well called Oregon Cam Grinding, INC 360-256-7465 Today talked to Ken Heard. he said he could regrind my 94 turbo idi cam for more lift and duration. he said you need to be ready to clearance the pistons for the valves. He said that he has several grinds to choose from or he can grind to your specs. Just thought I would pass on the info . need to study the cam specs to find out what changes to make. cost was 150.00 or so plus shipping.

 

WHY?

 

The cam in a 7.3 was never specificly designed for turbo boost. changing the valve lift and duration to more effeciently use the boost to burn more of the fuel put into the engine will make more power. this is why the idi stock cam holds back the engines potential. the psd uses a computer to change the fuel curve and event timing for a wider power curve and fuel mileage. the idi just needs a new cam profile to feed the BEAST.

 

I know of one ready made cam for these trucks, so if you go through with it, please let us know what you did and how it turned out.

 

stang, i am curoius, russ is also from oregon...... wunder if it is the same guy grinding em?

 

I will be rebuilding my engine in the next few month as we all know machine work takes time and money. this engine will be in a 18000lb motorhome with a allison at545. I hope to build 250 hp 425 torq {at the crank} I have lots of room for my 4" pipe from the turbo out through banks straight thru muffler. I have a cummins intercooler to install with a big electric fan. I am still thinking about lowering the cr to 20/1 and going with studs and 15 lbs boost with waste gated psd turbo. still a work in progress.

 

well I have been unable to find info on 7.3 IDI cam. I can't run a cam dyno program without the info. I might have to set up my engine with a degree wheel and dial indicator and just measure it in the block. what a pain.

 

Well after lots of surfing I have found the cam profile info on the idi. The cam is designed for a NA engine. What we need is a turbo specific cam profile. No one makes one that I can find. What I have found is a few outfits that have a regrind avalable. they all say it works in both NA and Turbo applications. All the Performance Turbo Cams I found had the valve timing changed to enhance the operation of the turbo instead of just forcing the the na cam to eek out more performance. IMO the bigest problem is valve overlap. when you put the back pressure of the turbo on the engine it puts a pulse of hot exhaust gas into the intake when both valves are open. This was adressed in several cam dynamics articles on this very problem. The "other brands" of diesel engines have had more performace dollers put into there cam profile. Well I think its time to "MINE" the other guys research and build a new cam profile from what I can learn from breaking down the info. I have alot of time to chew through some data because I'm saving up money for block recon (8 sleeves) I will post some numbers when when I have some more comparible info. Then we can tackle porting the heads to use the new flow, and cuting piston and valve clearance, and piston coatings.

 

My fingers are worn down to the nubs from entering all this data in the computer. been running Performance trends analyzer pro v 3.9 with all the info I can find on the 7.3. the program dosent have a mechanical diesel option for the injection system, but after getting the info on the engine more specific the performance numbers started to get closer to what we know is possible in stock trim with basic exhaust and air improvements. I will be putting together some comparisons of different cams and turbo combinations. after I figure out how to get the graph to be readable on the forum.

 

Nice, keep up the good work