Engine "Braking".......Does it hurt the motor ???

[Rusty Davenport]

Recently put a three speed automatic in without clean neutral feature........is the "drag" on the motor damaging the engine leaving it in third gear at the finish line and allowing the engine to slow the car down ????

the Turbo Action website says on a reverse pattern 3 speed turbo 350 that there is no engine braking in second gear......is that every turbo 350 or just a feature of Turbo action transmissions ????

[Jeff Lee]

My opinion is engine braking, primarily on an OEM piston rod, will elongate the big eng of the rod which causes the bearing to pinch the crank pin at the parting line of the rod. Bearing failure is a result.

[Chris Hill]

My gut says no, but I think Jeff is correct on the rod being loaded more. If your engine is running 7,000+ rpm, then you let off the gas, vaccum in the intake system goes through the roof. Intake runs high vaccum, not much air if any is compressed during compression stroke and the net load on the rod may be greater than at the top of exhaust stroke when rod is slowing down the piston. You would have to look at cylinder pressure traces to make sure though.

But to answer Rusty's original question, we've done it both ways with our stockers, and both ways seem to work ok

[Lambertcars]

You dont see much engine failure in nascar and they are basically doing the same thing.

Allen lambert

[trmnatr]

What about an aluminum rod small block that runs 8,100-8,400rpm past the lights with a TH400 with a trans brake ?

Click the engine in high gear or lift and leave the engine running? How much engine braking do you think there would be with a transbrake TH400 when you lift?

[greg fulk]

All I know is most if not all the Comp guys click the engine off @ the strip...I've always put my cars out of gear after the strip.

[trmnatr]

Originally Posted by greg fulk

All I know is most if not all the Comp guys click the engine off @ the strip...I've always put my cars out of gear after the strip.

Your car a stick car or an automatic? Is it a transbrake trans if automatic?

[gmonde]

one ,a drag race engine is set up for quarter mile ,most drag pans are designed for acceleration and on decel the oil is pushed forward,(some have trap doors not allow oil to collect forward of the pick up) but still can not collect all the oil starving the pick up,now i get mine in neutral once over the line and let the engine idle down,even when i ran the five speed clutched it at the line.,neutral let the engine idle down,why run the engine harder than it needs to by deceling from 7000 on down risking a dry sump
2 cents gmonde

[SSDiv6]

Originally Posted by Lambertcars

You dont see much engine failure in nascar and they are basically doing the same thing.

Allen lambert

However, NASCAR engines run rotating components, heavier oil weights, less spring pressure and smaller cams. Jeff Lee, Chris Hill and GMonda covered many of the issues. Engines with aluminum rods are more suceptible to damage than steel rod engines.

My recommendation is to click the engine "off" and not "Engine Brake"; you are not driving a Diesel truck.

[trmnatr]

Originally Posted by SSDiv6

However, NASCAR engines run rotating components, heavier oil weights, less spring pressure and smaller cams. Jeff Lee, Chris Hill and GMonda covered many of the issues. Engines with aluminum rods are more suceptible to damage than steel rod engines.

My recommendation is to click the engine "off" and not "Engine Brake"; you are not driving a Diesel truck.

See post #6, What about a small block that run 8,100-8,400rpm past the lights with aluminum rods and a TH400 automatic that is a transbrake so it is a reverse valve body so you cant put it in Neutral