Description:
AFR Mongoose LS3 heads heads bring a lot to the party with their 12 degree, 6-bolt design. We buy these heads as porter castings and machine them to perfection on our CNCs. The shapes we impart to the ports and combustion chambers reflect our years of experience on our own engine builds.
We know what makes power and also survives the beating of competition. It's not chasing peak air flow at max lift by excessively cutting away the metal around the valve guides. Peak air flow occurs at only one instant in the cycle. Our focus is more on average air flow across the entire cycle. For spring packages with 0.650 inch max-lift, quoting a peak airflow at 0.800 inches is irrelevant.
Of paramount importance for us is that our heads don't break and wreck our engines. We therefore do not chase flow at the expense of weakening the heads mechanical integrity. That's a concern that non-engine builders don't share.
Our process for machining these heads includes CNC porting and combustion chamber machining on our 5-axis with CNC valve job and bowl bowl blend on our Newen CNC seat & guide machine (see videos down below). We can optionally remove the 6-bolt provision for aesthetics when being used with a stock block.
The results we get are as shown in the Tables immediately below.
| LIFT | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 | 0.8 | 0.9 |
| Intake | 75 | 163 | 241 | 293 | 340 | 367 | 380 | 358 | 362 |
| Exhaust | 58 | 111 | 148 | 186 | 208 | 217 | 225 | 227 | 230 |
| Key Dimensions | |
| Intake Valve | 2.165" |
| Exhaust Valve | 1.600" |
| Combusion Chamber | 67cc |
| Intake Port | 260cc |
| Exhaust Port | 95cc |
We offer a variety of valve & spring packages for these heads to accomodate both naturally aspirated, boosted applications for use with both hydraulic and mechanical cams. Custom combinations are also available.
Standard Valve & Spring Packages
AFR/BTR: AFR solid stem valves with BTR high RPM dual springs, titanium retainers, 0.650 inch max lift.
Manley 1: Manley Extreme Duty exhaust and Severe Duty intake valves, NexTek dual valve springs, 0.660 inch max-lift, steel retainers
Manley 2: Manley Extreme Duty exhaust and Severe Duty intake valves, dual Manley NexTek valve springs; 0.660 inch max-lift, titanium retainers
And yes, we eat our own cooking. The ATR/BTR package is the new head on our 700hp, 408ci LS and bring more power in the process as can be seen in the video below.
Payment Types Accepted: Cash, Credit Card, Wire Transfer, ACH
Built by people who love motorsports for people who love motorsports
