The biggest and most confusing question that is across the table right now tiny what should I put in my motor? should I use an S&S 550 cam how do you feel about the S&S 475 or what about George Bryce 30-30 cam Screaming Eagle cams are damn near stock so you're getting ready to ask about that just take those questions to the Harley lol. Love the Gen 2 heads just the cams no bueno. And to answer your question honestly I don't F###kn know and anybody who just shout out a cam without actually going over the numbers will lose every time! Math is math and a wonderful world of physics come into play. Yes we should have listened in high school lol. Those pretty little numbers that come with your cam they call specs from the manufacturer yes they actually mean something when you're looking for certain things out of your bike you look for certain numbers to equate in your formula and yes I said formula engines are formulas not just a cluster f*** of parts put together! Now the different brands we use are known for different things durability is one of my top if not my number one cuz let's be honest how fun is rebuilding your motor over and over and over again we don't just put together a bunch of known name parts build it and send it now plenty of measurements are taken as well as there's no reason to put big valves in if the pockets in your piston aren't deep enough and they're just going to end up slapping that's how you get a bent valve. And damn sure would not put a high compression Big Bore Kit on a stock Harley crank without checking and addressing any high run out issues! When equating these formulas to figure out on paper what your horsepower and torque will be not on the dyno that's just the lie detector test yes our builds on paper equal with the dynos going to put out. how do you do that be realistic with your builds grab a paper and compression calculator! As the old saying goes there is no better replacement than displacement and for reliable horsepower that is very true! But where do the camshafts come in the job of the camshaft is to bleed off that higher compression that you built that engine too always wonder how these guys talking about that motor is a 13:1
12 :1 compression ratio on 91 well that my friend is due to camshafts depending on the intake closing degree you bleed off oh so much compression to get it down to that sweet spot Free tip most cams we use like 11.3:1 all the way up to 12:1 - 12.5 :1 that's still on 91 pump gas pretty high huh well that's where Durability comes in unless it's a race kit can't really help u there they are exceeding there limit if there not it's not a race motor 128 kit should be doing 190hp at least if it's a race motor I didn't make the rules I just build the motors but back to the subject You Can Literally Draw out what it will make on paper and if u can't well class is in
COMPRESSION can increase hp by a anywhere from 3-10% in mose cases
What does that have to do with a picking a cam you wonder huh well let's take it back to elementary an engine is an air pump how much air and fuel you can suck in how much air and fuel you can compress (keyword)how much how much you can cleanly ignite to force the Piston down and obviously how much exhaust gases can you get to escape so with that being said
COMPRESSION SUPER BIG THING WE COULD USE 90% THE SAME PARTS BUT I TWEEK A COUPLE THINGS AND GET 1.5:1 more compression then u and my cam and ur cam could be the same but I get way better results THE MORE I CAN GET OUT OF MY FOUR STROKES TRANSLATES TO HOW MUCH HORSEPOWER AND TORQUE I CAN GET you cannot beat physics nor can you trick numbers follow the rules to receive the best outcome and that's for advice in anything in life but mainly applies to our world of Harley engine building
-Tiny Built it
0 comments