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Stiffer valve springs let you run a lot more boost without blowing the valves open on intake and exhaust.Quote:
Originally Posted by c.h.i.e.f
Yes the 4BD2T is indirect injection and intercooled. The indirect injection is less efficient but it gains a little from the intercooling. All up it's 5% less efficient than the stock 4BD1T.
thanks dougal pretty simple now you explained it ... using stock springs what boost level will you start expecting problems? has there ever been models of 4bd1's/t that have had different pump ratings? or all the same pump just different tune? you also said you had problems with flywheel weight what did carcrafter do to overcome this do you know?
There are several guys running 25+ psi and I haven't heard of anyone floating valves with that. Unless you're running compounds I don't see a problem.
Yes there are differences in injection pumps for different markets. Usually 9, 9.5 or 10mm plungers. My engine is JDM and has 10mm plungers, everyone else seems to have 9 or 9.5.
I've decided in the last few days that a large chunk of my rumble is 5th gear bearings. My current MSA gearbox did 240,000km in a tip-truck before I got it. Carcrafter is running an extra adapter plate bolted to the factory flywheel, it gives the extra mass needed.
auh well doesnt look like it will be a problem for any of us then.... you say JDM what does that stand for? i asume it would be costly to get mine converted to have 10mm plungers? so technically yours should be capable of more fuel delivery? so your msa box is having a few issues ? (not bad considering the extra power and torque of your engine and age of box)
JDM is Japanese Domestic Market. My engine came out of japan as a used import.
There's no point worrying about bigger plungers until you're at the limits of your current ones.
auh thought it might have been something along those lines....how did you get hold of your motor? how much HP do you figure you have at the flywheel?
I'm pretty certain that the 4BD1T engine that Randy had in a F100 truck at the time when it destroyed the GM 700R4 auto transmission and blew the head gasket had the following mods for performance:Quote:
Originally Posted by c.h.i.e.f
Injection pump modified by Sheid Diesel to deliver 370 cc per 1000 strokes
Electric fuel pump in place of mechanical lift pump
Compound turbochargers - primary (low pressure) Holset HX52 (from ?), secondary (high pressure) Holset H?341 (from Cummins 6BT)
Custom exhaust manifold - equal length headers
Crane valve springs - 110 lbs replacement for Chev V8 note Isuzu retainers machined to suit the slightly smaller ID of the Chev springs
Thermal blankets for turbine housings
When the engine was originally fitted to the F100, it didn't have the modified injection pump (only had the screws tweaked and altitude aneroid removed), compound turbos (only single H?341) or Crane valve springs.
When the Sheid modified injection pump, HX52 primary turbo and Crane valve springs were fitted the transmission started to suffer and failed after a short time. The peak boost pressure was unknown - off the scale of the 60 psi gauge and only then did the stock head gasket fail (note head bolts were stock at this stage).
The 4BD1T engine was not dyno'd but Randy said it outperformed his Chevy with Duramax engine tuned for +200 HP over stock (stock Duramax IIRC is 330 HP ??).
Sheid didn't reveal all they did to the pump. The governor was changed to one they are more familiar with and allowed for more rack travel. No doubt the plungers and barrels were custom and probably the camshaft for greater lift to get 370 cc per 1000 strokes. Sheid build high performance diesels and many records have been set with their engines - see pic below for some of their work.
The pic below shows the stock 4BD1T turbo (smallest) alongside a H?341 and HX52 (largest) turbos.
That engine is now in his wife's Jeep, but with a single HE351 turbo, 30% larger injectors. He has started building another truck with Isuzu engine and that will have another pump modified by Sheid with even greater fuel rate and 100% larger injectors.
My injection pump (4BD1T) with stock 9.5 mm elements produced 180 cc per 1000 strokes on a test bench when the rack was pushed fully in with the governor removed.
Torque and power are related directly to fuel rate through the brake specific fuel consumption (BSFC), providing enough air is supplied for combustion.
Stock values from the tag plates (required in USA) for 4BD1 and 4BD1T are:
1980 4BD1: 53.9 cc/1000 st for 87 HP at 3200 rpm
1985 4BD1T: 70.4 cc/1000 st for 116 HP at 3000 rpm
1989 4BD1T: 70.0 cc/1000 st for 121 HP at 3000 rpm
Now 121 HP / 70 cc x 180 cc = 311 HP at 3000 rpm, so given a maxed out (180 cc) injection pump tweaked for over 4000 rpm, a 4BD1T can be expected to produce 300 HP with the right turbo and intercooler.
A TD5 turbo has a smaller compressor impeller (52mm exducer) than a 300Tdi turbo and is too small for the fuel rate that a 4BD1T pump is capable of.
Welcome back John.
Thanks for the info guys :) well that is something to throw at these people that say it can't be done :) I need to figure out this fuel issue out and then ill play around with things and probably throw the tb28 on
These 2 threads in 4btswaps has info from the Isuzu Injection Pump manualQuote:
Originally Posted by c.h.i.e.f
Bosch A Type Injection Pump
Bosch RLD Governor
Note the Isuzu pumps are made under licence from Bosch