I've acquired a windage tray for the slant. I understand the tray attaches to the main bearing bolts in the same manner as a LA motor. Are the slant bolts same thread size as the LA bolts?

The special bolts are the same thread size, but longer. Each bolt needs 1 or 2 hardened washers under the bolt heads. Mopar recomends using one washer and shorten the bol .150 inches, if a bottoming tap will not cut the threads deep enough. The installation kit should be still available, from Mopar. The part number is P3690930. The tray has been discontinued.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks for the info! Will check at the local dealer and see what the parts guy says.

How does a windage tray work? I'm guessing that it deflects oil for some reason down near the crank (since you're discussing the main bearings). What's the purpose? Just curious!

MJ

This is a quote from a Mopar performance book.

"Every engine that uses oil for lubrication has windage losses. Controlling windage loss can help make more power. This holds true for any engine. The more engine speed that you use, the worse the windage loss becomes. Remember, less windage means more horsepower.

So what is windage and why does less of it make more power? Windage is the friction caused by the crankshaft and connecting rod assembly rotating through an air/oil mixture. Windage trays are designed to scrape the oil that is thrown off the crankshaft away from the crankshaft and into the pan, and keep the oil that is in the pan from coming up for the crankshaft to drag through. Each connecting rod and main bearing has oil and oil pressure in it and, because of the oil pressure in it, some will leak out and get in the way of the rotating crankshaft assembly. Then theres oil that goes to the heads to lubricate the valve gear that has to get back to the pan somehow. This usually means that it falls back past the tappets and on to the crankshaft.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Interesting! Then why wasn't the slant just designed with a tray in place? Is there some kind of drawback?

MJ

Too expensive. From the factory standpoint it was, why spend that kind of money on an economy six cylinder that will spend most of its life buzzing along under 4000 RPM. You can put one on though if you like. Don't really know if they will help much on a daily driver though. Maybe some of the performance gurus can help you ou more than I can.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

A windage tray is not worth the $$$ and effort if you don't rev the engine over 5000 RPM.
DD

Thanks guys, I wasn't actually going to put one on (heck if I could find one!) but I was just more interested in what its for, etc since I'd never heard of one. Thanks for indulging my curiosity!

MJ

A windage tray does several things:

1), it prevents the "wind" whipped up by the spinning crankshaft from making little waterspouts out of the oil sitting in the bottom of the pan waiting to be picked up by the oil pump, reducing foaming and reducing the liklihood of oil starvation during hard cornering and braking.

2) It provides a nice smooth enclosure for the crankshaft so that the air whipped up by the crank just kinda spins with the crank rather than impacting the walls of the squared-off oil pan, thus preventing power from getting sapped from the crank to get the air moving again after its stopped by the pan walls..

3) it reduces the amount of oil that is kept rotating with the crank and speeds the return of oil sprayed out by the rod bearings back to the pan.


All in all, a windage tray is a great investment, even on a slow-turning engine like a 225 because it has such a long stroke that the crank throws and counter-weights travel through a pretty big arc and thus move a LOT of air at relatively low RPM. . On shorter stroke engines like, say a 340 or a 383, its still a great investment because those engines will rotate much faster. On a 318 that has a short stroke AND won't ever rev very fast- not much benefit.

Its certainly not worth dropping the oil pan *JUST* to put one in on any daily driver type car, but if you're in there already, by all means do it.

I do not agree. This is my personal opinion. Since a windage tray, with the hardware, for a slant, will cost about $150, it is not much bang-for-the-buck. It will only give a few HP, in the upper RPM range, and very little below 4,000 RPM, it is not cost effective on a street engine.

PS: I have one in both my engines, and my new engine will also have a crank scrapper, but depending on what gear I'm running, I turn my engine as high as 7100 rpm.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

OK, a few hp gain is pretty modest, but what is the effect on fuel mileage?

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Equally modest.

Thanks guys, learning more every day. If I had the unlimited cash supply, I'd do it since I'm hitting the oil pan anyway. But that $150 buys a new cam, some shocks, or many of the other stuff I actually MUST get vs. like to get. Ahhh, when is the Ed McMahon going to CALL!

It's like chicken soup when you're sick: Might help. Can't hurt.
Cost effectiveness depends on which costs and which effects you count. Money and time are only parts of the equation. Materials have costs, but some of us are pretty good at reduce-reuse-recycling. If you enjoy fabricating and tinkering on your car, quality time in the garage could be considered a positive effect, rather than a cost. Knowing that you have taken one more step toward optimizing your car for you is a definite benefit which is hard to quantify.
That said, there are areas of my own car that are much higher on the priority list.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO