JLO 440 55+ HP Dyno Run

[jpswift1]

Here's some really impressive numbers out of a JLO 440. It was turning out 55.5 HP around 8700 RPMs! Imagine putting this one in an Attex Thunderchief! Judging by the sound of it, this is a 4 bolt head 440, not the 6 bolt (5 port) later model when JLO was bought out and renamed as Cuyuna.

I own/have owned Attex Thunderchiefs, Chiefs, Superchiefs, and my favorite engine by far is a 440 JLO/Cuyuna (5 port). The 440 in my Thunderchief racer got a little bore and some port work and that thing will beat my G50B Chaparral powered Superchief all day. I absolutely love those 440's and sometime in the future I plan on building another one up (pretty wildly). And people sometime ask me if it has a supercharger when they hear the whine from the axial fan.

Here's George's video of the races from Ashtabula a couple years back. Hydromike has a huge lead and even with a late start, I fly past the rest of the pack. Mike and I are both running 440 JLO/Cuyuna/2si engines in our machines.

[Stonewall]

Wow, that race sounds like a million chainsaws..... Not a big fan of the 2-smokers, but that's some good horsepower from a 440... Some torque would make a nice addition...

[fmints]

very impressive

[North Country Tough]

I have spent a lifetime around two stroke mainly snowmobiles and competed in all forms of organised racing and built many engines,spent hours of dyno time and this all started back in the seventy,s.55.5 HP out of that engine is no small feat on the stock exhaust can ,my hats off to you nice job,I remember when JLO became Cayuna,it was around the time Ski Whiz had gone the way of the doe doe bird and Scorpion picked it up there were Whip.s and Bull whips and there fan cooled Cayuna powered sleds were way faster then most other stockers back then a lot to do with there better drive line design,but their engines worked well and yes they had a blower wine to them when they were winding out,wasnt long till the performance orientated Arctic Cat ,swallowed up Scorpion and used some of their designs,starting to ramble here anyway great job JP put a small 10 to 15 HP whaft of Nitrous for the back stretch and you are gigantic(throttle in a bottle) N.C.T

[Duck89]

Very cool! That's some power there!

[foxspoiler]

Jp, that is cool, could I ask what dyno and software you are using? I would love to have something like that to dyno my vintage sleds and of course the 6x6, love that smell of 2 strokes.

[jpswift1]

That's not my specific engine, nor my dyno or dyno software. It was just something cool that I came across on Youtube that I had to show you guys. I wish I had that kind of technology though.

[George]

I've always loved the whine of a JLO.