Engine mounting position

[Fred W.]

Hi all

I need to find out what the tolerance is, if any, for the angle of mounting an engine front to back. Im in the process of measuring this up at the moment and have found that if I mount the engine in a certain position it has a couple of very favourable outcomes. The most favourable is that I get to retain the stock sump but the engine ends up at an angle of about 2.8' front to back, the front being higher than the back. The engine is an LS2 from a Holden HSV commodore. Any help appreciated, thanks.

 

[Jac Mac]

If your talking 2.8° nose up, that is fine (bloody near perfect), helps with purging air bubbles from cyl heads cooling jackets.

P.S. To get the little ° after your degree number... hold the Alt key down & type 248... thanks to transplanted Kiwi Ross Nichol for that gem..

 

[Terry Oxandale]

These kind of angles were actually pretty common with the front engined RWD cars. My only concern with all of this (my LSx motor will be perfectly horizontal) is the rear-most pooling of transmission oil in the inverted 930 transaxle.

 

[Jack]

I agree with Ox. My LS/930 combo will be mounted level. The gearbox concern is the only reason.

 

[Troy]

Hi Fred. How did you go with this (see pic) cross member? Does the standard Commodore sump clear it?

I assume you have the wider engine bay (later RF chassis), but have you thought about how the engine mounts will go? The eng mounts in my car sit a fair way rearward (for the 302) than they need to be for an LS fitment, though I think you'll have an easier time of it with the later mounting plates / points.

 

[Russ Noble]

With regard to the comments by Terry and Molleur, I think the rearward pooling due to the inclination is insignificant compared to the rearward impetus given to the oil by the bottom of the rotating crown wheel.

In any case under normal operating conditions there will be oil sprayed absolutely everywhere by all the rotating components. The only time it will get a chance to pool anywhere is when the car is stopped and the motor is switched off.

 

[Jack]

Thank you Russ. You are absolutely right and I had not considered this, thanks.

 

[Terry Oxandale]

That makes perfect sense. Question for me would then be a previously discussed issue of the 930 using the manufacturer's original oil volume. I need to re-look at the case (I'm at work, late), but doesn't the inverted case spread the "floor" of the inverted case out over a much longer area than the normal upright gear casing's relief? My interpretation of this would be this spreads the oil out along the entire "floor" of the case (unless additional oil has been added) leaving less oil to be whipped up and about? But then again, hard acceleration (who would do that in a '40) makes this a mute point.

 

[Fred W.]

Hi Troy and all.

The motor sump and trans all seen to fit as if the RF chassis was built for it. I hope Im not speaking to soon because all the clearances are tight. My thoughts right from the start was that the sump would be miles to deep and I would have to replace it with a custom fab wet sump or go dry sump. I ended up clamping a plank under the engine bay at the lowest allowable point and then just sat the engine on the plank with the sump flat on the plank. As the post said it tilted the motor a bit and also the trans which brought that into a much better position. The trans then became the governor as it is now as low as it can go, see pic, without cutting bits out of the frame. It would seem that the dive shaft is at an OK angle but Im not sure I just hope so. As for the engine mounts there is heaps of room to fab up whatever I need, and the LS engine has an array of hole along the block to use for mounting brackets etc. Thank guys. I hope the pictured come out ok they are the first attempt at posting.

 

[Old Roaring Forties]

Looking good Fred,
The driveshaft angle looks fine, 8 degrees will afford you a constant 280km'hr by CV design - it's all about the speed at which the balls travel through the race (and it increases with angle) breaking down the lube the faster they go.

Any large hole you can fit a 5.4 Ford Boss in should be big enough for most other engines.

It looks like you are progressing well, great to see, regards Paul

 

[Jim Cowden]

Nice size shed Fred.

Jim

 

[Fred W.]

Thanks Jim

The dimensions are the exact same size as the hole in my wallet.

 

[Jack]

Fred W.
That is the most descriptive single sentence that I have ever heard! Cool!