I have an 8BA, Merc 4" crank, .030 over, Isky 400 cam, Chev 1.6 valves. This will be a street motor with no racing in mind. The heads are Navarro's that I had all the damage welded up and then resurfaced. I'm checking valve to head clearance and have about .060 with .018 valve lash. This is my first flathead and I'm not sure this is enough. What do you flathead guys think? Thanks Dan
If you have .060 thou clearance with the head torqued down and gasket crushed it should be fine, flatheads don't valve bounce.
could always check it with putty, blue tack and turn over slowly with heads bolted down to see if it cuts through it or paint valves with bearing blue , heads on turn engine over by hand , take heads off and see if theres any bearing blue on heads (where valves might be hitting) just to be sure , with mine i knew what my heads would except , what lift my cam was , turned it over slowly and knew i had clearance, this was my first flatty build , started it a couple of weeks ago and she runs like a dream
What I was told as a quick way to tell if you have enough clearance is to put the head on w/o the head gasket and just setting on there loose. Slowly turn the engine over by hand and see if the head lifts at all ?? If you have studs and the head is tight on the studs , be careful because the head wont move easily. Best is to have a couple of studs in so the head comes off/on easily as you check clearances .You can also put a light spring in the valve assembly as you are doing this so you can lift the valve easily and see what you have for clearance . I got one from a hardware store that worked great . Have fun !
.060 is more than enough, but still clay it to make sure you have room where chamber comes down behind the valves. If engine will turn without gasket, you have lots of clearance but you still need to worry about piston dome, because too much over the dome in quench area is bad for pinging and power....you want pistons at maybe 040-050 for effective quench/turbulence which is essential to efficiency.
Do what Bruce Lancaster said...... Isky spec. for the Max 1 cam is .014" lash. Happy flatheadin'....... 4TTRUK
I put the head on without the gasket and no bolts holding it down. The valve hit, lifting the head up. I must have screwed up when I checked it with the clay. You guys saved my ass on this one. I'm pulling the 400JR and going with the 88 grind and see what happens. Now try this one, Offenhauser sheet that came with the stud kit says to torque the heads starting at one end and work to the other end. I have always started in the middle and worked in a clockwise direction outward. Whats your thoughts?
Offy is the only one I know of that says torque the heads from one end to the other. I put a set of Edelbrocks on this weekend, their litature says center and work out. I wonder offy's reasoning for it?
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