Marshall’s Superior Technology
We interviewed Johnny Marshall the other day to find out the secrets behind why his camshafts are in the most sought after in Australian top alcohol racing.
Swish: To get an idea of what we mean by “superior,” what power and torque effects can we expect to see out of an MCC camshaft?
Johnny Marshall of Marshall Custom Cams: ‘A recent drag car come to mind – before we built a new camshafts, that car went 5.9 seconds – 240 mph, over the quarter mile. With an MCC Smooth Lobe cam profile, it now runs 5.5 seconds, finishing at 250mph. Conservatively, that’s an increase of around 250-300 HP.
S: Wow! that’s a significant improvement JM. What do you mean when you say “Smooth Lobe” camshaft?
JM: ‘Imagine a supercharged top alcohol engine revving, with maximum boost, to over 10,000RPM… Any minor flaw in the cam is going to have big effects on the valve train harmonics, causing valve train wear and damage to the valve springs. With smooth lobes on your cam, you reduce these issues significantly.’
S: Right, but surely all cams have smooth lobes?
JM: ‘Unfortunately not. Just looking out the lobe yes they will look smooth, but closer inspection via a cam doctor shows otherwise. Most cam grinders in the world today take a copy of a current camshaft to produce yours. By copying a cam profile, any error in the original cam is increased by 100% and more in the new cam. Multiple copies increase errors, and you end up with with a camshafts that can now produce massive damage in your race engines. At Marshall Custom Cams, we design and make the cam lobe to suite your engine package. The same guy, myself, designs and grinds that cam, and helps race teams get the most power out of put it in their engines.’
S: What does it take to know what cam your engine needs then?
JM: ‘I started as a mechanic at 15 – I’ve been in this industry 46 years now! I’ve been a mechanic, business owner, TAFE teacher, but mostly importantly, I’ve been around racing my whole life. I’ve been a crew chief and mentored young teams and guys who’ve gone on to lead crews. I know racing. Being around the cars, watching the car I’m going to work on, listening, reviewing it’s race data, and working with the vehicle allows me to know exactly what cam it needs. I’II admit, I’m extremely luckily but – you just can’t beat having over 40 years of racing and tuning experience.’
S: So most cam makers don’t use this methodology?
JM: ‘Nope, your typical cam manufacturer is a guy sitting behind the cam grinder all day. He isn’t out there at the track with the race car teams, he isn’t in tune with the vehicle and its engine. My methodology is unique, and is bred of a lifetime being around these race engines and the crews.’
S: Can you delve into specifics on the technology?
JM: ‘We used a custom-built Computer Aided Design (CAD) program to design the perfect camshaft profile for your individual engine needs. I call this “The Smooth Lobe.” You will not find this precision and technology with any other camshaft manufacturer that copy profiles – it is exclusive to MCC.’
S: So it sounds like what really sets you apart is the two-pronged approach: A wealth of experience, with exclusive technology, allows world-beating cam designs, while precise machining ensures that design is reproduced perfectly on a cam.
JM: ‘I’d like to think that’s exactly what sets us apart!’
To see how a Marshall Custom Cam could benefit your vehicle, Contact Johnny today.