Building a 408 with IndyBrocks
A new customer contacted me and wants to build a 408 and use these heads that he has "way too much $$$ invested in". Customer ships them and I decided to baseline them. These heads were previously serviced/refreshed and I flowed them as I received them OOTB.
Flow @ 28" 4.06" Bore 2.055"/1.6" valve diameters:
.1 62.9
.2 120.3
.3 179
.4 225.7
.45 245.3
.5 259.3
.55 266
.6 269
.7 259
I decided to clean them thoroughly and re-valve job them considering it looked like there was room for improvement. I also took a deshrouding cut which added .060" between the intake valve and chamber wall. A 30* backcut was also added to the intake valve in an effort to bolster the somewhat weak low valve lifts. After results:
.1 65.9
.2 135
.3 192.6
.4 232
.45 250
.5 265
.55 271
.6 266
.7 261
This is my first set of Indybrocks I get to look at and can see where they could use proper porting and the 93.5+% throat size is hilarious. Porting these is not part of the plan or budget. J.Rob
A new customer contacted me and wants to build a 408 and use these heads that he has "way too much $$$ invested in". Customer ships them and I decided to baseline them. These heads were previously serviced/refreshed and I flowed them as I received them OOTB.
Flow @ 28" 4.06" Bore 2.055"/1.6" valve diameters:
.1 62.9
.2 120.3
.3 179
.4 225.7
.45 245.3
.5 259.3
.55 266
.6 269
.7 259
I decided to clean them thoroughly and re-valve job them considering it looked like there was room for improvement. I also took a deshrouding cut which added .060" between the intake valve and chamber wall. A 30* backcut was also added to the intake valve in an effort to bolster the somewhat weak low valve lifts. After results:
.1 65.9
.2 135
.3 192.6
.4 232
.45 250
.5 265
.55 271
.6 266
.7 261
This is my first set of Indybrocks I get to look at and can see where they could use proper porting and the 93.5+% throat size is hilarious. Porting these is not part of the plan or budget. J.Rob