I have a dilemma in that in my desire to complete my A/C installation, the location of the pulley mounting hole on the upper right front of the head is missing the normal threaded hole. There is only one other threaded hole in the vicinity and that is occupied by the alternator bracket. In viewing photos of other 1970 A/C equipped 1800's, just to the right of the water jacket plug/disc is where the pulley bolt is mounted. Was I misinformed by the seller that my mounted cylinder head is the original that came from the factory or is it a replacement B20 from another model? If it is a replacement and not a "E" model head, my compression ratio would not be as designed and completion of the A/C system is not possible. Were their two different heads installed on B20E's?

Hello,

Yes, there were 2 different E heads.

1 of the features of the very early E heads are the 2 extra intake manifold studs. These 2 extra manifold studs are in the middle but below the level of the lower edge of the exhaust manifold where it mounts to the head.

If all original, the special intake manifold for the early FI head utilizes a special support bracket that bolts to a special motor mount bracket.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

As I have no "flats" above the middle exhaust ports, I guess I have a fuel injected "E" head. I wonder why they manufactured one "E" head with an a mounting hole for an A/C pulley and one without? What engine serial number does this head relate to?

What I can tell you is that according to the Volvo parts catalog, the 1st 1800E Volvos made came with that weird fuel injected cylinder head. IIRC, the catalog shows that 69 of the 1st 1800E Volvos got that head.

FYI, the early B20 carburetored heads don't have the mounting boss for the A/C tensioner bracket either.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Can the normal position for the A/C pulley mount bolt be drilled and tapped without any internal interference? I assume there is a water jacket behind the spot? I am still puzzled why this car is completely fitted with all the A/C components with exception of the pulley. Maybe the previous owner had to replace the head and then later discovered he couldn't complete the A/C reinstall, therefore selling it to me in the informed disconnected condition.

I wouldn't try to modify the head as there are other methods to mount an A/C belt tensioner assembly.

I know some of the B20 cylinder heads didn't have the mounting hole cast into the head for an A/C tensioner and that may apply to the very early B20E heads.

For those heads with the mounting hole for a tensioner, Volvo used a bracket that was mounted using 2 of the head bolts and a water pump bolt.

So you may need 1 of those setups or there is at least 1 guy selling his own design that uses the thermostat bolts and a water pump bolt to hold the tensioner bracket to the head.

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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Anyone out there that is selling Eric's suggested A/C pulley mounting bracket?

Are you upgrading the compressor to a modern version?

Yes, I purchased a Sanden 508 compressor modified mount from Robert Fultz. Since my car already had A/C but was missing the original York compressor, it prompted me to make the Sanden conversion. If you are considering the change, make sure you have the correct head with idler mounting threaded holes at the front just below the thermostat housing.

Bob also makes a bracket for installing a tensioner pulley on B18 heads and I think it should work on a B20.

FYI, his last name is Foltz and I know this because I once wrote him a check with his last name misspelled the exact same way. :-) :-)
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

If you have the holes in the head for the injector ports, its either a B20E head or the later (1972) B20F head. This link gives you a quick guide to identifying a B20E versus early or late B20F head.

http://www.v-performance.com/articles/volvo_b20_head_identification.html

On my 1971 142E with B20E, the alternator adjusting bracket does not mount to top of the head. In the last photo on this web page you can see the alternator bracket attaches to a hole just above the head gasket mating surface.

http://www.vclassics.com/motorsport/engines.html

You can also just barely spot the hole on the front face near the top of the head by the rad hose outlet. My B20E has a similar hole. It has never been populated so I don't know whether it is threaded or not. Would not be that hard to cut threads if it isn't threaded.