Here's our first Buick 455 from the junkyard--the one that ended up being cracked.
Buicks are pretty good, if not great. That's an opinion long held at CC dating back to the time we swapped an old Electra 225 motor into a Skylark wagon for summer fun, and then again when the Buick beat all comers in the now legendary CC shootout of all the GM corporate big-blocks.
Sadly, the state of gearhead living has changed drastically over the last five years, and even here in SoCal, the Buick 455 engine donors just aren't in the 'yards or on the streets like they used to be. In fact, when Editor Glad did finally score a junkyard 455 while planning for this latest Buick story, the block turned out to be damaged beyond repair. Instead, the engine core we used came from the voice of the industry, Dave McClelland, who keeps a few in stock to feed his original '70 GS455 four-speed convertible.
The Hooker headers are PN 1204HKR, and we wanted something more retro than ceramic silver,
With Buick cores starting to thin out, we figure you'd better get it right when you build one, not only to preserve the breed but also to live up to the Hemi-stomping heritage with some real street power. That's what this story is here for--to deliver the facts about what works and what doesn't on a simple, budget-built 455. We prowled the Buick message boards to learn what cams, heads, and intakes were most asked about, and those are the parts we'll test here for your edification. We'll give you the dyno-proven power using multiple combinations of two cams, four intakes, and three sets of heads. This month we'll kick it off with cam and intake testing using stock iron Stage 1-style heads, and next month you'll see how the iron heads stack up against the Edelbrocks and the entry-level aluminum offerings from TA Performance. Speaking of TA, we've got to thank Mike Tomaszewski over there, as well as local Buick fan (and owner of a 9-second, naturally aspirated GS455) Bruce Kent, both of whom loaned us parts and expertise.
The Baseline Long-Block
All the testing in our stories was done with the old McClelland short-block rebuilt by JMS Racing Engines. The combo is as basic as it can get and easily duplicated. The only nonstock components in the short-block are ARP rod bolts and Speed-Pro forged pistons, PN L2353F, in a 0.030-inch overbore (stock bore is 4.3125, so our bore is 4.3425 for 462 ci). The Speed-Pro slugs are the lowest-priced forged pistons you can buy for the 455; TA Performance sells them for $429.95 a set. However, they do have some drawbacks, including an old-school 5/64-inch ring pack and a hefty 758-gram weight. Also, the dished Speed-Pros do not have valve reliefs in 'em, but TA Performance also sells precut pistons for an extra $85, and that's what we used. For just an extra $235 to $250, you could get modern, lightweight, custom forgings with 1/16-inch rings, and the extra money could be well worth the opportunity for more compression.
Both cams we tested were flat-tappets, and while TA Performance supplied good, hard-faced
The Buick 455s were launched in 1970 with 10.0:1 to 10.5:1 compression, but that fell to 8.5:1 in 1971 and then to 8.3:1 before the engine was discontinued after the '76 model year. On our test engine, the compression represents what you'll get from a stock '71 to '76 junkyard 455 or what is running in your Buick right now. The Speed-Pro L2353F pistons start life with 27.8cc dishes, then add another 3 to 4 cc for the custom valve notches, bringing the total to about 32 cc. The compression height is 1.975, the stock rods are 6.600 inches, the stock stroke is 3.900 inches, and the production deck height is 10.57 inches. That adds up to pistons that are 0.045 in the hole, but JMS decked the block 0.005, so the real-world number is a poor 0.040 below the deck. The Fel-Pro Performance PN 1125 head gaskets have 4.385-inch bores and a 0.041-inch compressed thickness. Work those numbers with the 70cc chambers in the iron heads used this month and the compression ratio is just 8.77:1.
The heads we used are the stock, reconditioned units from TA Performance, and they use the Stage 1 valve sizes of 2.125/1.750 inches. The regular production 455 heads are the same casting as Stage 1 heads but use smaller 2.00/1.625 valves; TA uses the '74-and-earlier castings and opens up the valve size, just as the factory did. The '75 to '76 castings have factory 78cc chambers and are never used by TA. The '70 heads are 68 cc, and the '71 to '74 units have 71cc chambers that are milled to 69 to 70 cc during the rebuild process.
E3 spark plugs were used throughout the testing.
Our engine uses a bone-stock oiling system, though we found that even the low-volume oil pump gear needed to be shaved 0.010 inch to avoid an interference problem with the oil pump cover.
All our testing was done using an internally balanced flywheel borrowed from Bruce Kent, a Meziere electric water pump, Rockett Brand 91-octane gas, an MSD ignition, E3 spark plugs, and a set of Hooker headers coated by Jet-Hot. The headers are for a Skylark, feature 1 7/8-inch primaries and 3-inch collectors, and were run with 18-inch collector extensions. We used a Holley 750-cfm Street HP carb for every test, and it was determined through testing that 32 degrees of total timing made the most power.
Stare long and hard at this shot of the Edelbrock B4B (left) and Performer intakes and you
Small Cam, Dual-Plane Intakes
Our first round of dyno tests used the TA Performance hydraulic flat-tappet cam known as the TA-212. It specs out at a tame 218/230 degrees of duration at 0.050 tappet lift. The lobe-separation angle is 112 degrees, and valve lift is 0.459/0.470 inch using stock replacement shaft-style rocker arms (Sealed Power PN R857) with a 1.55:1 ratio.
Using what is perhaps the smallest cam seen in CC this decade, we ran four intakes across the 455: an Edelbrock Performer, an Edelbrock B4B, a TA Performance SP1, and a TA Performance SPX. Both Eddie units were dual-planes, and both TA castings were single-planes.
Interestingly, we inspected the two Edelbrock intakes and the only difference we could see in them was the shape of the carb pad and the fact that the Performer places the carb about 3/8 inch rearward as compared with the B4B. Presumably, this is so the Performer will line up the carb with a factory GS hoodscoop.
The dyno also couldn't see a difference between the Performer and the B4B, as they performed identically pull after pull, thereby blowing the old Buick bench race talk that the B4B is a better intake. Both cranked some numbers we were happy with, though: 426 hp at 5,300 rpm and 513 lb-ft at 3,500 rpm with more than 500 lb-ft from 3,100 to 4,100. With a near-stock idle quality, this setup proved to be the one we loved the most with the stock heads.
Our Holley 750 Street HP carb is fitted with a pair of Adjust-A-Jet blocks from Percy's Hi
Small Cam, Single-Plane Intakes
Next we moved on to the single-plane intakes, trying the smaller TA Performance SP1 and the larger, taller, more hard-core SPX that features a water passage under the plenum that can be used to cool the intake; we did not take advantage of that feature during dyno testing. Intuitively, both single-planes were out of place with the tiny camshaft, but true to our forecast, they made more peak power while giving up lots of bottom end. The pivot point in the curve was at 4,300 to 4,500 rpm; below that point, the dual-planes made more power, and above that point, the single-planes were superior. Looking at peak numbers only, the SPX intake produced 443 hp at 5,500 rpm and 500 lb-ft at 3,600 rpm. As usual, if you consider the average power throughout the entire curve, the dual-plane and single-plane look very similar because they just trade high-end and low-end power, so the overall average does not change much: In this case, the average numbers from 2,100 to 6,000 rpm only differ by 1 lb-ft and 2 hp. However, look at the power when plotted on a graph in this story and then consider the rpm range where you'd really drive a tame combo like this and you'll opt for a dual-plane with the small cam. It's a shame no one makes a high-rise dual-plane for the Buick.
As for comparing the SP1 with the SPX, it seemed the gnarlier SPX was better by a few numbers at the very low end and at the top end. Oddly enough, both single-planes made virtually the same power between 3,500 and 4,500 rpm. Averaging the power from 2,000 through 6,000 rpm, the SPX was superior to the SP1 by just 3 hp and 4 lb-ft.
Stare long and hard at this shot of the Edelbrock B4B (left) and Performer intakes and you
Big Cam, Dual-Plane Intake
Phase two this month involved repeating the intake tests but with a larger cam. The new 'stick is a TA Performance grind called the TA-413, a very popular hydraulic flat-tappet setup with 234/244 degrees of duration at 0.050, a lobe separation of 113 degrees, and a lift of 0.500/0.500 with the stock rockers.
Basically, it was a flop, probably due to our engine's low compression and stock heads. We only ran it with the B4B dual-plane, since we'd satisfied ourselves that it was identical to the Performer. What we saw in an A/B comparo from the small TA-212 cam to the larger TA-413 was a big-time loss of torque below 3,500 rpm. The larger cam didn't start to pull ahead until 4,700 rpm, and even then it only made 11 more hp than the smaller cam, though it did carry several hundred extra rpm. As for torque, the larger cam lost as much as 40 lb-ft at some points. The big cam with the B4B intake was the most mismatched combo of the test and proved it by producing the worst average power of any other cam-and-intake combo we tested.
Big Cam, Single-Plane Intake
Could it be that the bigger cam would show more promise with the single-plane intake? Conventional wisdom might point that way, but the test results demand some scrutiny to see if it's true.
Because the SPX intake had proven slightly superior with the smaller cam, it's the intake we chose for the larger cam. Again, the dual-plane B4B made more torque below 4,000, but the gain was not as dramatic, and the SPX single-plane leaped ahead dramatically above 4,600 rpm, posting the best peak horsepower number we'd yet seen: 459 hp at 5,600 rpm. Taken on average from 2,100 to 6,000 rpm using the big cam, the SPX delivered 349 hp and 452 lb-ft, and the B4B averaged 339 hp and 446 lb-ft. So with the bigger TA-413 cam, we'd opt for the SPX intake and then gear the car accordingly.
We feel this engine's standout moment was with the TA-212 cam and the Performer or B4B intake. With a strong, low-rpm, 500-lb-ft showing, it most loudly proclaimed the Buick-guy motto of Go Fast With Class, and it would have made for an ideal daily driver engine in the road barge of your choice, plus it would probably run fine on 87-octane. Bigger cams and intakes just made it a rumblier engine, and frankly a bit subaverage when you compare the drawbacks with the power produced. But that may change next month as we wave a few sets of better cylinder heads across it. Stay tuned.
Here's the Performer intake on the 455. Note how the carb is pushed back to line up with a
This photo compares the TA Performance SP1 (left) and SPX single-plane intakes. The SPX is
If you were choosing intakes by aesthetics alone, you'd go with the SPX every time. It jus
The two cams used in this test are the popular TA Performance TA-212 and TA-413. Cam swaps
Here are the Speed-Pro L2353F pistons custom-notched for valve clearance by TA Performance
This dyno graph compares the B4B intake (blue lines) with the SPX intake (red lines) while using the small TA-212 camshaft. Note the textbook trade-off between low-end gains with the dual-plane and high-end performance with the single-plane. In this case, we'd choose the dual-plane.
This graph compares the most low-end-friendly combo of the small cam and the B4B intake with the best high-rpm combo of the larger cam and the SPX intake. On average, they make the same power. But which would you choose? It depends on your performance goals, street or strip.
|Buick 455 Cam And Intake Power Chart |
|RPM ||B4B Intake ||TA-212-Cam |
|B4B Intake ||TA-413-Cam |
|LBS-FT ||HP ||LB-FT ||HP ||LB-FT ||HP ||LB-FT ||HP |
|2,100 ||441 ||176 ||425 ||170 ||401 ||61 ||390 ||156W |
|2,200 ||439 ||184 ||429 ||180 ||399 ||167 ||388 ||162 |
|2,300 ||441 ||193 ||437 ||191 ||398 ||174 ||390 ||171 |
|2,400 ||445 ||203 ||445 ||203 ||400 ||183 ||402 ||184 |
|2,500 ||451 ||215 ||453 ||214 ||404 ||192 ||415 ||198 |
|2,600 ||458 ||227 ||456 ||224 ||411 ||204 ||423 ||210 |
|2,700 ||465 ||239 ||456 ||236 ||422 ||217 ||434 ||232 |
|2,900 ||483 ||267 ||469 ||259 ||446 ||246 ||440 ||243 |
|3,000 ||493 ||281 ||476 ||272 ||456 ||261 ||447 ||255 |
|3,100 ||500 ||295 ||483 ||285 ||465 ||275 ||455 ||268 |
|3,200 ||505 ||307 ||490 ||298 ||474 ||289 ||464 ||283 |
|3,300 ||508 ||319 ||494 ||310 ||482 ||303 ||471 ||296 |
|3,400 ||511 ||331 ||497 ||322 ||489 ||317 ||477 ||309 |
|3,500 ||512 ||342 ||499 ||332 ||494 ||329 ||483 ||322 |
|3,600 ||513 ||351 ||500 ||343 ||496 ||340 ||488 ||344 |
|3,700 ||511 ||360 ||499 ||352 ||497 ||350 ||491 ||346 |
|3,800 ||509 ||368 ||497 ||360 ||498 ||360 ||492 ||356 |
|3,900 ||507 ||376 ||495 ||368 ||497 ||369 ||494 ||367 |
|4,000 ||504 ||384 ||494 ||377 ||496 ||378 ||495 ||377 |
|4,100 ||500 ||390 ||495 ||386 ||495 ||386 ||495 ||386 |
|4,200 ||496 ||397 ||494 ||395 ||492 ||393 ||492 ||394 |
|4,300 ||491 ||402 ||491 ||402 ||488 ||399 ||489 ||400 |
|4,400 ||486 ||407 ||486 ||407 ||483 ||405 ||485 ||406 |
|4,500 ||481 ||412 ||481 ||412 ||477 ||409 ||481 ||412 |
|4,600 ||475 ||416 ||477 ||418 ||472 ||414 ||479 ||419 |
|4,700 ||468 ||419 ||473 ||424 ||468 ||419 ||428 ||428 |
|4,800 ||460 ||421 ||468 ||428 ||463 ||423 ||436 ||436 |
|4,900 ||452 ||422 ||462 ||431 ||457 ||426 ||442 ||442 |
|5,000 ||444 ||422 ||456 ||435 ||449 ||428 ||469 ||446 |
|5,100 ||436 ||423 ||450 ||437 ||442 ||429 ||462 ||449 |
|5,200 ||429 ||425 ||444 ||440 ||435 ||431 ||456 ||451 |
|5,300 ||422 ||426 ||438 ||442 ||429 ||433 ||450 ||451 |
|5,400 ||414 ||425 ||431 ||443 ||423 ||435 ||444 ||457 |
|5,500 ||404 ||423 ||423 ||443 ||417 ||437 ||438 ||459 |
|5,600 ||394 ||421 ||413 ||441 ||410 ||437 ||431 ||459 |
|5,700 ||384 ||416 ||401 ||435 ||400 ||435 ||419 ||455 |
|5,800 ||371 ||410 ||388 ||428 ||390 ||430 ||408 ||451 |
|5,900 ||357 ||402 ||377 ||423 ||377 ||424 ||395 ||444 |
|6,000 ||344 ||393 ||362 ||423 ||364 ||416 ||383 ||437 |
|AVG ||459 ||344 ||458 ||346 ||446 ||339 ||452 ||349 |
|Automotive Racing Products (ARP)||JMS Racing Engines|
|Ventura, CA||El Monte, CA|
| || |
|Autotronic Controls Corp. (MSD)||Lucas Oil Products|
|El Paso, TX||Corona, CA|
| || |
|Edelbrock||Percy's High Performance|
|Torrance, CA||Camdenton, MO|
| || |
|Holley Performance Products||Rockett Brand Racing Fuel|
|Bowling Green, KY||Glenview, IL|
| || |
|Hooker Headers||TA Performance|
|Bowling Green, KY||Scottsdale, AZ|
| || |
|King of Prussia, PA|| |