LSOHOLIC

iTrader: (3)

Like the title says......

Looking for the GEN differences in valve spacing.

LS1 = ??

LS3 = ??

LS7 = ??


Where I'm going with this is.....could I make a "porter" casting LS7 fit on a 3.90" bore (obviously a smaller valve % throat....etc)...??
For the info I've been able to gather, it seems the LS7 intake valve is moved roughly 0.050" towards the intake...but still maintains the same center (forward & aft) as the LS1 valve spacing.

Any help would be appreciated.


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brobinson216

iTrader: (11)

Interesting topic with nothing to add more than. I should have bought that used CMM last year.

You could potentially be a new customer.

KCS

iTrader: (20)

LS1 = 1.91"

LS7 = 1.97"

LS3 = 2.01"

The LS1 and LS3 intake valves seem to have the same location in reference to the bore, but the LS3 exhaust valve is moved out more toward the bore, giving it the wide valve spacing.

The LS7 is narrower, but both valves have been moved over so that the intake is further from the bore and the exhaust valve is closer.

ColeGTO

iTrader: (3)

Do you know if the valve centers are "in-line" with the center of the bore or offset up or down from the bore center?

I'm trying to do a layout to check valve sizes of different heads in different bore sizes. With this I'd like to compare the shrouding of different examples to see if there is any corelation between engine styles and the perceived need for big cam splits to crutch another issue.


Thanks,
Cole

KCS

iTrader: (20)

I couldn't answer that with 100% certainty, but from looking at the "pierce points" of some of the heads, it looks like they're offset a little bit.

For example, EQ just released a cathedral port casting with the pierce points at (.830", .011") intake and (1.080", .011") exhaust. It looks as if these pierce points are basically X & Y coordinates from the bore center.