LS Mounts for Flatout Crossmember on a 55-59

[daveshilling]

Anyone want to share pics/details of their LS mounts on a FlatOut crossmember in their TF?

Looking at buying and modifying the welder series, but want to check with the collective mind first. Thanks !

[Dan in Pasadena]

Took me awhile to find them but I thought I had photos. We custom fabricated engine mounts that are welded onto a boxing plate immediately next to the Flat Out cross member.

As I was searching I found photos of the mounts but struggled to remember exactly where we mounted them? Finally found them. You can see the driver side one is shaped differently to go under the steering column.

Hope this helps some.

[daveshilling]

Originally Posted by Dan in Pasadena

Took me awhile to find them but I thought I had photos. We custom fabricated engine mounts that are welded onto a boxing plate immediately next to the Flat Out cross member.

As I was searching I found photos of the mounts but struggled to remember exactly where we mounted them? Finally found them. You can see the driver side one is shaped differently to go under the steering column.

Hope this helps some.

Yes, super helpful... I immediately scoured your build, I'm going to leave this here so I have it for reference:

Dan's Mounts

I have no plasma cutter, only a grinder, so those concave cuts are the worst!

[Dan in Pasadena]

It's been a couple years but I'm pretty sure the guy that installed my LQ4 had the pieces cut by a local place that has one of those high pressure water thingies (how's that for demonstrating my low tech vocabulary, ha ha?!)

As for cutting them with a grinder it'll just take more time and more grinding wheels! They don't have to have all the little "ears" or tabs etc. A square plate with rounded corners will work just as well (if not better/easier). We used ordinary rubber biscuit type isolators. Cheap and effective...I hope! Please post whatever you use, we all like pics!

[daveshilling]

Originally Posted by Dan in Pasadena

It's been a couple years but I'm pretty sure the guy that installed my LQ4 had the pieces cut by a local place that has one of those high pressure water thingies (how's that for demonstrating my low tech vocabulary, ha ha?!)

As for cutting them with a grinder it'll just take more time and more grinding wheels! They don't have to have all the little "ears" or tabs etc. A square plate with rounded corners will work just as well (if not better/easier). We used ordinary rubber biscuit type isolators. Cheap and effective...I hope! Please post whatever you use, we all like pics!

I found this random article while looking at LS Mount plates, and it looks like he attached his mounts directly to the crossmember:

LS Mount Article



Curious how his mount attachment point and yours could be so far apart... did you mount your engine closer into the firewall or did he mount his closer to the radiator?

I have a rebuilt steering rack from Flatout on the way, so once I swap oil plans I should have decent clearance, but I like the idea of getting the engine as far behind the front axle as possible too for weight distribution...

[Dan in Pasadena]

Not sure how my truck and that guy’s compare but I can tell you my engine is too close to the firewall. It doesn’t touch but I’d be a lot happier if it were maybe 1/2” to 1” forward. Mine was an error in that we bolted the bare cab onto the frame using too small bolts which gave the impression it was 1/4” clear. It’s actually tight.

Also, where did this guy locate the centerline of his crossmember? We moved my wheel centerline forward but I don’t remember just how much. This might account for why his approach is ON the crossmember while mine is not.

[_Ogre]

Originally Posted by daveshilling

I found this random article while looking at LS Mount plates, and it looks like he attached his mounts directly to the crossmember:

this is what i would do.
stock gm ls mounts and a simple bracket coming of the frame or x-member
these are my sbc mounts. stock gm sbc mount coming off the fatman x-member
other than the thick walled 3/8 tubing i used square tubing i had in stock
95% of the mount should resist torque, very little force applied in the x,y,z axis

[dsraven]

any time you are talking mounts be sure to have the bodywork (cab and rad support/rad at least) attached and the steering rack/box in place with steering column at least mocked up and connected as it would be. it saves future headaches. also, aside from what ogre mentions about torque affects, think about how the mounts will affect the exhaust system routing, engine removal/replacement, trans cooler line routing, starter swapping, p/s pump interference and line routing, a/c compressor and line routing, shift linkage or cable routing. think about room for the belt driven fan and hub or at least an electric fan set up and how much room is required for that. if going with a push fan to save room in front of the engine will there be room in front of the rad/ac condenser between the grille for the fan unit. some stuff that you think you will figure out later can turn into a whole bunch of work when the time comes to finish up the "small stuff" and you end up engineering a bunch of changes. think about adjustability for future considerations etc. sometimes a bolt on frame mount for the engine is preferable to something permanently welded in. it can give the engine more room in tight engine bays when removing/installing the engine, later, if the frame side of the mount can simply be unbolted and taken out of the way. if using a through bolt on the engine mount will there be room to get the bolt out without taking a bunch of other stuff off first. when the next job, fabbing a trans cross member, comes around also think about how the exhaust will get to the rear past the cross member, shifter linkages or cable interference, fuel lines, brake master cylinders and boosters, park brake mechanisms etc. how will the trans cross member stiffen the frame to assist the cab mounting flexing issues that come into consideration when the original trans cross member is removed.
anyway, just a few thoughts. sometimes the easiest way to fix a bunch of problems is to do one larger job right away, like a firewall modification, rather than a whole slew of the smaller jobs that only really became an issue because of the modifications required to get an engine sitting in the bay.
sorry, the quick reply came out to be a short story. hope it helps somebody

[daveshilling]

Thought I would pop in on this thread and add my mounts for searching purposes even though they're on my build thread as well.

I originally went with a straight tubing mount, but I ended up not liking those, as well as hacking them up because I moved the engine and needed to redo the mounts.

I came back to this thread, almost 3 years later, took another look at Dans mounts, and decided the 3 wall style, attached to my original tube/bushings at the frame would be my best bet. I liked Dans Ford flathead mounts better, but I already had this so I worked with what I had.

I mocked up with cardboard and a wood dowel as a steering rod, then refined the cardboard, then started cutting and welding. My air compressor is on loan so I couldn't use the plasma cutter which made it take awhile.

[mr48chev]

I'd have to say that by using Dan's photos and then using the cardboard to design your own you are exactly on the right path.