Another ? about Stealth heads

[eagleone1983]

Hi everyone. I know there is a lot of info about the stealth heads here and based on that I'm more than likely going to be getting a set. My question is are there any recommended upgrades that those of you that have bought them have done. I know they are "good" out of the box but I was just wondering if there were any parts 440source may have skimped on to get the price down. Also if any body was thinking about getting a set of the heads there is a waiting list which kinda sucks but I guess that means they are that good.

 

[dantrap]

A local guy i know is using the CNC version on his street 440+.030. After he got them a quick disassembly to make sure everything was clean and good was all that was needed. But he replaced the valve springs and retainers with the ones provided by his cam manufacture for his mechanical setup. The car ran good this summer, no problems.

 

[eagleone1983]

Cool but I have to ask...CNC version? I didn't realize there was more than one type.

 

[dantrap]

CNC Machined Cylinder Heads

We've taken something great and made it even better! Now our heads are available fully CNC Machined on both the intake and exhaust ports.

These are fully machined by Jeff Kobylski at Modern Cylinder Head in Michigan.

Heads are 100% CNC ported on their Fadal 5 axis CNC machine.

Modern Cylinder Head sizes and checks the bronze guides for correct clearance, then performs their precision multi angle valve job on their Serdi equipment. All valves are then lapped to verify a good seal.

Heads are then surfaced on Modern's Peterson RP 900MVA Surfacer.

Valve spring installed heights are checked and shimmed if necessary.

Finally all parts are cleaned and assembled.

All work is done 100% in the USA, at Modern Cylinder Head's shop in Michigan.

Part No: 200-1081 - Stealth Aluminum Cylinder Heads - CNC PORTED - ASSEMBLED PAIR - Price: $1995/pair

These might be in stock, good luck

 

[dantrap]

Here are the flow figures for the ported heads.

Flow Chart: CNC Stealth Cylinder Heads
Flowed at 28" on a 4.380" bore with a Superflow 600 bench.
Exhaust flowed with 2" tube.
Valve Lift: Intake CFM: Exhaust CFM:
.100" 75.0 72.9
.200" 156.7 124.8
.300" 219.8 166.4
.400" 266.2 198.1
.500" 298.8 219.3
.550" 306.2 228.6
.600" 314.9 233.3
.650" 320.7 238.2
.700" 320.7 243.8
.750" 321.6 248.2Flow Chart: CNC Stealth Cylinder Heads
Flowed at 28" on a 4.380" bore with a Superflow 600 bench.
Exhaust flowed with 2" tube.
Valve Lift: Intake CFM: Exhaust CFM:
.100" 75.0 72.9
.200" 156.7 124.8
.300" 219.8 166.4
.400" 266.2 198.1
.500" 298.8 219.3
.550" 306.2 228.6
.600" 314.9 233.3
.650" 320.7 238.2
.700" 320.7 243.8
.750" 321.6 248.2