In the specialty muscle car engine world, Pontiac retains one of the most loyal followings. With a heritage that includes some of the most iconic vehicles of the era, that loyalty is founded in a tradition of performance. For the hard-core Pontiac enthusiast, real Pontiac engines are the only way that performance is delivered. Engine builder Mark Dalquist of Throttle's Performance found himself in a convergence of circumstances that led him to build one of the most impressive examples of Pontiac performance we had ever seen for the 2013 AMSOIL Engine Masters Challenge.
As Mark tells us, "I have watched Engine Masters since the very first one, and it is far and away my favorite event of the year. I have always wanted to do Engine Masters, but the budget has never been there to do it right. The opportunity presented itself and we went for it. The engine we built was a customer's engine, and he wanted to do an engine for the AMSOIL Engine Masters Challenge. The one stipulation was that it had to be a Pontiac engine. It was actually the first Pontiac I have ever built."
One of the key elements to the success of the effort was building a team with the event experience and specialized knowhow that would be critical for a first-time competitor. The Throttle's Performance team included a number of veteran competitors from the deceased Dan Miller's early Chrysler Hemi team. Mark tells us, "I was doing some engines for David Vizard's big-block Chevy engine book, and one of them was an EFI motor, so I was looking for an EFI specialist. I saw what Scott Clark had done with the early Hemi at Engine Masters, and decided that he was the guy I wanted to do my EFI. Right after I finished the big-block for the book, we went right into the Engine Masters Pontiac. I asked Scott if he wanted to be involved with the Engine Masters team, and it just so happened that they didn't have an Engine Masters entry, so some of the guys from the early Hemi team came aboard my Pontiac Team."
Another key to the personnel puzzle was cylinder head man, Chad Speier. Mark continued, "I have been watching what Chad has been doing for a while, and he is a talented man with a grinder. When I started looking at the Engine Masters rules, out of the cylinder heads that were available for the Pontiac, I picked the Edelbrock Pro Port. It had the most potential because of the port location, and it allowed us to do our own chamber. I called Chad and asked him what it would take for him to do the cylinder head development and have them digitized and CNC a pair of heads. He asked what we were doing, and when I told him it was for Engine Masters, he jumped on board taking charge of the entire cylinder head program."
Brawny Bottom End
The foundation for this build was a bulletproof aftermarket Pontiac block from the specialists at Kauffman Engineering. Mark found the Kauffman block to be an impressive unit, "We used a Kauffman MR1 block. We started out with a different block and it was awful. It had a bunch of porosity, water leaks, and the machine work was terrible. It would have taken 40 to 50 hours to correct all the problems. I called Kauffman and they had a block on hand, so I told them to ship it out. The quality of the Kauffman block is absolutely phenomenal. It is probably the nicest aftermarket block I have ever used, and that includes all of the top names in the industry.
"This block comes with bronze bushed lifter bores, but I ordered them undersized so that we could finish size the lifter bores to our lifters. We decked it to 10.215 inches, and that left the pistons 0.015 inch in the hole, and the boring and honing. That was pretty much it for the block work on this one; the block really just didn't need anything more."
The bore and stroke combination comes to 428 ci, a displacement identical to some of the most powerful factory Pontiac engines. Per chance, the final displacement was derived by the bore and stroke combination that best suited the engine for competition. As Mark relates, "I asked Chad what we needed to make the cylinder head work, and he said ‘really it's going to take the biggest intake valve that will fit,' which for us was 2.350 inches. I asked how much bore would it take to get that to work, and we came up with the 4.350-inch bore.
"From there I started playing around with the stroke, and at 3.600 inches we were at 428 ci, which is a legacy Pontiac number. Our rod-to-stroke ratio with this setup came down to 1.84:1, which really isn't ideal for Engine Masters, but if I shortened the stroke up any more the ratio would have gone even higher. I wanted to keep the rod-to-stroke ratio under 1.8:1, and ended up at 1.84:1, but if I went with even less stroke I would have been over 1.9:1, and that would have been awful."
1. Looking into the crankcase of the Throttle’s Pontiac, the sheer beef of the Kauffman block greatly exceeds the strength of any production Pontiac block. The Scat crank features pendulum cut and profiled counterweights, and provides 3.600-inch of stroke.
2. This detail reveals the massive structure of the Kauffman block’s billet steel splayed main bearing caps. The block features the 3.00-inch Pontiac “small” mains, as opposed to the 3.25-inch mains used by Pontiac on their largest engines. ARP studs provide the clamping force, while the bearings are from SpeedPro.
3. The AMSOIL synthetic motor oil is pushed through the engine via a Melling oil pump. The pickup tube is welded in place and features a strut to prevent failure in service.
4. Holding the AMSOIL synthetic is a Stef’s fabricated aluminum pan, with a built-in screen and baffle system. This pan is an NHRA stock eliminator class legal unit for the Pontiac application.
5. Pistons are custom units from Ross cut for a 4.350-inch bore size specifically for the Edelbrock Pro Port cylinder heads. The Scat I-beam rods are for a big-block Chevy application and measure 6.700 inches, while SpeedPro bearings and Total Seal rings complete the package.