General 740Auto - 6 cyl.Diesel power

[zetor160]

Hello all,

Just wondering if ther is anyone out there who may be able to help with either advice or somewhat more in the form of help to assist me in my project of converting my 740 to 6 cylinder Diesel power??

This was going to be my summer project but now I have been informed that I will soon be losing the (loaned) garage where I was due to undertake the work.

If anyone knows anything or has any advice on this (non-standard) conversion) I would be more than happy to hear from you.

I would really like to keep this car for the foreseeable future and the only real way I can do that is by converting to Diesel.

I have the engine all ready to go fitted with torque converter, just need to be able to find a conversion plate/engine mountings if possible to save on time in fabricating my own.

I would also be open, of course, to swap/buy for a good VW 6 inline to make the job easier.

All advice appreciated

Gareth. Tel 07870 847672

[Clan]

its hardly worth it using the Vw you would average around 35 mpg bearing in mind diesel fuel is more expensive than petrol . Why not a 4 cyl diesel ? remember they put the 1.6 diesel in the new s80 and V70 and that works quite well giving 45 mpg or so .
The 4 cylinder 1.9 diesel from the V40 and manual M90 gearbox from a 960 would be perfect .

[zetor160]

Clan,

Thank you for your thoughts. My only problem would be that the VAG-PD engine would not really be man-enough for the weight of the 740?? - Prove me wrong - he he!

Plus..I am a 6cyl fan and having already got the engine I'd like to shoehorn it in there.

What I am looking for in particular from this conversion are low running/ servicing costs with no electronics to go wrong giving great long-term reliability, more than getting the ultimate fuel economy.

As i'm sure you know, the LD Nissan series of engines (although long in the tooth by now) have a great reputation for all of the above, having a cast block and head with a timing chain as opposed to belt.

Still open to suggestions..
Regards

[zetor160]

Why did I think you mentioned the Vag engine..?? Beats me!!

Ok..the V40 engine which I believe is a Renault based transverse engine.

You say this would convert to being an in-line motor without too much work?

May well be worth looking in to..

[Daim]

Originally Posted by zetor160

Why did I think you mentioned the Vag engine..?? Beats me!!

Ok..the V40 engine which I believe is a Renault based transverse engine.

You say this would convert to being an in-line motor without too much work?

May well be worth looking in to..

It will need a bit of electrical wiring... But it should be a rather easy fit - though the problem is, the M90 would have to be adapted so you'll need a custom "bell housing", as it has nothing in common with the D24 nor whiteblocks or redblocks (white and red are Volvo own engines). You'd have to look for a vehicle with RWD and the Renault 1.9d... You might be lucky with a Renault Traffic/Master (not quite sure if they are RWD but I thing the Master is and was available with the 1.9d). But then you'd probably need to make a custom gearstick linkage and adapt the prop tunnel to make space for the gearbox...

The D24 (2.4l VW 6 cylinder NON PD!!! It is a pre chamber (like in many older Mercedes) and has nothing in common with a VW PD diesel - except the fuel ) is - when adapted properly, a powerful and fuel efficent block. Just needs the correct settings.

-> higher fuel pressure
-> different injector valves
-> increase in turbo pressure
-> increase in injection volume
-> setting of injection "begin"

A friend of mine had a 940 with D24TIC (the engine to go with -> 122 hp, turbo, intercooler) running on vegi-oil (leftovers from chippies) and putting out - via rolling road - 178 hp and reaching top speeds of around 240 km/h (with LOADS of torque). That was of course combined to an M46 overdrive gearbox. He was looking for an autobox (ZF) but couldn't get one to cope with the power...

The fuel consumption, after a few tweaks, was quite good and at around 7l/100 km for that power VERY moderate! Something like 41 mpg or so...

Important is, if you want to convert to a D24 6 cylinder, is to first of all get all parts.

-> prop shaft
-> gearbox (manual/automatic - both have different bell housings!)
-> rear axle
-> radiator
-> intercooler piping
-> brake servo (as iirc the servo was smaller)
-> engine (look for one from a 940, they are better when it comes to durability! The ones in the 700 series tend to "boil" when used with a load for a longer time)

When all together, it is a rather simple plug and play. Glow relais, wiring, etc. - rather simple. I'd only toggle it, if I had a donor car...

[zetor160]

Thanks for your reply.

I would be very happy indeed if I could end up with a result only similar to your friends' car.

My car is an Auto, so I want to minimise the work by keeping it the same, plus, I rather like the auto anyway.

The engine which I 'hope' to fit is known for being well suited to running on SVO, the Nissan LD28.

Thanks again and let me know if you have any more thoughts!

Regards

[Daim]

If your Volvo has an automatic box, it won't fit the Nissan engine - simple reason: it is made for the Volvo redblock petrols and the AW70-72 (depending on version fitted) will not really run with a diesel - hence Volvo fitting the ZF slush boxes to all diesels.

I remember once seeing a 740 running a Mercedes 6 cylinder diesel from a W124 (300D) with the OM603 (legendary Mercedes diesel) and a turbocharger. At the same time, the Merc. automatic had been installed. The only thing needed was a custom piping for the intercooler and the prop shaft... It had in stock condition 147 hp (for a diesel in the late 80ies/early 90ies a lot) and is very forgiving...

Maybe that would be something looking into? 300D Mercs. sell here in Germany for nearly "sod all", as they aren't "eco-friendly" in the eyes of the German government...

[zetor160]

Originally Posted by Daim

If your Volvo has an automatic box, it won't fit the Nissan engine - simple reason: it is made for the Volvo redblock petrols and the AW70-72 (depending on version fitted) will not really run with a diesel - hence Volvo fitting the ZF slush boxes to all diesels.

I remember once seeing a 740 running a Mercedes 6 cylinder diesel from a W124 (300D) with the OM603 (legendary Mercedes diesel) and a turbocharger. At the same time, the Merc. automatic had been installed. The only thing needed was a custom piping for the intercooler and the prop shaft... It had in stock condition 147 hp (for a diesel in the late 80ies/early 90ies a lot) and is very forgiving...

Maybe that would be something looking into? 300D Mercs. sell here in Germany for nearly "sod all", as they aren't "eco-friendly" in the eyes of the German government...

Daim..
He He..I plan to make the Nissan fit by finding and/or fabricating a conversion plate for it - I want to keep the car with its original transmission if possible.

Having said that..I am not closed to the idea of putting a Merc 250/300 diesel in it either..that would be sweeet. I am just working with what I have at the moment, time will tell.

There were companies (10+ years ago) who fitted these Nissan engines to Volvo 700/900 cars often using original trannies. However they have all now disappeared, and it is impossible to find any of these conversion parts anymore.
Still scratching my head..and thanks for taking the time to reply

[hercules]

Hi Zetor160, just reading through this thread.

My father had this conversion done many years ago (early 80's - mid 90's)on a 740 (?) and replaced the petrol engine with a diesel engine from a Nissan Laurel + the gear box as well. This was a good job and we were able to drive her for many years. I know this doesnt help you much as you want to keep the automatic transmission.

This was done by http://www.eddietorrens.com/

We also bought an old volvo 244 estate with the conversion already done - this was ok but the problem here was that the gear box that was fitted was only 4 speed so wasnt as economomical and tented to heat alot.
We also had a petrol volvo that had been converted to gas - terrible job though the gas was fairly economical.

[zetor160]

Thanks a lot for this..It's interesting that you owned two of these converted cars.

Thanks for the linky too - looks interesting.

Just want a car that's reliable, simple to maintain and relatively good on fuel economy, coupled with the individuality of an old skool Volvo.

If you have any more info/links/knowledge/parts info etc. would be much appreciated - as is this post.

Regards