Better Cooling For Buick's
The mighty Buick engines helped keep Jeep viable in the 1960s and early 1970s as Kaiser sorted out its identity. During corporate transitions from Willys to Kaiser to AMC, Buick power made the sometimes less-refined Jeeps competitive with Ford and Chevy 4x4s.
One advantage of the post-Nailhead/Wildcat family of 1960s-1970s Buick engines is decent parts interchangeability—even extending to the Buick-designed Rover 215ci V-8 and the venerable GM 3.8L V-6. For example, many engines share the same aluminum timing chain cover, which has an integrated oil pump.
While there may be more AMC V-8 engines running around, the Buick V-6 found in factory CJ-5s and slapped in many an old Jeep is still putt’n around in odd-fire format, as is Buick’s later 231 even-fire cousins. In fact, the Buick 350 powered many a Wagoneer and Gladiator pickup into the 1970s. Modern advances allow classic Buick engines to be upgraded during routine maintenance. To illustrate, we have a ’69 CJ-5 with an OE “Dauntless” 225 V-6 that has a leaky crankshaft seal. The timing chain cover obviously has to come off to replace the crank seal, so we took the opportunity to upgrade both the seal and the high-flow water pump—critical to any off-road crawler at slow speeds.
TA Performance (TA), which specializes in Buick performance, recently tooled up its own line of high-flow water pumps. Company owner Mike Tomaszewski points out that the water passages of the Buicks are not the most efficient design. They take a circuitous path through the heads and are constricted through the head gaskets.
Engineering a performance Buick pump isn’t as easy as riveting a plate to the impeller. TA designed its impeller to fit in the timing chain cover, then cast the water-pump housing to fully encapsulate the top area. This forces water into the engine—there’s no backwash across the impeller’s vanes. Incoming coolant is forced under higher pressure into the engine, helping prevent cavitation at higher rpm.
Off-road the TA pump has two primary benefits. First, flow is consistent when the vehicle is on an angle. Second, electric fans function more efficiently since coolant is always being forced through the system.
Tomaszewski says that hardcore rockcrawlers with hot-running Buick engines can also change their pulleys to increase pump flow at lower rpm. The junkyard approach involves sourcing a large crankshaft pulley from a Buick 350 or 455 V-8; the Buick 300 V-8 offered the smallest OE water-pump pulley. Alternately, TAP offers lightweight billet pulleys, including overdrive water-pump models.
The 225 shown here is stock except for headers, so we kept the existing pulleys. The temp gauge barely got up to 180 degrees F after idling for about a half-hour with the TA high-flow pump and a new 180-degree thermostat.
Incidentally, the Dauntless 225 V-6 has notoriously low oil pressure at idle. To remedy this, TA recommends STP Oil Treatment (although not in cold weather). TA also offers a performance timing chain cover that has machined passageways from improved oiling. Oil pump fixes and upgrades are also available.
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• The oil-pump gears should be tight but spin freely in the timing chain housing. The specs call for 0.0023-0.0058 inch of clearance between the gears and cap. This can be checked with a straightedge and feeler gauges.
• The timing chain should be checked while the cover is off. At worse, Mike Tomaszeski recommends upgrading the OE nylon-coated cam gear (which can get brittle and strip) to an iron gear. These are included in many aftermarket timing sets.
• Adding a phenolic cam bumper is another piece of cheap insurance when the cover is off.
Removal/replacement basically goes by the book. Buick timing-cover gasket kits offer a choice of crank seal styles: a rope style (proven effective for decades) and a more modern neoprene (rubber) style. We installed both seals for comparison and recommend neoprene over rope. The rope seal must be contoured to fit the harmonic balancer, then staked into place on the timing chain cover. The rubber seal self-conforms to the damper and places less drag on the crankshaft. For optimal sealing when upgrading to neoprene, Mike Tomaszewski of TA Performance recommends filing down the three swedged areas on the timing chain cover and running a bead of RTV silicone in the cover’s bore.
Stabbing and timing the distributor is possibly the hardest part of the job. Clocking the oil-pump shaft to mate with the distributor’s spade can take some trial and error. And even with the distributor in its pre-disassembly position, the ignition timing will likely be off. The rest of the job is primarily remove/replace. For purists, TA Performance even offers Dauntless green engine paint.