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orthoxstice
orthoxstice New Reader
8/30/20 8:23 p.m.

I got this 1967 Volvo 122S Automatic off a friend in exchange for some work I'll be doing on one of his other cars. It sat in a field for an unknown number of years before his dad got it and put it back on the road, then he owned it, then he sold it to a guy who daily drove it (and allegedly never washed it because he "liked the look") before eventually buying it back again and letting it sit. The reason it sat is the BW35 seems to be blown up; it'll creep forward a bit and then rev without moving.

Anyway it was sold to me as a probably running car, but with plenty of question marks. Sounds good to me!

Interior is pretty thrashed. This was a rubber floor car, but the front section is missing. Lots of trash and scattered about, the remains of a half-smoked cigar stubbed out in the ashtray, and the high beam switch essentially ground into dust. I gave everything a cursory clean out and going over with the shop vac.

Here's the SU's that were apparently rebuilt sometime in the last decade but "probably need done again". More on that later.

Uh oh, our first problem. This car has one of those "hot" Bosch coils and a Pertronix ignition but some rodent (perhaps a purist) gnawed through the wires. I cut out the bad sections and spliced them with good connectors and heatshrink.

Then I opened the trunk and found:

A perfectly good new Pertronix unit still in the box. Oh well, I'll install that at some point probably. At this point I threw the jump pack on, pulled the choke, gave the pedal a few pumps and cranked it over. It actually started right up! And ran terribly, coughing, sputtering, probably only running on two cylinders; but it managed to hold an idle and even moved in reverse. Since I'd found some new NGK's, I pulled the old plugs and put in the new. I've read Pertronix can stand to have the gap opened up a bit so a re-gapped all of them to 0.032. Here's how the old ones looked:

Now at this point I planned to put the car in the air, drop the old transmission, and install the freshly power-washed unit that came on a pallet of parts with the car, pictured here:

But before I could, I realized I was smelling a lot of gas odor, much more than is to be expected with an old car. Now I've read about Amazons burning down because of the SU's so I took a look and sure enough the exhaust manifold was covered in gas. Luckily I only ran the car for like three minutes!

So that brings me to the end of today and a few questions for more experienced vintage Volvo owners out there:

The car came with this Weber and manifold setup (I believe the kit available from IPD?)

Should I install this? I have the one piece intake/exhaust manifold so I understand that in order to install this Weber I'd have to cut the two apart from one another. I'm not thrilled by the idea. The second option is to purchase some kind of header and then install the two together. The third is to attempt to rebuild the SU's.

- Thoughts about each of these potential plans?

- Are there other things I should be attending to straight away?

frenchyd
frenchyd PowerDork
8/30/20 8:47 p.m.

In reply to orthoxstice :

No to the Weber. SU carbs are so simple if you can't  figure those out the Weber is like the difference between play checkers and chess. 
 Different is not better. 
 

Parts for SU carbs are readily available check the add in the back of GRM magazine.  

orthoxstice
orthoxstice New Reader
8/30/20 10:08 p.m.

I had looked into SU rebuild kits and could certainly tackle that and I'd honestly prefer to stick with what the car has had its whole life. My interest in the Weber was really just because it was there and (seemingly) ready to go. Of course, now I realize that there's hacksawing involved it's a different story.

With the SU's though; the throttle plates in the manifold are a common source of vacuum leaks, correct? Both of the ones on the car seem to have some play, so I wouldn't be surprised if those bushings (or whatever they are) are worn out.

TurnerX19
TurnerX19 SuperDork
8/30/20 10:47 p.m.

If you have throttle plates in the manifold this car is a 1968 or 1969 car. A real 1967 will have a separate aluminum intake manifold and the only throttle plates will be the ones in the carbs. Fix/rebuild the SU carbs and sell the Weber, it is a performance downgrade. Remove and thoroughly plug the shaft holes from the manifold throttle plates. They can be wired open, but the vacuum leak issue by this late date is too likely to retain them, and they do degrade performance slightly. Better still find an early manifold and a header or an iron exhaust from a fuel injected B20E. Re-work the front exhaust pipe to accomodate. If the carbs have play in their throttle shafts oversize shafts are readily available as well as the needed reamer from Joe Curto. The fuel leakage is probably the jet tubes or their seals into the bottom of the float bowls. If at all possible please convert this car to a stick shift, the BW35 saps all of the fun and most of the torque form the car.

orthoxstice
orthoxstice New Reader
8/31/20 7:34 a.m.

Interesting! I'll have to try and decode the body number to figure this out, not sure how else to tell the year without any documentation with the car. I'll order an SU rebuild kit today. 

Torkel
Torkel Reader
8/31/20 10:16 a.m.

Amazon! Hell yeah! 

If you think that thing is rough, you should see what a lifetime of Swedish winters and road salt does to them over here...

noddaz
noddaz GRM+ Memberand UltraDork
8/31/20 4:51 p.m.

NOHOME
NOHOME MegaDork
8/31/20 5:02 p.m.

Fuel on the exhaust is a SU float stuck. You should be able to figure that out easy enough. The trick is going to be to get a filter as close as possible to the float bowls so that new E36 M3 from the decomposing fuel system stops getting to the float needles/seat assembly.

Once you get the float level set, the SU is the easiest carb in the world to tune. The fluid required for the dampers is no ig thing, pretty sure there is an ideal fluid for it, but having used everythig under the sun but Beer, they seem to soldier on.

 

The only real weak point is the throttle shafts where they go through the carb body, if there is a lot of of wiggle in that area, they will suck in air and make it impossible to set the fuel mix at idle due to the vacuum leak. The fix is to run more fuel mix at idle, but this then carries on as too much fuel for the whole range once off idle.

orthoxstice
orthoxstice New Reader
8/31/20 6:14 p.m.

I should have mentioned that the pallet of spares includes a used but "clean" fuel tank. So that's on the agenda. The car had an in-line parts store filter before the carbs and it looks fairly brown inside. 

TurnerX19
TurnerX19 SuperDork
8/31/20 11:05 p.m.

In reply to NOHOME :

See my post above regarding oversize throttle shafts. No need to struggle with the vacuum leak.

TurnerX19
TurnerX19 SuperDork
8/31/20 11:15 p.m.

In reply to orthoxstice :

Given the age of everything involved it is entirely possible this car had the engine swapped in from a later car, your photos do appear to be '64 to '67. The seats got head rests in '68, and clunky side marker lamps too, kind of mid year, they weren't required til '69. Single line brake master says the chassis is def. earlier, that was required in '68. I worked on lots of these when new, and still drive RWD Volvos today. I saw quite a few camshaft failures on B18 and B20 engines, ut we usually just replaced the cam and lifters without needing to go deeper, but most were sticks. The automatic cars gave their engines a much harder life. Maybe you got lucky and it has a B20 swap. The B18 or B20 designation is cast into the block in letters 2" high. 

TurnerX19
TurnerX19 SuperDork
8/31/20 11:19 p.m.

Another tid bit. I see that the coil has been changed. When new the ignition key switch and primary wires were in unit with the coil mounted on the fire wall. Armored cable under dash connecting them. Anti theft, but an expensive pain when either the coil or the switch failed!

frenchyd
frenchyd PowerDork
8/31/20 11:57 p.m.

In reply to TurnerX19 :

Once you ream the carbs and put in oversized shafts  start putting a little oil on the shaft on each side of each carb 

My approach is a couple of drops of motor on the throttle  shaft and a quick spray of WD40 aimed at the shaft to squirt the oil into the carb. 
Since following that practice at every oil change I've detected no wear in my throttle shafts. 
 

I've had debates with friends who insist I'm also forcing dirt and grit in but I'm pretty careful to wipe everything clean first. 

frenchyd
frenchyd PowerDork
9/1/20 12:04 a.m.

In reply to TurnerX19 :

Yes please go to the manual gearbox. ( unless there is a reason someone can't drive a stick? ). 
Finding parts and someone with the knowledge to rebuild it will be hard. 
If you absolutely need to keep the automatic change the fluid right away and again in a couple of months. After that you can resume normal fluid changes. 35,000 miles isn't it?  

orthoxstice
orthoxstice New Reader
9/1/20 12:07 p.m.
TurnerX19 said:

Another tid bit. I see that the coil has been changed. When new the ignition key switch and primary wires were in unit with the coil mounted on the fire wall. Armored cable under dash connecting them. Anti theft, but an expensive pain when either the coil or the switch failed!

Yes it has a Bosch blue coil that was put in with the Pertronix. I actually have a used spare stock coil but don't know if it works or not. It certainly looks strange with that giant cable shooting off it. 

orthoxstice
orthoxstice New Reader
9/1/20 12:09 p.m.

This will stay automatic for the short term since I have a spare BW35 that came with the car and do not have an M40 or whatever or any of the stuff. A manual car would be nice but a car that moves at all is my preference for now!

RoddyMac17
RoddyMac17 Reader
9/1/20 12:23 p.m.

One other thing to look at on the carbs, as they appear to HS carbs, is the seal at the end of the jet tube where it screws into the float bowl.  It's a square section ring that will shrink/crack/disappear with lack of use.   The seals are available, but typically when they go you just replace the whole jet.

 

 

TurnerX19
TurnerX19 SuperDork
9/1/20 10:18 p.m.

If you are planning to drive this there are two other must do items for any pushrod Volvo engine. You must use lead replacement additive in the fuel, and you must use engine oil with enough zinc or ZDDP additive. We saw camshaft failure a lot when they were new and all oil had enough zinc then. These are high compression enough with very soft valve seats so you will have valve recession without lead. On an overhaul you can go to hardened valve seats to cure that issue, but the camshaft wear will always need extra zinc or "classic car" special oil.

orthoxstice
orthoxstice New Reader
9/2/20 6:28 a.m.

Good point, I meant to ask about that earlier in the thread. It's unclear what kind of treatment (if any) this engine received prior to me getting it. Anyone have a preferred oil they like?

volvoclearinghouse
volvoclearinghouse PowerDork
9/2/20 7:23 a.m.

Subscribed, will type more later, getting coffee. I've been working on, driving, and racing Amazon's for almost 20 years. Great cars.

TurnerX19
TurnerX19 SuperDork
9/2/20 12:23 p.m.

In reply to orthoxstice :

Brad-Penn 20w50 classic car oil would be my 1st choice but there are others as well. If it has never been apart be aware that it has felt oil seals on both ends of the crank shaft. IPD made a replacement with modern seals. I don't know if it is still available, but it is a reasonably easy milling machine job to convert the seal holder in the back, and the timing cover. Do the rear for sure when the trans is out, the felts are certainly perrished by now.

volvoclearinghouse
volvoclearinghouse PowerDork
9/2/20 8:25 p.m.

A little known secret is that Mobil1 15W-50 actually still contains zinc...it's one of the very few modern oils that does, likely because it's not spec'd for any new cars.  We've run it in our LeMons car, which uses an old pushrod V8, and its a great oil.  Not too pricey, either, by the jug at Wal-Mart.  However, as with any synthetic, if the engine leaks at all now, it will probably leak worse with the synthetic oil. 

In my non-racing 122's I've generally run 15W-40 diesel oil.  It used to contain zinc, though they've since removed it.  It's still an oil designed for "dirtier" engines with more blow-by so it's a good fit for older cars, in my opinion. 

I've never run a lead additive, either, and never noticed any issues.  Unless you've got a B18B (the high compression version) the static CR on these is about 8.5:1.  The B18B was 10:1 or so.  Unfortunately I couldn't tell you how to tell the difference without some engine disassembly.

 

volvoclearinghouse
volvoclearinghouse PowerDork
9/2/20 8:49 p.m.

A couple of other things:

From that engine compartment pic it looks like the car used to have power brakes.  That bracket the coil is attached to looks like the old booster bracket.  Power brakes were sort-of rare, and not really desirable on these cars- they don't work great and the booster was failure-prone.  Better off without. 

The integrated manifold you have is actually one of the best-flowing manifolds they put on these cars.  As others have indicated, just defeat the butterfly mechanism and make sure there's no vacuum leaks and you should be good to go.  Alternatively, I have cut off the intake portion of these manifolds (not hard to do) and then used an older aluminum intake.  It does save some weight that way.  I have a few of the aluminum intakes around if you'd like to go that route.  Definitely wouldn't consider the Weber intake/carb at all.  Plus SU's wide open just sound so good. 

The other nice thing about this particular exhaust manifold is it has a dual pipe exit.  Most of the earlier ones were single.  The longer you run the dual pipes back in the exhaust, the better flow.  I've actually run straight duals all the way out the car.  It sounds really good that way. 

The automatics on these aren't great, but they are usable.  I dailied a '66 122 with the BW35 for a while and it was fine.  The automatic shifted somewhat harshly, kept the b18 on the boil, and returned fairly poor fuel economy (like, 20 mpg in mixed driving) but the car still had decent pickup and other than not getting to shift, was still fun.  Converting to a manual is some work- not hard, but involved.  I have several parts cars and can supply pretty much a whole "conversion" set, but as I said, it's some work.  Bellhousing, clutch pedal, clutch fork, master/ slave cylinders, different driveshaft, crossmember...  I'm also not 100% sure if the crank on an automatic car's engine will accept the pilot bearing for the clutch. 

The floats on the SU's can leak over time.  I found Nitrophyl (sp?) floats for the SU's in a Jaguar I've been working on recently, they weren't terribly pricey and they should last much longer.  Highly recommend you go that route.  SU's are great carburetors, just different from your standard 'Murican car carburetor.  But they can give good performance AND good fuel economy.  The chokes can be a little finnicky, though.  Definitely get a good fuel filter and put it between the pump and the carbs.  NO filter pre-pump. 

Make sure the dashpots in the SU carbs go up and down nice and smoothly and don't hang up.  I've rescued a few that hung up by VERY carefully lapping them with some scotch brite or similar pad.  The dashpots are match-machined to the carburetor housing, do NOT mix them up if you take both carbs apart. 

 

TurnerX19
TurnerX19 SuperDork
9/2/20 11:18 p.m.

The automatic b18s and B20s I have had apart had a spigot on the torque converter that was the same OD as the #202 pilot bearing on a stick. so the crank is the same. 

frenchyd
frenchyd PowerDork
9/4/20 5:12 a.m.

In reply to volvoclearinghouse :

You might mention the simple drop test on SU carbs.  Just pull the tops off the carbs making sure you have a little oil in each dash pot. With one  in each hand flip them over and catch the piston as it drops ( let the needle slip between your fingers) .  If both pistons hit your palm at the same time you're good to go. If one hits before the other switch pistons and try again.  
if each attempt is different then it's time to do a little clean up. 

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