windage tray info - joe lucia

[dean petrucelli]

can anyone please tell me the correct windage tray part number for a 6 quart oil pan gm part number 359942. This is going on a 63 shp fi motor. Is it the 3769768 or the 3927136 tray? I assume the studs are 3872718 - correct? thanks for you help again

[Joe L.]

Re: windage tray info - joe lucia

dean-----

For use with the GM #359942 pan you need baffle (windage tray) GM #3769768. This baffle is GM-discontinued but available in reproduction. The GM #3927136 baffle will not fit this pan; it is designed for use with the 69+ Z-28 and 75-81 Corvette L-82 pan and its configuration is COMPLETELY different than the 3769768.

You also require studs GM #3872718 which are still available from GM.

By the way, using oil pan GM #359942 requires the use of the 75-79 style oil pan gasket set and NOT the pre-75 gasket set. The 75+ gasket set is packaged with the oil pan if you have an NOS, in-the-box pan. Otherwise, use the 75+ gasket set or, preferably, the Fel-Pro OS-34510T one piece gasket for 75+ oil pans. If you use a pre-74 gasket set with the 359942 oil pan you will have a PROFUSE oil leak from the front oil pan seal.

[Tracy C.]

Re: windage tray info - joe lucia

..."the GM #359942 ......is COMPLETELY different than the 3769768"...

Joe,

Please help me understand the difference between these pans. I recently picked one of these up and need to buy the correct gaskets for installation on my 63 327.

Also, is the windage tray a "must have" even for an occasional rompity romp but mostly tender foot street application.

thanks,
tc

[Joe L.]

Re: windage tray info - joe lucia

Tracy-----

From 1963 to 1974 only two oil pans were used on Corvette small blocks. GM #3820000 was the "5 quart" pan used on the vast majority of Corvette small blocks. GM #3820001 was the "6 quart" pan used on most 63-65 SHP, mechanical lifter small blocks, some early 1970 LT-1, and all 70-72 ZR-1. The latter pan has an extended sump and will not be compatible with cars equipped with power steering.

In about 1976 the above-referenced pans were discontinued and replaced by GM #360866 and GM #359942, respectively. Both of these pans are identical to their predecessors, except that the front seal radius is larger. This feature matches all of the 75-79 style PRODUCTION oil pans and, supposedly, provides for improved oil pan sealing. The gasket set for the 63-74 style pans and the 75-79 pans (including the aforementioned SERVICE replacements for 63-74 PRODUCTION oil pans) are the same EXCEPT for the front oil pan seal. The original 63-74 pans used a front oil pan seal which is 0.22" thick and the 75-79 style (including the aforementioned SERVICE replacements for the 63-74 PRODUCTION oil pans) is 0.41" thick.

There is no windage tray currently available for the "5 quart" oil pan. So, if one uses that pan, there is no need to even consider a windage tray. If one uses the "6 quart oil pan", then I recommend that the windage tray be used, whether or not driving style otherwise necessitates it. All original "6 quart" oil pans used the windage tray and the internal baffling system of that oil pan is designed around the use of the windage tray.

[Tracy C.]

Re: windage tray info - joe lucia

Thank you Joe,

I'll compare the pan's front seal radius to that of my timing chain cover to determine the appropriate gasket thickness.

tc

[Joe L.]

Re: windage tray info - joe lucia

Tracy-----

Place a straight-edge across the oil pan rails above the front oil seal radius. Measure straight down from the center of the straight edge to the apex of the oil seal radius (i.e the distance between the center of the sealing radius and the straight edge). If the measurement is 2-1/4", then you have a GM #3820000 or 3820001 oil pan and require the 63-74 style gasket set. If the measurement is 2-3/8", then you have the GM #360866 or 359942 SERVICE replacement oil pans and require the 75+ style gasket set.

[Tom P.]

Re: windage tray info - joe lucia

The curved 3927136 Z/28 windage tray is the one which I use in ALL small block engines that I build. So far, I have not run across one single pan which it will not work with. It is true that with a couple of pans it has been necessary to VERY lightly tweek the front corners of the 3927136 tray. The original Z/28 pan had a channel running down each side of the pan for the 136 tray to mate with, but it still works fine with all other pans, especially the deeper Vette pans. I have used this tray on everything from 283 to SB400s. By the way, on SB400s, it is necessary to slightly slot the holes for the studs because the main cap bolts on a SB400 are just slightly wider.

[Joe L.]

Re: windage tray info - joe lucia

Tom------

My reasoning on the two windage trays is this:

The GM #3769768 was used for all 63-74 SB applications which utilized a windage tray in conjunction with the 3820001 oil pan. The GM #3927136 windage tray was used with all 75-81 Corvette applications which used the GM #360009 oil pan (or certain 67-74 Z-28s which used the same configuration oil pan). The 63-74 Corvette oil pans are configured completely differently than the 75-81 Corvette oil pans.

My reasoning is that although either of the above windage trays may physically fit within either of the above oil pans, the 3769768 windage tray was designed to work with the 3820001 (and SERVICE replacement 359942) and the 3927136 was designed to work with the GM #360009 (and predecessor and successor oil pans). Generally speaking, OEM external oil baffles are designed to work in conjunction with the internal baffling of the oil pan as a SYSTEM. The 3820001 oil pan has the "trap door" internal baffling; the 360009 has completely different (and, actually, quite minimal) internal baffling.

So, my thinking is that while either windage tray may fit in either pan, the actual efficiency of the baffling SYSTEM may suffer if the the baffles are not used in the as-designed system. I don't know any of this, of course, but since I don't know any of the engineering that went into this, I prefer not to challenge the wisdom of it.

Also, after the GM #3769768 was discontinued from SERVICE, the GM #3927136, which remains available to this day, was not specified by GM as a SERVICE replacement for the earlier baffle. That's another hint that they might not consider it an acceptable replacement.

[Clem Z.]

Re: windage tray info - joe lucia

the flat tray helps keep the oil in the trap door area of the pan.

[Tom P.]

Re: windage tray info - joe lucia

And I fully understand your reasoning. I have used 3927136 on so many engines, including several of my own, with never a problem, that I have become quite satisfied that it is an acceptable substitute (of course, as these things go, I'll probably have an engine blow up tomorrow!).

[Tom P.]

Re: windage tray info - joe lucia

Both the 62-earlier and 63 later pans had the trap door in the optional engines. The 62-earlier pans had 2 steps and the 63-later engines had the loooooooooooooooong, one step sump. Both were 6qt capacity with a filter. I use the long sump pan and the 2qt truck filter on my 56.

[Joe L.]

Re: windage tray info - joe lucia

Tom-----

I don't think that the 3927136 used on 63-74 Corvette pans will cause any major problems. Whether it will be as efficient, or even useful, as the GM #3769768 when used with these pans, I don't know.

By the way, I feel very confident that the 3927136 will work fine with most passenger car pans of the 68+ period. Those pans are configured and baffled very similar to the 75-79 Corvette pan. Most of the passenger car pans used no external baffle and little internal baffling. So, the 3927136 almost has to be an improvement for them.