Thread: V8 to isuzu

Lots of threads on this, the best LT95 is the one fitted to the Army 110 Perenties (

Originally Posted by Bearman

... The gears you need are FRC4500 and FRC4032, 45/26 teeth. This will give you the 0.996 ratio !...

Unfortunately you don't have one of those. Therefore the ratio from your Stage 1 is your best option.

You will have to change the engine mount brackets on your County to suit the position and shape of the 4BD1 engine mounts. Maybe even donor them off the Stage one.

You have to use the County axle assemblies because of the track width and they have the same diff ratios anyway!

Thanks this helps heaps.

You'll need to sort out a solution to the power steering pump as well.
I'm guessing your stage 1 doesn't have a pump fitted to the isuzu

Re the power steering. My hybrid has a 4bb1. Which as far as fitting a power steering pump is the same as the 4bd. The power steering pump has been fitted on the left lower side of the motor. The vee belts will be different to mine though as I have the water pump and the 24 volt alternator or mite be a generator on one belt . The 12 vollt alternator and power steering is of another belt driven from the water pump pulley. If you want I can post a pic of the bracket and tension-er.
Cheers Hall

Your 85 County should have an LT95 4 speed already in it ( same as the Stage 1 only different transfer hi gear ratio). Use the better one of the 2 and change the intermediate shaft hi range ratio. The gears you need are FRC4500 and FRC4032, 45/26 teeth. This will give you the 0.996 ratio that you need for the Isuzu. The Stage 1 box will also have a longer front transfer output housing and shaft and a DC shorter front driveshaft. For these reasons I would be using the County box if it is still OK- just put the Isuzu clutch bellhousing and longer clutch pushrod and throwout bearing from the Stage 1 box onto it. You will probably have to reshim the intermediate shaft anyhow. Drop the transfer sump on your Stage 1 and check what ratio is in it (do a tooth count) as it could already be changed to 0.996. The Stage 1 will have the small fat handbrake assembly whereas the County will have the larger better handbrake on it, but if you want to change the County one onto the Stage 1 box you will also need to change the output housing that the larger one is fitted on. Everthing is bolt up achievable if you have a bit of mechanical knowhow. As said above you will need the Isuzu engine mounts welded to the chassis in lieu of the V8 ones which are very different. The radiator is another story as the Stage one radiator mounts are different to the County. You can modify the County V8 one by swapping the inlet/outlet pipes on the tanks if the core is still OK. The PS is also another task also as some Stage 1 motors did not have provision on the timing cover for a bolt on PS pump. Do a search on here and you will have many hours reading on this conversion but it is all doable if you have the patience and mechanical skill. The only difference between an Isuzu army perentie box and a civvy Isuzu box is the more durable tapered roller intermediate shaft assembly in the transfer case instead of the standard shimmed roller bearing assembly. The gearbox and everything else in the transfer case is the same.

I used a Stage1 Isuzu radiator fan shroud on my County conversion, just had to do some minor mods to mount it up, but the lower edge sits nicely in the V8 radiator brackets and the fan is pretty central with the engine at nice height.

A 4-bolt PAS box will give you a bit more room around the pump, but not essential. Ideally you want the pump with outlet at the front, but I've seen some conversions done with the 4bd1 Isuzu truck pump that has the outlet on the RH side towards the box.

And stick a turbo on it at the same time. You wont regret it, and the smile doesn't fade

Steve

The stage 1 4BD1 should have a cover plate on the timing cover to use the timing gear for the PAS pump. Its on the RHS of the timing cover below the injector pump gear.

If the 4BD1 comes from another application the facility for pump may not be fitted, meaing you either have to change the timing case or fit a pulley driven PAS pump.

In relation to Bearman's post. The Army Perenties had the 0.996 ratio but on the road they are slow to get up to speed, many people prefer the Stage 1 Isuzu ratios, although they lose speed off the top. The choice is a preference thing.

To get it one the road, I would use what you have and change later if necessary.

Diana

Don't use the Stage1 LT95 as is - even if the V8 one is stuffed.
If the V8 one IS stuffed, then take the time to swap the front and rear output housings over to the Stage1 box (as well as the bellhousing).

Bearman has already mentioned some of the differences, but its more of a PITA than you think using the Stage1 box directly in a County.
- Front output housing and shaft are longer than County box (need a shorter propshaft so cant use standard county one, uni angles are greater, vibration, and issues with uni's binding with any lift etc)
- Front output flange is larger diameter than County box (and doesn't match any other Landy propshaft)
- Handbrake drum is smaller than County box so not as effective
- Speedo drive gears are different number of teeth than 110 (on the shaft itself - not just the plastic one thats easily changed), so impossible to get County speedo reading correctly with higher transfer ratio's like .996 or 1.113 etc

The Stage1 box in a County is just a world of hassle in my experience and although I've worked through all the shaft and speedo issues with mine I wouldn't do it again if I had a choice.

If you stick with the County box instead, all you need to change is the bell housing. Everything else stays as is, and you could even leave the box in the County and do the bellhousing in-situ if you wanted. I wouldn't recommend doing it that way, but it illustrates that nothing else needs to be changed to bolt it up to the Isuzu.

Steve