It's been quite a while since we featured our buddy Tim Cairone's Turbo Buick. In the April '10 issue we left off installing, dyno, and strip testing PerformaBuilt Transmissions' rebuild of the GN's original 200-4R along with its 10-inch billet, 2,800-stall converter. The original trans didn't hold up under the power increase from all the bolt-ons we dyno and strip tested, and also the stock-type remanufactured 12-inch converter offered too low of a stall speed for low e.t.'s we seek. The PB transmission and billet 10-inch converter lowered the 60-foots from an average of 2.2 to 1.65, and in turn the quarter-mile e.t.'s dropped significantly from mid 13s to low 12s. All the bolt-ons from the first three installments were worth over 100 rwhp and 200 lb-ft torque to the bone stock 100,000-mile engine. The beefy PB trans/converter really helped put the power to the pavement. After considering that PB backs its transmission and converter package with a 2-year unconditional warranty (racing included) we now felt confident to shoot for the 11s.
Initially we planned to pull...
Initially we planned to pull the motor at the owner's shop (Shore Wheels, Tuckerton, NJ) and clean up the engine compartment while your author performed an easy cam and head swap. Our friends Dan Smith and Jose Torres of Jose Motor Sports suggested we bring the engine to them to freshen it up. We took their expert advice and brought the motor to their nearby shop. When we dropped off the Turbo Buick V-6, Jose and Dan were ready to give it a teardown inspection just in case we needed to order extra parts. Here Jose pulls off the intake and heads. Sharp-eyed readers will notice the valvesprings from Part 2 of "Turbo Buick Basics." The stock heads would be exchanged for the ported and polished set that Jose spent many hours (30-plus) working on for us.
Next on our build plan was to replace the outdated stock hydraulic flat-tappet cam (0.400/0.422-inch lift, 193/196 duration at 0.050) for a more recent technology hydraulic roller-tappet stick (0.504/0.504-inch lift, 212/212 duration at 0.050) from Comp Cams. Also a set of well-ported stock iron heads by Jose Torres (over 20 years experience porting TB heads) of Jose Motor Sports would be beneficial for increased airflow through the forced-air fed Buick V-6. What began as a head and cam swap turned into refreshing the high-mileage motor because with so many miles on a turbocharged motor, it was the logical thing to do. The plan was a simple refresh (gaskets, seals, rings, and bearings), reusing the stock pistons and rods so as not to skew the gains we'll see from the roller cam and ported heads. Since the motor ran smooth, we didn't even bother to balance the rotating assembly. At Jose Motor Sports, Dan Smith (engine machinist/builder since 1970) would handle the machine work on the long-block while Jose would port the heads and assisted with engine assembly. These guys have been in the Turbo Buick business since the late 80s and have been known for being extremely thorough.
In this episode we'll feature the engine removal, teardown inspection, all the parts, gaskets, machine work, engine assembly, and port work to the heads. In the next episode we'll drop in the motor and check out the dyno and strip testing results. We're expecting big-time gains from the roller cam and ported heads. Together they will make for a lot of added airflow to be able to move more rapidly through the Turbo Buick motor.
It's obvious this motor was...
It's obvious this motor was never neglected when it came to regular oil changes. By 1987 the GM V-8s had roller lifters, but not the TB V-6. If the TB had a roller cam at the time it would have beaten-up more than just Mustangs.
The stock dished pistons were...
The stock dished pistons were in good shape and would be cleaned-up and reused. We elected not use new lightweight pistons and rods, which could add power and would in turn skew our test results of the swap to the roller cam and ported heads.
Once Dan removed the timing...
Once Dan removed the timing case cover we could see the original timing chain and gears (notice the nylon cam gear teeth) were still in place and intact. That alone told us how well cared for this TB motor was. Here the cam button and spring is removed. The cam button rubs against the timing cover (see the impression). High mileage motors are known to wear a hole right through into the coolant passage at the water pump side of the cover. That would spell disaster (coolant leaking into the engine's oil) and possible death to the Buick V-6. We immediately ordered a new timing cover from our friends at G Body Parts.
The rods and mains were checked...
The rods and mains were checked and fortunately showed minimal wear. Afterwards Dan measured the crank's mains and rods. They were still standard size; therefore the crank would only need to be polished.
There was evidence of some...
There was evidence of some blow-by, combustion gas getting past the rings, which is typical of a forced induction type motor when the boost is turned up. The pressed-in pins would stay in place (they checked out OK) while the rods were resized to accept stock size bearings. New Sealed Power rings (0.005-inch over) would reside on the stock pistons after a thorough cleaning, and they were checked for cracks. First the rings would be file-fit and gapped at 0.018-inch in the lightly honed cylinders (0.005-inch over) before being installed on the pistons.
The little V-6 ran well before...
The little V-6 ran well before teardown and we didn't anticipate any issues. Once the block was hot-tanked and cleaned up, Dan said the specs in the cylinders and mains were "on the money." The LC2 block is a rugged little piece, but like most production blocks there's a limitation to the amount of safe boost and horsepower they can handle. In this case, that would mean single digit e.t.'s, so we don't plan to exceed those limitations.
This is the original numbers-matching...
This is the original numbers-matching block to Tim's '87 Grand National and we're confident it will be built right for years of miles and smiles. The '87 crankshaft is known to be stronger than the previous year's and will hold up to our intended safe, street/strip style buildup. The oil pan will be cleaned-up, painted, and put back in service. The heads will be exchanged for the Jose-ported set we'll use and he'll put them in stock to port for a future customer.
Jose did a killer job porting...
Jose did a killer job porting us a set of heads (more on this later). A set of well-ported heads are essential to letting more air breathe through the boosted V-6.