LS2 Performance Heads

[Topspin]

Before I put my Dec. Hot Rod Magazine to bed, I thought I'd post some data from a very comprehensive aftermarket head test in that issue. They tested all the best cathedral Intake port (same as stock on our Rs) heads available, both a on a flow bench and also on a 408 cu. in. stroker engine. Now this info is only pertinent to LS2 owners, as the 5.3s bore is too small for most of these heads. I'll just throw out peak hp #s, so if you want more specific info just ask.
Test 1 - Stock LS1 head - 550 hp @ 6200 rpm
2 - AFR 245 622 6400
3 Dart Pro 1 613 6400
4 LPE Edelbrock 615 6600
5 Procomp LS1 629 6600
6 TEA LS6 618 6300
7 Texas Speed 621 6700
8 Trick Flow 235 619 6400
9 West Coast 619 6400
10 Warhawk 255 602 6500
11 Mast LS3 620 6600 This was a rectangular port
head thrown in for
comparison.

[Mike in AZ]

Thanks for the comparison. I'm guessing that this was done with a naturally aspirated engine. Is there a comparative "flow" measurement from the bench testing that is relevant? Would the camshaft specs be relevant also?

Curious, with an analytical (go figure) undertone......... I was planning to have West Coast do the heads on my "R" in the coming months and am wondering about "bang for the buck" a little too. Would you care to offer your opinion???

Regards,

Mike

[Topspin]

First let me apologize for the mess that the 1st post is in! When I made the post, and even now when I go to Edit, all the names and #s were in somewhat orderly columns as I intended. Don't know why, upon entering it, it turns into the cluttered mess with all the spacing removed.

Mike, here's the particulars on the test engine: 4.0" stroke, 4.030" bore with 11.0-1 comp. ratio, FAST car style intake with 102mm t.body, 239/247 - .624" - 114 lobe sep. cam, 30 deg. ignit. total, 1 7/8" x 3" Headers, and stock LS3 injectors. Also, all heads were required to have and tested for an 64cc comb. chamb.
I've had some hands on experience with porting heads and flow bench testing them. I know for certain that the highest flowing heads (strictly talking intake flow here, because that always the hardest thing to obtain and it's relatively easy to get the 70% exhaust flow) aren't always the best hp heads. In this test head #5 was lower flowing than most and sometimes by a significant margin, but had the best hp #s along with peak torque #s as good as the others. My feeling is any time you can achieve equal power with less int. volume you have gained in terms of throttle response and BFSC.
As far as value goes, most were new castings and all were allowed to be ported and seemed to be. The price range is about $2200 - $2800 for complete heads. Head #6 was a ported LS6 casting For $1350 from Total Engine Airflow, and looks like a real nice head for the money. The cost though is for porting on your castings. The West Coast heads were Edelbrocks with CNC porting priced @ $2385 with very large int. port vol.
If I was putting heads on my LS2 right now, I'd look very closely at head #5.
Oh yea, regarding the cam tested, it's way larger than anything I'd consider for my street SSR. Brain's fried for tonight - off to bed!

[BlueStreak]

[QUOTE=Topspin;924759]First let me apologize for the mess that the 1st post is in! When I made the post, and even now when I go to Edit, all the names and #s were in somewhat orderly columns as I intended. Don't know why, upon entering it, it turns into the cluttered mess with all the spacing removed.

This is one of the things that has bugged me since I became a member. No matter how you type it the site removes what it considers excess spaces and line feeds and tabs, much as it does with All Caps. You might try building your table in Word or Excel and then copy and paste. Sometimes that seems to work.

[RUN ROD RUN]

[quote=BlueStreak;924764]

Originally Posted by Topspin

First let me apologize for the mess that the 1st post is in! When I made the post, and even now when I go to Edit, all the names and #s were in somewhat orderly columns as I intended. Don't know why, upon entering it, it turns into the cluttered mess with all the spacing removed.

This is one of the things that has bugged me since I became a member. No matter how you type it the site removes what it considers excess spaces and line feeds and tabs, much as it does with All Caps. You might try building your table in Word or Excel and then copy and paste. Sometimes that seems to work.

It can be done ... just takes a couple extra steps. Here I used Words, then print scrn & paste to MS Pictures.


Sorry for the hi-jack Topspin.

[SSR Fenton]

The HP numbers were for a 408cu inch motor? For a stock LS2 should we expect the same percentage gains? The #5 Heads were about 14% higher HP than stock, can we expect 14% HP gains with standard stroke assuming same "test cam" (and manifold etc.)?

Considering the cam, if the agressive test cam 114 LSA was replaced with an aftermarket "daily driver" like a higher lift but same 116 LSA (same as stock) cam then arn't the HP benefits diminished compared to the test?

Just trying to figure out the value gain, using stock heads vs #5 test head, plus an aftermarket cam swap on a stock LS2. The stroker engine at 230HP over stock (>50%) is phenominal!! So, who's up for the tire test.

[TMZSSR]

I am running AFR Mongoose 205 Heads with Harland Sharp roller rockers and a 228 duration 600 lift Thumper Cam from Scoggins Dickey on my LS2, I have been told by Joe that this combo is outflowing my stock injectors. The 205 heads flow about 320 at 600 lift but have great velocity and instant throttle response because of the small size.

[Topspin]

Hey Brian, the stroker is indeed worth some power as is an increase in bore diameter. Larger bores really impact these types of heads with their larger valves and bigger port volumes.Also, big cams REALLY wake up these engines!
Car Craft did an interesting test that speaks to your question of what a stroker combo is really worth. They started with a stock LS3 and added GMPP cnc ported L92 heads and a decent size Comp Cam ( 231/239, .617"/.624", 113 lobe sep. ). This combo made 569 hp and 522 lb. ft. Bolting the same heads and cam onto a 4" crank combo resulted in 608 hp and 570 lb. ft., and at 200 rpm lower. Also the stroker made 500 lb. ft. 600 rpm earlier and held it 500 rpm later than the stocker, so it would really benefit our heavy trucks!

Thanks, Bluestreak and RRR for the excellent tips! I'm glad to know it's not entirely my fault that I made a mess.

TMZSSR, that sounds like a really nice street combo you've developed! Did you go 1 3/4" or 1 7/8" headers, with or without a Y-pipe?

[TMZSSR]

I have Kooks 1-7/8 headers with dual 3 inch cats and the y pipe.

[MoodyBlue]

Originally Posted by Topspin

Hey Brian, the stroker is indeed worth some power as is an increase in bore diameter. Larger bores really impact these types of heads with their larger valves and bigger port volumes.Also, big cams REALLY wake up these engines!
Car Craft did an interesting test that speaks to your question of what a stroker combo is really worth. They started with a stock LS3 and added GMPP cnc ported L92 heads and a decent size Comp Cam ( 231/239, .617"/.624", 113 lobe sep. ). This combo made 569 hp and 522 lb. ft. Bolting the same heads and cam onto a 4" crank combo resulted in 608 hp and 570 lb. ft., and at 200 rpm lower. Also the stroker made 500 lb. ft. 600 rpm earlier and held it 500 rpm later than the stocker, so it would really benefit our heavy trucks!

Thanks, Bluestreak and RRR for the excellent tips! I'm glad to know it's not entirely my fault that I made a mess.

TMZSSR, that sounds like a really nice street combo you've developed! Did you go 1 3/4" or 1 7/8" headers, with or without a Y-pipe?

Don't you just love a good Stroker. Man I love mine. Thanks Bro. Maybe more folks will go this way. I just love it when my Second Shift leaves about 20 feet of Rubber behind. This isn't even, when I'm really getting on this Stroker.

[SSR Fenton]

Originally Posted by MoodyBlue

Don't you just love a good Stroker. Man I love mine. Thanks Bro. Maybe more folks will go this way. I just love it when my Second Shift leaves about 20 feet of Rubber behind. This isn't even, when I'm really getting on this Stroker.

In every article I have read a stroker is worth 50 lb-ft right across the range apples to apples for the LS2. Just what the doctor ordered for our trucks.

[MoodyBlue]

Originally Posted by SSR Fenton

In every article I have read a stroker is worth 50 lb-ft right across the range apples to apples for the LS2. Just what the doctor ordered for our trucks.

I used 64cc Heads with Dished Pistons. Flat Pistons would have pushed me up to as much as 14-1 Compression. Pumped Gas is your goal. So stay under 12-1 and she will still kick behind.

[Topspin]

Hey Moody, is this combo in your R? If so, how about some details on the components you selected? My real interest is in the stroke and rod length along with how far the piston skirt traveled out of the bore.