JimMueller

iTrader: (9)

I'm not sure the best place to post this, move if desired. David compares CD, port energy et al between OEM LS3 head and AFR as-cast LS3 Enforcer 238cc head. He claims AFR has a CNC version of this head as well, I presume he's referring to the older 260cc Mongoose and maybe he'll do the same for it in the future. Does David's historical knowledge easily transfer to LS long blocks? Are there new ideas from say Darren Morgan, Tony Mamo, etc. that supersedes David's knowledge?

jhshnh

I’d love to see a forged bottom end with these heads and a low lash solid roller. It would probably surprise us. Especially the mamofied versions.

MuhThugga

He just released another video with some impressive gains after minimal port work.

Tuskyz28

I still HAVE NOT seen a AFTERMARKET LS3 worth the extra cash over stocks. Flow numbers are cool but we cant bench race those.

My cookbook thread showed multiple LS3 heads with different cams, intakes etc. They all run the same identical number at the drag strip. If i remember right one of the fastest LS3 headed cars in the thread had a some UNTOUCHED LS3 heads and a factory GM LS3 intake.

G Atsma

You're right. Everything I've seen about LS3 heads show it to be an excellent head for most mainstream applications, whether it be Richard Holdener dyno tests or flow tests.
It's a darn good head! And the LS3 intake is a great match for them. As I've said, adjust your preferred power level with a cam and/or a turbo or supercharger.

Y2K_Frenzy

I don’t know about the LS3 line of Enforcer heads but the others for Ford & GM are the same Chinese heads that every other Chinese head vendor sells. Except the Enforcers have AFR valvetrain & hardware. If memory serves they’re the same casting as ProComp in some applications. I believe I read that one of the offerings in the Enforcer lineup is a Chinese stock 243 head knock off.

MuhThugga

Typically, this is true. However, the LS3 Enforcer is an AFR design with 238cc intake ports and 2.080" intake valves.

Y2K_Frenzy

I just looked at the ad and AFR says they flow up to twenty more CFM than OEM. So it’s more or less an OEM head copy with smaller valves I guess. I think I can sneeze more than twenty CFM.

MuhThugga

It is a smaller valve, a 20cc smaller port, and a 12 degree valve angle. The interesting thing is that they put the head on a 416 stroker and had an issue with it falling on its face in the upper RPMs, but until that point, it was beating out the stock LS3 head.


This was before the port work, so I'm interested in seeing how it does with the minor cleanup. One thing to mention is that I had spoken with Mast about their small port LS3 heads for my 404, and they said that they have seen turbulence with their small port heads above 6500 RPM on 400+ cubic inch engines. So, I don't know if that is coming into play here. In the video, they are pointing at the camshaft's LSA, but I don't think an LSA is going to cause a plateau in the curve like they saw.

G Atsma

i actually wonder how much the stock LS3 improves with just a good multi-angle valve job and bowl blend. Those 2 things usually gain more than hogging the ports out.

zzracer

iTrader: (33)

Agreed! Also guys don't forget flow numbers aren't everything, got to look at velocity too!

Y2K_Frenzy

Even still I think it’s a head that’s marketed for someone that is needing or wanting an OEM replacement for their LS3. I don’t think it’s really intended to be a “performance head.” How do you think they would’ve done bolted down to a stockish 376?

MuhThugga

I've been thinking about doing this lately: valve job, bowl blend, and maybe some work on the exhaust ports.


I can't say as to how they would have done on a 376. If it truly is a turbulence issue, I would think that reducing the cubes would just move the turbulence further up the RPM range, possibly even moving it outside of the engine's usable powerband so it becomes a nonissue. Also, I went back to my emails with Mast, and they said the turbulence started at 6500, not 6000 like I said earlier.

To me, it seems like there is an issue with the valvetrain. Off the bat, the valve springs that come with those heads are rated to .600" lift, but the cam had something like .630" lift. Maybe I missed it, but I don't recall the video mentioning that they changed valve springs.

grinder11

iTrader: (1)

It would seem (keyword: seem) that they aimed for reducing port volume and valve size to gain velocity, then went with a 12° angle to gain back some unshrouded/unmasked flow.....