1800: Front Frame and Engine Block Questions

[ZTatZAU]

Hello, I'm hoping someone can answer these questions...

1) Did the front frame rail sections of ALL MODEL YEAR 1800s include the arc shaped pressed depression in the bottom surface as shown in the clay mold below?



I know the original 1967 front frame rails have this pressed depression but did any 1800s come without this arc shaped depression in the bottom surface of the front frame rail? It's pretty hard to tell from what's left of the frame rails on my '68 but one side looks like it could have been flat on the bottom. (Or repaired at one time!)

I know Brookhouse and a few other 1800 parts suppliers offer front frame rail patches but none that I've found include this pressed arc shaped depression on the bottom surface. Is anyone aware of any replacement 1800 front frame rail patches that do include this pressed depression? Did all 1800s have these depressions on the front frame rails?

2) B18 engine casting marks... I'm fairly certain the engines and drive trains in both of my 1800s are original to the cars. I am waiting to hear back from the Volvo Museum folks to verify this. In the meantime, I'm very curious about the casting numbers, shown below, on the blocks of my two B18B engines.

1967

1968


I've learned the numbers are the B18B block p/n, but I'm wondering specifically about the letters LBG on the 1967 and MBG on the 1968.

I'm guessing the first letter could be a YEAR code. (i.e. L=1967 & M = 1968) Consecutve years... consecutive letters?

The second letter (B) perhaps a MONTH code. And if A = January, B = FEBRUARY, etc., this could make sense with both of my chassis numbers falling just past the middle of the chassis numbers assigned for the 1967 & 1968 August to August production years. February would fall just past the middle of the production year.

And finally, I'm thinking the G could very well indicate Gotenburg.

Can anyone verify my speculations? Or set me straight on what these letters mean?

Thanks! ZT

[Army]

I think you will probably have to wait to hear back from the museum.

There are a few threads on this forum that tackle the subject (such as this one https://www.volvoforums.org.uk/archi.../t-138595.html) but as far as I can see they don't give you a direct answer to your questions.

I've been down a similar "matching numbers rabbit hole" with my Land Rover. On the whole I came to the conclusion that the letters cast into the blocks were foundry specific letters and did / do not have anything to do with the vehicle manufacturer / manufacture process. This might not be the case for Volvo of course.

On the whole from a matching numbers administration perspective those relationships are centred around the serial numbers and what was recorded by the manufacturer.

[cassell]

I can confirm that on a previous 1972 ES and my current 1973 ES they both had those depressions in the front chassis rails.

I never really understood why they were there but on the '72 car it was the worst point of corrosion which I had to repair by fabricating sections in 1990 as in those days the repair sections were not available.

Hope this helps?

[ZTatZAU]

Originally Posted by cassell

I can confirm that on a previous 1972 ES and my current 1973 ES they both had those depressions in the front chassis rails.

I never really understood why they were there but on the '72 car it was the worst point of corrosion which I had to repair by fabricating sections in 1990 as in those days the repair sections were not available.

Hope this helps?

Thanks Cassell, I appreciate your reply.

When you fabricated your front frame repair panels, did you include the depressions?

PLMK! ZT

[ZTatZAU]

Originally Posted by Army

I think you will probably have to wait to hear back from the museum.

There are a few threads on this forum that tackle the subject (such as this one https://www.volvoforums.org.uk/archi.../t-138595.html) but as far as I can see they don't give you a direct answer to your questions.

I've been down a similar "matching numbers rabbit hole" with my Land Rover. On the whole I came to the conclusion that the letters cast into the blocks were foundry specific letters and did / do not have anything to do with the vehicle manufacturer / manufacture process. This might not be the case for Volvo of course.

On the whole from a matching numbers administration perspective those relationships are centred around the serial numbers and what was recorded by the manufacturer.

Thanks Army!

I'd already seen that post and a few others as well. Most of the threads I've found have to do with engine type and serial numbers. And while this thread mentioned the block part number, I've seen no discussions about the three letter code just above it.

If I don't get any more info on the forums, I'll write to the museum archive folks. I'm presently waiting for chassis reports on my two 1800s but they advised responses will be slow due to covid. I almost hate to write them again now about the block letters and add to their workload.

ZT

[cassell]

Originally Posted by ZTatZAU

Thanks Cassell, I appreciate your reply.

When you fabricated your front frame repair panels, did you include the depressions?

PLMK! ZT

No, I simply created box sections without the depressions but with captive nuts for the anti-roll bar mountings, welded them into place, remounted the steering box and idler, anti-roll bar brackets etc and all was good. Heaven knows what the depressions were for?

Paul

[c1800]

“ Heaven knows what the depressions were for?”

To add structural strength and rigidity ?

[Derek UK]

Originally Posted by c1800

“ Heaven knows what the depressions were for?”

To add structural strength and rigidity ?

Agreed. The numbers on the machined pad are the actual engine numbers but the complete engine has to have the code that is on the adjacent pad combined with it. The one not shown will indicate the model year letter and the engine type.

As said the embossed numbers are just the numbers of the foundry moulds used to make the blocks. Also embossed are B18 or B20 and they are self explanatory.

[ZTatZAU]

Originally Posted by cassell

No, I simply created box sections without the depressions but with captive nuts for the anti-roll bar mountings, welded them into place, remounted the steering box and idler, anti-roll bar brackets etc and all was good. Heaven knows what the depressions were for?

Paul

Thanks Paul,

If you wouldn't mind me picking your brain some, did you fabricate your frame rails by folding in a pan brake or make the bottom and two sides separately and weld the three pieces together?

Thanks!

Originally Posted by c1800

“ Heaven knows what the depressions were for?”

To add structural strength and rigidity ?

That makes perfect sense to me c1800.

Can you confirm that all model year 1800s had these depressions in the bottom of the front frame rails?

Or have you, or anyone else, ever seen original 1800 front frame rails without the depressions?

Originally Posted by Derek UK

Agreed. The numbers on the machined pad are the actual engine numbers but the complete engine has to have the code that is on the adjacent pad combined with it. The one not shown will indicate the model year letter and the engine type.

As said the embossed numbers are just the numbers of the foundry moulds used to make the blocks. Also embossed are B18 or B20 and they are self explanatory.

Thanks for your reply Derek!

I am familiar with all the B18 block casting marks and stampings except for the three letter "foundry code" above the block part number.

I'm guessing the three letters indicate a manufacturing date and perhaps location. Can you, or anyone else here, explain the meaning of these three letters and/or how to decode them?

Thank you! ZT

[Army]

Originally Posted by ZTatZAU

...

I'm guessing the three letters indicate a manufacturing date and perhaps location. Can you, or anyone else here, explain the meaning of these three letters and/or how to decode them?

Thank you! ZT

As I said before I don't know for sure but I don't think that sand casting forms would be changed on a monthly basis. The three large letters might refer to a whole foundary location however...

...I wouldn't be too polite and wait for a response from the museum. If you want to know ask (I for one will be interested to hear what they say)!

EDIT:-

Forgot to say - my PV544 has designer dimples on the chassis rails too (which must be for added stiffness I suppose)