3B MAX KM's

[crushers]

i got 4 machined blockes, 2 rebuilt heads, 4 macnined internals, pistons by the box full, blasted and painted oil pans etc etc, etc...
a short block that was rebuilt 20,000 ago.

3Bs coming out the ying yang and everything i drive has a different engine...

 

[Eric Winkworth]

Wayne I need an oil pan, how much?

 

[crushers]

let me put my hands on one and i will PM you...
cheers

 

[Eric Winkworth]

cool thanks.

 

[magnus_heydoc]

I don't know about you guys but my OD only goes to 99999. How do you keep track of these several hundred thou that you rack up on a diesel? I just nicely dropped a 3B in my old 76 so in time I'll have no idea what's on it for mileage. Besides, I just turn it on and let it idle for hours just to listen to it!
I need one of those gauges that measures hours.

 

[Behemoth60]

Can I play too?

The 3B is one tough SOB of an engine!

I have a 1986 BJ70 with 598,000 kms on it. I'm too cheap to figure out where the intermittent coolant leak is, so it gets hot a few times a year (but never too far into the red....). Plus it's been on fire twice. Despite the abuse of being a working truck for 10 years, then a daily driver for another 9, it was making over 420psi compression last time I tested it. Lumpy Bastard says it pulled harder than his with a freshly rebuilt engine!

After I rebuilt Tippy's engine in 2001, I mistakenly installed the new EDIC motor without a HAC on it. This means there is no limit to the amount of fuel that can be forced down the poor thing's throat. it was making awesome power, but drenching the city in the deepest darkest cloud of smoke you could imagine. I drove it like this for about 1 week (it was my daily driver, after all). Later that week I finally received my Pyro and installed it and took it for a test drive. Before I got to the end of the block the pyro was pinned. It only goes to 800C (1500F) . I drove this engine with the pyro's over 800C for a week! Anyway, this made short work of the cheap ass aftermarket head gasket. A factory cometic Multi-Layer-Steel gasket was installed, the HAC was finally discovered missing, and the fuel dial back to a more reasonable temperature. When the head was removed after running this much heat, it was NOT cracked, nor were the pre-cups. It was an aftermarket high-nickle head, however.

Anyway, this engine is still running today with 60,000 km's on it. It developed a slight knock during it's week of cooking... I think it's the #4 wrist pin is loose, and the cylendar is slapping the valves on #4. That didn't stop me from driving it to Alaska. Twice. And it isn't stopping me from running 17lbs of boost either! These little bastards can take it.

My theory is that so long as a 3B has plenty of clean oil in the pan, clean coolant in the head, and clean fuel in the tank, there's almost nothing that can stop them.

Peter Straub

 

[brownbear]

I don't know about you guys but my OD only goes to 99999. How do you keep track of these several hundred thou that you rack up on a diesel? I just nicely dropped a 3B in my old 76 so in time I'll have no idea what's on it for mileage. Besides, I just turn it on and let it idle for hours just to listen to it!
I need one of those gauges that measures hours.

on can spec cruisers they have 999,999 km odo's. not the low ones.

so my odo reads currently 241,000kms on it. 84 BJ60 CDM

what year and model do you have?

good to hear Peter! thats comforting.

 

[Eric Winkworth]

See I told you guys it was possible, I was looking at a CDN spec 3B that the odometer had fliped over and it red 60 000 or so I think. Why would the guy lie, it started up fine but almost brusied my leg when I drove away, it needed a match not a restoration, I just couldn't believe it ran thats what sold me on these trucks.

People can buy a new car and pooch the motor with 100 000 on it that doesn't mean some guy that take care of the same car can't get 500 000 out of it.

Maintence Maintence Maintence

 

[Cruiser rookie]

Hey guys
I recently had my 3B turbo'd and also had the a pyro and boost gauge installed.I was wondering what you guys think is a safe operating temp for this setup.Max boost is set up at 13psi,i have only logged a few hours on it since the installation.The pyro does help especially when pulling the long BC hills.I drove from Abbotsford to Whistler and i had to watch on the long hills on th Sea to sky,but i was trying to maintain 100km at all times.So far very very happy with the work my friend has done.Still getting used to the sound of the locker also.Thinking of getting an intercooler fabricated next along with a manual boost adjustement dial.
My friend used all new parts,including the turbo and managed to fit a 3" exhaust and did this for under the cost of the AXT set-up.My was th guinea pig but it is the nicest turbo set up i have seen yet and i will try to get some photos as soon as i go digital.He also ceramic coated the exhaust pipe and wrapped the turbo in a heat shield material.If anyone else interested please let me know and i will let him know of the interested parties.
I haven't pushed the pyro anywhere into the yellow as of yet but 900 to 1000 was the highest so far.
Looking forward to your info.
Cheers

 

[Gold Boy]

Why did they drop the compresion in the 13BT.... for the turbo right?

Thanks

Simon

 

[cruiser_guy]

i got 4 machined blockes, 2 rebuilt heads, 4 macnined internals, pistons by the box full, blasted and painted oil pans etc etc, etc...
a short block that was rebuilt 20,000 ago.

3Bs coming out the ying yang and everything i drive has a different engine...

Wayne, how much for a 3B block machined with pistons, cam and lifters delivered to my shop in Guatemala?

 

[crustyBJ60]

The 3B is one tough SOB of an engine!
there's almost nothing that can stop them.

Peter Straub

Dude! shhhhhhhhh, don't tell anyone that!

crusty

 

[crushers]

Wayne, how much for a 3B block machined with pistons, cam and lifters delivered to my shop in Guatemala?

you pay shipping and crating and i will sell you the set for $1000 CND...

 

[Behemoth60]

Why did they drop the compresion in the 13BT.... for the turbo right?

Negative. For the Direct Injection.

From Gasser theory, you'll remember that max. compression before pre-ignition is somewhere in the 13:1 range. This also means that the minimum compression for a compression ignition engine is around 13:1.

More compression than 13:1 does 2 things for you.

1. the higher the compression ratio, the more efficient the burn of the fuel. I'll spare you the thermodynamics, but needless to say, maximum possible efficiency of both the carnot and otto cycle internal combustion processes are related to the overall compression ratio.

2. In order to cold start a compression ignition engine, the compression must be some marginover 13:1. 17:1 seems to be where most engineers have landed for DI engines, and 20-22:1 seems to be the range for IDI.

More compression causes a significant problem, however.... The more you compress the intake charge above the threshold temperature it takes to ignite the fuel, the more work (i.e. energy or power) your engine does with no purpose. basically, once the engine is started, all the energy that your engine consumes to compress from 13:1 where the air is hot enough to ignite the fuel -> up to 17 or 20:1 or even 22:1 where the intake charge is significantly hotter than necessary, is lost energy. While the max theoretical efficiency goes up, the lost power to compression increases with diminishing returns on efficiency.

Race diesels are decompressed down to 15 or even 14:1 Again, nothing to do with the 50 to 100psi boost they are running, everything to do with limiting the lost power due to over compression. So they have to start on ether... no big deal for a racer.

Peter Straub

 

[Tapage]

wwou .. I always think. most compresion is better .. But letme underestand fine the idea. Why the gas engines try to up the compresion ratio, to get more power . ? exist the ideal compresion ratio for all egines .. ?

 

[MadmanCruiser]

Better late than never i suppose...

I have a truck with 410,000 KM (still starts great in the winter), and a truck with over 500,000 (probably getting close to a rebuild on that one...still runs great though - winters are just a bit tough).

Adam

 

[Behemoth60]

wwou .. I always think. most compresion is better .. But letme underestand fine the idea. Why the gas engines try to up the compresion ratio, to get more power . ? exist the ideal compresion ratio for all egines .. ?

Gassers try to maximize compression due to the thermodynamics of the otto-cylce. Compression ratio defines the maximum theoretical efficiency, and the higher the compression ratio, the higher the efficiency, which to a driver, means more power from less fuel.

However, most gas engines can't make much more than 13:1 due to two factors... First of all, the compressed air/fuel mixture get's close to the combustion temperature of the mixture, and the hot exhaust valve often contains just that little bit of extra heat needed to ignite the fuel before it's supposed to burn.

Interestingly, I've been told that with shperical rotating valves that the compression can be pushed to 15:1 since there's no not exhaust valve in contact with the combustion mixture.

Furthermore, in the world of gassers, lowering compression on highly boosted engines becomes a factor as the mass of the air compressed 13:1 at even just 6lbs of boost can overheat the mixture and cause it to pre-ignite. This is why blown or turbo charged gassers often run low compression pistons, often down to as low as 6:1. This, however, is striclty gasser thinking, and is not the reason that diesels run lower compression pistons.

Even of more interest, it's possible to get 'low compression pistons' for the early IDI domestic engnies, such as the early Navistar and 6.2/6.5 Gm diesels. They are usually around 18:1, down from 20-22:1. These are used for high performance engine builds, but unlike gasser theory, this has nothing to do with pre-ignition concerns. This has to do with lowering the compression to reduce the engery lost to over-heating the intake air, and reduce the energy losses due to pushing all the intake air through the tiny pre-cup hole. They are a lot harder to start cold, however and may need ether to start. Cummins has a few special race prepped engines that they've put into Dakota's which run 15:1 compression in these DI engines.

Peter Straub

 

[Greg_B]

Peter…thanks for the late nights and scratchy eyes…

Your post started me on a search to see why 15-18lbs for DI and 20-25lbs for IDI are the optimal numbers. I’ve found no reading stating why higher compression numbers then these are not used with diesel. Still knowing very little, I would think it had everything to do with economy of scale, where the engine structures would have to be huge to compensate for the increased load…and not energy lost in the compression stroke. Do you have any links to online material that explains this better?

In this search I have found some interesting stuff. I offer it here, to be torn apart, in the spirit of learning…

1) IDI engines have a slightly higher compression ratio to compensate for the loss of heat of compression of the air flowing into the pre-chamber, and the swirling air inside the chamber. This, coupled with the pressure drop in the pre chamber requires a higher compression ratio to get compression ignition going.

2) DI engines are typically 10%-20% more efficient then IDI engines, partially from the loss of heat energy into the head (then the cooling system) through the pre-combustion chambers

3) Compression ratios for gasoline engines are typically under 10:1, unless using a ping sensor and auto control unit. Anything higher and pre-ignition can be an issue: “Pre-ignition may lead to detonation and detonation may lead to pre-ignition or either may exist separately.” The combining of the fuel and air mixture in gasoline engines before the compression phase is what requires lower compression. In either case, my reading indicates it may not be simply from the valve, but any surface in the combustion chamber.

4) Because diesels compress the air first, then inject the fuel near the top of the cycle, pre-ignition is not an issue.

5) Diesel burns slower then gasoline. This means when the diesel is injected near the top of the stroke, by the time combustion completes, the piston is moving down, so the shock of ignition is less then on a diesel then on a gasser. This slight inefficiency in the diesel design is more then made up for in greater thermal efficiency.

6) Turbo or super charged gassers typically lower the compression ratio, to compensate for the increased pressure of boost, so auto ignition will not become a concern.

7) Diesels do not have to lower the compression when adding a turbo, because the fuel is not mixed with the air before the compression phase. If you can get rid of the heat, have a clear pathway in and out for the air, and the structure will stand the increased forces…bob’s your uncle.

8) There are lower pumping losses on a diesel when compared to a gasser (ok…the 3B has a throttle plate) so pumping loss (compressing the air), and loss when pulling air into the ignition chamber past the intake valves is less of a concern for diesel engines then gassers.

9) The greater thermal efficiency of a diesel engine makes pumping loss even less of an issue.

gb

 

[crushers]

2) DI engines are typically 10%-20% more efficient then IDI engines, partially from the loss of heat energy into the head (then the cooling system) through the pre-combustion chambers

gb

if this is the case then why does the 13BT have a pporer overall fuel economy than the old 3B?

 

[Greg_B]

if this is the case then why does the 13BT have a pporer overall fuel economy than the old 3B?

Yes, good question. I have no answer, other then...these are all generalizations.

And maybe...just maybe the 3B is really a magnificent engine, with the utilization of the Richardson Comet Mark III combustion process, combined with a butterfly valve throttle control system...eeking out every last available ounce of energy, despite being an archaic IDI engine...
gb