This is from the Hydroplane Racing League rule book.
http://hrlhydroplane.com/wp-content/uploads/2016/03/HRL-Annex-V7.pdfCAMSHAFT & VALVETRAIN
The ONLY 2 camshaft accepted are:
Option 1: HRL Camshaft. It MUST be purchase through the Hydroplane Racing League –
HRL, Coordinator 450-371-6144 ext. 224 – Anne-Marie Leboeuf
Option 2: Comp Cams # 12-675-4
You can buy it directly from any distributor
A. Stock diameter magnetic steel solid flat tappets lifters. Maximum size 0.842” No
hydraulic lifters
B. Stock size push rods only. Size 5/16” all the way. (No titanium or exotic material)
C. No mushroom or roller tappets. No rev kits.
D. Double roller or standard timing chain only. No gear drive or belt drive.
E. Roller rocker arms allowed. NO shaft rocker arm systems. 1.50 Ratio Only
F. Stud girdles allowed.
G. Valve Springs - Any valve spring may be used, Maximum size: 1.250’’ (+ or – 0.010’’)
diameter
H. Spring retainer: steel only, no exotic material
I. No cam roller bearing allowed
J. Standard diameter cam bearing only
K. Any alteration of the original form is prohibited.
They run SBC with solid flat tappets for 5 mile at about 7200 RPM when the prop is in the water and flash 10,000 if it comes out of the water.
My machinist builds these and one of his 5 litre engines holds the 5 Mile Closed Course World Record for MPH. He doesn't have camshaft problems and his favorite oil is Valvoline 15/40.
Kevin
