Winter Project - Intake Valve Upgrade

[Jagdpanzer]

Working the heads over this winter installing a larger intake valve package I work out with Ferrea. Stock 39 mm intakes valves, seats, and springs to be replaced with 41.8mm stainless steel valves, springs and titanium retainers.Though 16% larger in area the Ferrea valve, locks and retainer weigh 8 grams less than the stock pieces. This setup is designed to work with a set 0.500" lift cams being made. Right now I plan to leave the stock exhaust valve setup more or less as is.








new valves in mock-up head

[XfireZ51]

Phil,

You leaving the exhaust cams as is?

[Demps]

Phil,
Very nice. I hope you're still interested in LT5s if I ever move close. I'm afraid you'd cost me some serious coin.
Ted

[Jitse]

Nice upgrade!
I can see you relieved the intake side of the chamber a bit too, machineshop relieved intakes on my lt5 heads, it helps for sure in better flow.

[XfireZ51]

Originally Posted by Jitse

Nice upgrade!
I can see you relieved the intake side of the chamber a bit too, machineshop relieved intakes on my lt5 heads, it helps for sure in better flow.

When you are doing that, are u shaving the heads to maintain CR or increase it?

[Jagdpanzer]

Originally Posted by XfireZ51

Phil,

You leaving the exhaust cams as is?

No, new exhaust cams as well. Haven't finalized the design but will probably go with something around 0.450" lift so I can stay with the stock springs and retainers. These bucket lifter heads don't give you much room to play with like the pushrod crowd enjoys.

[Paul Workman]

Originally Posted by Jagdpanzer

Working the heads over this winter installing a larger intake valve package I work out with Ferrea. Stock 39 mm intakes valves, seats, and springs to be replaced with 41.8mm stainless steel valves, springs and titanium retainers.Though 16% larger in area the Ferrea valve, locks and retainer weigh 8 grams less than the stock pieces. This setup is designed to work with a set 0.500" lift cams being made. Right now I plan to leave the stock exhaust valve setup more or less as is.








new valves in mock-up head

Juuuust lookin' at your combustion chambers, Phil. Looks too like a bit of relief applied to the chamber wall adjacent to the intake valves, AND the quench area looks to be reduced a bit as well. Did you do the porting? If not, who did (if I may ask)?

Looking familiar... (I did my own porting w/ advice and guidance fm the "FBI" gurus)

[Jagdpanzer]

Paul,
I did the rough out porting work you see in the photo. On this build I will be going with 4.125" bore pistons and the 4.000" Bryant crank I used last time with the 402 CID motor. Also going with 6.000" rods this time for improved piston stability and reduced piston bore dropout at BDC. This doesn't leave much compression height for rings and dishing the piston tops for achieving the 12:1 compression ratio I'm shooting for. Stock combustion chambers measure around 39-40 CC. The chamber in the photo currently measures at 44 CC. 20 CC is probably max the piston tops can be safely dished to. Therefore I will probably have to take at least a couple more CC out of the combustion chambers to reach 12:1.

[Johnny5]

Thats awesome, how much does that cost and how much hp does it add?

[XfireZ51]

Phil,

Have u thought about using lighter lifters available from Sam?