Aug 28, 2013

Flooding SU carburetors

When the B20B engine was idling for a couple of minutes the SU carburettors always began to flood. I played with the floater height, replaced the floater needles, put back in the old ones, took the carbies off..... Nothing really helped. The only result was that I now can rebuild and tune SU HS6 carbies with my eyes closed.

And as the SU HS6 carburettors are mounted just above the exhaust  flooding can be dangerous too!

It must be something else, something outside the carbs....
Well, I fitted a new aftermarket mechanic fuel pump in the car and I've heard that new fuel pumps often gave a higher than desired pressure. And another thing was I fitted a new camshaft with a fresh "eccentric lob" what would cause an even higher pressure (caused by a longer stroke).

Mechanism Mechanic Fuel lift pump
Mechanism Mechanic Fuel lift pump

After market Fuel pump Volvo 122S
After market Fuel pump Volvo 122S

There are three solutions to solve this; one is to fit an extra or extra thick gasket between the fuel pump and the engine (shorter stroke > less ml fuel/stroke) and number two is to place a Fuel Pressure Regulator (FPR) between the fuel pump and the SU carburetors. Three is to buy an original fuel pump (I'll keep that one in mind if I ever need a new fuel pump..)

A twin SU HS6 carburetor can handle a pressure of ca. 2.5 - 3.0 psi.
To measure the pressure you need to disconnect the fuel line from the carbies and put the adapter from the gauge in the fuel line. The fuel in float bowls will keep the engine running long enough to measure the pressure. It was 4 psi while the engine was idling!

Measuring the fuel pressure Volvo Amazon
Measuring the fuel pressure
After installing the adjustable Fuel Pressure Regulator I set it on 2.5 psi. No more flooding! As the car is still in the shed I don't know if 2.5 psi is enough while driving it so maybe I've to set it on 3 psi.

Fuel Pressure Regulator / FPR in the Volvo 122S
Fuel Pressure Regulator in the Volvo 122S

 Btw the Fuel pressure gauge can also be used to measure the vacuum of your inlet manifold. This should be around 18-21 with an idling engine (no matter what engine). Of course I couldn't resist this opportunity... All good!

Measuring the inlet manifold vacuum
Measuring the inlet manifold vacuum 

Aug 27, 2013

Radio and new Dashboard for the Volvo

The radio that was in the Volvo 122S since 1970 wasn't working too well. So I decided to put in a nice new one. BTW they call it a Media Player instead of Radio nowadays... whatever...
I did like the looks of the old school radio so I only disconnected it and left it in the metal dashboard.
After some desktop research I found a nice Radio for just under $100,- with Blue tooth and, very important, remote control.  It's a Sony DSX-A50BT (if you wanna know :0)

Now I had to find a good "out of sight" place for the new Radio and speakers. The glove shelf is mounted on the firewall with two screws, and even better the distance between the screws is almost ideal for the new Radio. Now you probably also understand why I needed a radio with remote control...

Radio mounted with brackets in Volvo 122S
Radio mounted with brackets in Volvo 122S

I bought 4x 20 cm long metal brackets with holes. The brackets were easy to bent but strong enough to keep the radio and front speakers  in place. The distance between the holes in the brackets was the same as the mounting holes in the radio so that part was easy.

The old antenna was still in good condition but as I didn't want to drill another hole in the fender I found a nice spot under the dash and mounted it with two tie rips.

External Antenna hidden behind dashboard Volvo Amazon
External Antenna hidden behind dashboard Volvo 122S
Two 220W 4-way Pioneer speakers were used as front speakers. No particular reason for Pioneers, I just found them new in a box in a Saab 900 wreck (but that's another story).
As I didn't want to drill more holes in the body I took longer top bolts for the bonnet mounting, made the holes in the brackets a bit bigger and bolted them on the inside thread of the longer bonnet bolts.

Speakers mounted on longer bonnet bolts Volvo Amazon
Speakers mounted on longer top bonnet bolts Volvo 122S

Speakers mounted on longer bonnet bolts Volvo 122S
Right speaker mounted with brackets on longer bonnet bolts

Left speaker and Radio hidden under dashboard Volvo Amazon
Left speaker and Radio hidden under dashboard 

 Can you remember the old original dash pad? After more than 40 years in the harsh Australian sun it was cracked, shrunk and totally useless. I tried to repair it but it was too deteriorated. Buying a new original one seemed like trowing money in the well known pit. Then I found a good solution; a polyester replica of the original dash pad. Looks exactly the same as the original and won't crack or shrink in the hot sun.


Old cracked dash pad Volvo 122S
Old dash pad Volvo 122S

Old cracked dash pad Volvo Amazon
Cracked...

Old dashboard Volvo Amazon
....

New polyester dash pad Volvo 122S
New polyester dash pad Volvo 122S

It was a bit fiddly to fit the polyester dash pad. You have to drill the holes in the dash pad yourself. This is because not every 122S has the pre-drilled mounting holes in the metal part of the dashboard in the same spots. So it's a lot of measuring (and a bit of bending) but after a couple of hours I was happy with the results.


New polyester dash pad Volvo 122S
New polyester dash pad Volvo 122S

New polyester dash pad Volvo 122S
New dashboard Volvo 122S