LQ9 (317 castings) vs Zo6 (243 casting)
04-29-2015, 04:16 PM
#1
Pro
Thread Starter
LQ9 (317 castings) vs Zo6 (243 casting)
I posted this in another section of the forum and didn't get a response. Trying here because I see a lot more rabid high performance people here.
So, here goes:
I have heard and read conflicting information on whether the LQ9 (317 casting) ports are the same and flow as well as the Z06 243 casting. Many people say yes but often that's just because they have heard or read that don't support it with flow bench data (I think I've even seen it in articles by GM reps). Yet others say no and I have seen posted flow bench data that says the LQ9 does NOT flow as well as the 243. During my working career I frequently used statistical analysis to solve problems so personally, I am skeptical of many written "facts" until I see them proven.
I have been a hobbyist porter on the small block Chevy for years and I am now about to port a set of LQ9 heads and I would like determine if they are or are not basically the same as the 243's.
If anyone on the forum is interested in the results and would provide an unusable 243 casting I will do some measurements and report back on the forum the results. And no, I'm not trying to get a freebe 243 casting - it would only need one good set of ports (intake and exhaust) and otherwise could be totally trashed. I will measure passage sizes by caliper and also cc them. I may be able to do a flow bench check but can't guarantee that. I don't need valves either. As with any manufactured product you would expect some variation from head to head but it should be a minor difference. If someone has already done this comparison, and has actual data, please advise.
I would be willing to pay shipping to 37857. And, if for some strange reason, the provider wants the head back I will ship back to them at if they pay return shipping.
So, here goes:
I have heard and read conflicting information on whether the LQ9 (317 casting) ports are the same and flow as well as the Z06 243 casting. Many people say yes but often that's just because they have heard or read that don't support it with flow bench data (I think I've even seen it in articles by GM reps). Yet others say no and I have seen posted flow bench data that says the LQ9 does NOT flow as well as the 243. During my working career I frequently used statistical analysis to solve problems so personally, I am skeptical of many written "facts" until I see them proven.
I have been a hobbyist porter on the small block Chevy for years and I am now about to port a set of LQ9 heads and I would like determine if they are or are not basically the same as the 243's.
If anyone on the forum is interested in the results and would provide an unusable 243 casting I will do some measurements and report back on the forum the results. And no, I'm not trying to get a freebe 243 casting - it would only need one good set of ports (intake and exhaust) and otherwise could be totally trashed. I will measure passage sizes by caliper and also cc them. I may be able to do a flow bench check but can't guarantee that. I don't need valves either. As with any manufactured product you would expect some variation from head to head but it should be a minor difference. If someone has already done this comparison, and has actual data, please advise.
I would be willing to pay shipping to 37857. And, if for some strange reason, the provider wants the head back I will ship back to them at if they pay return shipping.
04-29-2015, 09:46 PM
#2
Safety Car
If you look at the intent of the LQ9, I would be more inclined to thinking they do flow than not. That and they came out well after the 243 did, but again this is all just speculation.
