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B18 and B20 heads 44mm valves?

Vol242vo

Vol242vo

Keep it clean...
Joined
Feb 24, 2005
Location
Spokane, WA
Can anyone shed some light on these heads I was given in a recent 122 purchase?

The one marked 2TBG clearly has bigger valves. Outside of that I?m a newb with these heads.

A8-E6-D44-F-C4-DA-445-C-986-C-1-BF67-B742-D55.jpg


AEA454-F7-56-AC-4193-A555-CBBC51-B9-DC23.jpg


BC772-F47-E713-4-A9-B-AF32-1-A82-EE47845-D.jpg


D821-F212-37-B2-41-CB-BDEC-07791-ABA6-F2-A.jpg


D244-EA97-29-F6-4634-8-DAE-F2-A30699481-F.jpg
 
B18 heads have 40mm intake and 35mm exhaust valves with 11/32" stems. They use an umbrella style seal that sits on top of the retainer. Casting letters are visible with the valve cover on. The intake ports have a recess for alignment rings.

Early B20 heads have 42mm intake valves and 35mm exhaust valves with 5/16" stems. They use a typical seal that fits onto the top of the valve guide. Casting letters are under the valve cover. The intake ports have a recess for alignment rings.

Late B20 heads have 44mm intake and 35mm exhaust valves. They have the same stem size and seals as the early B20 heads as well as the casting letter location. The intake ports are larger and the recess for the alignment rings are gone.
 
Carbureted engines built after '72 received the same cylinder head as the fuel injected engine only the injector holes weren't machined. Late heads use dowel pins to align the manifolds instead of the rings.

The Competitiom Service heads used similar castings.

StageHeads.jpg
 
I was going to comment on the undrilled injector pads. Being in WA it could have been a later model carbed car, or a boat head, or an R-Sport head, or even a later production parts-counter replacement head for a carbed car.
 
JohnMc said:
I was going to comment on the undrilled injector pads. Being in WA it could have been a later model carbed car, or a boat head, or an R-Sport head, or even a later production parts-counter replacement head for a carbed car.
Click to expand...

Now I need to know more, haha! Someone told me this head was ?rare? but I haven?t confirmed anything yet.
 
That would be the rarest type of un-drilled injector heads. If it was an R-Sport head, it would have a stamped part number on the top side, along the side the intake manifold sits. I don't think any of the other types of heads have the stamped numbers.
 
hiperfauto said:
Look for a part number stamped into the flat area above the center exhaust ports.
Click to expand...

Have two 1974 Canadian/European 44/35 carb heads similar to your photo here at the shop that were found and purchased in BC Canada and another purchased in Europe with this same type of pad and serial number. Sought them out because they are reported to have ports and wall thickness similar to the Stage III and IV Volvo Comp/RSport heads and are a good basis for a ported racing head.
 
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I was under the impression that 'only' R-Sport heads had the stamping, but I could certainly be wrong, that's just the only head I've seen that was stamped.

But I gather that hiperfauto (who knows a LOT more about old Volvo's than I do) is saying that more of them have part numbers. In which case you'd need to google up the part number and see what it says.

Perhaps the regular production car heads that were used in the factories didn't have stamped numbers on them, but parts department heads did, maybe boat motors did, and the R-Sport heads (I thin technically sold as parts department parts) did.

So what number is stamped on it?
 
EDIT: And I checked on my phone and see you posted pics (my work blocks most pic hosting sites) - that's not a Volvo part number, it's too short and in the wrong spot. The part numbers are on the top surface of the head, near the middle, on the manifold side.
 
The part number if present will be stamped above the center 2 exhaust ports. The number shown in your photo is stamped on the gasket surface by a machine shop.

I'm not sure if my images are displaying in your browser. Apparently Chrome won't display images stored on my server because it's HTTP not HTTPS. Firefox displays them without issue.

I've attached the image of the part number that I posted earlier in case you didn't see it.
 

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