New motor being built. Currently I'm running the 289. It has a lot of RPM potential, and some decent torque, but I'm at a point now where I would like to give up a little RPM (go from 8k down to 7K as a max RPM) and increase the torque a bit. The new motor is a stroked 351W that will displace 383 CID (6.3L). I chose this combination over the larger stroker kits because it uses the longest rod of all the other combos which provides a nice rod length/stroke ratio, so my RPM limit will not be hurt too much with the stroker.
And nice rods as well:
The headers were finished today. Now I understand why headers are so expensive. I had to fabricate new headers because the new AFR heads have a different bolt pattern than the old heads have. Also, the headers are so tightly fitted to the car that even if I could use the old heads, the fact that they will now be 1" higher and wider in the chassis would prevent me from using the old ones.
After sending the headers to Jet-Hot for a nice ceramic coatings.
An OEM Crossmember was modified, and new motor plates were fabricated as a front mount.
Internals have been assembled and the timing cover, pump and front plate assembled. this is what it looks like without the carb on top.
A trial fit of the 383 into the Z engine bay. The left photo shows the motors sans the headers getting fitted and angle matched to the differential. The right photo shows the headers in place. The header jig worked perfect and all built-in clearances between the steering rod/ frame rails/ T/C bushing bosses are perfect.
View of the completed motor from directly over the top and from the right front.
In order to make the transmission survive the increased torque (increased from 295 to close to 500 lb/ft), I installed G-force gears and cluster gear along with the mainshaft. Often overlooked on this upgrade is the overdrive gearset (5th gear). After investigating the many failures with the OEM overdrive gearset on high torque motors pulling hard in 5th gear, I also chose to upgrade it. Below are photos of the 5th gear compared to the OEM gearset. The G-force gears are on the left side in each photo.
The larger (6.3L) motor in fully installed and running at this time. Significant changes from the previous smaller motor are more power and torque, and more heat, specifically, oil temperature issues. The 289 rarely had oil temperatures that exceeded 210º even in the heat of summer, but the 383 now routinely has oil temperatures exceeding 245º. In an effort to reduce oil temperatures I've installed a cooler at the floor of the radiator intake duct, horizontally mounted, and next to the radiator. A recent test drive in 101º temperatures (Arkansas summer) indicated a max temperature of 210º. This was a 35º drop, which was expected and indicated good airflow through the cooler. Photos forthcoming.
Induction system will be changed to the Weber 48 IDA induction set-up as soon as the bugs are worked out. Chokes have been increased to 42mm (from 37mm), linkage is being modified to correctly synchronize the left and right banks, and the intake was milled recently to tilt the carbs inboard 8º in order to fit everything under the hood blister. Photos forthcoming.
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