valve clearance

i have .090 exhaust and .092 intake valve to piston clearance. Is this acceptable in a race only motor? I feel its a little tight. The motor will go to 7500. Do I need to disassemble and rebalance?

I'd run it with steel rods, green oil, shaft rockers and alcohol.

I'm not sure I'd rebalance but, I'd be looking for more exh. clearance. Is this the SBF deal?

Lem Evans wrote:I'm not sure I'd rebalance but, I'd be looking for more exh. clearance. Is this the SBF deal?

yes its the small block. I am working on the motor for next year should I source a cutter to use with a cylinder head?

h beam rods 15.5 to 1 shaft rockers green oil and alky lol



I have the big block car almost finished. just the wiring to complete. Then I trip south.

only 1 race left around here for this year.

would a .010 thicker head gasket do? the pistons are .010 down in the hole now

I'm not sure it'd ..."do" but it'd be .010" you did not have before.

are you checking v/c with valve lash or without? how are you checking?

with the valves lashed at comp's specs

Larry Williams wrote:with the valves lashed at comp's specs

ok,so that was an idea.

I will live IMO at the .092 as long as you don't float anything and your valve springs are good.

Larry,

I'd suggest that you Not put a thicker head gaskets on it. Like Lem, I am only concerned about your exhaust valve to piston clearance. The intake is good to go. I'd like to see around .105 to .110" clearance there on the exhaust. So,,,, either advance your cam some, (which will open up your ex. to piston clearance) or R&R the pistons and cut a little deeper exhaust valve relief in the piston. The weight of the alum. material that you'll be removing is flyshit, so do not even worry about rebalancing. Besides that, many engine builders overbalance engines all the time.

Charlie Evans

c.evans wrote:Larry,

I'd suggest that you Not put a thicker head gaskets on it. Like Lem, I am only concerned about your exhaust valve to piston clearance. The intake is good to go. I'd like to see around .105 to .110" clearance there on the exhaust. So,,,, either advance your cam some, (which will open up your ex. to piston clearance) or R&R the pistons and cut a little deeper exhaust valve relief in the piston. The weight of the alum. material that you'll be removing is flyshit, so do not even worry about rebalancing. Besides that, many engine builders overbalance engines all the time.

Charlie Evans

Thanks Charlie. Comp calls for 106 lobe center this cam is installed at 105.5 I think I will take your advice and remove the pistons again and have them cut.

I'd advance the cam a degree ... maybe 2.

Larry Williams wrote:

c.evans wrote:Larry,

I'd suggest that you Not put a thicker head gaskets on it. Like Lem, I am only concerned about your exhaust valve to piston clearance. The intake is good to go. I'd like to see around .105 to .110" clearance there on the exhaust. So,,,, either advance your cam some, (which will open up your ex. to piston clearance) or R&R the pistons and cut a little deeper exhaust valve relief in the piston. The weight of the alum. material that you'll be removing is flyshit, so do not even worry about rebalancing. Besides that, many engine builders overbalance engines all the time.

Charlie Evans

Thanks Charlie. Comp calls for 106 lobe center this cam is installed at 105.5 I think I will take your advice and remove the pistons again and have them cut.

i'm sure you already know this but even after you cut the pistons be sure and check v/c a few * +and- so you'll know what kinda room you have to play with later on if you want to move the cam any.

very good idea ty

cool40 wrote:

Larry Williams wrote:

c.evans wrote:Larry,

I'd suggest that you Not put a thicker head gaskets on it. Like Lem, I am only concerned about your exhaust valve to piston clearance. The intake is good to go. I'd like to see around .105 to .110" clearance there on the exhaust. So,,,, either advance your cam some, (which will open up your ex. to piston clearance) or R&R the pistons and cut a little deeper exhaust valve relief in the piston. The weight of the alum. material that you'll be removing is flyshit, so do not even worry about rebalancing. Besides that, many engine builders overbalance engines all the time.

Charlie Evans

Thanks Charlie. Comp calls for 106 lobe center this cam is installed at 105.5 I think I will take your advice and remove the pistons again and have them cut.

i'm sure you already know this but even after you cut the pistons be sure and check v/c a few * +and- so you'll know what kinda room you have to play with later on if you want to move the cam any.