Whatever the case, I flipped out at the "hardcoreness ($$)" and merely labelled it as "interesting...." I'd like to see some USDM tuners like Portflow or whoever else has the ability to do this "mod"

 

I could definitely understand the upgrade if it follows reshaping of the ports, that way you get smooth flow from entrance to exit, makes perfect sense, but I dunno about just doing the manifold by itself.