Description:
Our CNC-ported GM LT heads are pretty darn good. These CID heads are better and by a lot! Here's why:
- We buy these heads as porter castings which allows us to impart whatever design we like to the runners and combustion chamber.
- These heads were designed from ground up for competition, not transportation
- They are made in the USA using premium aluminum alloy with no remelt under the watchful eye of CID's owner
- The deck is about 0.25 inch thicker than OE heads
- The six-bolt design provides a lot more clamping power if paired with a six-bolt block. These are pretty rare now but should be coming from the usual suspects in the foreseeable future.
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 starts with CNC porting and combustion chamber machining on our 5-axis. This is followed by CNC valve jobbing and bowl blending in a single operation on our Newen CNC seat & guide machine (see video down below).
The air flow results we get are as shown in the Table immediately below.
| Valve Lift: | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 | 0.75 | 0.8 |
| Intake | 91 | 157 | 232 | 284 | 331 | 351 | 353 | 358 | 362 |
| Exhaust | 52.4 | 110 | 151 | 198 | 222 | 230 | 236 | 236 | 236 |
| Intake Valve: | 2.130" |
| Exhaust Valve: | 1.600" |
| After Intake: | 276cc |
| After Exhaust: | 110cc |
| Max Lift | 0.65" |
| Chamber Volume | 58cc |
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. The standard spring & valve package comes with GM titanium intake and Manley stainless steel exhaust valves with a Manley dual spring kit. Call us at 815-725-2727 to discuss your requirements.
Pricing is per pair.
Start weight: 34.4 lbs Finish weight: 31.0 lbs
Payment Types Accepted: Cash, Credit Card, Wire Transfer, ACH
Built by people who love motorsports for people who love motorsports
