HO Motor

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07-26-2009, 12:41 AM

Captn_tyler

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HO Motor

What is the difference between the HO and SO motors? I cant seem to find out, besides the fact that dodge said they make a little more power at stock.

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07-26-2009, 01:27 AM

01quadcab

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ho motor has a different vp pump, more compression and doesn't like the electronics as well as a so motor.

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07-26-2009, 09:01 AM

dukeboy_318

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the timing and compression are slightly different, not much, they are okay, it seems more power can be made on an SO motor then the HO for various reasons

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07-27-2009, 03:27 PM

Mr.Krabs

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yeah,pistons have a smaller bowl in them,and the VP is a little different.

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07-28-2009, 10:39 AM

kazairl

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If I'm not mistaken the piston cooling jets may be a little different as well. Though that could be only on the 03-04 HO motors as opposed to the 01-02 HO.

From what I can gather from my internet gleaning the HO VP has 7mm Plungers and the SO has 7.5 mm plungers. The HO injects at a little more pressure than the SO and has slightly smaller injectors. However Because of its bigger plungers the SO can move more fuel and therefore make more power.

Static compression on the SO is 16.3:1 the HO is 17.1:1

Quote:

"copied from dodgeram.org"

What's new in the ETH engine:

Electronic Controls: New ECM calibration and fueling algorithms.
Fuel Pump: Increased fuel flow in the Bosch VP44 injection pump.
Injectors: Designed to provide increased fuel flow.
Injector note posted to the TDRoundtable by tgbol:
ETH injectors (3946306) flow 600cc at 100bars for 30 seconds
ETC injectors (3944828) flow 640cc at the same test.
Turbocharger: Revised wastegate setting for 26psi at the turbocharger outlet.
Manifold boost specification is 43.5 inches Hg / 21 psi
Head: Valve seat inserts for added durability.
Pistons: New pistons with higher 17:1 compression ratio.
Flywheel: New flywheel with 330 mm diameter clutch (vs. std. 310 mm)

FWIW: Reports from owners indicate that ETC engines are more responsive than ETH engines are to the major fueling boxes.

Thats all I know and most of it could be wrong.

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