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Engine off set

Started by Migge, January 09, 2019, 01:57:56 PM

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Migge

Saw CSX 7079 at SPA in 2018 and was wondering about the engine position. Seems that it is a bit off set. Any ideas why?

Migge


Migge


A-Snake

The differential is centered in cars but the pinion is offset so the driveshaft is also offset to join the pinion. In many cars the drive shaft is long enough to allow that offset to be made up along the driveshaft with the u-joints. With Cobras short driveshaft the engine has to be slightly offset to align with the differential. The offset is just more noticeable with the Webers. I can post photos of a leaf spring Cobra that shows the offset.   

A-Snake

Notice the air cleaner offset.

Migge

Of course it's allways better to have a straight "Line" between gearbox and diff. But that means different engine mounts or different engine brackets at the chassis rails. I have never noticed that?



A-Snake

Notice engine offset to the right.


Migge

So it's a fact that the complete engine/gearbox package is offset to the right for ALL regular production Cobras??

CSX2259

The original CSX2000 Cobras had the offset per A-Snakes description and reasons.
The early CSX7000 Cobras did not have an offset like the original 260/289 Cobras and had drive shaft angles that were very bad given the length of the drive shaft. Both the aluminum and glass bodied cars had this problem, for whatever reason nobody at SAI in Zvegas bothered looking at an original chassis to copy the mints and the offsets, the mounts utilized a regular passenger car motor mount where the originals used the hipo designed mount. When SAI ordered aluminum chassis from Kirkham the chassis was void of engine and transmission mounting brackets. The problem was not that difficult to correct on the Kirkham chassis but the glass body chassis cars were very difficult to correct due to the "Daytona" backbone or trellis that ran from front of the car to back of the car.
Later Superformance built CSX7000 Cobras did not have this problem and utilized the CSX2000 Cobras engine and transmission bracket locations.

Migge

Thanks for the information.

Sometimes it's easier to mount the diff offset  and using a shorter lefthand driveshaft.

mickmate

Small block and big block cars had a 1/2" offset of the drivetrain to the right side for the reasons explained above.

pbf777

Quote from: A-Snake on January 11, 2019, 01:08:07 PM
The differential is centered in cars but the pinion is offset so the driveshaft is also offset to join the pinion. In many cars the drive shaft is long enough to allow that offset to be made up along the driveshaft with the u-joints. With Cobras short driveshaft the engine has to be slightly offset to align with the differential.


     I understand that this is an older posting, but since it has been renewed by another today, so please permit me to comment.   ::) 

     If the O.E.M. wanted the engine centered in the chassis, and if it were the differentials' offset positioning due to if the diff. itself were centered, then the O.E.M. would just reverse the relationship to create a centered pinion receptacle; which they have done many times in the past.  And there is no requirement for the differential to be "centered", and in many examples it is not as engineered by the O.E.M.'s. 

     There are many considerations for the placement of componentry in the chassis, and yes the engine and transmissions' centerline is generally preferred to be "somewhat" in alignment with the pinion shaft of the differential; but for example the universal joint manufacturer actually recommends that they "not" be in true alignment with one another.  Rather they generally recommend something like a 1-1/2° to 3° minimum offset for a longer service life, this as to work the roller bearings, creating rotation within the caps and about the trunnion, this enhancing the movement of the lubricant and also reduces the tendency for particularly the trunnion to become "staked" by the rollers.  Values in excess of say 5° to 7° starts to accelerate the heating and wear rate, though still acceptable, past 12° to 14° really is to avoided but often witnessed particularly in "Jacked-Up" 4 X 4's.    :o

     So why is the engine offset to the passenger side of many vehicles, not just Cobras?   :-\   Because it was decided a long time ago that along with perhaps needing the space in the foot-well for pedals & feet in operation, the owner, whom most often paid (paying  ::) ) for the vehicle, and most often drives the vehicle, the manufacturer is trying to make that person feel better about their choice by making it feel roomier for them, this at the expense of the passengers somewhat, but whom really rarely complain as even if they might feel even a bit cramped, it still sure beats walking!   ::)

     Scott.

98SVT - was 06GT

Quote from: pbf777 on June 30, 2023, 09:02:57 PM
     So why is the engine offset to the passenger side of many vehicles, not just Cobras?   :-\   Because it was decided a long time ago that along with perhaps needing the space in the foot-well for pedals & feet in operation, the owner, whom most often paid (paying  ::) ) for the vehicle, and most often drives the vehicle, the manufacturer is trying to make that person feel better about their choice by making it feel roomier for them, this at the expense of the passengers somewhat, but whom really rarely complain as even if they might feel even a bit cramped, it still sure beats walking!   ::)
And there you have the sole reason. Oval track cars back in the day ran the whole drive train offset to handle better. NASCAR even went so far as to offset the bodies to make the cars appear to be straight when they weren't. Todays spec chassis has negated that cheat.....
Previous owner 6S843 - GT350H & 68 GT500 Convert #135.
Mine: GT1 Mustang, 1998 SVT 32V, 1929 Model A Coupe, Wife's: 2004 Tbird
Member since 1975 - priceless

Harris Speedster

My 1969 Italia has the engine off set to the passenger side.
Maybe about 1 inch each side.
Noticeable like the cobra above.
The Italia has a 50/50 weight distribution,

I always assumed that it was to off set the drivers weight, which it does, correct?
Few of my early 65 Shelbys had trunk mount batteries, weight distribution ? >> located to opposite of driver in trunk.
Just thinking out-loud !
John
Is this the first futuristic exotic in the world?
Size of an ac cobra, but built in 1935 !
https://www.autopuzzles.com/forum/features-stories-and-photos/harris-fwd-speedster-the-story/?PHPSESSID=v4pqtv6hep4ff4rvalrc9qsnj7

Cobrabob

If compensating for driver weight were the reason for the offset, then right hand drive Cobras should be offset the other way. Is that the case?