Siamese bore daily driver???

[drobertson]

Recently I have noticed that ma mopar now makes a 440 small block crate motor.... but it's a siamese bore block. From what I understand, these engines run hotter, and therefore you'd need an upgraded cooling system. Would daily driving an engine like this be bad? OR would I be fine as long as I keep the block less than or equal to 215 F degrees? Just throwing out a question. I'd like to eventually toss one of these crate motors into my 73' 318 charger.

A. 440 Super Commando Crate Engine - 530HorsepowerBig block power and cubic inches in a small block package! Mopar's 440 SuperCommando small block stroker crate engine gives you over 500 horsepower onpump gas, and offers the compact size of a small block.1 P5153523 Crate Engine, 440 Super Commando, 530 Horsepower, 540ft-lbs. TorqueSpecifications:· Bore: 4.185"· Stroke: 4.000"· Compression Ratio: 10:1· Block: 340 Siamese Block with Four-bolt Mains· Cylinder Heads: Aluminum· Intake Manifold: Single Plane Four-barrel· Camshaft: Hydraulic, 251°/257° Duration @ .050", .603" Lift· Oil Pan: Eight-quart Center Sump Street/Strip Oil Pan· Crankshaft: Forged 4340· Pistons: Forged· Valves: 2.080"/1.600" Stainless , w/ 5/16" Stems· Connecting Rods: Forged 6.123"· Rocker Arm: Aluminum Roller with 1.6:1 RatioNote: Crate engines that change the emissions performance of the vehicle maynot be legal for use on vehicles regulated for highway use in California and otherstates. Horsepower and torque ratings based on test engine. Ratings may varyon individual engines. -mopar performance small block pdf catalog
:headbang:

 

[MOPOWER871]

I had a Mopar Performance 440 siamese bore 440 driven lots on the street, no problems on the street. Would recommend high volume water pump, and a up to par radiator. Good luck.

 

[drobertson]

I had a Mopar Performance 440 siamese bore 440 driven lots on the street, no problems on the street. Would recommend high volume water pump, and a up to par radiator. Good luck.View attachment 295921View attachment 295922

Thanks. Thats a sweet car you have!

 

[Hemirunner]

The siamese bore overheating myth dates back to the old 400 inch sbc engines that overheated due to other issues but the siamese bore got the blame. I've ran siamese bore mopar blocks on the street for years with no issues.

 

[drobertson]

Well I'd better start saving my pennies. I wonder if the stock sb k frame will withstand 540 ft lbs of torque?

 

[747mopar]

My last Chevy motor was a stout 400 small block which is a Siamese bore with 2 steam ports holes which I plugged off, no problems at all running it on the streets daily. In my opinion allot of the myth about Siamese bores being bad came from those damn steam ports on the 400, the head gasket would always fail right there and leak water into the combustion chamber causing problems. FelPro came out with a gasket that restricted a couple spots and required drilling another to get the cooling right then just plug them off and you were good to go.

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My 400 never overheated with those little mods done...

 

[rumblefish360]

Well I'd better start saving my pennies. I wonder if the stock sb k frame will withstand 540 ft lbs of torque?

It's not the K frame that is the issue but the Uni-body itself that will need sub frame connectors, leaf spring reinforcements (torque boxes at the min.) and a suspension.
Wide sticky tires optional.

Welding in plates on the K frame wouldn't hurt anything. Just weight. The engine is not at a lower level where K frame reinforcements are needed. When you get to approx. double the power plus, then you might see a bennfit to it, though a move to a tubular K would be the better move.

 

[glassman]

Every Mopar flathead six is a Siamese bore block. No issues and nothing new to Mopar