Help identifying pistons and cylinder heads
It makes me wonder and I tend to over think, but was it that they needed heads and thats all they had, or did they think they were "upping compression" and didnt know bout the ports and the smaller runners or did they even care I suppose it doesnt matter but I had someone on the interwebz tell me to "put 318 heads " on my 340 because it will "raise the compression" and I always wondered if they were serious or...:)
Yes, by putting the teen heads on the 340/360, yes, compression will rise. Break out the calculators and dial indicators, cc those chambers!!!!
The problem here is the smaller ports will restrict breathing at a lower rpm than the correct oem heads would. How much I don’t know.
As
@mshred had said in early posts…..
The increased compression is a plus on one hand, the small valves and port size are the flip side. A big minus. The thinking, *I Think!* is an attempt to increase the efficiency with the smaller chamber, valve size and comp ratio. It’s a solid thought IF you’re attempting more mileage.
Now the heads are stock and the valves are small. Installing the 360’s 1.88/1/60 valves and porting the head out to its best potential would yield a minor increase in terms of flow. Obviously I think (danger!) none of us would travel this route since the port can’t be made big enough to feed a decent street performing 340/360. Though the head would still be OK for very mild camshafts and acco. gear. On a 318, it would be a very good street head.
Maybe so, the previous owner just used what he had in hand. Said screw it, it is what it is and away it goes.
IF Maurer can find decent, cheap and local OEM heads, that would be really good. New aluminum is just expensive for a cheap build but better suited on a stock 340 over the oem head. Very good on an upgraded 360 even if it’s still a low compression engine. He can run pump camel pea 87 octane without issue with even a really nice upgrades camshaft. Like he has in thought now.