Hello and Identity crisis - Strange frame and engin numbers.


I am Chris and I have just joined the forum. Great site, and very useful for the T3 rebuild I am in the middle of. I have had the bike since 1992 and it has been unused for at least a decade.

At least I thought it was a T3. The VIN plate had been painted over so I cleaned it off. This is what I found:

Frame No. VG 163** . The Engine number VE 1015**

I looked up the number plate on the internet and found that someone claimed to have owned a V5 1000 with the same reg sometime in the distant past.

The frame tables suggest that it is a G5 Convert, and the engine number does not seem to conform to any frame number that I can find (VE frame numbers start at VE 111, my engine number starts at VE 101 )

From http://www.thisoldtractor.com/guzzitech.dk/gb_en_technical_moto-guzzi-frame-numbers.htm

V 1000 I Convert VG 11111 - VG 25693
V 1000 G5 VG 18744 - VG 25693
1000 SP & 1000 SP-NT VG 18781 - VG 25693

I will take the heads off at some later point and measure the barrels.From memory I think they are 83 mm but I could be wrong.

Can anyone tell me if the frame and engine numbers should match, and whether the VG frame suffix and VE engine number mean that the bike is a hybrid.



Welcome Chris…what year is yer bike…

Hi Chris, as most parts on Tonti framed bikes are interchangeable it is no surprise that in 30-40 odd years bits get mixed and matched. Mine has had an engine swap as well as many other modifications and changes, it now appears to be a different model, started life as and 850T and now looks like a 750S with a 950 Le Mans spec engine. To me that is fine as I made the changes, I guess that for you it may be different as you are just discovering them!

We will try and help you identify it all, as Kate said the year would help.

Best wishes Chris

Frame and engine numbers will not match

Hi, yes according to that your VG 163** does match the range for V1000 Convert.

In those early days frame and engine numbers did not match, that is a more modern thing.

‘VE’ suggests Le Mans, but I didn’t think the engine numbers had letter prefixes. Pretty sure mine didn’t. But not unheard of for Le Mans motors to be swapped into T3’s etc. What do your carburettors look like? T3 would have had the VHB30 ‘square slide’ carbs.

However with the Convert frame, this does sound like it could be a home brewed mongrel.

OR, as it is registered as a T3 (I presume?) it’s quite possible original frame was bent in a crash and so replaced with a second hand Convert one. Number heavily painted over to hide the fact.

Thanks Chris / Kate

The VIN plate says 1979. I should have mentioned, it also says that the engine capacity is 948. The side badges say 850 T3.

I am in the middle of a total rebuild, frame paint, all bearings and new wiring loom (the thing that finally took it off the road all those years ago). Fortunately as you say, all Tonti frames are much the same. I am sure the engine mystery will become clearer once I take a head off and measure the bore. In practice, the make and model are immaterial. I don’t imagine there are many factory spec bikes are left out there. I am asking out of curiosity as I had assumed for the last quarter century I had a T3. Now I find it is some sort of Frankenstein, possibly with the T3 badges as the only T3 part. :unamused:

Thanks Mike.

I reckon you might be right about the frame being swapped. The engine has has 30 mm VHB square slide carbs. Given that the frame showed up as a G5 1000 when I typed the reg into Google, it suggests that the VIN belongs to a G5 that has been modified toT3 standard.

It is registered as a T3. Time to dig the log book out of my “filing system”. That could take a while !

In that case, given also the 948cc engine plus the VHB square slide carbs, it all makes perfect sense if it is in fact a V1000 G5 that has been dressed up as a T3 lookalike. So no frame or engine replacements were involved.

Does it have a long sidestand with a square-ish foot on the end?

mine has VE on the engine block before the * - the guzzi manual shows this too…i ‘guess’ that as the block was similar across models, they were produced and stamped the blocks with sequential numbers between the stars, then the 2 letter prefix added once the engine was built up to whatever spec of bike it was going in to… which would explain why there doesnt seem to be a list of sequential engine numbers… just been out and looked at mine, and my '81 le mans 2 has a VE engine number about 2000 numbers below yours!

so yes looks like the correct range of frame for convert, with a le mans block (at least)… as a quick method to see if the heads are LM, the inlet manifolds on the LM are held on with M6 screws versus M8 on the cooking models…

It is not unusual I have a Convert engine in an 850T frame but the bike looks like a 750S :smiley:

Hi Chris.
That is a nice bit of kit. I have always loved the way Guzzis can be transformed. I have a LM1000 which as far as I am concerned fell out of the ugly tree and landed very hard. Once the T3 is finished, it might end up as a 1000S and I may be coming to you for advice :slight_smile:

Ignore the silencers

I have had a look and the inlet manifold is M8. All will be revealed when I pull the heads. Seems MG engine numbers are mysterious. I suspect the reason why your LM has a number 2000 below mine is that they had blocks of numbers for different engine configurations. Could be wrong, but it might explain the 2000 unit difference.

Thanks for checking your out.

Remember the M8 studs are in the head, the bottom end could be from a different bike, as it is on mine.

I recently bought a VE le mans 1 engine on ebay, all the numbers are correct for a mk1 series 1 850 le mans and it was fitted with small valve heads and later 850 nickasil cylinders, i knew about the heads before i bought the engine as they had the m8 inlet manifold screws, so it just goes to show it pays to know your stuff when buying guzzi bits as people like to play!!

OK so I still think it’s a G5 in disguise. I ask again what does the sidestand look like? G5 had a long stand like T3 California (tho not absolutely identical), whereas the European version of T3 had the short sidestand (aka, the “chocolate fireguard sidestand” )

Also when heads are off measure the cylinder diameter, if 948cc then should be 88mm.

If 850 (844) will be 83mm.

If Le Mans motor then will have dome topped pistons. If flat then it ain’t.

Mike, the cylinder heads could be from another model as I noted above, mine are but have been ported and flowed for 36mm carbs. I think you are trying to hang a tag on something that doesn’t need one. It is a Guzzi engine in a Guzzi frame. The size of the engine is relevant, but the exact model the frame came from is not apart from what is recorded on the registration document.

There are loads of T3s out there that have swapped the LH bottom frame rail so that they can have a better side stand, so I really don’t think this is a true guide to the original model. In my opinion the frame number is more important, but also in my opinion it is all academic, the bike has a frame and an engine.

Hi Mike.

It has not had a side stand in the time that I have owned it. I have just bought one that fits at the front rail joint (Chocolate fireguard I suspect.) I will put some photos of the frame rails on when I get time. I will also measure the barrels.

I’m inclined to agree with Chris. 1 engine, 1 frame, one day it will be one bike !!! I have no plans to sell, so it will do what it has always done, chug along and get me from A to B (sometimes).

If it is a Bitsa, then it could have any combination of the two bikes (or more). If not, it could be a G5 in T3 disguise. I was really asking about the numbers because I need to get a new VIN plate, and don’t know what to put on it. I presume that the old data including 948 cc will be the best bet, rather than having a fight with DVLA.

is there a need for the vin plate only one of mine has one

The regs say;
"Vehicle Identification Number (VIN or chassis number) is required on all vehicles first used on or after 1 August 1980. except those which are:
kit cars
amateur built vehicle

Mine has a W reg plate (Aug 80 to July 81) so in theory needs a VIN plate. It has been painted black since I bought the bike, so obviously MOT inspectors are not too fussy about this. It would be annoying if I found the MOT inspector who does care… so I thought I would get my retaliation in first and get a VIN plate before presenting the bike.

This despite the VIN plate stating DOM 1979. But the number is stamped into the frame and is legible.

Given that I can buy a VIN plate, stamp it myself and partially cover the VIN number stamped into the frame, I am not sure what additional security a VIN number provides. I just don’t want to get into any bureaucratic BS with DVLA to put a bike that I have owned for a quarter of a century back on the road.