HP/TQ from milling heads??

[beaver2489]

I'm putting a set of '69 351W C90E heads on my 88GT. The guy I bought them from owns a machine shop and he milled them .04 I think he said, did a 5 angle valvle job, and ported them. Here's the whole setup I'm putting together, how much hp/tq do you think I'll get flywheel??

-C90E 351W heads ported, milled .04, 5angle valve job
-TF street heat intake w/ 1" spacer
-B303 cam
-1.6RR
-70mm TB
-75mm MAF
-24# injectors
-255 fuel pump

atleast 350hp flywheel right? I'd like to learn to drive the car well with this setup and get 12's. Something to keep up with LT1's and LS1's...

 

[Blandnuts]

Um, roughly 330-340hp at the flywheel maybe... I'm not too familar with those heads but I'm assuming they are 2.02 intake and 1.60 exhaust? I'm running heads that are about the same as yours (windsor Sr.), with cleaning up of the ports and 54cc chambers. When I was running a combo without any work done to the heads or fuel system I put down 258hp and 311tq (untuned). I would think you'd be higher then that maybe at about 280hp at the wheels...

Also if you haven't bought a cam yet, and your heads are anything similar to mine, you might want to check out another cam. Something that will help the heads flow better on the exhaust side (spilt pattern)? Once again I don't know how the port job was done and what not, just a suggestion. I know I hate buying parts twice.



fred

 

[5.0fox]

im currently setting up a pair of do02 heads for my 302 using 2.02 1.60 valves and im porting them. did the machine shop grind off the hump in the top of the exaust ports? if not have them do this they are completely useless and it will let the exaust side flow alot better

 

[beaver2489]

my C90E heads have 1.94-I 1.60-E valves with 5 angle job, milled .040, and fully ported. He knows what he's doing so I figure he did the exhaust humps. My buddy that is helping me has the same setup on his 85gt but his 351W heads weren't milled...he hit HIGH 11's. He's estimating my setup to get around 350hp flywheel if tuned right, and the heads to flow 230-250cfm intake. Does the valve job and milling really give ya ~40hp/30tq flywheel? thanks guys

 

[wildstang347]

little word of advice, check your P2V clearances........also if angle milled (most common) to decrease combustion volume, valve train geometry changes slightly, moveing valves from reliefs slightly increaseing chances of serious problems. valve reliefs on factory pistons were never intended for large valves so it becomes a critical issue sometimes necessitating flycutting reliefs even for your relatively low lift cam.
better 2 be safe then sorry.