dwicker

iTrader: (5)

Here's my logic: if you can swap run the LS3 heads (with giant 2.165 intake valves that are meant for a 4.065 bore) on to a smaller 4.000 bore without problems, I would think you should be able to run LS7 heads (with only slightly larger 2.20) valves on a 4.080 bore. Anyone tried it?

Figure I've got an LS3 block bored to 4.080

Greg Fell

iTrader: (9)

its also placement in the chamber, not just the size of the valve.

67RSCamaroVette

iTrader: (63)

I don't know the answer, whether they clear or not... but the angle of the valve relative to the combustion chamber is different. The LS7 heads are 11 degrees, which is more vertical.. more vertical = more clearance needed.

njc.corp

i think from memory its the valve angle-

i would stick with what gm says-min of 4.100 bore-

Wnts2Go10O

iTrader: (12)

shallower angle gives you more clearance.

Jason 98 TA

iTrader: (4)

we're working on a 4.095 bore l92 configured with PRC CNC Ported LS7 heads! Look for testing & results shorlty!!

N4cer

iTrader: (11)

Yup.

kistlerjm9

iTrader: (24)

yes but the shallower angle put the valves closer to cylinders not the pistons. increased ptv clearance yes. valve to cylinder yet to be determined on a .080 bore.

Old SStroker

Assuming the valves don't actually touch the sides of the cylinder bores, wouldn't it be more important to determine how well a given head/bore size combination moves air, and choose the head and bore size from that information?

I'm not advocating a minimum bore size, just looking for more power. There are lots of ways to get from here to there BTW.

Jon

OneQuickCoupe

iTrader: (1)

Grab an LS-7 head if you have one laying around or borrow one from your friends. Bolt the head onto an empty block and reach your hand down into the bottom of the cylinder. Now scribe a line around the outside of the cylinder bore onto the head. That should give you an idea of what your looking for. It should show how close that big intake valve is to the bore, etc.

Merry Christmas by the way.

D.J.