Ls3 Small Bore Heads for Ls1 Engines

[paul_3rdgen]

I have a stock LS2, how would these perform compared to an AFR 215 cathedral port head?

[Ryan@BallisticSpeedParts]

Interesting... What would the benefit/power gains as compared to stage 2 243's?

Curious as to this as well.  Has anyone installed these small bore stage 3 heads on a stock displacement cammed engine?

We haven't done any back to back testing against a stage 2 Ls6 type head.   In terms of flow, a typical stage 2 Ls6 is generally in the range of low 300's to 320 cfm, our as cast head flows 326 cfm and our cnc head flows just over 350 cfm. 

In terms of power production all of our testing was done on a stock displacement Ls1 block using the same off the shelf grind 232/239 cam and same 241 heads for all testing.  Our As Cast (Stage 1) gained 48 hp, and our CNC'd version (Stage 2) gained 55 hp.  Keep in mind this was using the same cathedral port type cam for all testing, so power production should come in higher with the correct cam spec for this style of head.  Compression ratios were also kept at the same stock ratio.

[Ryan@BallisticSpeedParts]

Normal LS3 heads work on an LS2. Why did you mention them in your list? Also did I miss the pricing on these?

Thanks zbrown for the answer...less valve shrouding is the benefit with our heads on a 4" bore motor as compared to the standard Ls3 head.  Our intake valve is less shrouded due to its size when compared to the large 2.165" intake valve of the  standard Ls3 head.

Here is some pricing info:
Stage 1 (As Cast): $1,299 per pair (Ferrea valves included)
Stage 2 (CNC): $1,899 per pair (Ferrea valves included)

-Valve springs are optional and are $200 for dual springs with steel retainers or $300 if you want titanium retainers.

[Ryan@BallisticSpeedParts]

I have a stock LS2, how would these perform compared to an AFR 215 cathedral port head?

We haven't tested against the AFR's but I think they would be in for a real fight.  Our stage 2 head outflows the 215 by over       30 cfm at high lift and substantially outperforms in every other lift also.  Your larger 4" bore would also really maximize the power potential of our heads.  And if price is a factor, we're doing good there too.

[zbrown]

That is a nice price

[AKINA FC]

Do you offer a larger chamber? 74cc is what I need.

[Ryan@BallisticSpeedParts]

Do you offer a larger chamber? 74cc is what I need.

Sorry we do not, 70cc is the largest we offer.

[gnx7]

what is the deck thickness?

Nice price for a set of killer flowing heads.

[Ryan@BallisticSpeedParts]

Deck thickness is 5/8"

[spacevomit]

What is the minimum bore you can run this on? Would it work on a 4.8l/5.3l? Could one use the LS9 headgaskets with these, or is the bore too big on those?

[Ryan@BallisticSpeedParts]

Sorry, minimum bore required is 3.898", they will not work on 4.8/5.3 apps.  Also Ls9 headgaskets will definitely work, their bore size is just right.

[MPbdy]

You could always chamfer the top of the bore on the smaller engine. Valve shrouding may negate some benefit.

[digitalsolo]

I keep trying to justify doing these on my car, haha.   Nice pieces for the price.

[Ryan@BallisticSpeedParts]

I keep trying to justify doing these on my car, haha.   Nice pieces for the price.

You can always find a way to justify more horsepower 

[Ryan@BallisticSpeedParts]

Great results just provided by a happy customer and Ls1Tech member, 45 HP gain...only using a 224/230 cam and stock LS7 Exhaust Manifolds!

http://ls1tech.com/forums/dynamometer-results-comparisons/1625005-last-6-speed-dyno-our-383-ls-test-mule-new-post.html

Got the results in.

They were just as advertised and they picked up 45 rwhp and 35 rwtq over my 241 heads and ls6 intake manifold.  I am pretty happy with that considering they are just the as cast versions.   This was performed on the same dyno, so I know the gain is true.  Compression ratio was the same before/after, so the gain came from flow.

What is puzzling is why my numbers are so low though.  Cam only with the 241s, I only made 340.  Adding the ls3 heads/intake pumped me up to 385.

I am going to get to the bottom of it.  The bottom end just seems too healthy to be spitting out poor numbers.  It revs smooth and does not burn oil. I think it is either the cam is ground wrong, or my torque tube and rear are eating the power.  My rear whines like crazy and my torque tube's bearings are shot.

I am going to remedy all 3 and see if I can get back on the dyno.  I am putting in an AI 230/238 cam now.

But the important part is that the heads gained me 45 rwhp, so money well spent in that regard!  In my experience, that is pretty much what any head swap is going to gain you anyway.  I have seen anywhere between 40-50ish rwhp over stock 241s when swapping heads on an ls1, so these definitely work.  You may see 65+ with ported cathedrals and a fast, but that comes at a greater cost.  These are a good budget option.