Sometimes a gamble will pay off… and sometimes it won’t. Our Volvo needed more than just a fresh cyliinder head to run well. After the ported and rebuilt head was bolted on, we noticed right away that, although stronger, the engine was still off-song. A compression check indicated that the #2 hole was still at 90 psi, while the others had all evened out at 130 psi. (A good B20B should be around 150)
So, the decision was made to pull the ailing engine and bring it down to Ron Brothers at Performance Diesel (386-253-0383) for a rebuild. In a few short hours the motor was removed and trailered to Ron’s shop. A teardown indicated that the top ring on the #2 piston was broken, while the other rings were due for replacement as well. In addition, the camshaft was very worn, almost to the point of being humorous. After a few hundred thousand miles, the cam wears out its lobes, limiting how far the valves open.
We’ve decided that the best route for our project is to build what amounts to a hot street motor that has been balanced and bored .040” over, coupled with a combination type cam that doesn’t sacrifice the low-end of the powerband. Coupled with our already installed IPD header (it came with the car) and 2.25” exhaust with a Dynomax Race Magnum muffler (this system was bent up locally for only $160 with muffler), this should yield good solid power up to about 6500-7000 RPM without difficulty.
For now we’ve also chosen to stay with the dual SU carbs that came standard on the car. Our buddy J.K. Jackson is rebuilding the very-British carbs and putting new bushings on the throttle shafts where they pass through the body. While a stock B20B is rated at 118 horsepower, we feel that a realistic goal is approximately 140-150 ponies with these carburators.
While the engine is out, we have been cleaning up the engine compartment with Simple Green and a pressure washer. This combination quickly removes years of accumulated filth. We are taking the opportunity to also sandblast and paint nearly every thing in the vicinity to give our Swedish lump a good makeover.
Since this car will be entered in track events in the future, we also decided to update the single circuit master cylinder with a dual circuit unit. With the help of Duane Matejka of Foreign Autotech, we found a master cylinder from a 68 P1800 that has the dual reservoirs and also has a matching mounting flange bolt pattern. Later 140-series master cylinders would have worked as well, but have a horizontal bolt pattern instead of a vertical one. We’re also going to take the opportunity to replace the brake lines with stainless braided lines to firm up the pedal a bit and replace the aging rubber lines.
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