FordGuy100
Registered User
See, somebody is catching my drift. If we got rid of the IDI part of our 6.9/7.3 IDI's, and converted them to direct injection, then I would think that we would be able to get a lot of power out of them.
performance ?
- Thread starter dairieman36
- Start date
See, somebody is catching my drift. If we got rid of the IDI part of our 6.9/7.3 IDI's, and converted them to direct injection, then I would think that we would be able to get a lot of power out of them.
tractorman86
Registered User
that and cut about 400lbs off, who needs jenny craig!!
Dirtleg
Full Access Member
Why not do some retro engineering if this is what you want and fit a mechanical injection setup to a PSD. Would certainly be less complex than manufacturing new heads. If you're doing away with the IDI part of the IDI then a PSD is a better place to start IMO. I like the idea of the 12 valve injectors and inline IP.
tonkadoctor
Full Access Member
Cylinder combustion pressures, NOT compression ratio, and flow are the limiting factors in building a high performance engine.
It's all about how much fuel and air you can physically cram into a given space in a given amount of time and igniting it at the perfect moment to make maximum power, getting the exhaust out and not turn the engine into a grenade.
The IDI engines are....... high compression 22 - or 22.5 to 1 compresion ratio, 2 valve per cylinder, manual injection pumps and indirect injection meaning the fuel is injected into the pre cup instead of directly into the cylinder.
Most modern diesel engines are lower compression engines around 17:1 ratio, 4 valve per cylinder, computer controlled and direct injection into the cylinder.
Extreeme performance diesels for pulling or drags are low compression engines from about 11:1 - 12:1 compression ratio, highly modified valves, ports and injection systems..... some computer controlled and some not.
If you were 2 compare 2 engines the 7.3 IDI and the 7.3 PSD you find both have the same cubic inch displacement by bore and stroke, have 2 valve heads but there is physically more volume to cram fuel and air into the PSD because of the lower compression ratio and more fuel and air simply makes more power. The PSD is also a bit heavier built and can handle higher cylinder pressures and power that results.
Same thing that applies here, also applies to gas engines, even down to a a 1 cylinder naturally aspirated 28 cubic inch 12 HP Briggs and Stratton flathead or smaller.... Everybody always wants to shave the heads, deck the block and put on the smaller chamber 11 HP head to increase the physical compression ratio, put in bigger valves and hog out the ports........ Wanna make more power
...... Leave the block and head surfaces alone except to true them, run the 12 HP head,which gives you more volume to cram more air and fuel into the engine which gives you a lower calculated compression ratio but it actually effectivly raises the real compression ratio when you cram more into it, just smooth the path for the fuel/air mixture to travel (shortest distance between 2 points is a straight line, remember that one from math class), thin, lighten, swirl polish and 3 angle the stock valves and actually reduce
the huge factory exhaust port size to the proper intake to exhaust size......... OOPS!!!!! Giving away my engine building secrets
There's a lLOT more to this stuff I ain't gonna get into here, but those are some of the basics.... Get the fuel/ air mixture in, ignite it properly and then get the exhaust out...... More in+Ignition+faster out= more power.....It's that simple
It's all about how much fuel and air you can physically cram into a given space in a given amount of time and igniting it at the perfect moment to make maximum power, getting the exhaust out and not turn the engine into a grenade.
The IDI engines are....... high compression 22 - or 22.5 to 1 compresion ratio, 2 valve per cylinder, manual injection pumps and indirect injection meaning the fuel is injected into the pre cup instead of directly into the cylinder.
Most modern diesel engines are lower compression engines around 17:1 ratio, 4 valve per cylinder, computer controlled and direct injection into the cylinder.
Extreeme performance diesels for pulling or drags are low compression engines from about 11:1 - 12:1 compression ratio, highly modified valves, ports and injection systems..... some computer controlled and some not.
If you were 2 compare 2 engines the 7.3 IDI and the 7.3 PSD you find both have the same cubic inch displacement by bore and stroke, have 2 valve heads but there is physically more volume to cram fuel and air into the PSD because of the lower compression ratio and more fuel and air simply makes more power. The PSD is also a bit heavier built and can handle higher cylinder pressures and power that results.
Same thing that applies here, also applies to gas engines, even down to a a 1 cylinder naturally aspirated 28 cubic inch 12 HP Briggs and Stratton flathead or smaller.... Everybody always wants to shave the heads, deck the block and put on the smaller chamber 11 HP head to increase the physical compression ratio, put in bigger valves and hog out the ports........ Wanna make more power
...... Leave the block and head surfaces alone except to true them, run the 12 HP head,which gives you more volume to cram more air and fuel into the engine which gives you a lower calculated compression ratio but it actually effectivly raises the real compression ratio when you cram more into it, just smooth the path for the fuel/air mixture to travel (shortest distance between 2 points is a straight line, remember that one from math class), thin, lighten, swirl polish and 3 angle the stock valves and actually reduce the huge factory exhaust port size to the proper intake to exhaust size......... OOPS!!!!! Giving away my engine building secrets There's a lLOT more to this stuff I ain't gonna get into here, but those are some of the basics.... Get the fuel/ air mixture in, ignite it properly and then get the exhaust out...... More in+Ignition+faster out= more power.....It's that simple
