Thread: Which is better - 2.25 petrol or 2.25 diesel?

....plus diesel is more readily available up the top end as well........I think for sheer ruggedness and reliability you can't go past the diesel.

My thoughts on the matter.

If you have both then I'd go the diesel. I don't think I'd ever bother removing a good petrol to drop in a diesel, but from a clean slate I wouldn't hesitate.

I changed from a 2.25P to a 2.25D. Wished I had done it years ago and would never go back. With a few tweaks a 2.25D can perform as well as a stock 2.25P and use 30-50% less fuel at the same time.

IMHO they are simpler to work on than a 2.25P. As for the injector pump, the CAV DPA is quite a good little pump and has been used on a whole range of engines - even Kubota tractors!

I have replaced all the seals on the pump myself. Not too hard. I don't know if my pump has ever been rebuilt since it was made in 1979. They go for a long time if you keep the fuel clean.

If you are worried though you could always carry a spare pump and a couple of spare injectors.

Downsides:
If overheated the injector nozzles will crack and may fail completely.
The precombustion chambers can drop out of the head if not properly peened in or overheated.
The engine which donated IP and ancillaries to my rebuilt 2.25D had both of these issues - it had been fully rebuilt (head resurfaced - no peening) - then overheated (I suspect). This resulted in one of the precombustion chambers trying to punch a hole through a new 0.040"OS ACL piston.

Some early 2.25Ds also had problems with snapping cranks apparently...

In my case, I have never had any issues at all with mine. The only time mine has stopped has been when I have run a tank dry, and needed to bleed the IP to get it going again.

I think Ben has just about covered it. In general I prefer diesel, but like Shonky I would think twice about swapping a good petrol for a diesel (unless I got given a good diesel engine!). Also, Ben comments that you can bring the performance of the Diesel up to that of the petrol with a few tweaks - but similar tweaks can put the petrol ahead again! Unfortunately, I don't know of anything that will get you reasonable mileage from the petrol engine!

The one big advantage the petrol engine has over the diesel is that it will stand abuse much better (mainly because it has the same mechanicals but less stressed). For example, run it out of water? probably no dramas if you let it cool. Neglect service? It'll keep running, although life will be shortened. Dirty fuel? Clean system out and good as new (Don't try that with the diesel!)

But still, overall, I would prefer the diesel.

John

oh I dunno, with a good filtration system you can run the diesel on near on anything....

and as for out of water killing them, nope, I ran mine near on out getting up to townsville for the cape trip.

The petrols got a bit more top end and more torque but the diesels got it nailed for the spread of torque and fuel economy, they also dont mind getting wet.

I wouldn't hesitate to go the diesel, just think, NEVER do plugs, leads, points, timing or carbies again.
Just oil and filter changes, and put in fuel.
I've had both, and would never go back to a petrol car.
There's also the better fuel economy.
It's all win.

My 2c

Fraser

I'm thinking of the doing the same thing. Fortunately, I located a series 3 diesel with 4 spare engines. Grouse.
Is the bulkhead different in a petrol 2a to a diesel 2a?

Iam sure all 4cyl fire walls are the same wether petrol or diesel. Half your luck finding 3 diesels I still have to go down Tamworth way to get mine lol.