he said offset ground crank. I dont know what that means if you could teach me i would appriciate it? And why destroke? Oh and I asked before but no1 answered, what is the known N/A hp record so far or what do people think we can make N/A?
7.3 idi performance rebuild
- Thread starter lbzbuick
- Start date
Black dawg
Registered User
my thought on de stroking is maybe less motor=more mpg.
hesutton
The Anti-Anderson
John's N/A 7.3 IDI put down 143.9HP and 261.3 ft/lbs. (at the wheels) on TS Performance's dyno at the '09 Rally. Best I've seen.
Heath
seawalkersee
It needs a turbo...
The advantage of a destroke is for more RPMs usually. There is no fuel to be gained or lost because of that. That is like saying I want a 7.3 because it is a fuel hog and the 6.9 just does not use enough. Sure 20" is no laughing matter, but to have it done for milage is purely not going to work.
Offset grinding the crank is simple. You have a circle like this O. By using a smaller rod/bearing combonation, you can grind down the top of the same circle O to use a smaller circle like o. If you put the two next to eachother Oo, you can see that the center of the smaller circle is lower. If that is on the down side of the rod, you can see that it moves the center of the rod bearing circle lower in the stroke, and will do the same at the top of the stroke. Usually not a lot to be gained by that AFAIK. Other mods are usually done to get more.
SWS
Offset grinding the crank is simple. You have a circle like this O. By using a smaller rod/bearing combonation, you can grind down the top of the same circle O to use a smaller circle like o. If you put the two next to eachother Oo, you can see that the center of the smaller circle is lower. If that is on the down side of the rod, you can see that it moves the center of the rod bearing circle lower in the stroke, and will do the same at the top of the stroke. Usually not a lot to be gained by that AFAIK. Other mods are usually done to get more.
SWS
Black dawg
Registered User
Just to clarify, I would like to build a small ci idi motor just for the hell of it. My focus would be economy. It takes a certain amount of power to go down the road, Having a motor big enough (ci wise) to produce 5 times that amount is wasting fuel as pumping losses.
typ4
Full Access Member
yes. pm is being wierd.
ocnorb
IDIT
seawalkersee
It needs a turbo...
Yeah...You would have to build one a LOT smaller than what we have in order to do what you are thinking. Like I said, 20" less than a 7.3 gets about the same milage. So you need something in the 5.0 range and then, how much money are you going to spend to get an engine that small?
SWS
SWS
Ok cool. How do you want me to get ahold of you about doing this because I have the engine torn down right now? You dont have to be rushed because its just a project and not my daily driver. Technicaly i have never driven it lol
seawalkersee
It needs a turbo...
Ehhh...it depends on what you are going to do with it. Everybody starts off with the "I want the best parts ever" thought process, but then they don't know what all else is involved with that process. You can use the coatings to keep the heat on the piston lower and on the side to reduce the friction. If you are going to crank up the boost, you really need to knock down the piston crown to allow for the extra material/coating, and the correct bore on the side for it for the same thing.
SWS
SWS
Well my goal is a powerful N/A motor. Now I know there are limiting factors so I dont care what people think because why are most of us here, in my opinion to learn about these engines and to see what is possible. Does anyone know what cylinders are common for cavitation because I would like to sleeve those cylinders and what sleeve are best to use?
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