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I decided to have Reher-Morrison provide the cores. Sometimes heads can have core shift and I wanted to let the head porter pick the casting to use rather than me dig up a set of used heads and hope that they didn't have some issue that I missed.
I'm happy with the time and attention Darin Morgan spent with me on my project and Reher-Morrison excellent customer service. Each of the half dozen or so people I spoke with was nice and very processional. Darin also spec'd out a custom cam to meet my goals and still be daily driver friendly.
It was fantastic to be able to call Reher-Morrison and actually get in touch with knowledge professionals. Several other well known shops that I contacted seemed to only wanted to quickly sell parts with no attention to my specific goals and customized according. At this point my favor vendors are RPM Transmission, WS6 Store, Hawks Motorsports & Reher-Morrison. All of which have been A+ on this and other projects.
These LS3's make a solid 30 - 35hp more! These port programs were designed by Darin Morgan and available through Speier Racing Heads.
These are the small ports, Darin even has a set on his Ls3 Camaro, it makes like 450+ to the ground and runs 11's with only a cam, ported heads and Darin cut open the intake. It's his DD. He's really a Good guy.
These guys know that the LS3 does NOT need much, if any additional port volume. It's more about the final shape, which is done through minimal material removal. I have noticed when comparing CNC'd OEM heads that TSP's LS3 heads, for example, have one of the smallest final port volumes, yet flow better than most competitors. (yeah, I know cfm is NOT the only indicator of head performance, but it is one of the players). It appears R-M is in tune with this philosophy too.
Very old thread, as are Ls3 heads. Depending on how much cam or better said*which cam Hyd. or LLSR with compression, your gonna have a Wildebeest. 550+rwhp depending on how much RPM. Easy $.
I had contacted Darin last year about ordering LS3 heads; he seemed to drop off the radar when attempting to make follow-up inquiries about the design goals. Should I be contacting Reher-Morrison directly?
I'm hoping to hit 525 rwhp for TA that's about a 100 + more than the TA makes now
Originally Posted by JimMueller
I had contacted Darin last year about ordering LS3 heads; he seemed to drop off the radar when attempting to make follow-up inquiries about the design goals. Should I be contacting Reher-Morrison directly?
When I call Reher-Morrison asked about their LS3 heads, they put me through to Darin. I suggest calling Reher-Morrison directly.
These guys know that the LS3 does NOT need much, if any additional port volume. It's more about the final shape, which is done through minimal material removal. I have noticed when comparing CNC'd OEM heads that TSP's LS3 heads, for example, have one of the smallest final port volumes, yet flow better than most competitors. (yeah, I know cfm is NOT the only indicator of head performance, but it is one of the players). It appears R-M is in tune with this philosophy too.
Port volume is neither good nor bad, it depends on the purpose. But for 95% of ls3 builds you're exactly right
Actually, most LS3 heads could just get by with a CNC porting of the exhaust port only, as it is widely known to be the weak spot in the LS3 port setup. You don't see exhaust-only CNC jobs offered by anyone I have seen though I would think anyone would do it if requested. For the 95% you mention, it would be enough and give things a little kick where needed
A little teaser on the flow test. It wrapped to day, I just have to get the data in a spread sheet. The intake port is stable and doesn't back up even at like .750 lift. On the flow bench the port sounds "clean" when being flowed.
IIRC correctly typically a SF-1020 bench typically flow about 15-20 cfm less than a SF-600. All of my test data is from a conservative SF-1020.
Through the WS6 Store/VR ported LS3 Fast Intake Manifold we saw the heads flow well over 300+cfm
A little teaser on the flow test. It wrapped to day, I just have to get the data in a spread sheet. The intake port is stable and doesn't back up even at like .750 lift. On the flow bench the port sounds "clean" when being flowed.
IIRC correctly typically a SF-1020 bench typically flow about 15-20 cfm less than a SF-600. All of my test data is from a conservative SF-1020.
Through the WS6 Store/VR ported LS3 Fast Intake Manifold we saw the heads flow well over 300+cfm
Would be interesting to flow it with a mid runner.
I think given the flow data below it would be very interesting to test the mid-runner.
The testing took longer than expected but I think the data collected was worth the wait. The flow bench had a bearing failure with on one of the internal orifice plate if I understood correctly in the middle of the test. After the flow bench was repaired, calibrated and a "known cylinder head checked" to confirmed my testing started over from Ground Zero.
We found an interesting result and to ensure accuracy re-ran the entire series of tests to confirm the results.
All testing on SF-1020, at 28 inches with a 4.060 bore. The owner told me this SF-1020 typically reads 15-25 cfm less than the typical SF-600. Previously, many know cylinder heads that claim 300+ cfm of flow delivered ~280 cfm on this bench. Based on data collected in another set of tests this SF-1020 tends to flow very similar to another heart breaking flow bench one of my NASCAR friends used to test several sets of heads. In short, I think these flow numbers are as accurate and fairly measured as is possible for an enthusiast to acquire.
A few comments on the testing. I took a WARR 92mm TB and a pair of Nick Williams 102 TB's to also test with the intakes. The TB,'s had no effect on the flow numbers. The WARR 92mm TB bases on flow bench testing does not restrict the stock LS3 intake. Neither of the Nick Williams TB's had any effect on the WS6 / VENGEANCE Racing Ported LS3 LSXR intake. Engine dyno testing might show an effect but flow be
No clay intake radius was used on the cylinder head. The intake port was tested bare. No pipe on exhaust.
The two gray column are RM cylinder head intake and exhaust flow in cfm
The blue column is LS3 intake & RM head, note the LS3 intake kills up to ~50 cfm of flow similar to what an LS6 intake does with cathedral heads.
The green column is the WS6/VR ported LS3 Fast LSXR intake. It reduced flow by a small amount at high lift and helps enhance low lifters flow.
The pink column shows how the WS6/VR ported LS3 Fast LSXR intake.increased or decreased flow at various lifts compared to the bare RM head.
This was the very first time I had actually saw an intake manifold match with a cylinder head so well that it enhances flow any any lift.
I did notice the cylinder head intake port sounded crisp & clean when being flow tested. Some cylinder heads have a muddy turbulent sound when they are flow tested. A cylinder head with a dirty sounding port usually isn't a very good head.
Note dyno and track testing are the ultimate measure to make judgements by not flow bench numbers. I think flow bench testing when properly done can help us evaluate parts.
Last edited by 99 Black Bird T/A; Jul 31, 2017 at 08:14 PM.
Kind of what i always thought. If you have stock ls3 heads and running around 6500 rpm the stock ls3 intake is a good piece. If you're running ported heads or higher rpm then ditch it
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