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 Post subject: Duratec m5od trans?
PostPosted: March 17, 2023, 8:35 am 
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Joined: January 18, 2011, 1:23 pm
Posts: 37
Has anyone used one of these in a locost? I have one in my possession and it seems to be rather large with an annoying fluid drain sump that sticks down almost as much as the bellhousing parts i intend to cut off. Anyone have pics?


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 Post subject: Re: Duratec m5od trans?
PostPosted: March 17, 2023, 10:07 am 
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What are you cutting off? I have a 4.0l M50D sitting here.

Build a chassis big enough to take it and clear the top of the duratec by 1/2 inch with the pan an inch below the rails.

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 Post subject: Re: Duratec m5od trans?
PostPosted: March 17, 2023, 1:43 pm 
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Location: Under the weather. (Seattle)
Yes, it's pretty bulky, and the NC Miata 6-speed is similarly so. If you need a more svelte off-the-shelf RWD Duratec transmission, the NC Miata 5-speed might be a better option for you.

Let me see if I can find some time in the next few days to lug out my transmission and throw it in my 'frame' to take a few pics and measurements. I'm not sure there's as much to gain as you're hoping. The stock oil pan hangs down below the bellhousing, and if my memory serves, even the low profile (high cost) aftermarket wet sump from Raceline still only saves ~1 inch... And I'm not sure how much lower the body of the transmission could even go while maintaining clearance above the chassis tube(s).

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 Post subject: Re: Duratec m5od trans?
PostPosted: March 18, 2023, 1:13 am 
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Joined: January 18, 2011, 1:23 pm
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Miatav8,MstrASE,A&P,F wrote:
What are you cutting off? I have a 4.0l M50D sitting here.

Build a chassis big enough to take it and clear the top of the duratec by 1/2 inch with the pan an inch below the rails.

Whatcha doin with that 4.0 trans? Thats got the "good" ratios

The oil pan im gonna use is 75mm tall so i was gona shave off everything that sticks below that.


Last edited by flyguyeddy on March 18, 2023, 1:16 am, edited 1 time in total.

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 Post subject: Re: Duratec m5od trans?
PostPosted: March 18, 2023, 1:15 am 
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Driven5 wrote:
Yes, it's pretty bulky, and the NC Miata 6-speed is similarly so. If you need a more svelte off-the-shelf RWD Duratec transmission, the NC Miata 5-speed might be a better option for you.


Id love to use the nc miata trans, but they are very pricey near me, and all the sellers seem very sketchy.

The oil oan im gonna use is a steel fabricated puzzle piece type thig you weld together. Not as cool as the aluminum raceline but definitely cheaper.


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 Post subject: Re: Duratec m5od trans?
PostPosted: March 18, 2023, 3:20 am 
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Location: Under the weather. (Seattle)
As I see it, there are a couple of issues.

First is the (structural) oil pan. The Miata transmission has 4 oil pan bolt holes, a wide spaced pair near the top of the oil pan and a narrow spaced pair near the bottom of the oil pan. The 75mm pans have mounting holes for the widely spaced upper pair, and allow you to shave the bellhousing flange into the unused narrow spaced lower pair. However, the Ranger transmission only has 3 bolt holes into the oil pan. The drivers side near the top of the oil pan and the narrow spaced pair near the bottom of the pan. This means that you'll only be bolting into the oil oil pan on one side, which is certainly not what I'd call structurally efficient. If I'm not mistaken, here's where the block/pan interface would be:

Attachment:
IMG_20230317_233455849.jpg


Second is that I don't see where you're going to get any benefit from the shortened pan anyway. As far as I can tell, it's going to be sitting well above the bottom of the chassis. Here is a side shot of the transmission as level as I could get it, assuming the ribs on the sides of the case are reasonably parallel to the internals. Consider the unmodified bellhousing flange as flush with the bottom of the chassis.

Attachment:
IMG_20230317_233735116.jpg


With a 1" tube shown for reference, you'll see that the 'annoying' drain sump still has ~1/2" of clearance to the bottom of the chassis.

Attachment:
IMG_20230317_233929594.jpg


Now you may be thinking that if you take 1" off the bellhousing flange and bring it to level, that means your drain sump would be protruding from the bottom of the chassis by another ~1/2". However, that would only hold true if you also eliminate a critical tube in any Locost frame I've ever seen. Otherwise you find yourself with a mere ~1/4" clearance between the frame tube and the 'high' point under the transmission.

Attachment:
IMG_20230317_234008462.jpg


So even if you were so confident in rigidly mounting the engine that you were willing to bring the whole transmission the rest of the way down until it effectively rests on the frame tube, the drain sump would still be above the bottom of the chassis, and the bellhousing wouldn't actually be hanging down far enough to even worry about. The 75mm oil pan would actually be sitting notably above the bottom of the car... And that's assuming you don't run any kind of triangulation under the transmission, which would push it all even higher.


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Last edited by Driven5 on March 18, 2023, 8:11 pm, edited 1 time in total.

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 Post subject: Re: Duratec m5od trans?
PostPosted: March 18, 2023, 8:23 am 
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flyguyeddy wrote:
Miatav8,MstrASE,A&P,F wrote:
What are you cutting off? I have a 4.0l M50D sitting here.

Build a chassis big enough to take it and clear the top of the duratec by 1/2 inch with the pan an inch below the rails.

Whatcha doin with that 4.0 trans? Thats got the "good" ratios


It's for a Bronco II.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS cheap viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
Frame LxcockpitWxengbayH
Lotus 7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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