technical question for 15bft & 4bt cummins ? (1 Viewer)

[xtremitys]

Before people tell me it cant be done , i want to know how it can >>>

I was thinking last night about the poswibility of boring out & sleeving a 15bft block to a bigger size & machining a 4bt cummins crank to fit the 15bft block as it has 119.9mm stroke ( compared tothe stock 108mm .) Or a crank that would fit it . Been tryn to find info on crankshaft dimensions length , size ,mains , journal sizes ,et,etc anyone know of links to sites of original dimensions for each crank ?

 

[Hulsty]

Offset grind the 15B crank?

Why the need for more capacity than a 15B ? I would imagine you could get some pretty decent power and torque from a stock 15B

 

[cruiserbrett]

gotta figure if the bore spacing would even allow for something like that. LOTS of measurements will need to be the same.

Other options out there too:
Hino/UD/Fuso/Isuzu etc might be other options.

 

[xtremitys]

cruiserbrett >> trying to find a link for crank dimensions of both cranks , sure to be a crank around thats close , seen it done with other engines heaps of times . 15BFT or even a 14BT is the perfect candidate to Hotrod those engines as they are built solid & well designed ,like people used to do the 1uzfe . i think the 4bt crank is a bit longer , bore spacing more spaced out , hhhhm....

i have pulled a 14bt down before so am fully aware of it . To me the 14/15bt engine seems better than a 4bt cummins , 14/15 have a stronger built bottem end ( cummins has more meat /wieghtaround the block ) the cummins has alot more stroke , hence the torque it puts out . cant see why you can push a 15bt out to 4.7ltr approx , the good thing about these engines is they are short in length & can easily fit any cruiser with space to spare for other things .

theres no replacement for cubic inchs the old sayn gos ((-: i reckn it wouldnt cost that much if you did alot yourself , alot of the cost is machining .

Offest grinding weakens a crank & you can only gain so much before you start welding the crank for more , starting to look around at possibilitys

some people have more fun building engines , 4x4's , project while other have more fun driving around , rock crawling ,etc

 

[Dougal]

There is a very good replacement for cubic inches. Compound turbos.

Instead of adding cubes, focus on squeezing more cubes into the same space.

 

[xtremitys]

Dougal>> i was thinkn a strokd & sleeved 15bft with compound turbos actually or just a good.sized vnt ,with dual stage intercooling theres a new gt25 vnt on ebay now but a litle small , i used to know a company in japan that had the prototype versions that u could buy that garret, holset ,ihi ,etc ,used /made .

I just need a challenging technical project to keep my brain settled at night & stock builds dont cut it for me at all lol. The fiji tour thing will be a 1-2yr goal to work towards if , think i will go with the delica spacegears as alot of mining companys use them . Saw a mint low klm one for 2k witha damaged engine , easy fix (-;

 

[Dougal]

First question would be, how much fuel can you get from a 15BT injection pump?
That will set how much boost you can actually use and from there what sort of turbo setup is best.

Got a link for the turbo on ebay? Promise I won't snake you.

 

[xtremitys]

First answer would be , wont use the stock pump , will do a custom commonrail injection using 2nd hand parts , i reckn it would be easy to rig up , hardest part is tuning the aftermarket open loop ecu via laptop as never done it before , would have to someone to teach me , knowing how many cycles , time of cycles per as coomonrail injectors inject severl millisecond cycles per burn each cylinder , will start learning it . Seen a fuel map on loptop hooked into an ecu , like where do u start lol looks like a big jig saw puzzle with different colours lol

On my android , pain in bum to copy & paste on here , will get u link next time on laptop . U mean the link to the gt25 vnt? They only $330 brand new & fully adjustable , non electronic version a enough flow for 250hp at flywheel they state . Or u mwan the othr site ? Deleted from my ebay contact list pissed off at myself few yrs ago for always spending $$$ on car/truck stuff lol have to find it again , best place for wickd turbos real cheap .

 

[Dougal]

I think you'd be onto a hiding for nothing with the commonrail attempt. It was 1995 before car manufacturers could make it worthwhile.
Get a 15BT pump on a test bench and see how much fuel it can put out (cc/1000 shots).

 

[xtremitys]

Common rail has been out a lot longer than 1995. Its the same principles as a petrol injected holden , ford , etc except the fuel pump is mechanical like a bosch cp3 & higher pressure , do u drive a carby engine or fuel injected as family car ?Commonrail term is exactly the same as petrol fed injectors , it has a high pressre common fuel rail that feeds injectors , most people who get a jap engine import engine say a 2jzte,1uzfe for example will run an aftermarket engine management . In nz theres link as u know , in oz theres haltech , ems ,wolf/aem , etc . europe has autronic ,et,etc.

Theres heaps of fuel only aftermarket engine management , they are normally 1/2 price of fuel/ignition units , 2nd hand ones are few hundred $$ .plus theres performance diesel ones like zeus,etc. Have a read of the latest diesel power magazine , shows how simple they are , common sense really .

With aftermarket engine management you can run different settings at a flick of a switch ,eg economy , towing , power/performace , that adjust fueling , timing , wastegate actuation , blow off valve ,Thermo fans , water spray ,, engine temp , etc, etc soon.be able to flush the toilet too with no hands lol. how do you do that on an injection pump ?

Plus alot ecu/engine management systems now are in waterproof housing , alot like cummins , cat ,etc are bolted side of the block. Its just the next step , like when diesels were naturaly.aspirated & then they put turbos on them , alot of old school people dont trust turbos as its not what they know , wasnt in thier generation , like some people are against EFI diesel engines ( do u use a remote control for ur plasma/lcd tv or do u get up & change channels by hand everytime ?) commonrail sounds different than electronic fuel injection , its for marketing reason , it sounds totally different so it must be a new thing NOT !!!

 

[xtremitys]

Common Rail Fuel Systems

 

[cody c]

I believe the cummins has a fair bit more space between piston centers. I wonder if you could get more stroke out of it and a bit of width.

Could you use a 4BT pump on a 15btt?

some pieces of wiki info:

4bt: With a cylinder bore of 4.02 inches (102.1 mm) and a piston stroke of 4.72 inches (119.9 mm), the engine had a wet weight of 745 pounds (338 kg). In recent years it produced 130 horsepower (97 kW; 132 PS) and 355 pound-feet (481 N·m) of torque.


B engines

Code Capacity (cc) Bore (mm) Stroke (mm) Direct injection Turbo Intercooler

B 2977 95 105
11B 2977 95 105 yes
2B 3168 98 105
3B 3431 102 105
13B 3431 102 105 yes
13B-T 3431 102 105 yes yes
4B 3661 102 112
14B 3661 102 112 yes
14B-T 3661 102 112 yes yes
15B-F 4104 108 112 yes
15B-FTE 4104 108 112 yes yes yes

 

[cody c]

So, based on the pink numbers, the 15B-F/15B-FTE has a larger bore than the 4BT already. just the stroke of the cummins is longer.

But, the 4BT is an anchor, the 15B-FTE has got to weigh like 200 pounds less, maybe even more.

 

[Dougal]

Common rail has been out a lot longer than 1995. Its the same principles as a petrol injected holden , ford , etc except the fuel pump is mechanical like a bosch cp3 & higher pressure , do u drive a carby engine or fuel injected as family car ?Commonrail term is exactly the same as petrol fed injectors , it has a high pressre common fuel rail that feeds injectors , most people who get a jap engine import engine say a 2jzte,1uzfe for example will run an aftermarket engine management . In nz theres link as u know , in oz theres haltech , ems ,wolf/aem , etc . europe has autronic ,et,etc.

No, it's very different.
EFI petrol engines are squirting at an inlet port under low pressure and low accuracy, all that matters is they are open for the right amount of time to squirt the right amount of fuel.

Only in the last few years have we seen direct injection commonrail petrol engines which are similar to diesel commonrail. Holdens SIDI is one example, VW/Audi's FSI engines are another.

Commonrail has milliseconds to control several injection events at extremely high pressure. Inexcess of 30,000psi. The ECU's required are beyond any consumer level or consumer programmable hardware. Believe me when I say a functional system is beyond DIY. Any leak in your fuel rail or fittings will have the power of a water-jet cutter.

If you wanted to make your own CR system the only realistic option is to start with a Bosch diesel motorsport ECU (you might get one for $10k) and try to make parts from a later CR toyota engine fit. You will have issues trying to find injectors that will fit and work, 2 valve engines usually run canted injectors where the modern 4 valve CR engines run injectors up-right. If you manage to get the hardware to work, you will have around 6 months coding work to get the software maps working properly.

None of the aftermarket petrol engine management systems will work.

I find a lot of people thinking different tunes at the flick of a switch is a good thing, but it's pointless.
There is only one tune you need, that is the best one your engine and turbos can safely support.
The max power and max economy tune on a diesel is the exact same tune, the only difference is what you do with your right foot.
If a tune isn't safe to tow with, then it's not a good tune.

I know a little bit about EFI diesels, I have two myself which I have remapped myself.

 

[xtremitys]

Well thats no what i have been reading thru performance diesel sites ,alot pull off thier stock closed loop ecm/ecu & run aftermarket , theres heaps dedicated diesel efi injection systems out the , i will ask that question about aftermarket petrol / gas ecm/ecu units . Most are infinatelly adustable & easily fire multipli injections per burn . I was talkn generally last comment , sayn efi petrol is same overall design as commonrail ( injectors, fuel pump ,sensors , ecu/ecm )
It would be a good challenge to do after the engine build pers'e )

 

[Dougal]

There is one outfit on 4btswaps.com who managed to make a commonrail 4BT. But they did so using mostly parts from the commonrail ISB motor which is closely related.

Honestly I'm struggling to see the benefit. You end up with a system that is a lot less tolerant of dirty fuel and a lot harder to trouble-shoot. The best compromise between tunability and toughness is an electronically controlled rotary pump like the VP44. It's hard to beat a straight mechanical pump for toughness and reliability.

 

[xtremitys]

I see ur point for a daily driver , weekend warior ,etc but if people dont experiment then nothing will move forward & we"d all be cavemen tryn to survive & not being eat by a taranasaurus & the wheel would neva have been invented lol has nz got the wheel yet ? LoL

Theres too many people sayn why/how you cant do things , need more thinkers finding or creating ways how to do things & makn them happen .

 

[Dougal]

Yeah I have a few wheels lying around.

I think R&D in compound turbo sets is the best way to progress. The instrumentation and experimentation will keep you out of trouble for a long time yet.

 

[xtremitys]

Cody > car makers & engine manufacturers use off the shelf pumps from . Companys like bosch , denso etc or they contract those companys to design & make them a one prototype for their engine , then mass produce it , so you could fit virtually any off the Shelf pump suitable match to go on any diesel engine.

Dougal > Its likely that will happen as will need $$ for other things as you do ( bills , etc ) atleast run the engine in well & truly will a rotary injection pump ,etc > made that mistake before on a green engine, freshly built & stuffn around to get the settings vacuum lines , injection timing right f#cks up running the engine in & does more damage than good , learned that mistake already lol But i defeinatelly plan to stroke it , bore & sleeve it min . Got my work cut out ahead ((-;

anyone know a good engine importer in Qld or Australia that you can get a 15Bft as a rebuilder core ( less turbo & assessorys ) or one with a damaged piston ,etc fairly cheaply ? ( Read on mud someone buyn a 14bt cheap thru a importer in brisbane witha hole in one piston cheaply)

 

[cody c]

ya, I brought up the cummins pump as I figured it would have more fuel capacity than the 15B pump.

If it is as simple as swapping pumps, then source the pump (if required) and electrics and then work on the fine tuning I guess. Might find more info on isuzu or cummins swap sites regarding the pros and cons of other pumps. Im under the impression that the pumps the 4BT uses have a lot to do with the engine vibration/harmonics rattling vehicles apart around them, versus the "suzy" pump which is a bit smoother.

This is turning into another common rail vs. EFI debate though.