senicalj4579

iTrader: (41)

I have 241 heads. Was thinking on getting 243 heads and sending them to Advanced Induction but it looks like they can do a great job on 241s. How much more power will the 243s give me vs the 241s? 10-15rwh? Im wondering if the 243s would still be worth it?

02_Orange_D1SC

iTrader: (27)

yeah i bet you'll get 10-15 horse more outta the 243s and btw good choice goin with advanced inductions i have there 226 package and im very pleased

a-low

iTrader: (26)

I was wodering the same thing. Wonder why does it cost more for the 241 vs 243 port job
Maybe the 241 might produce more torque due to smaller intake runner?

Camaro99SS

iTrader: (4)

I went with their "High Compression" 241 port. They told me on a h/c LS1 there's a ~8-12hp difference. The machine work is higher on the HCR 241 because they do more work in the combustion chamber and re-shape the valve angle to give the same PTV clearance as a stock 241 head. I'll have dyno results here shortly.

Jason

01 ss vert

iTrader: (1)

Subscribed. I'm very interested as well. Please post results here, even if you start another thread. Thanks!

wildcamaro

iTrader: (15)

I would think since the 243 is already superior to the 241 then it will cost more $ to make the 241 flow like a comparable cnc'd 243...but since you already have the 241 i would get those cnc'd since you would have to spend at leaset 350-400 to get the 243s...now if you can get your hands on some z06 valved 243s then you get the added valve benefits as well..

Jersey Mike

iTrader: (9)

I wish A.I. would chime in here.

Considering there's a $350 price difference between stock 241s and stock 243s, it would be great to hear from the source themselves what each head can produce after their port job, (obviously, paired with the proper cam, respectively).

JB_97ws6TA

iTrader: (6)

According to their website...

226cc 243 produce between 450 and 500
219cc 241 produce 420 to 460
High Compression 219cc 241 produce between 440 to 470

All with supporting mods of course. So if we are staying on the conservative side of the spectrum that means that the 241 is ~30 hp down and the High Compression 241 is ~10 hp down. I doubt that someone would see such a vast difference between each set of heads outside of a max effort build but I have been wrong before. I wish I was home right now because I did a side by side comparison with their advertised flow numbers and the percent increase or decrease at each respective lift. I will see if I can dig that up...

JB_97ws6TA

iTrader: (6)

I just went through this same decision process, in this post I averaged the percent change in the flow rates but if someone wanted the percent change at each lift (I only figured up to .600) than I can probably dig that up.

https://ls1tech.com/forums/15730006-post9.html

Jersey Mike

iTrader: (9)

I checked the link out and that's a very solid post. Thanks for taking the time do compile it and link to it for everyone.

mark21742

I should have, but didn't have mine flow tested I have around 8-10 hours of hand porting into my stock 241's, milled and valve job with 57cc chambers.....I can tell you the butt dyno showed a large difference in feel when I tested them

thunderstruck507

iTrader: (18)

Depends I guess. How many people pay $1000-1200 for a FAST intake to get 10-15rwhp?

Some shopping around could land you $300 or cheaper 799 which are the same as a 243. If the port job is a little cheaper that will absorb some more cost. They will also have higher resale value if you switch later.


The 241s will no doubt be excellent performers, but if you think there's any chance of regretting missing out on that extra power, I would go ahead and get the better heads now.

Think of it as comparing buying a ls6 intake to a $500 FAST. Can't go wrong either way, just depends on your "long run" plan.

01 ss vert

iTrader: (1)

Very good point.

01 ss vert

iTrader: (1)

3.8% intake and 1.1% between the two, I vote 241s ported, especially since you already have them.

SweetS10V8

iTrader: (4)

I'm not a cylinder CNC porting expert.......

But I dont see why they couldnt CNC the #243 port into the #241 head, because the #241 head is a 200cc runner where the #243 head is 210cc.

Unless there is a dramatic difference in port shape, I would think the #241 would accept either port job because it has more avaliable material because of its smaller initial intake port size.

Make sense?

JB_97ws6TA

iTrader: (6)

From what I have read about the differences between the 241 and 243 is not necessarily in the port but it is in the chamber. The 241 has a less efficient combustion chamber and I would imagine it is much more difficult to get that into a better shape because of all of the variables. I am no expert but to dramatically change the shape of the chamber would require you to sink the valves further in the head which then would affect the bowl and the turn radius so I am assuming that there are tradeoffs in this department. Advanced Induction has their High Compression 241 that does have alot more work done in the chamber and they have apparently found a good balance which is why they are able to make almost comparable numbers to the 243. Again they are "almost" as good probably due to the previously mentioned factors.

mark21742

Water jackets might be slightly different in the 241's so that it wouldnt allow the slightly larger ports....maybe

thunderstruck507

iTrader: (18)

I also consider it a benefit to have the CNC heads in hand before tear down. Then all you have to do is reassemble instead of waiting for shipping, porting, and return shipping.

You also get to sell your 241s complete when you're done. That's another $100-150 less in the long run of things.

JB_97ws6TA

iTrader: (6)

There really is no debate on which heads are in fact all around better, the 243 wins hands down. While I was doing research on my build is where I ran into a seemingly widespread misconception that 806/241 heads are garbage and do not even compare to the 243 heads, which is simply not the case. LS1 heads in the hands of a competent porter can and do make good power and shouldn't be ruled out as a viable option for budget minded individuals that are not chasing a number on a dyno.

01 ss vert

iTrader: (1)

That would be my guess as well.