Big Blue on the dyno

Got Big Blue(my '92 F-250 with Banks kit and Stage 1s) on the dyno. It put down a respectable(but disappointing) 197 RWHP (that's close to 260 crank HP). The dyno was only loading to 20%, and the truck didn't spool nearly as well as it did on the highway getting there.

[@verrinne1]

Sounds like jakes

[@MacRobbSimpson]

The wonderful sound of a straight-piped IDI decelerating.

[@robertatwood2503]

Have you ever had any experience with propane injection on one of these things

[@robertatwood2503]

Little clarification I'm not looking for horsepower I'm just looking for for fuel mileage

[@MacRobbSimpson]

Not personally, no. I once experimented with just feeding propane vapor down the throat and actually got the engine to idle on it with the key off.... My feeling is that it's not /generally/ worth it: It's a /fuel/, not an oxidizer. N/A, you already are starved for oxygen. With a turbo, generally you have enough fuel available(with the pump cranked up) for the air. It's only once you have a big enough turbo to exceed that(custom turbo setup) and don't have an IP big enough to feed it that you can use the propane injection to good impact. I'd probably look at water/meth injection at that point, because that actually does two things - the water cools and lowers EGTs, while the methanol will burn(fuel). That EGT reduction is useful at that point, along with the water flashing into steam helps with pressures and power output I think. The other problem with propane is detonation. You have to feed a small enough amount in there that it's below the lower flamability limit by itself, so you don't get it to burn until the primary fuel(diesel) is injected. Otherwise you get pinging and /lose/ power.

[@robertatwood2503]

@@MacRobbSimpson yeah I had EGT issues with the last one number 8 lifted off the block and spitting water out I have a pro more engine to go in it I just want to make sure that I don't have to go through this again

[@MacRobbSimpson]

Hard to understand you, but I'm hearing that you had a head gasket leaking water, and a promar engine to replace it? Pretty sure that will help, but a leaking head gasket isn't caused by too high EGTs. If anything, it's too high water temps, or perhaps more than 20 psi of boost(on a 7.3). Stock bolts are the weak point with the IDIs - If you want peace of mind, get ARP studs. Too high EGTs for too long can burn valves or start to eat away at the pistons(top layer getting melted off), or possibly cause head cracks if the water boils out. The key to protecting your engine is making sure the water temps are kept below 230F or so, and it's always full. No letting it get low, and no using non-Motorcraft thermostats.

[@robertatwood2503]

@@MacRobbSimpson truthfully I don't know I know it was overheating and is now leaking water from the head on number 8 Yes it has a lot of weight welding machine utility bed probably around 4500 pounds on the truck Fuel mileage is really secondary to keep in the engine cool the previous owner ran water in the engine is full of some kind of crystalline substance I've ran all kinds of stuff in there trying to get it out not happening that's the reason I was going to protect my freshly rebuilt engine from the exhaust gas temperature monster they didn't stud it and for what I give for it they damn well should have Without doing too much rehab a water-methanol system I believe would be the best choice thank you