81 firebird
stoned_pimp420
10-01-2008, 08:48 PM
i just bought a 81 firebird 3.8 for 200 dollars, i've got a 72 HO crane engines 350 in a 72 G30 van with a 350 turbo trans i want to get at LEAST 500 to the ground with this combo i know it is impossible stock but some starting ideas would be nice, cam/heads bottom end recommends would be great 4 bolt 350 std. 4" bore I was thinking 355 stroker bottom but if that can't be done let me know what can be done!!!!!!!!!!!
MrPbody
10-02-2008, 10:14 AM
A G30 should have TH400, not TH350 in '72. What is a 350HO crane engine?
A 355 is a 350 Chevy bored .030". It is not a "stroker". The term "stroker" indicates the engine has had a crankshaft change, usually with a longer stroke than "standard". 350 Chevy has a stroke of 3.480" standard. The most popular "stroker" small block is 383. That is a 350 block, bored .030" over, with a 3.75" stroke crankshaft installed. There are others...
500 RWHP is a tall order from a normally aspirated small block. It CAN be done, but it's expensive and will be a parts "eater". It would be easier to use a 500 GBHP (flywheel) engine and put a 200 "hit" of nitrous on it. That would get you there with the smaller engine.
A better solution would be to simply use a larger engine, more capable of making big power without beating itself to death. Big block Chevy in the 502 range, could easily do it, without the need for power adders (nitrous, blower, etc.). Another good choice would be a 505 Pontiac, since it's a Firebird. Not as well-known as the 502 Chevy, a VERY capable performer. Pontiac engines have come a long way in a short time regarding power production and durability. They also make more torque than BBC, at a lower RPM. A "purist" would scoff at the Pontiac with a Chevy engine.
In any case, the '81 is quite a heavy car (>3,700 lbs.) and calls for a high-torque engine more than a high HP engine. Either the BBC or Pontiac fits this description better than the small block. You need a 650 HP small block to move this car as easily as a 550 HP big block or 500 HP Pontiac would.
Jim
A 355 is a 350 Chevy bored .030". It is not a "stroker". The term "stroker" indicates the engine has had a crankshaft change, usually with a longer stroke than "standard". 350 Chevy has a stroke of 3.480" standard. The most popular "stroker" small block is 383. That is a 350 block, bored .030" over, with a 3.75" stroke crankshaft installed. There are others...
500 RWHP is a tall order from a normally aspirated small block. It CAN be done, but it's expensive and will be a parts "eater". It would be easier to use a 500 GBHP (flywheel) engine and put a 200 "hit" of nitrous on it. That would get you there with the smaller engine.
A better solution would be to simply use a larger engine, more capable of making big power without beating itself to death. Big block Chevy in the 502 range, could easily do it, without the need for power adders (nitrous, blower, etc.). Another good choice would be a 505 Pontiac, since it's a Firebird. Not as well-known as the 502 Chevy, a VERY capable performer. Pontiac engines have come a long way in a short time regarding power production and durability. They also make more torque than BBC, at a lower RPM. A "purist" would scoff at the Pontiac with a Chevy engine.
In any case, the '81 is quite a heavy car (>3,700 lbs.) and calls for a high-torque engine more than a high HP engine. Either the BBC or Pontiac fits this description better than the small block. You need a 650 HP small block to move this car as easily as a 550 HP big block or 500 HP Pontiac would.
Jim
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