About twincamdyno.com
twincamdyno.com is one of six free engine dyno simulators built by McGonster Monster Motors, a one-man shop in Collinsville, Oklahoma. I'm Mike McGonigal — a professional motorcycle mechanic by trade who has built everything from 10-second Mustangs to Harley Twin Cams. I've built Twin Cams for customers and for myself for years; it is the engine I know from the inside. The tools started as a spreadsheet for my own builds and turned into this.
Every calculator is checked against published dyno pulls — dealer and shop chassis-dyno videos with the Dynojet sheet on screen, rear-wheel, with the correction factor noted, plus Fuel Moto's published 103 cam shootout — and re-checked when we find a new one. The parts lists are real part numbers you can buy today; if something is discontinued or unconfirmed, the dropdown says so.
The site is free because the parts links pay for it. When you buy through a link here, we earn a small commission and you pay the same price. We link the part we would buy, not the one that pays the most, and the calculator does not know or care which link you click.
The other five tools: 351 Cleveland, SBC 350, BBC 454, Milwaukee-Eight, and Predator 212. The network home is mcgonster.com.