Bolt mains?
05-19-2003, 11:23 PM
#1
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Car: 1983 Trans Am
Engine: N/A
Transmission: N/A
Bolt mains?
Ok Ok.. gimme all the flak you want for this. But I have been reading about engines, and 4 bolt main keeps appearing as part of the car vernacular.
What exactly is a 4 bolt main.. 6 bolt main.. etc?
I probably should know, but I dont
What exactly is a 4 bolt main.. 6 bolt main.. etc?
I probably should know, but I dont
05-20-2003, 12:09 AM
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Car: 1985 Pontiac Trans Am
Engine: 355 with stuffs.
Transmission: 700R4
Axle/Gears: 4.10 Posi
Ok this is a pretty simple one to answer. 
when you hear 2 bolt or 4 bolt main, that refers to the number of bolts that hold the main bearing caps for the crankshaft. 2 bolt main = 2 bolts per cap. 4 bolt main = 4 bolts per cap. All thirdgen V8's have the 2 bolt main setup. That doesn't mean they are bad engines. The 4 bolts are a bit of a stronger block, but you can make a 2 bolt into a 4 bolt.
when you hear 2 bolt or 4 bolt main, that refers to the number of bolts that hold the main bearing caps for the crankshaft. 2 bolt main = 2 bolts per cap. 4 bolt main = 4 bolts per cap. All thirdgen V8's have the 2 bolt main setup. That doesn't mean they are bad engines. The 4 bolts are a bit of a stronger block, but you can make a 2 bolt into a 4 bolt. 
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05-20-2003, 01:43 PM
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Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
Originally posted by StealthElephant
thats a nice looking crank in the 2nd pic
thats a nice looking crank in the 2nd pic
It's just a stock cast crank ground down .010" on both the main and rod journals.
As you can see, the machine shop here is pretty good. That shine you see on the 2nd and 3rd rod journals is from the SMOOOOTH radii and the micro-polished finish.
It only cost me $380 to get the block crank done.
I like living in a small town.
05-21-2003, 04:25 PM
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Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
Originally posted by Ukraine Train
here's a six bolt block. this was an LS1 on display at the detroit auto show this year
here's a six bolt block. this was an LS1 on display at the detroit auto show this year
Right Click, Save Picture As....
05-21-2003, 06:47 PM
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Car: 1994 Nissan Pathfinder
Engine: 3.0L V-6
Transmission: Auto
dude, that pic helped a lot. know i EXACTLY know what you're talking about. the 6-bolt was a little hard to visualize though. not the most all-encompassing pic. shoot, were there even 6 bolts in that pic?
05-21-2003, 06:52 PM
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Car: '87 Camaro LT
Engine: 355 L98
Transmission: T56
Originally posted by bredfearn
the 6-bolt was a little hard to visualize though. not the most all-encompassing pic. shoot, were there even 6 bolts in that pic?
the 6-bolt was a little hard to visualize though. not the most all-encompassing pic. shoot, were there even 6 bolts in that pic?
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