SB Chevy '292' head ?

[rod]

I have a pair of 292 'Turbo' [misnamed] heads. any idea what the original CC's of the chamber would have been.
Thanks Rod in AZ
yes, I know these heads are older than half the guys here!!!

[MAURICE BLENDHEIM]

Hey Rod in AZ…The first production run for these heads was in 1971 and the second production run was in 1973. The second run were improved over the first batch. The stock combustion chamber volume was 66cc. Hope this helps…MB.

[Mike Taylor 3601]

Wasn't first version 492 with angle plugs and still had heat risers?
then second was 292,had heat risers deleted and raised the angle plugs higher in chambers?
First thing to watch out for is spring seats,have to cut pocket OD with shim in place or likely will hit water or soon after crack there,don't cut to match original depth.
292 was prone to crack in intake runners probably had to do with amount of porting done that has been done.
Mike Taylor 3601

[carl hinkson]

Originally Posted by Mike Taylor 3601

Wasn't first version 492 with angle plugs and still had heat risers?
then second was 292,had heat risers deleted and raised the angle plugs higher in chambers?
First thing to watch out for is spring seats,have to cut pocket OD with shim in place or likely will hit water or soon after crack there,don't cut to match original depth.
292 was prone to crack in intake runners probably had to do with amount of porting done that has been done.
Mike Taylor 3601

292 were called the turbo heads and came out just before the Bowtie heads and were prone to cracking between the valves.

[Dwight Southerland]

The 492 angle plug head was merely the 492 casting with the plug hole machined at an angle. The 492 casting was the last casting that is a replacement for the "double hump" Chevy head. It share the same port and other characteristics as the 186, 041 and 441 castings - accessory mounting holes on the ends, crankcase vent holes between the pushod holes, temp sender hole beween the exhaust ports. It used the classic "64 cc" combustion chambers and was used as a replacement for all the high performance engines back to '61. Some were machined for 2.02/1.60 valves and pushrod guide plates with screw in studs, some were not. Over the counter purchase mostly. That casting was used for the first "off road" offering of a high performance head with angled spark plugs.
The 292 head got its name from the rumor that it was developed for a supposed Indianapolis stock-block engine program that Smokey Yunick was involved in that included a small displacement (209 ci) engine with turbochargers. It has the classic combustion chamber but was cast with much more material in the combustion chamber and ports. The as-cast port shapes were considerably changed from the previous castings and it became the basis for hot rod cylinder heads for several years. This was the first true factory race-purposed small block head from Chevrolet offered over the counter. Smokey Yunick's book discusses the origins of the casting some.

[rod]

I dug out an old Chevy/GM performance parts book. and sure enough it showed 66 CCs. I also found where I had CCd those heads many years ago after AFR did them, they were 68 CCs. I just had them flat milled the absolute min. to get them true [cut .013] but have yet to CC them. probably first part of this week.
I also had one cyl. flowed to get the numbers and they flow pretty good for old iron heads.
thanks for the help guys.
Rod in AZ