1960 Fuel Injection - 290 or 315

[Duke W.]

Re: 1960 Fuel Injection - 290 or 315

I've never heard of an Al cylinder head that did not need and have valve seat and valve guide inserts. I have always heard that these heads had a "cracking problem", but if they really thought there was an Al alloy that didn't need seat and guide inserts, that's probably the reason why they were unsuccessful.

Sometimes GM saw light when there really was none.

At that point in time Al heads had been common on aircraft engines for over 30 years, and they all had seat and guide inserts - usually a bronze alloy for the guides and a very hard valve seat materials like stellite, and these are in common use today on Al heads, which have pretty much replaced cast iron even on the least expensive cars.

Duke

[Clem Z.]

Re: 1960 Fuel Injection - 290 or 315

i bet those heads that have been shown on this board were never fully machined for guides or seats. GM built enough allison aircraft engines to know you needed guide liners and seat inserts in aluminum heads. porosity was more of a problem as even in early BBC aluminum head water passages were sealed with "water glass",sodium silicate to stop the water seepage.