turbo_joe
Registered User
Can anybody tell me if there is a difference in cams from turbo 7.3 to non turbo, im sure there is a thread somewhere on it if i searched but im at work and dont have that much time
thanks
thanks
camshaft
- Thread starter turbo_joe
- Start date
turbo_joe
Registered User
oh one more question,turbo marine pistons??? whats the compression ratio on them?
No difference in cam. dont know about marine pistons, most all of them are 21.5 to 1 turbo or not. Piston pins are bigger and the tops are anodized.
turbo_joe
Registered User
Anybody know who does custom grind cams? and how would i go about getting lower compression pistons, i really want to build a turbo idi but want to run more than what, 15 psi? what would i need to run higher boost? head studs, new headgaskets, does anybody make o-ringed heads for theese? any input would be greatly appreciated
icanfixall
Official GMM hand model
The cam is the same item in both 6.9, 7.3 & 7.3 turbo motors. Russ (typ4) has a cam in his motor that he had specially ground. Otherwise there isn't any aftermarket cams available to us. Mahle makes the pistons for our motors in OEM. They made the pistons just about from the beganing. They have a low comp piston. I'm running a set in my motor that I milled 12 thousands off the tops. Then I ceramic coated them in Tech Line CBX. About 15 thousands is all Mahle recommends taking off the tops because it positions the top ring too close to the heat of combustion. The yops of all turbo and non turbo pistons is around 570 thousands thick. If you plan on running boost higher than 12 lbs you will need an intercooler. Otherwise the boost above 12 lbs is going to be 300 degrees + going into the motor. Thats not going to make any useable hp either. Studs are needed and ARP has the studs in 7 inch lengths. They are not designed for our motors but they work great. Just about 3/8th inch too long at the top side. You can machine that extra off on a lathe if you have one. Otherwise be careful with the deep socket. The extra length going thru the nut will interfere with the socket and the torque will be off. There has been some questions here about the valves and pistons. Thats do the pistons chase the valves or the valves chase the pistons. The specs for stock pistons are they raise up to 31 thousands out of the block. I have run my motor at 54 to 57 thousands piston height and would not recommend it. Thats just too close of a tollerance for piston to valve. That motor burned down and every piston had a mark from the valves on top. It was not measureable but you could see it and not feel it. My motor I'm running now has a piston height of 24 to 26 thousands out of the block. Most here like the Felpro head gaskets. They are around 75 thousands thick and are about 10 thousands thicker than the OEM. Some will only use the OEM gaskets too. Other like Victor Reinz. Just don't use a no name aftermarket gasket and never use a pan gasket. They usually leak. Nearly everyone just use a good RTV for the pan gasket. Its what the factory manual tells us to use. I like permatex copper plus. Oil has no effect on it. O-ringing the heads is way overkill but if you want it find someone that really knows how to do it on our heads because of the precup chambers. A CNC machine would be required for that. Its not simply a round circle thats cut in the head and block because of the cups. There really isn't any aftermarket hp improvements for our motors. You can invest in Mels Moose pump and his injecters for added hp improvements. I'm running his pump and its really something special. The added preformance is great and towing I still get 16 mpg. A turbo is needed along with an intercooler to get all the hp this has to offer.
Clydesdale
Full Access Member
So with all that ^, numericaly, what did that translate into at the wheel on a dyno? and out of your wallet? (having read that you were a machinist, and assuming you did some of the work yourself, translate it inot a potential real world cost for the non machinist, e.g. some one who would have to pay for it to be done)
DeepRoots
Tug Engineer
typ4, wouldn't there be alot more power from a turbo if the camshaft had more valve overlap? I'm thinking better scavanging.
or wouldn't it be feasible with this engine due to clearance reasons?
I really need to tear this engine apart just to see how everything fits/clears.
or wouldn't it be feasible with this engine due to clearance reasons?
I really need to tear this engine apart just to see how everything fits/clears.
It is the clearance issue more that anything, and yes the more "clean cool" air in the cylinder the better the combustion and so on.
The other issue with an na engine is you would want to scavenge the exhaust real well or you would have reversion which would pollute the incoming air.
With a turbo the cam does a lot less "thinking".
The other issue with an na engine is you would want to scavenge the exhaust real well or you would have reversion which would pollute the incoming air.
With a turbo the cam does a lot less "thinking".
Clydesdale
Full Access Member
Or in other words, even with thousands thrown at this motor, it still won't out run a Cummins, reliably?
It will outrun it, at least up to 105 mph geared 3.55 in od... I dont think reliability is an issue on any diesel if it is maintained.
It is just easier to get power out of a Cummins, more aftermarket support, kinda like a chevy.
BTW I have about 2800.00 in parts and machine work and balancing. But I have good parts connections and that was 2 years ago.
It is just easier to get power out of a Cummins, more aftermarket support, kinda like a chevy.
BTW I have about 2800.00 in parts and machine work and balancing. But I have good parts connections and that was 2 years ago.
Clydesdale
Full Access Member
Thats what I wanted to know... so for under a grand, I can help it to breather better, and run little stronger... but serious power is kind of cut off til I spend a lot bit...
Okay with stock, even 10 or 20% more would be all I could foreseeably want.
Okay with stock, even 10 or 20% more would be all I could foreseeably want.
icanfixall
Official GMM hand model
Ok.. On my motor work I paid for the machining to be done. That was a valve job on the new ported heads. The block was sleeved, lined bored on the crank and the block was decked. I used the turbo rods and did the balance work on the pistons myself. Then all the rotating parts front to back were balanced and spun up to 5000rpm if I remember correctly. The block was decked twice and too much was taken off. The pistons stuck up out of the cylinders way past the 31 thousands max spec. So I bought another set of Mahle pistons. This time they were the low comp type. They still were to high so I milled 12 thousands off the tops and then ceramic coated them with the Tech Line CBX. That was around $125.00 per set of 8. How much rwhp.... I really don't know but its plenty. I will be dynoing this but just not soon. I have other things working at this time. No secrets either. For a list of costs I'll try but this is my costs that I got.
Mahle low comp pistons $550.00
rod & main bearing $43.00 & $48.00
inconel exhaust valves $304.00
gaskets $275.00
valve job $200.00
oil pump $139.00
new bare heads $680.00
lifters $135.00
Sleeve all 8 cylinders $800.00
block machining approx. $650.00
ARP head studs $252.00
Total $4131.00
I probably left out some items but you can see what it costs. Since the rebuild I installed the BTS trans at a cost of around $4800.00 and the Rodney Red all aluminum radiater costing $625.00. Then the Gear Vendors costing around $3200.00 plus the driveshaft work. Then the Moose Pump but that cost is partictular to my pumps needs when Mel got it so yours will be differant. It was much less that what some think and no... It wasn't 7 or 8 hundred dollars... Much less than that. Plenty of money for a truck not really worth the investment but I did what I wanted to get what I wanted. I could have bought any new truck but.... Thats what everybody does and I really don't like the style or the electronics. I want something simple that I hopefully can fix on the roadside with all the "stuff" I keep behind the rear seat. For some I spent way too much but for me I'm still looking for the next motor buildup.... Its happening now but no time frame when it will be done. This new motor will have differant head and precup chamber work in it. I got a set of new bare heads that cost me $140.00 for both of them. So its easy to try something with them that may kill them and not be out a lot of money... Just my time and effort. I think the trick in building a motor that breathes as easy as it can with all cylinder volumes exactly the same plus balance work will make the best power and longer running motor. These motors are not a gass motor. We just cram in as much air as we can and the smoother it gets in and out the better it will make horse power.. I think russ (typ4) knows what I'm doing with the precup chambers in the heads. He is running his heads with that machine work now. What I did was fabricate a ball end mill with a demension of 1.168 to even out the ruff chambers in the heads. Then I CC them to be sure they were all the same and they were. This was really a tricky job on a bridgeport mill getting them all the same depth and diameter. The hi nickle block and heads machines easily but doing this in a blind hole is the tricky part. The heads have the injecters pulled up out of the chambers 60 thousands for emissions requirements. I dropped the chambers that much and opened them up to the 1.168 because thats what I felt I could run for a comp ratio drop. That motor ran great too... Till the freeze plug the shop installed wrong poped out pulling a grade. I watched the coolant temp and it never moved. No coolant on the sender... No telp reading. What finally made me feel something was wrong was when my oil temp passed 330 degrees. Then power fell off, motor clattering from thing oil and the pistons stuck to the cylinder walls they got so hot. But the black anodising on the tops never came off either. I scuffed the shirts of 6 beyond reuse... Only 5200 miles on that build... Damn crappy machine shop...
Mahle low comp pistons $550.00
rod & main bearing $43.00 & $48.00
inconel exhaust valves $304.00
gaskets $275.00
valve job $200.00
oil pump $139.00
new bare heads $680.00
lifters $135.00
Sleeve all 8 cylinders $800.00
block machining approx. $650.00
ARP head studs $252.00
Total $4131.00
I probably left out some items but you can see what it costs. Since the rebuild I installed the BTS trans at a cost of around $4800.00 and the Rodney Red all aluminum radiater costing $625.00. Then the Gear Vendors costing around $3200.00 plus the driveshaft work. Then the Moose Pump but that cost is partictular to my pumps needs when Mel got it so yours will be differant. It was much less that what some think and no... It wasn't 7 or 8 hundred dollars... Much less than that. Plenty of money for a truck not really worth the investment but I did what I wanted to get what I wanted. I could have bought any new truck but.... Thats what everybody does and I really don't like the style or the electronics. I want something simple that I hopefully can fix on the roadside with all the "stuff" I keep behind the rear seat. For some I spent way too much but for me I'm still looking for the next motor buildup.... Its happening now but no time frame when it will be done. This new motor will have differant head and precup chamber work in it. I got a set of new bare heads that cost me $140.00 for both of them. So its easy to try something with them that may kill them and not be out a lot of money... Just my time and effort. I think the trick in building a motor that breathes as easy as it can with all cylinder volumes exactly the same plus balance work will make the best power and longer running motor. These motors are not a gass motor. We just cram in as much air as we can and the smoother it gets in and out the better it will make horse power.. I think russ (typ4) knows what I'm doing with the precup chambers in the heads. He is running his heads with that machine work now. What I did was fabricate a ball end mill with a demension of 1.168 to even out the ruff chambers in the heads. Then I CC them to be sure they were all the same and they were. This was really a tricky job on a bridgeport mill getting them all the same depth and diameter. The hi nickle block and heads machines easily but doing this in a blind hole is the tricky part. The heads have the injecters pulled up out of the chambers 60 thousands for emissions requirements. I dropped the chambers that much and opened them up to the 1.168 because thats what I felt I could run for a comp ratio drop. That motor ran great too... Till the freeze plug the shop installed wrong poped out pulling a grade. I watched the coolant temp and it never moved. No coolant on the sender... No telp reading. What finally made me feel something was wrong was when my oil temp passed 330 degrees. Then power fell off, motor clattering from thing oil and the pistons stuck to the cylinder walls they got so hot. But the black anodising on the tops never came off either. I scuffed the shirts of 6 beyond reuse... Only 5200 miles on that build... Damn crappy machine shop...
Actually there is ( or at least there was last time I checked ) a performance cam available for these engines through Summit racing. Only drawback is it's a solid lifter cam, one step forward , two steps back. Go from factory hydraulic roller lifters to solid lifters 
granted, if you were just pulling and such, it would be OK, but that would be a maintnence pig
granted, if you were just pulling and such, it would be OK, but that would be a maintnence pig
Your best bet is to pull the heads, have them properly done, arp studs then intercool it and turn up the boost and fuel, that is the most bang for your buck IMO.
I can get you a cam like mine. It is a little more lift than stock IIRC,I can find out monday. They designed it to give more torque on na engines.
icanfixall
Official GMM hand model
This is what the stock cam is.. The intake lift is 0.2535 and the exhaust lift is 0.23508.
The intake opens at 17.2 degrees btdc
it closes at 42.8 degrees abdc
the exhaust opens at 51.2 degrees bbdc
the exhaust closes at 20.8 degrees atdc
The intake opens at 17.2 degrees btdc
it closes at 42.8 degrees abdc
the exhaust opens at 51.2 degrees bbdc
the exhaust closes at 20.8 degrees atdc
