All five main caps have 4 cross bolts and 2 main studs and are made from 7075 alloy billets. The 4” stroke crankshaft is made from EN26 material and is around 30% stronger than an equivalent 4340 crank, however they take 120 odd hours to machine and cost around $3,000 (Australian). The crank features 3” mains and 2.4” big ends, and obviously the large journal overlap also aids strength significantly. Ross pistons fill the 4.44” bore and swing on super tough Sainty billet rods, which are significantly beefier than hemi fuel rods. A dry sump rounds out the short block. 

The cylinder heads attach to the block with 18 evenly spaced head studs, providing higher and more even clamping force. On the first generation BTV a single 1.9” exhaust valve and a pair of 1.6” inlet valves were used. Although the total valve area using 2 1.6” inlet valves is equivalent to a single 2.25” inlet, the total inlet valve circumference is approximately 10” compared to 7” for a single 2.25” valve head – significantly increasing low-lift flow and allowing the use of far less radical camshafts to achieve the same flow. The second generation BTV features significantly large 1.8” inlets and a 2” exhaust valves coupled to larger square inlet ports and revised valvetrain geometry to improve reliability.

The valves are driven via billet alloy rockers from a single overhead camshaft per bank driven off the crank via an adjustable gear drive. A pair of 14mm spark plugs neatly fit between the outer side of the inlets and the exhaust with plenty of meat to prevent torching – a typical problem in the cramped chamber of a 4-valve nitro motor. The chamber itself is a modified hemi configuration. The low valvetrain mass and general geometry allows very low spring pressures, as little as 120 lb seat pressure can control the valves at 10,000 rpm which is significantly less than a hemi with its heavy valvetrain, long rocker geometry and heavy large diameter valves.

Not merely content to design and manufacture their own engines, a whole host of further parts are theirs as well. That includes the 88 GPM fuel pump, barrel valve, mag drives, clutch, cannon, reverser, management for clutch and fuel, 12” diff, dry sump system, and even the chassis are Sainty designed and built items along with hundreds of other components, including almost every stud, nut, bolt and washer in the entire car.

So how well does it work, and what does it cost to run, you may ask? 

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Keep in mind that nobody on the Sainty team is what you would consider an experienced NHRA tour nitro tuner, and they are definitely in uncharted territory as far as getting help is concerned. The first generation Sainty BTV ran into the 5.25 zone, though more typically they ran in the mid to high 5’s. Many problems were found with the first design such as a tendency to break rockers at just the wrong moment. The Sainty team took advantage of a layoff during a lack of racing in New South Wales and Victoria (the Sainty Engineering shop is located in Sydney NSW) to revise the design to produce the secnd generation BTV motor with the aim of producing considerably more power and providing a big step up in reliability.