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4 psi should be plenty safe, even with mid-octane levels. At 4psi, your valves are fine too.
keep total timing under 35. You are borderline on requiring an intercooler. If you do choose to add a decent cooler, you can probably increase boost to 6 ish. Your tight squish is really helpful. Retarding the cam will bleed a little combustion pressure at lower rpm, but will increase pressure above 4,500 rpm (and your Procharger makes more boost with rom so be careful). Are you EFI or carb? Detonation is sometimes hard to detect with boost - knock sensors and EGTs help, but familiarity reading plugs (for detonation, mixture, and proper hear range) is especially useful. |
Originally Posted by mcollinstn
(Post 4771466)
4 psi should be plenty safe, even with mid-octane levels. At 4psi, your valves are fine too.
keep total timing under 35. You are borderline on requiring an intercooler. If you do choose to add a decent cooler, you can probably increase boost to 6 ish. Your tight squish is really helpful. Retarding the cam will bleed a little combustion pressure at lower rpm, but will increase pressure above 4,500 rpm (and your Procharger makes more boost with rom so be careful). Are you EFI or carb? Detonation is sometimes hard to detect with boost - knock sensors and EGTs help, but familiarity reading plugs (for detonation, mixture, and proper hear range) is especially useful. |
Originally Posted by mcollinstn
(Post 4771466)
4 psi should be plenty safe, even with mid-octane levels. At 4psi, your valves are fine too.
keep total timing under 35. You are borderline on requiring an intercooler. If you do choose to add a decent cooler, you can probably increase boost to 6 ish. Your tight squish is really helpful. Retarding the cam will bleed a little combustion pressure at lower rpm, but will increase pressure above 4,500 rpm (and your Procharger makes more boost with rom so be careful). Are you EFI or carb? Detonation is sometimes hard to detect with boost - knock sensors and EGTs help, but familiarity reading plugs (for detonation, mixture, and proper hear range) is especially useful. |
Valve stem to guide clearance measured, intake 0.0018",exh 0.0021". For my understanding it is fine.
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Your stem clearance is normal.
If you were looking at a high boost motor, the guide material and stem clearance would be more of an issue, as well as the exhaust seat width and face width at the hot "edge" of the valve. At your low boost numbers, it's not a huge worry. You do need to monitor charge temperature (IAT) exiting the throttle body and make sure it stays under 150 degrees. Sometimes you're fine for short bursts, yet long pulls WOT start crawling upwards as the intake plumbing Temps rise. Let that be your signal to back off the sticks a bit or add cooling capacity between the blower and the plenum. |
Procharger
How about a 502 with stock cam 1622 Marc 483 lift very mild duration???
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Pro
Merc cam
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Originally Posted by GPM
(Post 4771452)
Maybe add an intercooler for safety, are you planning to run a thermostat in the engine ?
Originally Posted by mcollinstn
(Post 4771871)
Your stem clearance is normal.
If you were looking at a high boost motor, the guide material and stem clearance would be more of an issue, as well as the exhaust seat width and face width at the hot "edge" of the valve. At your low boost numbers, it's not a huge worry. You do need to monitor charge temperature (IAT) exiting the throttle body and make sure it stays under 150 degrees. Sometimes you're fine for short bursts, yet long pulls WOT start crawling upwards as the intake plumbing Temps rise. Let that be your signal to back off the sticks a bit or add cooling capacity between the blower and the plenum. https://paceperformance.com/i-630462...il-shield.html |
I had similar engine's to yours but I had dart aluminum heads and vortech superchargers and they never really ran right until I added the intercoolers
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Originally Posted by JaniH
(Post 4772053)
I have been considering to use the gm lifter valley baffle. Now when the boost came In the play I definetly going to order the baffle. Thanks!
https://paceperformance.com/i-630462...il-shield.html |
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