Naturally Aspirated Built Motors from Trackspeed Engineering
 

Trackspeed Engineering Naturally Aspirated Built Motor

With naturally aspirated track car builds becoming more and more popular, we've decided to put together an engine package that is geared towards track day addicts and racers alike. We've put a major emphasis on reliability, longevity, and ease of use with these motors - the goal is to build a motor that can be revved harder than a factory engine safely, will make slightly more power, and will last just as long or longer than a junkyard motor under track conditions.

If you're familiar with our Forced Induction longblocks, you'll notice a lot of similarity and a few key differences in our latest motor's parts list.

-OEM Mazda 10:1 +0.50mm oversize piston
-Carrillo Pro-A connecting rods
-Carrillo Rod Bolts
-ACL Race main, rod, and thrust bearings
-ARP head studs
-ARP main studs
-Boundary Engineering "Street/Strip" oil pump with billet gears
-Supertech Viton valve seals
-Gates Racing timing belt
-OEM Mazda seals and gaskets
-Full cylinder head refresh (hot tank, new manganese/bronze valve guides, 3-angle valve job, pressure test, and resurface)
-Supertech valve springs
-Supertech titanium retainers

Pistons:
Instead of opting for a high-compression forged slug, we've decided to stick with an OEM Mazda piston for a few reasons. Keeping the compression down in the 10:1 range sacrifices a couple of ponies, but it allows the safe use of 91-octane pump gas without excessive timing retard. A factory piston also allows us to run significantly tighter cylinder wall clearances than we typically run with a Supertech forged piston, which means that our Naturally Aspirated motors will last just as long as a factory motor will.

Connecting rods:
Instead of sticking with the standard H-beam selection, we've opted to move up range a bit and go with Carrillo's Pro-A connecting rod. With H-beam rods weighing in at ~530g, the Pro-As are a massive improvement, weighing just 440g each. Shaving 8/10ths of a pound out of the reciprocating mass of the engine significantly reduces the load on the bearings, which will assist in both high-RPM use and long-term reliability.

Valvetrain:
Our Forced Induction motors use a factory solid-lifter valvetrain setup in order to reduce costs, but with a naturally aspirated motor we felt that it was necessary to make a basic upgrade. Supertech's single-spring kit uses a stiffer valve spring and a titanium retainer to reduce valvetrain weight and allow for high RPM use, even with VVT heads. Supetech's shim-under-bucket cam followers are also available as an added option for those of you who are looking to add aftermarket camshafts and really spin the motor hard.

The rest of the engine is exactly what you would get in our Forced Induction bottom end. ACL Race engine bearings provide exceptional support and feature a nickel sub-layer which will show up in oil analysis testing, allowing the end user to know exactly when the engine needs to be removed and serviced. Boundary Engineering's street/strip oil pump provides improved flow and pressure, and our testing has proven that their Billet gears are stronger than the OEM oil pump casing itself. ARP main and head studs replace the factory hardware, and a Gates Racing Kevlar timing belt replaces the OEM timing belt. Except where a high-performance upgrade part has been selected, our motors feature 100% OEM seals and gaskets, including an OEM water pump and OEM idler/tensioner pulleys.

I know there's a growing contingent of guys here who are N/A track junkies, and this is a great option for guys who are looking to keep it simple.

Glad someone is finally offering this type of build. This is almost exactly how we set up or N/A motors. So much fun to be had with a good tune and bomb proof 150whp N/A motor and standard recipe track suspension.

Tons of fun, as we both know. ;) Thanks for the idea, E. An accidental missed shift and overrev in Rover at MRLS killed the '01 VVT longblock we had been running, so we used the opportunity to make this idea a reality. This motor is designed to survive the same type of accidental overrev without even batting an eye.

Once the turbo kits are on the market we have plans to start playing with some head porting and cam packages designed to improve power across the torque curve. Should be a nice addition to both of our motor packages.

I loved the feel of my built N/A motor and would jump at the chance to do one again. The list you have put together seems well thought out and makes be want to turn the 94 I have sitting around into another track N/A car.

Combine this motor with some XIDAs and have a hoot of a track car.

Other than the pistons, is there anything in the N/A build that would be less than ideal for a forced induction setup down the road?

this is so awesome right now.

Anything special for intake/exhaust planned?

well if spending moneys on a built head - for forced induction I would use SS valves (and possibly inconel exhaust valves)

Not really. The factory piston is less tolerant of detonation, but it would be no different than adding a turbocharger to a factory '01 motor - we would still suggest that the power stay under 250whp, but this motor would last a lot longer than an OEM longblock at 250whp.

Just got back from Thunderhill - the TSE N/A longblock in Rover ran both sprint races (30mins Saturday and 50mins Sunday) as well as a 4-hour enduro without skipping a beat. I'll be on the dyno tomorrow perfecting our 129.5whp PTE map as well as a 150whp high-power map for Miata Challenge. I had to fight it to get under 130whp - this motor really wants to make big power. It's nice being able to shift as fast as you can, with reckless abandon, and be 100% confident that hitting the wrong gear wouldn't be a big deal at all. :)

Our NA radiators should be back in stock fairly soon too - with 90*F temps at the track this weekend, Rover ran the entire 4-hour enduro sitting right at the thermostat opening temp (195*F). :) No fancy ducting, no vented hood, just factory plastics and a TSE dual-core radiator.

Are you ever going to do anything for 3rd gen Camaros?