80Stang
Well-known member
Hi fellas, just to let you know I got my new alum head installed today. Yep, no big deal, but I thought I'd share some info to everybody. Someone may find this info useful.
The head is a stock CI alum head with intake valves 30-degree back-cut and some polishing done to the chambers, which were measured to be about 57.2 cc. The intake back-cut gives this head more than 20% average gain in flow within the range the cam lifts. Wow...
The springs are Sealed Power VS-733, 302 exhaust springs from the 70's. Seat pressure is about 90lbs with stock install height. Victor Reinz teflon stem seals, Comp Cams spring seats, Ford 4.0 V6 retainers, Comp Cams 5/16" 7-degree locks. Previously I had the Comp Cams 52lbs stock "performance" springs on my log head, dying at about 5300rpm. Now the new springs on the new head will allow revving all the way up to where the cam allows. More than 6K expected, but I guess the cam dictates the power curve to start falling at around 6K or a little earlier.
Rockers are vintage (==very old, but brand new) adjustable stock ratio. The whole rocker arm shaft assebly was bought from a dealer in US for $99 as a one time occassion.
Holley 390 carb was cleaned and refreshed. I tossed the secondary metering plate and installed a Quick fuel plate instead, which uses stock Holley jets and thus converts the carb to allow easy changes in secondary jets. The carb sits sideways, primary bowl facing right.
I have a shift light and a wide-band lambda waiting to be installed. I have a feeling that I like the shift light to let me know that I'm above 5500rpm for example, so I'll know when I really need to thing about shifting. This thing revs up pretty wildly on first gears. The Innovate wide-band I might try here but I find the narrow band being useful too although some may find it useless. To me it shows about enough for tuning the engine.
A dyno session on the rolls is on the plans, and possibly on Sunday I have some reference from race track for previous lap times plus on August there will be a day at the drag strip too. No intention not to measure if the investment really was worth it.
The head is a stock CI alum head with intake valves 30-degree back-cut and some polishing done to the chambers, which were measured to be about 57.2 cc. The intake back-cut gives this head more than 20% average gain in flow within the range the cam lifts. Wow...
The springs are Sealed Power VS-733, 302 exhaust springs from the 70's. Seat pressure is about 90lbs with stock install height. Victor Reinz teflon stem seals, Comp Cams spring seats, Ford 4.0 V6 retainers, Comp Cams 5/16" 7-degree locks. Previously I had the Comp Cams 52lbs stock "performance" springs on my log head, dying at about 5300rpm. Now the new springs on the new head will allow revving all the way up to where the cam allows. More than 6K expected, but I guess the cam dictates the power curve to start falling at around 6K or a little earlier.
Rockers are vintage (==very old, but brand new) adjustable stock ratio. The whole rocker arm shaft assebly was bought from a dealer in US for $99 as a one time occassion.
Holley 390 carb was cleaned and refreshed. I tossed the secondary metering plate and installed a Quick fuel plate instead, which uses stock Holley jets and thus converts the carb to allow easy changes in secondary jets. The carb sits sideways, primary bowl facing right.
I have a shift light and a wide-band lambda waiting to be installed. I have a feeling that I like the shift light to let me know that I'm above 5500rpm for example, so I'll know when I really need to thing about shifting. This thing revs up pretty wildly on first gears. The Innovate wide-band I might try here but I find the narrow band being useful too although some may find it useless. To me it shows about enough for tuning the engine.
A dyno session on the rolls is on the plans, and possibly on Sunday I have some reference from race track for previous lap times plus on August there will be a day at the drag strip too. No intention not to measure if the investment really was worth it.
