 Kaase removes the custom Moroso...  Kaase removes the custom Moroso valve covers to reveal the valvetrain setup and stud girdle from Jomar. |
 Racers familiar with the Tiger...  Racers familiar with the Tiger heads are probably scratching their own heads right now. Tigers are set up for shaft rockers, right? Well, shaft rockers would be illegal in the Engine Masters competition because Pontiac didn't use them on production V-8s. So JKRE was forced to devise his own stud-mounted rocker system. Here you see the angles of the Crane roller rockers. |
 These custom intake rocker...  These custom intake rocker stands were fabricated by Kaase to make the system work. "I didn't want to use offset seat lifters," he says, "so with these stands I was able to maintain proper valve-to-rocker contact even with all that side pressure on it. Guideplates didn't work at all." |
 Here you can see the work...  Here you can see the work that was done inside the ports and the port match of the flanges to the intake spacers. |
Bottom-End Highlights
The bottom end is comprised of an interesting assemblage of components. Its IAII block was sleeved to reduce the bore size to 4.310 inches, as it was an early development block that had already been overbored prior to Jon receiving it. See the captions to learn more about this block's attributes.
Kaase also decided to reduce the main journal diameter to just 2.500 inches like a small-block Mopar, so he had to install inserts to reduce the main size from the as-delivered Pontiac 3.00 inches. Why even smaller mains? You may think it's to reduce friction, but Kaase says otherwise. "I reduced the main size so the crank wouldn't need so much oil and require higher pressure that would throw a lot of oil out of the short-block, since it's a wet-sump motor with no crankcase vacuum. I wasn't really worried about friction because the engine doesn't run at very high rpm." He also used Calico coating on the bearings so he could run slightly tighter clearances on the mains and rods to further reduce the amount of oil thrown out of the short-block. "The coating reduces friction, but will also catch dirt so it won't scratch the crank as much," he says.
Normally, small mains and a long stroke would raise concerns about crank strength, but Kaase handled that by ordering a Bryant Racing billet crank. "I knew the billet crank would hold up," he says, "and despite the long stroke it wouldn't flex because of the material and because it has counterweights in the center as well."
The rods feature a 2.00-inch big end and a 0.927-inch small end. They are 0.940 inch wide and a seemingly short 6.500 inches. "I'm not a fan of long rods," Kaase says. "I think shorter rods make the piston move faster at top-dead center, so if the engine is prone to detonation, getting the piston past TDC faster helps a little bit. With a 4.350 stroke, you can't fit much more rod and still have a piston with enough compression height to maintain the strength that I want." What about rod angularity causing increased side loading of the cylinder walls? Since AllPontiac.com specifies a minimum of 0.200 inch wall thickness with a 4.400 bore, it's not a problem with this block, according to Kaase.
Regarding weight reduction of reciprocating engine parts, Kaase says, "I didn't take time to make things light with this engine, because I felt durability was more important. Also, the acceleration rate on the dyno (330 rpm/second) is not that fast, so weight isn't really a big deal. For instance, the pistons weigh about 650 grams each--I would not want them lighter, because I want to maintain strength."
Speaking of the pistons, the custom CP slugs, aside from the design features mentioned previously, were also gas ported to ensure good ring seal. The pistons are drilled on the piston deck though to the top ring land behind the ring. When the piston rises and cylinder-pressure builds, some of that pressure enters those ports and pushes the ring out to seal more tightly against the cylinder wall.
Pertaining to the cam choice, Kaase says, "With a couple of years' data from other engines, we had somewhat of a baseline. We had two cams made for this engine--one with 257/261 degrees duration at 0.050 and the other with 261/268 degrees duration at 0.050. Though it didn't produce much more power than the other, I decided to go with the larger cam. The 107-degree lobe-separation angle was based on previous tests, and we tried different rocker ratios, but the 1.8:1 ratio, which happens to be the highest ratio allowed in the competition, made the most power."