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Discussion Starter #1
I am looking for aprox 475-600+hp.

I have a 7FB 400hp AWAC, circa 1986. I also have a 8PN 425hp circa 1996.

I need to rebuild a 3406 B/C within the next few months as the "E" model I am using now just has to go!!

Either way, both motors need 6 new piston packs, 6 Injectors, Turbo.

The head from the 7FB is a square port head, this would be the better one of the heads to use of the two heads. I have thought this all along, and have read it in several posts on here. I have a matching square port manifold to go with the head.

Which of the cams would be the better one to use for a build? Are both cams just to limited? Where would the limit be for each? Ideas for a different cam? Cat only please, ballpark price as well.

Is the C/E crank really worth bothering with? I have one B model crank, and one C/E.

I know the 8pn pump would be the better pump to use as it has a pop of 2800psi as apposed to the 2500 of the 7fb pump. I would prefer to stay with the small dish pistons like what is used in the 8pn.

When I ran the 8pn, the engine was completely stock, including timing. I really liked how smooth and quiet it was. Nothing like the 7fb which was always rank sounding, which either way is better than the “E”.

I haul a walking floor, 6 axles at 100,000 everyday. I currently am holding 4.6mpg running a moderately harsh run (with a 355 "E" model with a power harness and a pinched wastegate hose). On a scale of 1-10, I would say it is a solid 7-8 simply because of how hilly it is and how much speed-up/slow down due to small towns. The rest of the run is smooth and 55mph zone. The others that run the same route and I all judge a truck by one hill in particular. A 45mph run is all you can get for it, and right now I pull 32 mph at the top with a rto 13 speed, and 3.55 with 24.5 tall rubber. A 2010 KW with a 500 isx/18 speed/4.33/24.5 tall rubber pulls this hill at 44 mph.

In the very least I want to hold the 4.5 mpg, with little smoke, only a slight haze to a slight puff of smoke from the shifts. Long trails of moderate to black smoke are nice, but draw to much attention.

Other things of thought.
Oil squirters?
Oil pump/pressure relief valve upgrade?


Any and all help is greatly appreciated!!
:rock
 

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Junior Member
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I am looking for aprox 475-600+hp.

I have a 7FB 400hp AWAC, circa 1986. I also have a 8PN 425hp circa 1996.

I need to rebuild a 3406 B/C within the next few months as the "E" model I am using now just has to go!!

Either way, both motors need 6 new piston packs, 6 Injectors, Turbo.

The head from the 7FB is a square port head, this would be the better one of the heads to use of the two heads. I have thought this all along, and have read it in several posts on here. I have a matching square port manifold to go with the head.

Which of the cams would be the better one to use for a build? Are both cams just to limited? Where would the limit be for each? Ideas for a different cam? Cat only please, ballpark price as well.

Is the C/E crank really worth bothering with? I have one B model crank, and one C/E.

I know the 8pn pump would be the better pump to use as it has a pop of 2800psi as apposed to the 2500 of the 7fb pump. I would prefer to stay with the small dish pistons like what is used in the 8pn.

When I ran the 8pn, the engine was completely stock, including timing. I really liked how smooth and quiet it was. Nothing like the 7fb which was always rank sounding, which either way is better than the “E”.

I haul a walking floor, 6 axles at 100,000 everyday. I currently am holding 4.6mpg running a moderately harsh run (with a 355 "E" model with a power harness and a pinched wastegate hose). On a scale of 1-10, I would say it is a solid 7-8 simply because of how hilly it is and how much speed-up/slow down due to small towns. The rest of the run is smooth and 55mph zone. The others that run the same route and I all judge a truck by one hill in particular. A 45mph run is all you can get for it, and right now I pull 32 mph at the top with a rto 13 speed, and 3.55 with 24.5 tall rubber. A 2010 KW with a 500 isx/18 speed/4.33/24.5 tall rubber pulls this hill at 44 mph.

In the very least I want to hold the 4.5 mpg, with little smoke, only a slight haze to a slight puff of smoke from the shifts. Long trails of moderate to black smoke are nice, but draw to much attention.

Other things of thought.
Oil squirters?
Oil pump/pressure relief valve upgrade?


Any and all help is greatly appreciated!!
:rock
You're wanting to get rid of an E for a mechanical B or C?

The E must have issues........
 
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Discussion Starter #3 (Edited)
Yes, it is only a 355hp, and has absolutly no consistancy in how it runs. The only thing that is consistant is the fuel mileage at 4.6. Other than that it doesn't run the same from one run to the next. I can make one run and have it run "like never before", and the very next it runs like it has 3 million miles on it. :no: It has less than 75,000 miles on the last inframe!

Even my old B model, which I didn't know the history of, and turned out to have 3 Cat packs and 3 aftermarket packs, mileage was completly unknown, ran much smoother than this E model. The B model was holding 4.3 mpg up until the last 5,000 miles or so before I stopped running it.
 

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Discussion Starter #4
Anybody have any thoughts?

What would be a good combination of piston packs/injectors/turbo/cam for a hp output of around 550+.

I have read many posts about "use this part #" injectors or this part number turbo on such and such a serial number engine to make good hp (500+). I simply need to start from scratch with decently matching parts. The tuning afterward isn't really an issue.
 

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The other guy
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I am looking for aprox 475-600+hp.

I have a 7FB 400hp AWAC, circa 1986. I also have a 8PN 425hp circa 1996.

I need to rebuild a 3406 B/C within the next few months as the "E" model I am using now just has to go!!

Either way, both motors need 6 new piston packs, 6 Injectors, Turbo.

The head from the 7FB is a square port head, this would be the better one of the heads to use of the two heads. I have thought this all along, and have read it in several posts on here. I have a matching square port manifold to go with the head.

Which of the cams would be the better one to use for a build? Are both cams just to limited? Where would the limit be for each? Ideas for a different cam? Cat only please, ballpark price as well.

Is the C/E crank really worth bothering with? I have one B model crank, and one C/E.

I know the 8pn pump would be the better pump to use as it has a pop of 2800psi as apposed to the 2500 of the 7fb pump. I would prefer to stay with the small dish pistons like what is used in the 8pn.

When I ran the 8pn, the engine was completely stock, including timing. I really liked how smooth and quiet it was. Nothing like the 7fb which was always rank sounding, which either way is better than the “E”.

I haul a walking floor, 6 axles at 100,000 everyday. I currently am holding 4.6mpg running a moderately harsh run (with a 355 "E" model with a power harness and a pinched wastegate hose). On a scale of 1-10, I would say it is a solid 7-8 simply because of how hilly it is and how much speed-up/slow down due to small towns. The rest of the run is smooth and 55mph zone. The others that run the same route and I all judge a truck by one hill in particular. A 45mph run is all you can get for it, and right now I pull 32 mph at the top with a rto 13 speed, and 3.55 with 24.5 tall rubber. A 2010 KW with a 500 isx/18 speed/4.33/24.5 tall rubber pulls this hill at 44 mph.

In the very least I want to hold the 4.5 mpg, with little smoke, only a slight haze to a slight puff of smoke from the shifts. Long trails of moderate to black smoke are nice, but draw to much attention.

Other things of thought.
Oil squirters?
Oil pump/pressure relief valve upgrade?


Any and all help is greatly appreciated!!
:rock
OK. Use the 8PN block, crank, front and rear covers, water pump and big oil cooler. Use pump, advance, and injectors off the 7FB. Ad 0R3590 cylinder kits to match compression and the crank. Use dual oilers which it may already have, the 8PN oil pump and add a shim in the cup of the spring holder. 0R3421 nozzles, max the rack according to the tech article, use the 8PN turbo and 7FB manifold. Use the square port head from the B or a new 3674 square port. 550+ on the ground. ;)
 

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Discussion Starter #6 (Edited)
OK. Use the 8PN block, crank, front and rear covers, water pump and big oil cooler. Use pump, advance, and injectors off the 7FB. Ad 0R3590 cylinder kits to match compression and the crank. Use dual oilers which it may already have, the 8PN oil pump and add a shim in the cup of the spring holder. 0R3421 nozzles, max the rack according to the tech article, use the 8PN turbo and 7FB manifold. Use the square port head from the B or a new 3674 square port. 550+ on the ground. ;)
The advance on the 7fb is the old style short nose. The 8pn has the long nose. I have heard that the long nose advance is a better unit. Opinions?

Wouldn't the 8pn pump be the better one? I am not second guessing your knowledge Tony, I have never had a pump apart (between the front and the govenor housing that is). The 8pn is a dual scroll is it not? Wouldn't the 2800 psi of the 8pn be a better choice? Is the cam lobe in the 7fb pump just a better choice due to it's profile?

The 0R3590 kits must be a combo kit between a wide rod journal (8pn/3406e) and the larger dish of the 7fb due to the use of 3421 nozzles? Yes/no?
What do the or3590 kits run for compression? 14:1/16:1? I would prefer to start with 16:1, but will deal with 14:1 if i have to.

I will be in need of a turbo as the one that is on the 8pn is a complete mystery. There is no tag on it. I need to get what numbers I can from it and post them up to see if anyone can ID it.

Which cam would be best to use? What about a new one that is better than both? Ballpark price? probably $2000+??????

What about the timing? Stock or kicked to 17.5*?

Stop screw in advance? Max it, or just remove it and file it away?
 

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If you RELY want to make the power you say you do you have to build it like Tony said. You need the 14:1 ratio so you have the room for the aditional air you will need with the OR3421 nozzels. Use the 7FB pump bucuse of its ability to flow more fuel and the 20 some degrees of time advance, the 8PN pump is limited on potential fuel delivery and the timeing advance does not give enof timeing with out timeing fast initualy. You want the C crank for the wide rod bearings. tos the stop screw and time it to spec with the 7FB pump. max the rack and put in Tonys spring. Maby if Tony thinks my explination of why you need to do it this way is off a bit he will ad to it but maby not .
 

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Discussion Starter #8
If you RELY want to make the power you say you do you have to build it like Tony said. You need the 14:1 ratio so you have the room for the aditional air you will need with the OR3421 nozzels. Use the 7FB pump bucuse of its ability to flow more fuel and the 20 some degrees of time advance, the 8PN pump is limited on potential fuel delivery and the timeing advance does not give enof timeing with out timeing fast initualy. You want the C crank for the wide rod bearings. tos the stop screw and time it to spec with the 7FB pump. max the rack and put in Tonys spring. Maby if Tony thinks my explination of why you need to do it this way is off a bit he will ad to it but maby not .
I assume that the barrels are smaller on the 8pn?

If a 8pn can make 583 hp (marine i assume), then why can't I get 550 or more out of one built more for the road? As I said I would really prefer to use the smaller dish pistons and nozzles to match.

I take it that the long nose advance doesn't have the same kind of range as the short nose advance?

IIRC the 7fb has 12* of initial advance whereas the 8pn had 9.5*.
 

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The other guy
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As per your requirements, just build the 8PN and crank it. Don't know why your staying so hi with compression or anything else really
 

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Discussion Starter #10 (Edited)
So upon doing several hours of reading I have determined that I will be building the motor as follows:

8pn block, 8pn crank, 8pn advance/pump
8pn packs
stock 8pn Cam, unless someone cam come up with a better one from CAT. 3012 cam (standard 7fb cam?) would it be better than the 8pn?
Square port head with matching exhaust manifold.
OR6051 turbo
OR8785 nozzles
7W4990 double oilers
131-7123 main idler bushing.


Anything else that i missed?
 

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So upon doing several hours of reading I have determined that I will be building the motor as follows:

8pn block, 8pn crank, 8pn advance/pump
8pn packs
stock 8pn Cam, unless someone cam come up with a better one from CAT. 3012 cam (standard 7fb cam?) would it be better than the 8pn?
Square port head with matching exhaust manifold.
OR6051 turbo
OR8785 nozzles
7W4990 double oilers
131-7123 main idler bushing.


Anything else that i missed?
I used 14.5-1 compression steel tops on my C build. I agree with everything except the head. I know this will cause controversy, but i would use the round port head, and E or C15 round manifold. Yes the square is good for all out crazy power, but the round is good for all around quick spool and performance, and low EGT.

Worked for me, but I will not guarantee it will for you.
 
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Discussion Starter #12
Thanks for the info Sledman!

What kind of EGT's were you running with the round port?

That is one of my concerns about using the 6051 as well, how is it spool wise? Is it a dog that builds alot of pressure, or is it quick and builds good pressure?
 

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Thanks for the info Sledman!

What kind of EGT's were you running with the round port?

That is one of my concerns about using the 6051 as well, how is it spool wise? Is it a dog that builds alot of pressure, or is it quick and builds good pressure?
EGT never went past 900 UNTIL I tried the square manifold. Then it ran pretty hot. The 6051 spools a little slow at first but moves a lot on the top. I saw 40+ psi with 2 rounds of fuel.
Unless you are after big power, use the round port. Faster response and better engine brake performance.
 

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Discussion Starter #14
EGT never went past 900 UNTIL I tried the square manifold. Then it ran pretty hot. The 6051 spools a little slow at first but moves a lot on the top. I saw 40+ psi with 2 rounds of fuel.
Unless you are after big power, use the round port. Faster response and better engine brake performance.
How was the spool with the square port vs the round port manifold? Did you get to try the setup with a round port head as well?

Is there another turbo with alittle faster spool that builds about the same levels up top?
 

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How was the spool with the square port vs the round port manifold? Did you get to try the setup with a round port head as well?

Is there another turbo with alittle faster spool that builds about the same levels up top?
Here's the deal #1 I ran into. I built my C model with the round port head and manifold. Ran it for several months...dialed it in perfect. 2 rounds of fuel, STOCK timing. 6-6.5 consistant MPG, 900 max EGT, 40-45 PSI boost, and never over 200 water temp.

Started reading on here about how the round port manifold was junk.....so I installed a log manifold. Immediately saw drop in performance....lost 8-10 psi boost, and gained 150 degrees EGT. MPG also dropped to 5.

Reinstalled round manifold, and all the above went back to normal. I also tried this on my C15 with the same outcome.

Deal #2.....my 88 W900 with a 4MG, square head. I always thought it made good power. 2 rounds of fuel, and slight advance on the static to clear up some smoke. Overhaul time the reman head I got was the round port. Built the engine, installed a round manifold, and instantly saw improvement in all the above. Old W900B never got over 5.5 MPG, and went to 6 the first trip. Lower EGT's, water temp, quick spooling, etc.

This is just what has worked for me. People will argue the square port is better. I disagree, based on the work I have done. For all out racing, I'm sure the square would be better. I am not in the racing business, I'm in trucking....to make money. Any improvement in performance and MPG is a plus for me.

As far as a better turbo, Mr. Haney can answer that question. The OR-6051 did outstanding on my 3406C, but not so good on my C15. Maybe Kurt will be along in a bit.
 

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Discussion Starter #16
Thank you Sledman!

I was very curius about the manifolds and weather things would work the way you described. It only makes sencce that the round port would have better spool and lower EGT's. I simply don't have the expereince with having an engine built this way to actually see the results first hand.

As you said, for all out racing, I am sure that the square port would be best as it has a higher flow capability, but that is only til the exhaust hits the turbo anyway. The round port has a lower flow capability (at the same volume), but the port velocity of the exhaust gas will be much higher, thus resulting in a quicker spool and lower EGT's.

When the 7fb was in my truck, the turbo lag was moderate. When I shifted you could count to 2 before the turbo would respond, in the meantime it was blowing dark smoke and trailing twice the length of the truck.
 
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