Looking "junk" ESR cylinder

[C-Leigh Racing]

That is a good idea, because if those large holes in the head were closed up quite a bit, more of the coolant flow would be directed to the front of the casting instead of over top of the head dome.

Would need to study & see what could be used to close up those holes. Dont know if JB Weld would hold up under the hot coolant, maybe something like Devcon or Lab-Metal ??. Once closed up, could drill in the smaller hole to restrict flow in that area.

Looking at the head pic as it sits, I would probably leave the coolant opening over top of the exhaust port as it is, but the one to the right, which would be the left front of the cylinder & head once bolted on, would open it up a bit more to cool that area of the cylinder more.
Neil

[F-Red]

I talked to a tech at JB Weld, they said the regular JB would perform well with the heat and coolant properties. I do have some Devcon, very nice product.
So you would only enlarge the left side of the head, not the right too?

[C-Leigh Racing]

I talked to a tech at JB Weld, they said the regular JB would perform well with the heat and coolant properties. I do have some Devcon, very nice product.
So you would only enlarge the left side of the head, not the right too?

Looking down on the head when mounted, right side of the cylinders run just a bit cooler than the left side. I'm figuring from how the intake flow is directed, at an angle to the right side, the charge is wadded up on that side so the engine will run richer on the right & then leaner on the left.
Most every time an o ring blows, it will be on that left front side, so heats got to be higher in that area.
Neil

[Pumashine]

I cut ob-round slots 1/8 thick aluminum with the holes to match stock gasket on my Polonda. Epoxied them in because we were using o-rings with no gasket provision. Worked great but it is alot of time consuming work.