Isuzu position vs 300Tdi

[rick130]

How much further back (if any) does the 4BD1 sit in the chassis/engine bay compared to a 300Tdi ?

Is it hard back against the firewall like a 200Tdi ? [edit] It can't be, the air filter sits between the head and firewall, doesn't it ?

Any measurements or drawings around ?

[flagg]

I don't have any drawings, but I can take measurements and photos if you like of a factory 4bd1 that was an LT85. What will help? Where do you want the measurements from?

[130man]

Hi Rick, I don't have the 110 county with Isuzu any more so can't give you exacty figures but you are quite right in that the air filter housing was horizontally positioned across the engine bay behind the engine. I would think the gap would have had to have been at least 150mm or possibly more like 200mm. Getting pretty soggy down here now, no likelihood of bush fires this week. How is it up your way? Cheers, Ross.

[rick130]

Pretty sure I have 4BD1 dimensional drawing here, so if it isn't too much trouble, say the back of the head to the firewall ?

I know the height of the heads will be different and therefore the distance not exactly comparable due to the tilt of the driveline axis, but it'll give me an idea.

[edit] I have 4BG1T drawing, and it's pretty light on dimensions. oh well.

[rick130]

Nice and wet up here Ross, it's just been good, steady rain so far, but the wind is picking up a bit ATM too.

Hopefully get the river running again soon too. :D

[edit] You're the man to ask Ross.

TD5 or 4BD1 ?

Which way would you jump after having both ?

[130man]

Hi Rick, off road, the 4BDI was fabuluous. Absolutely perfect for the task. On road, the TD5 except for initial take off, after that it is nicer to drive. I had the LT95 four speed gearbox , so the Santana LT85 five speed may have made the on road performance of the Isuzu better. Since most of my driving time is on road, I am happy with the TD5. Cheers, Ross.

[Slunnie]

Rick, without really knowing, they haven't kept it in the same spot as that used for every other engine in there have they? I just seem to think that they dont often seem to move the gearboxs in them when they fit different engines - the only exception I can think of to this is the Series Rovers. I thought that everything with an LT230 ran the same front propshaft and likewise when I changed my Series from an LT95 to a ZF/LT230 it ran the same propshafts and everything bolted into the same mounts. Just makes me wonder if likewise they have retained the same gearbox positions within the Defender chassis for those engines also.

[rick130]

Simon, the engine positions have changed all over the shop, they just seem to change the bellhousing length so that the g/box and t/case are roughly in the same position.

The 200Tdi was right back hard against the firewall, the 300Tdi is well forward, maybe 200mm or so.

Serg has acquired an R380 short bellhousing and input shaft from Ashcrofts as he's going to slip the 2.8 right back one day just for better weight distribution.

I was just wondering where the 4BD1 ended up in the scheme of things and if it was further back than the 300Tdi it might slightly mitigate the extra 140kg over the front axle. (the weight is the one thing that puts me off an Isuzu)

My Tdi is still going like a train even with the fuel turned right up and the abuse I dish out, but there's always that niggle in the back of my mind it's a bit soft.

While there's more to get out of it re a VNT and better I/C and maybe a little head work, it just seems like attempting to make the proverbial silk purse out of a sows ear when there are two better/stronger options available.

[uninformed]

and having the time to do the VNT/IC/Head etc with it being your work truck would be hard...

I know the Isuzu will outlast the next world war, and can make some gooood power. IMO the weight and torque pulse are not so good.

Seems that the TD5 is giving a good run for its money and would seem the smarter choice for turbo/IC/head work + chip and still not be silly reliability wise. You could atleast build this up while still running the Tdi and have it sorted for a swap.

hmmm Ashcroft T82 6 speed conversion......

IMO I would not spend any money on the Tdi other than that which will keep it on the road...yes that probablyt means your new rad, but Im sure when you do the swap you can sell some of the parts...

[rick130]

And I want to build up another t/case soon, this one is starting to whine and you can bet your bottom dollar the centre diff thrust washers are stuffed but you need a 1:1.003 input gear for the Isuzu and the Tdi sure as hell won't pull that in the interim.

Did DA ever get around to doing a T82 conversion ?

[LowRanger]

And I want to build up another t/case soon, this one is starting to whine and you can bet your bottom dollar the centre diff thrust washers are stuffed but you need a 1:1.003 input gear for the Isuzu and the Tdi sure as hell won't pull that in the interim.

Did DA ever get around to doing a T82 conversion ?

Hahahahaha I just fitted a reco transfer and it howls like a banshee :D

[rick130]

But I didn't build your t/case :p

and straight cut teeth don't count either :D

[uninformed]

not sure on the T82, id guess on the back burner...id like to think that with the number of Td5 sales and the fact the R380 LR OEM 5th gear bearing no longer available that they do end up completing it :cool:

[LowRanger]

But I didn't build your t/case :p

and straight cut teeth don't count either :D

No you didn't,but a certain workshop up your way did:mad:

No straight cut gears either,just a modified housing to stop the leak at the intermediate shaft.;)The noise is only on acceleration,so I am guessing that it is the mesh between the crown wheel and pinion gear:(

[LowRanger]

not sure on the T82, id guess on the back burner...id like to think that with the number of Td5 sales and the fact the R380 LR OEM 5th gear bearing no longer available that they do end up completing it :cool:

Yes I think it has gone quiet on this front,as there is no mention on the web site and no talk about it for a while.

[rick130]

It'd be a mesh issue but I'm guessing between the input/inter/hi-low range gears.
No CWP in the t/case, just the four pinion gears for the diff.

In all honesty its been a bloody long time since I've rebuilt anything with gears in it too, and noise didn't matter a jot when everything used straight cut teeth :D

[LowRanger]

With all the other noises in the vehicle I just put up with it,but I may run some Redline shockproof in it,to see if it quietens down.

[rick130]

Heavy Shockproof probably would.

Much the same reason I run 80W-140 SAF-XA in mine, plus it leaks out more slowly :D

[Mocky]

Hi

The distance from the rear or the rocker cover
to the center of the firewall where the vin plate is located
is 245 mm on my 85 Isuzu county


Mocky

[Bush65]

I have posted the following pics in the Isuzu forum before and the faxes (pdf format for 6x6) were posted there by another member. I have added them again here because I don't have time to search for the relevant threads.

The pics are my 4BD1T in my 86 trayback (the original 4BD1 engine and gearbox was remove and transplanted into a rangie by the previous owner of the trayback). There are a few differences between my engine and original, as fitted by JRA. Most notable as far as these pics are concerned are:
My 4BD1T has the Isuzu truck flywheel housing, gearbox and bellhousing, and viscous fan and the LH engine bracket for the engine mount (which is kicking the top of the engine over to RH side – needs to be modified).

The tape measure is held against the bulkhead (below the compliance plate, where it steps back a little) for both pics and readings should be close enough to any other Land Rover with factory 4BD1 installation, allowing for a little parallax error and the viscous fan drive on my 4BD1T.
https://www.aulro.com/afvb/images/imported/2013/01/96.jpg

https://www.aulro.com/afvb/images/imported/2013/01/97.jpg

AFAIK the gearbox position wasn't changed when JRA fitted the 4BD1 engine, however they changed the engine mounts from what was used with the V8 - they are considerably further forward. By a quick measurement the centre of the engine mount looks to be approximately 30 to 35 mm ahead of the spring perch or about 345 mm behind the chassis crossmember.

I don't know (never had one to measure) how the length of the bellhousings for LT95 and LT85 compare from V8 to Isuzu installations (as you can see in one of the pics my Isuzu truck bellhousing is very short.

Note in the faxes what Isuzu call the LH engine foot is wrong in the drawings for the JRA installation. Also in the parts list, there is a second LH engine foot (the correct one) in the list of loose parts. These faxes are for the later 4BD1T as fitted to army 6x6 and mostly apply also to the late 4BD1T as used in Isuzu trucks.

[rick130]

Excellent, thanks John.

It looks to be roughly in the same position as the 300Tdi.