Engine swap for 169

169 has clocked up nearly 40000km's since it was put back on the road earlier this year after spending several months being brought back up to standard for our organisation to us for awareness tours. I also went throught the process of getting the GCM upgraded so I could tow our big trailer while away. After spending most of those km's battling to keep a reasonable pace it has come time to retire the little Perkins and put something in with a bit more potential. After listening to all the disscutions on this forum and doing a lot of research and also chatting with a few of you as well as Paul Knott. I decided to go with a 6bt Cummins with a 6 speed Allison adapted to the NP 205.
After a lot of prep getting the engine and gearbox ready the OKA was taken of the road this week. We jacked it up 300mm and removed the front axle. After disconnecting all the essentials we lowered the engine, gearbox and transfer all together with a gantry crane and a jack. We have since done a trial fit up of the transmission and transfer case to check the front tail shaft clearance on the Allison sump. Thankfully the clearance was ok.
The next thing is to clean up the engine bay ready for soundproofing and cleanup some wiring. We will then lift the Cummins and Allison in to workout some mounts etc.
I will put up some pic's in the next day or so.
If any of you have any advice on the best way to sound proof the engine I would be happy to hear it.
Rob

Rob
When I did the Humvee which was a metal box with NO soundproofing or insulation I cleaned the underneath with degreaser and then paint prep to get it all clean and dry. Actually did the interior as well as there was nothing to get wet either. Then stuck Hushmat which was a bit cheaper than Dynamat but essentially the same, it also came in a black version as well plus was available locally in Oz in larger sheets than the Dynamat at the time. Then I stuck underbonnet insulation onto the Hushmat in the actual engine bay from that mob that advertise in the Open Road in Dandenong. You can also get a similar product from Whitworths or boat places which is cheaper but I found that stuff absorbed and held water in the foam section and then over time it delaminated in various spots. Guess it doens't get wet in boat engine bays!
Fitted Hushmat inside to all vertical and horizontal surfaces except the footwells and anywhere that was likely to get wet. In the footwells I cut and shaped closed cell foam sleeping mats to suit and placed them under the floormats, everywhere else I stuck it down with contact glue, I've actually done this to every 4wd I've ever owned including the Oka and it is relatively cheap. I just use the cheapies from Kmart etc and makes a huge difference to heat and sound.
Then I fitted marine carpet over the lot inside. Quite a few other Humvee and H1 owners made the comment that my Humvee was much quieter than any they had ridden in! I've had similar comments re 374 and I've only done the Hushmat and closed cell foam inside so far.

Looking forward to see how your conversion goes Rob.

The little Perkins has done a sterling job, with well over 400k kms and nearly 20 years old.

These guys do spray on sound and heat barrier. Lizard Skin


Maybe a combination. Spraying on this first???

Just a teaser

One more

Looks promising Rob!
Cheers,Joe

Good to see.

I did some work to get 169 ready for a 6bt. Mainly bigger Air filter, the intake pipe up coffin panel is 4 or 5 inch for memory. Think the fuel lines was upgraded as well.


Pollack Valve

have you got any pic's of the adaptor, Allison to np 205

I'm weighting for mine to arrive!!

I will have it together in the next couple of days, will post pic then

I thought I should update things a little. To date we have plated the chassis on the inside and along the bottom to prevent more cracking around the engine mounts. We have made the engine mounts, gearbox and transfer mounts and put another cross member in to hold a cradle that supports the gearbox and transfer. We have also made the mount for the spring actuator for the handbrake. I have also had the gearbox to transfer adaptor welded. For those also welding adaptors be sure to allow for machining after it's welded. I had to take 2mm of the transfer face to get it flat and running true to the gearbox end then I had to rebore the bearing and seal dia to get them true and to depth also the bore will shrink with the welding. When I purchased the adaptor from the state they told me it would not need machining after welding they were wrong.
I have also finished converting the Allison to 4x4 after changing the tail housing and c5 piston and will take it to Sydney this week to have it checked on a dyno. I think I have solved my starter problems as well, it looks like I will be able to use the Perkins starter with a different pinion tooth count, we will see.

This beats reading any X rated website......

Ralley wrote: I For those also welding adaptors be sure to allow for machining after it's welded. I had to take 2mm of the transfer face to get it flat and running true to the gearbox end then I had to rebore the bearing and seal dia to get them true and to depth also the bore will shrink with the welding. When I purchased the adaptor from the state they told me it would not need machining after welding they were wrong.

]

Rob
The fact that the adapter was out of square after welding tells me that it probably has a large amount of internal stress. I would imagine that the parts were spigoted and then pressed together before welding ( at least that's how I would have done it) .
If so, for it to be then 2mm out of parallel is a huge amount. Machining would not remove the stresses

Normally a part like this would be stress relieved between the welding and machining phase. I'm not trying to put the mocker on it, but it would worry me greatly if it was mine.
Pete

Rob
the starter on the Allison bell housings is on the LH side & RH side for manual.
the Perk starter fits & auto ring gear has 150 teeth.

thanks for the pic if the adaptor.
we have made a 1 piece direct mount the np 205 to the Spicer g/box.
in stead of the Allison circle, Spicer plate & longer tube.
spigoted & welded inside & out to relieves stress but still had to skim the faces to true it up.

will be simple to make an Allison circle & shorten the tube.

will post some pic;s later.

Yes Peter the parts were a slide fit, the only part that pulled is on the one side with the support. Every time you put a weld down you introduce stress so it was expected, from my experience I think now it's been re machined it should be fine.

Hi Rob,

Picked up a 6BTA today and I am looking at a 12 month project for 351. I'm
going to strip the motor and make sure all is good before installing.

One of my concerns are the engine mounts. Did you make any drawings?
If you did are you willing to share? If not did you just dumby fit the
motor and then fabricate.

Also did your motor come with a hydraulic pump. Or did you make the perkins
fit. Or did you buy a new one. If so do you remember where as the 6BTA I have
got has got that opening blocked off.

I am planning on keeping the spicer at this stage so will this make a difference
to my engine mounts compared to yours.

I am watching your post with great interest and am really grateful for the photo's
you are putting up.

Cheers Brian

Brian
The hydraulic pump mounting position on the 6BT is a standard SAE fitting so as long as you have the correct gear to fit the engine and the gear fits on the shaft a standard pump will mount up.
I've got a standard ZF 6BT pump and gear that bolted straight on after the plate is removed.
You can get the Perky one fitted with a new shaft but it isn't really worth it, just as easy to get a 6bt pump and gear. Pretty much any hydraulic place can supply one to fit or do a search on ebay
as there are lots available.
Just make sure that it has similar or better specs than the Perky pump as it needs to run the hydroboost for the brakes and the power steering.

Hi Brian.
The first thing I did with 169 was to lift it up high enough to fit the cummins in from under neith. We then levelled it front to back then side to side then made brackets to mount the front tow points to a steel bench and welded them to it. We then took a heap of pics and measured things up the best we could including the angle of the engine ( I was surprised how much difference there was between the angle of the rear diff and the transfer case about 3deg) . After removing all the old we then fixed the craked chassis and plated it on the bottom and on the inside. We then mounted the gearbox to the engine and lifted it into position and moved it around until we were happy with the clearance all round. We then levelled the engine and set the angle to suit our application. We then made the mounts to suit at the same time making them much stronger than the old ones. As fare as I understand those that use the spicer just modifie the old mounts and end up with the gearbox in the same place. I think my engine being a genset engine has different mount points on the block, we used 6 12mm bolts on each side of the block for the mounts and we are using 2 of the original mount bolt holes each side of the chassis and will drill and tap another 4 each side to give us 6 a side. If you use the original engine mount brackets be sure to strengthen them, I had to fix a cracked inner mount when I first bought 169.
The hydraulic pump is also a ZF. I purchased this of a guy on eBay, he specialised in power steering pumps it was $150 US secondhand with the right gear. I then put a seal kit through it.

Brian as Rob said before you start check the angles between the transfer case and both diffs as it is surprising how far out they are in standard trim. Also check the angle of the engine in situ as you then have a ballpark figure for everything to end up at.
I put wedges under the rear diff saddles to rotate the diff nose up to obtain a better rear tailshaft alignment when I fitted the auto and Nissan transfer case, lots of Oka's have had this done to stop them chopping out rear uni's as in standard form the diff nose tends to point down.

Thanks Rob and Peter,

Any knowledge I can gain I am sure will help me later and make it a lot easier.

Yes I thought of measuring the angle of the Perkins before removal for a ballpark.
I will check all angles too, as I don't want to start chewing up uni's.

Ok so it seems to remove the old and then fabricate or modify for the new.

I'll have a look on ebay for those pumps.

Thanks heaps.

Brian.

While filling in time while waiting for a starter to try. I started looking into the radiator. On closer inspection I found I was only supplied a 3 core when I had it recored last year. I will look into getting a thicker core but was also wondering if I could get the core lengthened at the same time and adjust the tunnel to suit the radiator being lower. The problem I can see with this is the clearance on the steering arm on the bottom of the radiator. The axle is out at the moment so I was wondering if anyone could tell me how close the steering arm goes to the radiator at full compression in an XT.

Thank