cylinder head flow data

[ameristar1]

Has anyone flowbench tested 6.9/7.3 cylinder heads? I am thinking about doing a buildup that can rev out really well, but my cam grinder needs specific airflow data so he can do his thing. Are uncut cam cores still available?

 

[icanfixall]

I'm not sure where you would find an uncut cam but calling a can builder may help. Flow testing the heads has not been done that I have heard of. Try talking with Barnett Performance. The offer 3 diffreant head porting options. Remember these motors are a big air compressor... The more air you force in... The more fuel you can burn which makes for more horse power. Most run a turbo and around 12 lbs of boost. Thats 12 lbs pushing against the intake valve before it opens. Then the air volume fills the cylinder with the same 12 lbs od air. Then it compresses that into around 40 thousands of an inch area. Thats alot of volume being compressed. Usually these motors run arounf 450 lbs of cranking compression. Mine runs 530 lbs of compression....

 

[ameristar1]

Thank you for the response. The thing that I have been looking at as far as taking the performance to the next level, and one of the major advantages of the IDI over the PSD, is the fact that there are no electronics to hold back the party. I heard about the puller engine that the owner of Hypermax put together a long time ago that got banned because of the way it ran ( something like over 1000hp in an IDI no less ).
Here's the basic plan; make sure that the bottom end is strengthened where it needs to be, maintain the stock static compression ratio, but alter the cam timing so that it can rev out to about 4500-5000 rpms like a gasser. By pushing the hp and torque curves slightly higher than normal ( at least for a diesel ) the pressure curve will be less dynamically down low which will take the strain off the motor and make it less detonation prone saving the head gaskets and pistons while at the same time broadening the powerband and improving power. This way there will be less time for abnormal combustion to occur. I know that at this point it's all theory, but after doing some research about the way diesel combusts inside the engine, the rev limit corresponds well with the limitations of efficient combustion of the fuel and the atomization characteristics of the old school fuel injection system. The only other thing that would be done is to barrier coat the pistons and prechambers to help with thermal losses of the IDI. I don't know if doing the prechambers has been done by anyone else, but I am willing to give it a try to see what would happen.

 

[dyoung14]

to run high boost you will have to low the compression ratio, if i was going to build a hot idi i would start with a good late model 6.9 put all new factory bottom end in it balance for 5000 rpm or so, cut the compression ratio to 18:1 ceramic coated pistons, get some stiffer valve springs, port and polish brand new 6.9 heads, put all new 7.3 valves and rockers in them, defintly headstuds, get a custom ground cam like you talking about, and a custom twin turbo set up, what i would use is a wastegated psd turbo, and a non wastegated hypermax turbo, a psd intercooler, moose pump, moose injectors, ceramic coated mainfolds ceramic coated exaust pipes from manifolds to the turbo then rapped in a double layer of header rap to make sure the heat stays in,nitrous maybe for a run down the drag strip, and even water methanol injection to keep egt's way low, then i would break it in very slow probly 5000 miles or so with the boost set to 10 psi and not take the engine above 2500 rpm and not tow anything, then at 5000 miles crank the boost way up and the fuel way up and the rev limit to 4500 rpm and i think 30-35 psi of boost is possible and close to 500 hp at the crank, thats my opinion anyway but i guess i day dream to much

 

[ameristar1]

Hey, there is nothing wrong with daydreaming. How about taking it one step further and remote mount the twin turbos, wastegated with a used boost electronic boost controller? That'll show 'em!