Hi guys, I have a 2006 C6 A6 with 145,000 miles on it. Mods include K&N breather, LG Long Tube Headers, and a Circle D stall converter. I recently swapped my LG G5XB cam for a new LG G5X3 114 cam. I have factory 243 heads that have just had a competition valve job including new guides, valves, Comp 921 Springs Comp pushrods, and Comp trunnion upgrade. I also had new GM lifters installed and a new LG race chain and a new oil pump I am being offered the opportunity to trade my newly reworked heads and a $1000.00 for a set of new AFR 210cc or 230cc heads, installed. I've been told I might want to avoid the AFR heads due to the high mileage on my bottom end. Looking for some advice and or opinions regarding the swap.

Thanks

 

70 looks and no advice...what's up with that?

 

Don't have those heads and haven't installed them. But I will say if you have a shop you trust I think it is wise to listen to their advice. Take everything on this forum with a very skeptical eye, this coming from a mechanic. I don't see how mileage makes a aftermarket head any better or worse on bottom end. I do know that head/cam/bottom end is a delicate package to get right. Tuners make for good resources on what works and doesn't if you have one already you use.

 

Pips making the offer do you trust them seemingly they are taking a quite a lost question is where are they planing to make up for it, another prob I see you have to drop the car off to them.

I would trade but prefer to do the job myself.

Oh yeah for the 230 cc.

 

Where your 243's ported also? I don't see a reason for you swap heads. AFR's have a thicker deck which they say is good for boosted applications.

 

Engine components tend to wear pretty evenly top to bottom. Worn valve guides cause some blow-by which relieves stress on the bottom end. When you recondition the valves the cylinder pressure goes up and new stress is put on the old crank/bearings/pistons. Did the mechanic mic. the cylinders to determine the wear at 145k miles. Uping compression ratio can definitely introduce new stress to the bottom end. These LS engines have a pretty good bottom end but there is a limit to what all high-mileage engines will take.

 

AFR 230 is too big of a head for and engine that small, unless you are wanting to turn 9000 RPM with it. The AFR 210 is a solid performer with a nice set of larger valves, good valve angle, and well thought out ports. Makes really good flow numbers while maintaining a lot of air velocity for a street car in the sub 7000 RPM range.

Trick Flow has a number of options on the cathedral port side of things too. Again just do not go crazy thinking that bigger is better, when it comes to street setups that isn't the case.

You could always go to a LS3 style head too, aftermarket or OEM and move over to the larger OE style port if future modifications might be there for that. I know LG has done some LS3 head/intake swaps on LS2's with that X3 cam and put down over 480 whp in the past (manual trans cars), so that is a thought as well.

Either way, if you do keep the LS2 style port, it needs a way better intake than stock if you want to get the most from a cylinder head change.

 

So how is a cathedral 230 cc port to big .....
but a OE LS3 port @ 260cc isn't????

 

If you look around you’ll find the big LS3 ports leave a lot to be desired, typically they leave a lot of VE on the table sub 5,000 rpm.

HP Research knows their stuff

 

if they have bronze guides you might have to switch to aftermarket rocker arms

 

You have to look at a number of things like cross sectional area, actual flow vs runner size at certain lifts, valve size, short turn, how straight the port is, valve angle........and at the end of the day, $.

The other thing is price, we can talk all day long about what is good, better, and best but the fact is you can pickup used LS3 heads for cheap and have some pretty decent results. I never said they were ideal and if you look at most of the dyno graphs or drove one they are going to be down in torque vs a AFR 210 head but is it worth the extra $$...and that is a answer only each customer can decide.

Now if it was a risk factor as far as parts breakage...that's a different story.

 

Not evident based on the post quoted.
Comprehension is fundamental.

I would never put a LS3 Head on a sub 4.060" Bore,
Especially on a DD Vette.

My point is that the AFR 230 is NOT to big for a LS2
with appropriate sized cam, something like
~227/231 .620"/.610" LSA 114+3 with FAST 102,
LS2 TB with VMax Velocity Ring to eliminate
Step/lip @ plenum entrance.

Or.....Cam Motion LLSR 236/242 (hydraulic equivalent. ~230/236
Adjusted for Lash) with Mamo MOTORSPORTS MSD, still
LS2 TB, PEAK @7000-7200 RPM ~520 RWHP (Not 9000 LOL!) shift @
7500 RPM still very daily drive able.

 

The original poster considering only two heads AFR 210cc or 230cc heads
so others maybe not matter but sense some has been said about the ls3 heads on a 6.0 ls2 I must say I have done this swap and the results? the little ls2 best the whp made by the stock ls7 @ the rear wheels of the corvette zo6 with a manual in a 06 GTO with auto transmission with only a 232 intake duration cam

 

For what you have listed there, I wouldn't argue with you. Smaller sized cam's with the proper intake valve closing point, even with a big head and little to no overlap will work very well. That is one of the reasons the stock LS3 has the throttle response and flat torque curve that it does...among other things.

From my testing in the past at another job I have seen with bigger cams with a bit more over lap the smaller heads will generally perform better in the idle to 6800 rpm range even on slightly larger engines like say a 402 LS2.

I would say for the most part on a street car you would be better to opt for a smaller sized port vs a big one for a stronger torque curve.

While I don't have access to the dyno runs a number of years ago I had done back to back on a 402 GTO with a rather large cam..high 230's / mid 240's duration between a AFR 225 and 205 given the rest of the build the same and again in that 1500-6800 RPM range the 205 head would generally carry 12-18 more hp/tq across the board and they would start to meet around 6200 or so (going off memory) and produce roughly the same peak numbers.

Same could be said on a stock LS2 short block comparing a LS3 head / intake vs a AFR 205 / FAST 92 setup. Both make approx 495 rwhp but the AFR would tend to carry 10-15 more ft-lbs in the sub 4000 RPM range. That was on a 2007 C6 manual car, back in 2007 or 2008 when we did it.

So a lot goes into the setup, and like your examples prove is that how the entire thing works. Just knowing those cam's that he had/has in the car and how they work compared to heads he was looking at...the smaller ones generally tend to work out a little better with the LG cam's. At least from what I had seen in the past.

 

I think the LS3 is a little too big as well but it works great with small cams. I know the OEMs do this with 200 @ .050 cams and the large heads like the LS7 and LS3 and it does work pretty well.

When the cams get larger though it seems the smaller heads make more average hp in the middle as Brian Tooley has always alluded to etc. Kind of like Tony Mamo's smallish TFS 260 based LS7 heads too.

At 6500 and down it seems like the smaller heads work quite well. With a higher rpm manifold and / or larger engine you need the larger heads for sure and at some point you can't make them large enough!

I think Anthony was really talking about the stock CID LS2 6.0 and the usual 6500 rpm and below long runner manifolds. In this range the 210 might be better for a driver car. I know he tuned and installed hundreds of head/cam combos before so just looking at it like that.

On 416s we often used the TFS 235s and they always ran awesome but on a 364 (6.0) that would equate back to a TFS 205 even. Of course you aren't gonna lose a ton of power or anything either from running the 230 but I don't know if you'll gain a lot either on a 6.0 at lower rpm.

 

Are you looking for streetability also? What's the stall speed of your DD converter?

 

Stall speed is 2800. This is my daily driver so streetability is important. Currently heads are on hold. I am going to install FAST 102 BETWEEN NOW and .Christmas. Then I will begin looking at heads again. I will likely go with AFR 210s or 215s or a similar head from another vendor.

 

Ported LS3 heads/intake.

KW

 

With your cam, the intake will make a very big difference even with the stock heads. If you're budget constrained, I'd go with it over the heads. Otherwise, for $1k installed, I'd swap the heads to the AFR 210s at the same time as you put the new manifold on. Seems like a great offer for new heads, installation, and misc (e.g., fluids, gaskets).

 

That sounds WAY too good to be true.