ameristar1
The One Blue Thing
Does anybody know a source for uncut cam cores for the 6.9/7.3 engine.
Camshaft blanks for the 6.9/7.3
- Thread starter ameristar1
- Start date
icanfixall
Official GMM hand model
Give Howards Cams a call. I bet they get there blanks from offshore like most other manufactures do.
david85
Full Access Member
What are you planning?
ameristar1
The One Blue Thing
After the time spent on this board, I've hit a wall with the IDI. And based on most of the combos that have been built, I haven't seen a streetable motor that has cracked 300hp without breaking something.
After looking at everything, and getting frustrated about it, hesutton with a dynograph from this past meet showed what the problem is. I kinda suspected it, but if the hp and torque curves are what he says they are, it's all tied to the camshaft. It falls flat on its face after 3000 or so.
Jones Cam Designs did a turbo cam for a 351W for me, and the computer program he has and the quality of his work is really good. Just need a camshaft core to get the job done.
My thinking is, just get this thing to run better before the boost, and the amount of boost needed to make the power won't be as high. Since there aren't any published headflow numbers for the 6.9/7.3, I'm going to get them flow tested also.
I view this as a challenge now, not for max power, but just to make a 6.9/7.3 IDI do a respectable, streetable number without tons of exotic parts.
After looking at everything, and getting frustrated about it, hesutton with a dynograph from this past meet showed what the problem is. I kinda suspected it, but if the hp and torque curves are what he says they are, it's all tied to the camshaft. It falls flat on its face after 3000 or so.
Jones Cam Designs did a turbo cam for a 351W for me, and the computer program he has and the quality of his work is really good. Just need a camshaft core to get the job done.
My thinking is, just get this thing to run better before the boost, and the amount of boost needed to make the power won't be as high. Since there aren't any published headflow numbers for the 6.9/7.3, I'm going to get them flow tested also.
I view this as a challenge now, not for max power, but just to make a 6.9/7.3 IDI do a respectable, streetable number without tons of exotic parts.
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Why not just call a cam grinder compane like erson or competition cams and pick their brains. I believe both can custom grind to applications/ specs and probably have some great ideas towards getting more out of the cam. A problem you have is the rpm limit which also has to do with the injection pump. The international buses use the same cam as our fords but the pump has an internal governor. Funny thing about turbos though is that they like stock to mild agreesive cams better than a full race type cam. Greatest cam gains seem to be a little more intake duration. Of course more lift is not an option in our engines.
dyoung14
Is getting worn out
what someone needs to do is build a engine that can handle about the 4400 rpm range, with a cam that makes power there and an ip that puts more than enough fuel out and some combo of turbos that will work good foe the aplication the it would be the ultimate idi
ameristar1
The One Blue Thing
What is the limitation? Is the piston to valve clearance really tight on these engines? I'm only asking because I don't know how much room there is stock.
ameristar1
The One Blue Thing
what someone needs to do is build a engine that can handle about the 4400 rpm range, with a cam that makes power there and an ip that puts more than enough fuel out and some combo of turbos that will work good foe the aplication the it would be the ultimate idi
That's the idea. After 4500 rpms the fuel lag is kinda bad, so the fuel is getting thrown out the pipe. The rotary pump can be spun to 4500-5000 rpms, so that's not the issue. It's just keeping the bottom end together at that speed.
4000-4200 rpms and a deep cryotreat of everything.
dyoung14
Is getting worn out
with shaved pistonsd and maybe have some deeper valve realiefs cut into the pistons then you could probly run quite a bit bigger cam shaft
ameristar1
The One Blue Thing
I know I am not the only one out here that has considered these things, has anyone come close or done a high rpm IDI that gets driven on the street? Or even did a cam swap that worked out well?
FordGuy100
Registered User
Russ has a towing cam in his truck, and it performs really well. When I rode in it the bottom end was amazing in that truck.
ameristar1
The One Blue Thing
What's his handle? I'd like to find out who made the cam. By the way, beautiful truck.
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Mat J
Way down south
dyoung14
Is getting worn out
there is a guy on fte that just joined and bought a truck with a custom turbo and intercooler setup it also has a tweaked pump, its got a c6 trans and on normal accelaration it dont shift it self till about 3000 and if he floors it it will go past 4000 rpm right now his max boost is 5 psi with like 8-900 egts he supose to be turning the pump up,
Myself i have been wanting to have a high winding idi cause im not afraid of them, yea i know im crazy
Myself i have been wanting to have a high winding idi cause im not afraid of them, yea i know im crazy
These engines got like 21.5 to 1 compression which doesn't leave much room in the cylinders. The pistons have valve reliefs cut into them which is also a sign of limited valve space. It's one thing to shave a little off the top of the pistons but to cut the valve reliefs a little deeper could take away enough piston integrity to cause failure.
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