NASA Great Lakes racer Dan Piña has been the 944 Spec National Director for as long as we can remember, with a couple of national championships to his name. Of course racing and winning is fun, and all well and good, but the health of the class depends on competitor interest.
Keeping people interested in the class means keeping costs down and keeping parts available, which is where 944 Spec faced a couple of challenges.
One, because the engine blocks are made of Alusil, most machine shops do not have the skills or equipment to bore them properly. Alusil is a hypereutectic alloy of 70 percent aluminum and 30 percent silicon. Porsche isn’t the only manufacturer to use the material for engine blocks. BMW also has been using Alusil-coated cylinder walls since 1996 because it eliminates corrosion problems caused by gasoline that contains sulfur.
Two, once you allow a competitor to bore a block, you need to ensure a supply of pistons for those oversize bores.
The 944 Spec rules used to stipulate stock blocks and pistons, but because of the age of these cars — 1983 through 1988 — and the decreasing availability of solutions to blown engines and scored piston bores, something had to be done.
Dan Piña set out to find the solutions to these problems to foster continued growth of the class, which has spiked a bit in 2021. We caught up with Piña to find out more.
Q: We understand you’ve been busy for the last two years ensuring a solid future for 944 Spec. What issues were you trying to fix?
A: The previous rules set did not allow for damaged bores to be repaired, forcing racers with damaged engines to have to hunt down entire replacement blocks with perfect bores. This became more problematic in certain areas of the country, but all in all these rules weren’t conducive to racers budgets nor keeping cars on track. With non-scored blocks becoming harder and harder to find, it was time make a change in the rules.
Q: So, you got a piston manufacturer to make pistons specifically for a NASA racing class? How did you talk them into that?
A: I met with several piston manufacturers at PRI back In 2019. I had a few companies I really wanted to use, but needed to keep my options open. Most companies were willing to make a replacement piston set, but had huge minimum order requirements (roughly $10,000) and long lead times. Next I interviewed a buddy of mine who builds race engines for Dinan, which is now owned by Carbahn. He gave me tons of great input based on their experiences with piston manufacturers with their Alusil BMW engines. From this, I decided to go with CP Carrillo.
I purchased and shipped CP an 1988 piston and asked them to copy it exactly in design and weight. While they were reverse-engineering it, I was busy redesigning the 944 Spec logo. I gave this new artwork to all the racers. Unbeknownst to them, this was specifically designed — along with a font — to be laser-etched onto the piston tops for NASA tech official enforcement.
Once I had the first prototype set in my hands, I immediately put them into a car for durability and performance testing.
The last step was to work with CP Carrillo on pricing. The original price bracket was going to be substantially more than it is now. I made sure to remind them that this new part we created would be the only aftermarket option for 150 racers in NASA 944 Spec racing alone. Not to mention the PCA rulebook is typically an exact copy of my rules.
Q: OK, let’s talk about 944 engine blocks. What’s so special about them?
A: Most aluminum blocks engines use a ductile steel sleeve, which essentially provides a very traditional combustion chamber. The 944 block, however, has an Alusil block. The bores do not use the traditional cross-hatching that steel bores do, thus require specific pistons and rings.
Q: So, now you can sleeve them or have them bored? Are there any weight or other performance penalties that come with an over-bored engine?
A: I have come up with two solutions for people looking to reuse damaged-bore blocks. Racers now have the choice of using 100 mm pistons —original size is 100 mm — or 100.5 mm pistons coated for Alusil bores or a 100 mm piston prepared for steel-sleeved blocks. Steel sleeves are spec’d by L.A. Sleeve out of Sante Fe Springs, Calif.
To create these pistons, I sent CP Carrillo an 1988 piston to copy. To ensure there was no advantage using the 100.5-mm piston over the 100-mm piston, I had CP Carrillo reduce the crown height to keep the cc volume the same between them.
Both piston sets will be scrutineered to the same dyno cap as every motor in competition to ensure there’s no advantage.
Q: How can 944 Spec racers find machine shops that can bore Alusil blocks?
A: Finding shops that can bore and polish — not hone — Alusil blocks can be difficult in some regions, hence the option for sleeving. I spoke with Steve Dinan who ensured many of his facilities around the country can properly prepare these blocks. Otherwise, for racers that don’t have this luxury, sleeving is the easy answer.
Q: You mentioned something in a previous conversation about how an Alusil block is machined. Can you give us the details on that again?
A: Unlike steel combustion chambers, Alusil bores are not cross-hatched. Alusil bores are polished smooth surfaces created by using a proprietary paste and felt style pad. These bores require a specific piston coating which CP Carrillo is very familiar with.
Q: Don’t 944 pistons use iron piston rings? How does the Alusil hold up?
A: The biggest difference in 944 rings and most traditional rings are their thickness. CP-Carrillo recognized this and had 944 specific rings made for our sets.
Q: So, which is better: steel sleeves or an over-bored Alusil block?
A: Whichever you can get built locally. There is no performance difference. So really it breaks down to cost and your ability to have the machine work done. Having sleeves installed into a block obviously would cost more in labor and parts, however, should something catastrophic happen in the combustion chamber the ease of changing out a single sleeve could be easier and less costly than having to hunt for a new block.
Q: How are the 944 Spec fields around the country these days?
A: The 944 fields have had a resurgence in several areas. SoCal recently hosted a 17-car field while the Great Lakes region gained nine new racers this season. The 2021 NASA Championships entry list is on par with the Spec E30 list.
Q: What’s the one piece of advice you would give to someone considering racing a 944, whether it’s 944 Spec or another class?
A: Spend the time/money to have the motor properly built by a reputable Porsche engine builder. Once built right, these motors can be abused like a Japanese motor and will last seven seasons without a major rebuild. It will be a little pricey up front, but save you tons of heartache down the road.