c.h.i.e.f 's 110 Isuzu county

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Originally Posted by Dougal

John, did you look at shaving the LT230 and MXA to create clearance or was the interference big enough to preclude this?

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It was too long ago for me to remember how much they interfered but it was substatial.

What I do recall quite clearly is that:

1. it looked possible from preliminary measurements - but these involved paralax errors.

2. Then I stood the gearbox vertical (bellhousing on floor) and tried to position a partly stripped out LT230 over the gearbox output shaft, but with the front output housing against the gear case the LT230 input wasn't within coee of the gearbox output unless the LT230 was spaced back further than what I was aiming for.

3. I never took measurements while trying this balancing act, not simply because my hands were full and neither contained a measuring device, but because it would not lead to a solution.

The MXA is a larger box than an MSA gear centres, etc. But in the type 6-R version both 5th and 6th are overdrive, and 6th was added within an extension housing that bolts to the rear of the main case. Because of the ratio of 6th, the OD of the gearwheel is larger than any other in the box and the extension case to house it protrudes further widthwise than the main case.

Thanks John.
It's that fat extension case which I'm wondering about. I will be swapping bodies on my rangie at some point and need to redo the gear-linkage and transfer adapters at that point anyway to go to the "short stick" gear-lever position. The allure of 6 gears is strong and made worse by recently buying a 6 speed manual tdi car.

Do you recall how far back the 4BD1T sat in your rangie chassis? Mine has the PS pump clear of the crossmember by about 40mm.

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Originally Posted by Jitterbug

I used to work for DAF trucks and spent a reasonable amount of modeling the vibrations of a 4 cylinder diesel engine (i did my dissertation on this and continued to develop it when I worked for them full time).
The aim was to get the excitation frequencies (the rpm where most vibration was transfered to the chassis) outside of the standard rpm range.

It may be that 1600rpm is one of the natural frequencies for your engine and rubber mount combo.

To move this you can either change the mass of the engine (not really practical) or change the stiffness and damping properties of your rubber engine mounts.

I am sure i could dig out the simulation program i developed if you are interested.
You need to know mass of pistions, postion of pistons in relation to position of engine mounts etc. And you would need Matlab to run it...
Probaly easier just to use a softer mount to move the natural frequency down to a lower rpm (from memory i think that it the way it moves - lower 'k', lower Fn (Frequency, natural)). If you go too low there is a danger of introducing another excitation frequency at the top of your rpm range (2xFn).

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Thanks for this...any help or info you can provide on anything is always welcome....
So in regards to stiffness would it only be applicable to the engine mounts or all the mounts (gearbox and transfer)... So engine mounts can reduce the vibration but how much compared to extra inertia on the flywheel I wonder...

I also done what John done by roughly lining the lt230 up behind the mxa and by the looks of it is as John mentioned (front output of the lt230 fouls on the bulge of the extension)...by the looks of it in my situation making the spud shaft short as possible the overall length from bell housing face to the rear of lt230 will end up being around 45mm longer than the lt85/lt230 (800mm)...as for rangies I have no idea so I'll let you pair talk about that ...:D

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Originally Posted by Dougal

Thanks John.
It's that fat extension case which I'm wondering about. I will be swapping bodies on my rangie at some point and need to redo the gear-linkage and transfer adapters at that point anyway to go to the "short stick" gear-lever position. The allure of 6 gears is strong and made worse by recently buying a 6 speed manual tdi car.

Do you recall how far back the 4BD1T sat in your rangie chassis? Mine has the PS pump clear of the crossmember by about 40mm.

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Sorry, I can't remember how far back it was. I changed to a different steering box outside the chassis rail and put the engine as far back as I could.

[ame=http://www.youtube.com/watch?v=QPN-fDErYZA&feature=youtube_gdata_player]Matt's Video - YouTube[/ame]

I think it's stuffed mate, a suzi shouldn't sound that good :D
I'll be happy to take it off your hands :angel: :wasntme:
Sounds killer, can I at least order one? :p
Cheers
Muppet

Sounds bloody good Matt. What aircleaner and exhaust setup are you running to create such a whistle?

How is the boost and smoke?

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Originally Posted by Disco Muppet

I think it's stuffed mate, a suzi shouldn't sound that good :D
I'll be happy to take it off your hands :angel: :wasntme:
Sounds killer, can I at least order one? :p
Cheers
Muppet

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Hahah I wish I could order one it would be so much easier :angel: I'll give you a trip in it if your ever down my way when it's finished...

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Originally Posted by c.h.i.e.f

Hahah I wish I could order one it would be so much easier :angel: I'll give you a trip in it if your ever down my way when it's finished...

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I'll hold you to that :D
We used to cut through cessnock when we lived in tamworth, however we sold that property :)
I might have to make an exception for that kind of turbo whistle though :D :angel: