V5C fuel type / Heavy oil / historic vehicle

Hi, I have a 1980 Series 3. I bought it a few years ago and had been on SORN. It was originally a petrol engine but a previous owner had converted to a Cummings diesel. When purchased it, the previous owner told me that the V5C records were petrol and as it was done prior to their ownership it was too complex to get amended ( no letter from the garage who undertook the work ).
It's time to get her back on the road. I sent off my V5C along with some hand written info showing the conversion was done in 1986 ( handwritten info on certificate printed inside perkins 200 series owners handbook )
A couple of weeks ago I checked the online MOT checker and she is recorded as a diesel.
Last week I got my V5C back and whilst the engine number has been changed, the fuel type was still petrol
I phoned the DVLA and was informed they would contact the relevant department.
Today, I have received a new V5C with fuel type as Heavy Diesel.
Should I accept Heavy diesel given the ease with which I have had the V5C amended andfor fear that my paperwork (which is scant but as far as I am aware honest ) would be further reviewed and and be changed back to the original.
Finally, as the paperwork suggests a 1986 conversion, would the fuel type of Heavy oil affect the historic vehicle status?
Many thanks
B

Pretty sure they used to list diesel as heavy oil, maybe they still do.
With regards to classic status, must be hundreds of land rovers which have been changed over the years

Just checked and my series 2 is listed as heavy oil for fuel type on the v5.
Same for my 1993 90.
Same for my 2006 D3.

So in light of the above heavy diesel would be good enough for me.

djc said:

Hi, I have a 1980 Series 3. I bought it a few years ago and had been on SORN. It was originally a petrol engine but a previous owner had converted to a Cummings diesel. When purchased it, the previous owner told me that the V5C records were petrol and as it was done prior to their ownership it was too complex to get amended ( no letter from the garage who undertook the work ).
It's time to get her back on the road. I sent off my V5C along with some hand written info showing the conversion was done in 1986 ( handwritten info on certificate printed inside perkins 200 series owners handbook )
A couple of weeks ago I checked the online MOT checker and she is recorded as a diesel.
Last week I got my V5C back and whilst the engine number has been changed, the fuel type was still petrol
I phoned the DVLA and was informed they would contact the relevant department.
Today, I have received a new V5C with fuel type as Heavy Diesel.
Should I accept Heavy diesel given the ease with which I have had the V5C amended andfor fear that my paperwork (which is scant but as far as I am aware honest ) would be further reviewed and and be changed back to the original.
Finally, as the paperwork suggests a 1986 conversion, would the fuel type of Heavy oil affect the historic vehicle status?
Many thanks
B

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Heavy oil is Diesel.

Being diesel won't effect Historic Status, having a non Land Rover engine will (I think).

There is a points system where you declare any modifications, including engine changes.

Turboman said:

Heavy oil is Diesel.

Being diesel won't effect Historic Status, having a non Land Rover engine will (I think).

There is a points system where you declare any modifications, including engine changes.

Click to expand...

I think heavy oil is in fact heavy oil, and is an old term from when they bunkered ships with heavy crude oil, so heavy/thick that they have to heat it up to somewhere near 100 degc to make it viscous enough to work in the fuel injection system.

lynall said:

I think heavy oil is in fact heavy oil, and is an old term from when they bunkered ships with heavy crude oil, so heavy/thick that they have to heat it up to somewhere near 100 degc to make it viscous enough to work in the fuel injection system.

Click to expand...

I think that is right. But it said Heavy Oil on the log book of my diesel Mondeo, so suspect it is the same thing for DVLA purposes.

Also interested in whether the actual engine in his motor is a Cummins or a Perkins. Seems to be some ambiguity in his post.

It's all diesesed

Turboman said:

I think that is right. But it said Heavy Oil on the log book of my diesel Mondeo, so suspect it is the same thing for DVLA purposes.

Also interested in whether the actual engine in his motor is a Cummins or a Perkins. Seems to be some ambiguity in his post.

Click to expand...

Sorry, my error. It is a Perkins 200 Series
D

djc said:

Sorry, my error. It is a Perkins 200 Series
D

Click to expand...

What is the capacity of that engine?

As far as I can remember, the cubic capacity is all that appears on the V5 about the engine.

Similar situation to my 11A.
I sent V5 back earlier this year with handwritten note explaining it had been converted to Diesel some years before.
It was a LandRover Engine of same capacity. I was deliberately vague, as I didn't know when it converted.
V5 returned couple of weeks later with Petrol replaced by Diesel.
I know the OP had a Perkins Engine, but it could have come from an Austin Rover product so thus acceptable ?
Heavy Oil, Heavy/Diesel or even Derv are all the same, even though 'Derv' isn't !

I seem to recall that if any major change to a historic vehicle is something that was fairly common at the time they were being built and any change was done within 10 years of its first registration then its fine,

Heavy oil is like treacle when cold, the alternative name for diesel is gas oil, never heard it referred to as heavy diesel?