Buick Turbo V6 Engine Build Overview - Buick Power Part 1

Chris Endres May 1, 2002 0 Comment(s)

Once upon a time, in a decade long ago, Buick built a kick-ass little turbocharged V6 engine and dropped it into the handsome rear-wheel drive Regal. Rated at (wink, wink) 245 horsepower (in 1987), the mill was strong enough to push the barn door-like Buford down the dragstrip in the high 13-second range at about 98 mph. While this may not sound like much to brag about these days, in the mid-eighties, a high 13-second car was damn quick. As such, the blown Buicks were known to give the Corvette guys of the day fits, and contributed to more than a little inter-division rivalry inside GM. The turbo engine was so good that even Pontiac did the unthinkable by commandeering the V6 for installation in its 20th Anniversary Trans Ams.

The Turbo Buicks quickly became a favorite of the street racing set, as they were quiet and stealthy, had prodigious torque on tap and a hard-hooking factory four-link suspension. Basically, all the key elements were in place to make them the perfect weapon of choice for the urban street brawler. Many a big-block musclecar was humbled by the upstart buzzin' half-dozen. In a short time, the mill proved itself very responsive to minor bolt-ons, being just a few key parts (and traction) away from high- to mid-twelve second timeslips.

Buick's turbocharged V6 made not only incredible power, but it also proved itself as a durable piece, able to shrug off startling amounts of abuse with nary a complaint. While it was strong, it was not completely immune to the ravages of detonation. As the years passed, the casualties began to mount. A bad load of gas here or an over boost situation there made history of untold numbers of head gaskets, or in worst-case scenarios, hard parts such as pistons. When the worst happened, many turned to their local machine shop for assistance in rebuilding the engine. While a few had good luck with the local rebuilds, scores more did not. Soon it was discovered that GM had hundreds of new old stock replacement engines in inventory. This seemed to be the perfect solution, as the factory engines had certainly proven capable of taking their lumps. Alas, GM's supply of crate engines ran out in the mid-nineties, leaving Buick performance fans again in search of a viable solution.

Enter Jack Merkel Performance Engines. "I saw that there was no one filling the demand for 10- and 11-second street car engines," said Merkel. "I spent a lot of time fixing other peoples' mistakes in these engines, and decided I could do a better job." Merkel has recently moved into the same building as Ron's Custom Auto and is the primary supplier for Buick engines to RCA. While there is no direct connection between the two, there is a shared dedication to the turbocharged Buick V6 powerplant and a wealth of engine-building knowledge resulting from this closeness. Merkel offers a wide range of services ranging from stock rebuilds to custom crate engines such as the one we are about to detail for you here.

While it is true that almost any competent machine shop has the ability to properly rebuild a Turbo V6 engine, the trick is whether they will do it correctly or just apply the usual Chevy small-block conventional wisdom to the rebuild. A shop doing the latter is asking for trouble. Merkel: "If you build a Buick V6 like a small-block Chevy, be sure you pack a large shovel. You're gonna need it to pick up the pieces." Finding a machine shop that understands the special needs of a Buick is a daunting task, to be sure.

Jack Merkel Performance Engines performs many mods for the unique needs of the Buick turbo V6 engine. Due to its rather unorthodox oiling system, the engine has some unique bearing clearance needs. "Common small-block Chevy thinking manifests itself by allowing too much bearing clearance. This works fine for the SBCs, which commonly spin 6-, 7-, or even 8-thousand rpm. But the Buick motors usually spin 5200-5600 rpm max. They have very high cylinder pressures at low rpm and can produce in excess of 600 lb.-ft. of torque under 3000 rpm. If the main bearings are hemorrhaging oil pressure at low rpm, the rods are going to be in an oil starvation situation. They will overheat and this will cause a spun bearing," explains Merkel.

Another key element in the machine work phase of the buildup is the act of balancing the rotating assembly. "V6s are notorious as rough running engines," said Merkel. "I have found that the crank is usually close but the rods can be all over the place." According to Merkel, it is not at all uncommon to see connecting rod weight variances in the 5-8 gram range. While that might not sound like a lot, it makes all the difference to engine smoothness and longevity. "It makes a tremendous difference in the way the car runs. You can really tell a difference at high rpm, as well as with the car just idling in gear," said Merkel. "It is a lot smoother."

What follows is the first of three parts that will take us to a completed Buick V6 capable of running low 11s. We will deal with the basic machine work on the block and rotating assembly in part 1, concentrating on those tricks that are unique to the Buick V6. Part 2 will focus on short-block assembly and special oiling issues unique to the Buick V6, and part 3 will deal with the induction. Follow along as Jack Merkel takes us through the machining steps of building serious Buick power!

SHORT-BLOCK SHOPPING CART*
ARP rod bolts - part No. 123-6002... $122.77
ARP main studs - part No. 123-5401... $64.95
Pro Gram Engineering billet main caps - part No. B4.1V6C... $199.95
TRW forged pistons - part No. L2481F-30... $469 per set
Speed Pro plasma moly rings - part No. R10499-30... $140.47
Fel-Pro two-piece neoprene rear main seal - part No. BS-40613... $22.23
Federal Mogul main bearing - part No. 107M... $94.29
Federal Mogul rod bearings - part No. 6-3755APA... $32.57
Federal Mogul cam bearings - part No. 1755M... $14.36
Federal Mogul core plugs - part No. 381-8073... $9.24
Comp Cams custom grind cam - part No. 206/206... $200.00
Speed Pro timing set - part No. 220-3129... $71.01
Federal Mogul high volume oil pump kit - part No. 224-518-V... $44.86
Federal Mogul oil pump thrust plate - part No. 224-518TP... $14.69

TOTAL SHORT-BLOCK LABOR
(including machine work) $1900.00
total short-block cost: $3299.00

* Note that some items which appear in the shopping cart will not be discussed until the next installment. Also, the total short-block turnkey cost is less than the actual total.

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