Weird threads used by Volvo in 1950/60’s

[142 Guy]

Originally Posted by Burdekin

PVs were metric, Amazons imperial.

Interesting! A little search indicated that the B16 engine was equipped with metric fasteners. Does that mean the whole car was metric or just the engine? Were all Volvos prior to the 544 / B16 all metric?

In 1962 Volvo introduced the B18 engine followed by the opening of a 544 production facility in Canada in 1963. I expect that the Canadian 544s were all imperial because most Canadians couldn't even spell metric in 1963. Did the 544s on the east side of the Atlantic continue on with metric to the end? Since the Amazon production overlapped with the 544 and early ones had the B16 engine, were the early Amazons metric or were they imperial? Producing both metric and imperial fastener B16 engines at the same time would be a bizarre corporate decision.

I have never worked on one; but, I have heard anecdotes that the early 240s that came equipped with B20 engines had fasteners with metric sized heads; but, imperial threads. A weird form of soft metric conversion. Presumably Volvo did not want to retool the B20 since it was in its final year of production. Cheaper to do a run of weirdo custom bolts? If Salop Farmer thinks he had a problem figuring out bolt sizes, pity the unsuspecting mechanic trying to fix an early 240 - if the story is true.

[Burdekin]

Originally Posted by 142 Guy

Interesting! A little search indicated that the B16 engine was equipped with metric fasteners. Does that mean the whole car was metric or just the engine? Were all Volvos prior to the 544 / B16 all metric?

In 1962 Volvo introduced the B18 engine followed by the opening of a 544 production facility in Canada in 1963. I expect that the Canadian 544s were all imperial because most Canadians couldn't even spell metric in 1963. Did the 544s on the east side of the Atlantic continue on with metric to the end? Since the Amazon production overlapped with the 544 and early ones had the B16 engine, were the early Amazons metric or were they imperial? Producing both metric and imperial fastener B16 engines at the same time would be a bizarre corporate decision.

I have never worked on one; but, I have heard anecdotes that the early 240s that came equipped with B20 engines had fasteners with metric sized heads; but, imperial threads. A weird form of soft metric conversion. Presumably Volvo did not want to retool the B20 since it was in its final year of production. Cheaper to do a run of weirdo custom bolts? If Salop Farmer thinks he had a problem figuring out bolt sizes, pity the unsuspecting mechanic trying to fix an early 240 - if the story is true.

I’m just going from what I have read that PVs were metric and they swapped over to imperial for the Amazon. I was surprised too that the PV was metric and no idea why they changed.

[Derek UK]

As the PV was introduced in 1947 I would guess that Volvo at that time used all metric fasteners. The change on the Amazon to UNC/AF/ whatever you want to call it. maybe due to wanting to keep the Americans happy as it was envisioned as the main export market.

[WSU303]

As someone who owns a 1961 PV544 (with a B18), I can categorically say that it is NOT metric, except for some fasteners that have been replaced during past ownerships.

Perhaps some of the earlier cars used metric (interesting about the B16), but the 544 was definitely all imperial as of 1961.

[Army]

Originally Posted by WSU303

As someone who owns a 1961 PV544 (with a B18), I can categorically say that it is NOT metric, except for some fasteners that have been replaced during past ownerships.

Perhaps some of the earlier cars used metric (interesting about the B16), but the 544 was definitely all imperial as of 1961.

My PV544 from 1961 also has a hotpotch of meteric and US standardised threads. I get the impression most are of the US standards or were originally so.

When I put it back together I'll pay greater attention.