Casey72
Well-known member
I got the 393C installed and running. It sounds amazing. Starts instantly, idles beautifully at 900 RPM, revs nicely when out of gear. However, on the road it loses power after 3500 RPM and will barely rev and accelerate beyond 4000 RPM, making the burbling noise and running less than smoothly. The PA 10" torque converter flashed at around 3500 RPM with the milder 351W the new engine replaced, but only flashed around 3000 RPM with the new Cleveland. The issue occurs both before and at WOT, so I doubt an issue with the FI changing modes. The converter isn't doing anything questionable that I can tell.
After some research and experimentation with timing and FI settings I've pretty much eliminated the Atomic EFI and torque converter as culprits, noting that both worked just fine before I pulled the Windsor. I'm looking at the valve springs which were installed on the heads by MPG years ago before they sat unused while I was busy with the GWOT. The springs were recommended by Comp for the slightly milder hydraulic roller I had intended to use for this build, but Comp also confirmed that they were compatible with the solid roller I ended up with, despite it being a stiffer grind.
393C engine specs:
4V iron heads, Comp springs (supposedly compatible with cam)
Weiand single plane intake
Hooker SC headers, Pypes 2.5" exhaust
Bored .030"
10.4:1 compression
Comp solid roller 242/248 @.050", 279/285 adv., 106 ICL, 110 LS, lash .016"/.018"
MSD Pro Billet Dist.
Atomic EFI (controlling timing) with HV fuel pump and return line
Timing 12 deg idle, 10 deg vac adv., 34 deg. total, all in at 2000 RPM
101 octane VP unleaded (for now)
So, am I on the right track? Anything else I need to check out before going for new valve springs?
After some research and experimentation with timing and FI settings I've pretty much eliminated the Atomic EFI and torque converter as culprits, noting that both worked just fine before I pulled the Windsor. I'm looking at the valve springs which were installed on the heads by MPG years ago before they sat unused while I was busy with the GWOT. The springs were recommended by Comp for the slightly milder hydraulic roller I had intended to use for this build, but Comp also confirmed that they were compatible with the solid roller I ended up with, despite it being a stiffer grind.
393C engine specs:
4V iron heads, Comp springs (supposedly compatible with cam)
Weiand single plane intake
Hooker SC headers, Pypes 2.5" exhaust
Bored .030"
10.4:1 compression
Comp solid roller 242/248 @.050", 279/285 adv., 106 ICL, 110 LS, lash .016"/.018"
MSD Pro Billet Dist.
Atomic EFI (controlling timing) with HV fuel pump and return line
Timing 12 deg idle, 10 deg vac adv., 34 deg. total, all in at 2000 RPM
101 octane VP unleaded (for now)
So, am I on the right track? Anything else I need to check out before going for new valve springs?