Worth going from stock 243's to p/p 853/241?
01-10-2008, 08:01 PM
#21
just have the 243 worked over...you'll be much happier
https://ls1tech.com/forums/new-ls1-owners-newbie-tech/213148-jrp-s-faq-commonly-asked-questions.html
http://ourworld.cs.com/jrp98ls1/stockheadflow.jpg
https://ls1tech.com/forums/showpost....2&postcount=41
http://ourworld.cs.com/jrp98ls1/stockheadflow.jpg
https://ls1tech.com/forums/showpost....2&postcount=41
Last edited by rickyracer25; 01-10-2008 at 08:12 PM.
01-10-2008, 08:20 PM
#22
http://www.motorsporttech.com/fbody_engine01.asp
01-11-2008, 08:14 AM
#23
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im with harvey birdman attorney at law or red birdman whatever lol but the 241 will make more power under the curve and more peak. im not going to say it will make more power between, say .050'' and .200'' lift cause it may not. but overall average tq and hp will be up
01-11-2008, 09:16 AM
#24
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243s have a little advantage in that there is more meat to port. You can remove and smooth the step coming into the bowl where 241s don't have enough aluminum behind it. the combustion chamber on the 243 is optimized over the 241s as is the exhaust port. I've also seen more people hog the hell out of a set of 243s to get over that 300cfm at .600 and absolutely ruin the low and midrange because the ports are shaped wrong and the velocities are way down.
Your questions was specific to swapping a set of stock 243s to a set of modified 241s. To me, bone stock 243s vs ported 241s with larger valves and proper valve springs is absolutely a no brainer. A properly ported 241 with the larger valves will out perform a stock 243. If you had the choice of buying equally messaged heads, I'd choose the 243; again, all things being equal.
Your questions was specific to swapping a set of stock 243s to a set of modified 241s. To me, bone stock 243s vs ported 241s with larger valves and proper valve springs is absolutely a no brainer. A properly ported 241 with the larger valves will out perform a stock 243. If you had the choice of buying equally messaged heads, I'd choose the 243; again, all things being equal.
01-11-2008, 11:26 AM
#25
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Take a look at the flow charts for heads ls1(i.e. 241,853) vs ls6(243) how can you even say that?? ^^^^^^^
http://www.motorsporttech.com/fbody_engine01.asp
http://www.motorsporttech.com/fbody_engine01.asp
Soo, that's how I can say that
If the 243's ARE better ported than the 241's ported, the difference is small...
01-11-2008, 12:00 PM
#26
did you even read his posts like #6 or #8 in that thread??????????
Yes the 241's will produce more right now but what I'm saying is to get the 243's worked over they will!!! make more power if done correctly
Well the LS6 castings flow better, have better velocity, and different combustion chambers, also I believe the runner shape is slightly different.
When choosing a head, it is more important to look at mid lift flow #'s than peak.
.250>.300>.400
since this is where the power needs to be made. So ideally you match your cam specs to the heads potential at mid lifts and avoid potential choking or worse over porting situations.
When choosing a head, it is more important to look at mid lift flow #'s than peak.
.250>.300>.400
since this is where the power needs to be made. So ideally you match your cam specs to the heads potential at mid lifts and avoid potential choking or worse over porting situations.
Yes the 241's will produce more right now but what I'm saying is to get the 243's worked over they will!!! make more power if done correctly
I think Predator is trying to tell you that even ported LS1 heads can't make the same power potential as LS6 heads. I (we) aren't saying that ported LS1 heads aren't going to be better than STOCK LS6 heads. What we are saying is, stock for stock, LS6 heads are at least 20 horses better than stock LS1 heads. And if you were to port both, LS6 heads are going to be better still.
01-11-2008, 12:41 PM
#27
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^ yes I read it all. He said the ported 243's are better than ported 241's, which is true. The difference though is very minimal. He mentioned midlift numbers actually being more important and the differences are even smaller between the two. I know the 243's are better, just not by much...
"Depends on who ports them" is also what he said, so keep that in mind
I wish I could find that thread I'm thinking about where it shows the small differences quoted from a magazine. The consensus was that the 853/241/243's when ported will all net very similar numbers. 243's might come on top, which I believe they did in that magazine, but the difference is not much at all. Maybe 10cfm if I remember correctly.
I'm not arguing that the 243's arent better, all I'm saying is that it's not by as much as some might think...
"Depends on who ports them" is also what he said, so keep that in mind
I wish I could find that thread I'm thinking about where it shows the small differences quoted from a magazine. The consensus was that the 853/241/243's when ported will all net very similar numbers. 243's might come on top, which I believe they did in that magazine, but the difference is not much at all. Maybe 10cfm if I remember correctly.
I'm not arguing that the 243's arent better, all I'm saying is that it's not by as much as some might think...
