When I installed my Race Rites with ARP head bolts, I had to clearance the bottom of the header flange above the head bolts at each location so that the header would properly mate up to the exhaust ports on the head. This is not uncommon.
You are grinding the bottom of the flange for clearance.. It has nothing to do with "header tuning"Does that mess up the header tuning?
I meant denting the pipes, not grinding the flange.You are grinding the bottom of the flange for clearance.. It has nothing to do with "header tuning"
no it will not hurt the flowI meant denting the pipes, not grinding the flange.
There is an EngineMasters episode on MotorTrend Channel where they bashed close to 2 dozen dents into a set of headers on the 450+ hp small block while on the engine dyno, some more than 1/2 way closed.I had to bash down no. 4 cylinder pipe. Ended up bashing quite a bit down, hope it doesn't affect the exhaust flow/pressure too much.
There is an EngineMasters episode on MotorTrend Channel where they bashed close to 2 dozen dents into a set of headers on the 450+ hp small block while on the engine dyno, some more than 1/2 way closed.
It did absolutely nothing to hurt power.....the hosts Frieburger and Dulcich were both rather stunned that it had zero effect on the power the engine made.
I was surprised myself
My problem was the arp bolts but also that the pipe for no.4 cylinder was hitting the thicker lower section of the race rites. See the photo.It’s not the headers or the heads, it’s the ARP head bolts. They have a taller head than OEM head bolts. If you prefer, swap the lower, short head bolts for OEM head bolts and you should be fine if you don’t want to grind the flange on the header.