L-Series Relocation

[baby_Carlton]

Hi everyone,

 

I'm in the process of building an N/A L28 for my 240z and was looking to move my engine back about 2-3" back towards the firewall.  I intend on simply fabricating a thick steel bracket that would accomplish this using the stock motor mounts but I'm curious to see what solutions are out there.  I haven't found any threads on this topic on any of the major Z websites but if anyone has links I'd appreciate them.

[grannyknot]

I suspect you're not finding much on it because the benefits would be minimal I think, you would shift the front/back weight ratio a bit and  bring the stick shift back to a more comfortable position, any others?

But it shouldn't be too hard to do, come up with 2 plates that mount to the stock engine mount at the back of the plate and the front of the plate secure it to any holes between the engine mount and the timing cover, the 2 larger bolts on the timing cover might do the job if something closer can't be found. The stock engine mount would be secured to the plate depending on how far back you go.

 

The transmission mount would have to be cantilevered towards the back unless you build new mounts on the trans tunnel then shorten the drive shaft.

[ZHoob2004]

If you're going to go through the effort, I think the way to go would be to leave the mounts in the stock location on the block and move the mounts off the crossmember and onto the chassis rails like how the v8 kits do. Then you can slot/redrill the crossmember mounting bolts and shift that forward to get some caster gains while you're at it.

[tioga]

I know this is all just dreaming but. The wheels are already far forward in the fender openings and like to rub the lower valence as built. You need to section some front fenders and move the wheel arch forward while you are doing all this. I wonder if any of the aftermarket fiberglass fenders have ever moved the opening forward. None that I am aware of. It would be nice to jack some caster in these things. 

[baby_Carlton]

4 hours ago, grannyknot said:

I suspect you're not finding much on it because the benefits would be minimal I think, you would shift the front/back weight ratio a bit and  bring the stick shift back to a more comfortable position, any others?

 

Those are two benefits I'm going for here.  My 240's weight distribution is fairly decent as is but I'm chasing less weight over the front axle.  Looking at these engine mounts, it doesn't seem like an exceptionally arduous task.  The plan is to shorten my driveshaft more (already altered swapping to an R200 long nose), currently looking into cantilevering the transmission back.

 

Attached are my corner weights (roll bar, full interior, half tank, full steel body, alloy wheels).  I'm guessing I would shift only about 1-3% of the car's mass backward.  Not massive, but interesting to me nonetheless.

 

3 hours ago, ZHoob2004 said:

If you're going to go through the effort, I think the way to go would be to leave the mounts in the stock location on the block and move the mounts off the crossmember and onto the chassis rails like how the v8 kits do. Then you can slot/redrill the crossmember mounting bolts and shift that forward to get some caster gains while you're at it.

 

I've considered this and I believe it is easier (though maybe not better) to move the engine back using steel plates similar to what grannyknot mentioned.  Could you show me an example of the chassis rail mounted motor mounts?

 

2 hours ago, tioga said:

I know this is all just dreaming but. The wheels are already far forward in the fender openings and like to rub the lower valence as built. You need to section some front fenders and move the wheel arch forward while you are doing all this. I wonder if any of the aftermarket fiberglass fenders have ever moved the opening forward. None that I am aware of. It would be nice to jack some caster in these things. 

 

Yes, I've had to section my airdam to fit my tires and now that I'm switching to a larger tire setup (ZG flares) I think this will become more of an issue.  Haven't seen any fiberglass flares that do something similar to what your talking about other than maybe a Z-speed or Rocketbunny kit given how large they make the front end look.

 

 

Edited February 5, 2020 by baby_Carlton

[ZHoob2004]

Both of these feature an additional crossmember as well. I'm not sure if it's necessary or not, but it shouldn't really hurt.

 

 

https://www.technoversions.com/MotorMatchHome.html

 

[tube80z]

19 hours ago, grannyknot said:

I suspect you're not finding much on it because the benefits would be minimal I think, you would shift the front/back weight ratio a bit and  bring the stick shift back to a more comfortable position, any others?

 

Actually the benefit is a lot more than you might think, at least for a racing car.  I did this with an old car of mine where I set the motor back so the 1st cylinder was on the axle centerline.  To do this you need to cut into the firewall.  Even moving the engine back to where it almost touches will give you some benefit.  It's mostly on how fast the car will change direction.  At the time we had a number of cars with identical mods and suspension tuning.  The engine setback car was always quicker than the others.  The advantage depended on the track design so if there were more changes of direction then it was a bigger gap.  The total change for my car was about a half a percent of weight shift to the rear.  All the easy things were already moved towards the rear axle.

 

Once you've move all the easy parts to the back of the car then this can be looked at.  Mine was a hack job at best (finishing someone else's project).  The motor mounts were done using a flat plate that bolted to the block and allowed the motor mount to be moved a couple of inches.  Similar thing done on the engine crossmember mount location.  Sorry, photos have long since gone for all this.  You do need to be mindful of the oil pump interfering with the front ARB.  If you go far enough then you have the rack/crossmember to deal with.  

 

Hope this helps,

Cary