Precise Powertrain Positioning?

OK, so I'm turning the E30 into a front-mid-engined car by moving the whole thing behind the subframe. When I have tackled this sort of thing before I have had physical help and the cars were body on frame so you could move the frame in relation to the motor/trans and so on with two people and some leverage.

This time - unibody E30 on jack stands and working alone. What do you guys do? I was thinking that I could bake a "cart" with scrap steel and HF casters to attach to the block and support the engine/trans at the right angle. Then roll it under and lower the body with the engine hoist, then position/shim the jackstands until it was right on. Aside from the tedious effort of welding up a cart I use once and then cut up - it seems like a good plan on the surface.

How do you fine folks get good precision when positioning two heavy things in relation to one another working alone with primitive shop tools?

Ratchet straps are your friend, they can be great extra hands to support stuff.

Why not just slam together some 2x4, maybe set on top of one or two HF 4 caster mover's dollies?
Then use the ratchet straps to firmly bind everything together after you get it supported and positioned the way you want.

+1, wood is easier to cut than metal. Those things really do hold a lot of weight. I have a SBC and a 2004R trans sitting on them in my garage.

I've made and used wood dollies in the past and it has worked fine. Dropping your motor would probably be a bigger deal. Also, think of using the cage in your car as scaffolding. With how far back you're moving things, you should get some great support from the cage and some ratchet straps while you get things secure.

Whole new firewall huh? Shifter's going to end up way back there as well... Interested to see how this works out. How are you planning on supporting the engine?

Why are we giving you ideas outside of a build thread anyway. Where are the pictures?

mr2peak wrote: Whole new firewall huh? Shifter's going to end up way back there as well... Interested to see how this works out. How are you planning on supporting the engine?

The shifter has a 10" linkage so... it can be shortened or if I can go further back - it's not much effort to flip the motion given the way the shift rod on the trans is operated. I expect to go about 8" rearward and up 1" (so the body can go lower to the ground...) based on measurements. A good deal of the tunnel will need to be redone so working with what is there isn't necessary.

The engine will be supported by 1.5x120 roll cage tubing arms welded to flanges plated to the front frame rails and potentially triangulated to the roll cage front down tubes. The factory aluminum arms on the engine block will be reused as well if at all possible. I'll turn some nylon bushings on the lathe to keep the vibes from blurring the instruments and mirrors. The transmission will have the rear cross member it has now only relocated rearward and use nylon bushings too.

Most of the hard parts to my way of thinkin' will be trying to make the new firewall and engine cover not look like an idiot working alone in his garage botched the whole thing together in one drunken weekend. So... basically a lie :)

mazdeuce wrote: Why are we giving you ideas outside of a build thread anyway. Where are the pictures?

You know how you are still stringing out that "I bought a 911" thread here a few months later? People will put up with dribbles of 911 info... because they are really cool cars that not everyone has laying out behind their house. This is an engine-less E30 with body damage and a bent trailing arm from last season's mis-steps. No one wants to see it on jack stands with no updates for weeks on end so I'm holding off until after all the initial failures are made and things start to look good... then putting up a wall of "Great Success" pics :)

On second thought... mistakes are funny. I'll start a thread as soon as I get back from the lumber yard with cart building materials. I am hoping to get serious this weekend.

There is no way it could be anything but awesome when you have to run to the lumber yard to get wood to work on your race car. You are GRM.

Note how I did it on my N600:

http://grassrootsmotorsports.com/forum/build-projects-and-project-cars/2011-n600-west-coast-challenger/33452/page1/

Scrap wood and lag bolts are cheap. Due to the garage used at the time, we had to have everything portable. The car was on pallets that were attached to 4 Harbor Freight dollies and the car could be moved around during mock up. The powertrain was mounted to non-moving supports that were easy to install at the beginning of the day and remove at the end of the day. Wood is extremely easy to work with and cheap. It's not extremely precise, but you can add shims/spacers or cut it down as required to adjust after initial mock up. This assumes it's a one-time deal. Obviously if you were doing the same swap five times you'd want a better jig. However, even then, it might be easier to figure out the engine position in wood and then build a jig out of metal once that is done the first time.

Bryce