exhaust manifold interior dimension - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

aga · 04-03-2013, 07:33 AM

good day guys. i'm researching into making my own exhaust manifold (T3 for a borgwarner) and the supplier has two similar dimensions... one is 42.16 mm diameter with a 2.7 wall, the other 42.4 with 2mm wall. obviously its good to have thick walls on the manifold, but the resulting inner diameters are 36.6 on the one, 38 on the other. which diameter better fits the SR20? does anyone know the area of the head port? one head flange from a website is offered in 1.5 inch diameter which is 3.81mm...close to the thin walled pipe. any ideas?

04-03-2013, 07:33 AM	#1
aga Zilvia Junkie Join Date: Mar 2013 Location: Athens, Greece Age: 46 Posts: 580 Trader Rating: (0) Feedback Score: 0 reviews	exhaust manifold interior dimension good day guys. i'm researching into making my own exhaust manifold (T3 for a borgwarner) and the supplier has two similar dimensions... one is 42.16 mm diameter with a 2.7 wall, the other 42.4 with 2mm wall. obviously its good to have thick walls on the manifold, but the resulting inner diameters are 36.6 on the one, 38 on the other. which diameter better fits the SR20? does anyone know the area of the head port? one head flange from a website is offered in 1.5 inch diameter which is 3.81mm...close to the thin walled pipe. any ideas?