I am 84 YO., and building my last SBC 400 and will be over

[oldhead]

I am 84 YO., and building my last SBC 400 and will be over 1100 hp like my old one. its a world block and has sbc mains. What wrong with SBC mains? Thanks for your answers Bob Oldhead

[F-BIRD'88]

What happened to the old one.?

[oldhead]

The old one was a Dart and like alot Darts cracked the main webbing at the oil hole Oldhead

[superpursuit]

I am 84 YO., and building my last SBC 400 and will be over 1100 hp like my old one. its a world block and has sbc mains. What wrong with SBC mains? Thanks for your answers Bob Oldhead

I assume you are talking about the difference between 400 mains and 350 mains.

400 mains = 2.648" at the shaft.

350 mains = 2.448" at the shaft.

The 400 mains being larger will handle a bit more load at the expense of slightly higher oil temp at the bearing.

The 350 mains being smaller will not handle as much load but will have slightly less oil temp at the bearing.

People building very high revving engines usually go for the smaller mains but with yours being supercharged you may want the higher load capacity of the 400 sized bearings.

Other peoples opinions may vary as they always do.

I hope this helps.
Allan.

[Little Mouse]

I would second that and the crank would be a bit stiffer. I guess money no object dart I assume still makes the compacted graphite option. It's all the rage in commercial class 8 truck engine block now then there using computers to lighten the blocks weight where they can using the stronger iron.

[Little Mouse]

I would second that and the crank would be a bit stiffer. I guess money no object dart I assume still makes the compacted graphite option. It's all the rage in commercial class 8 truck engine block now. Then there using computers to lighten the blocks weight where they can using the stronger iron.

[swampbuggy]

Good day Oldhead; you said your Dart block cracked in the main web at the oil feed hole. There are several Dart blocks to choose from so this begs the question, exactly which Dart block are you speaking of and how long was it hammered before it cracked ? Mark H.

[Chris_Hamilton]

I got nothing to add other than I love that you are 84 and building an 1100hp SBC.

[enigma57]

Roger that! I'm 72 and its hard enough (physically) just building these 'last' 2 engines (350 Chevy for son's Camaro and 292 inline 6 for my '57 sedan).

Good on you Oldhead,

Harry

[xanadu]

Sounds like its an end to a fun Era of engine building.
Congratulations, i will be having a beer for you
All the best with your engine

[Orr89rocz]

If i recall, oldhead has had that dart block for a dozen years. I guess time caught up to it and it cracked. Surprised it broke tho, if a little m block it should live forever at 1100 hp. But 10+ yrs is alot who knows

350 main 400 main....doesnt the larger main take away material from the cap? So while the crank is stiffer and stronger, the cap is weaker? Or is everything dimensionally enlarged to account for the larger bearing size?

Either way 1100 hp can be done on 350 mains all day long with good crank. But blower cars usually want the bbc snout and a 400 main there may be advantageous. Turbo car would be fine on 350 mains

[rebelyell]

I got nothing to add other than I love that you are 84 and building an 1100hp SBC.

Nothing to add either but kudos to Bob

[Kevin Johnson]

If i recall, oldhead has had that dart block for a dozen years. I guess time caught up to it and it cracked. Surprised it broke tho, if a little m block it should live forever at 1100 hp. But 10+ yrs is alot who knows...

Cough. At least 17 years. I remember when he posted this and thinking about him lighting up the rear wheels.

I have a dart SBC. 400 block and heads with no steam holes...On the Dyno made over 1100 hp.(Blown) its in a street car with AC,I drive it with the AC on when its over a 100 out in Bumper to bumper traffic for more then 3 years.No holes,no problems... OLDHEAD

[ClassicComp]

I think this is the guy that has a Holley dp on his car and the secondary’s are controlled by a cruise control unit on something.
He was supposed to post pics,

[Kevin Johnson]

oldhead_and_Chewie_AC_is_running.gif