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B234 block doesn't fit very naturally in a 240. The motor mounts are designed to mount on a wider 700/900 crossmember (which in turn, isn't the same as the 8V 700/900 series crossmember). And they sort of reach around the external oil pump on the left side. So welding up custom motor mounts as a minimum. And depending on what you are going to do for ignition, it doesn't leave you with any engine mounted sitributor options - you can't fit the head mounted distributor because there's a firewall there, and you can't use a block mounted distributor because there's no intermediate shaft.
I'm at the 99.5% done stage on my 16V turbo swap in my 245 (all back together, fluids added, it was late and dark last night when I hooked up the battery, the lights came on... and the starter wouldn't do anything... Left it to look at today in daylight). Here's a rough breakdown of what I've needed to do to make it work in a 245.
1) Bottom end. I'm using a late model B230FT block with piston squirters. The H-beam rods and forged pistons weren't necessary for putting the head on, but I did need to have valve reliefs carved into the pistons. There are some people who get by without that. I figure they are on fairly thin ice, but frankly, any 16V motor that loses a timing belt is going to mangle stuff inside. Something to ponder.
2) Distributor. I should have moved on to EDIT os coil-on-plug by now, but for the time being I'm keeping with the LH2.4 style crank sensor triggered ignition with a distributor (Bosch ECU replaced with Megasquirt). There's no room for the head mounted distributor. I had to get a geared intermediate shaft ('94 B230FT came with a smooth disc) and use a block mounted distributor. Then the issue moves on to the way the 16V head sticks out on the intake sede a couple of inches farther. the thermostat housing ends up bing right where the cap and wires would be on a regular 240 distributor. Solution is to use a 'crab' cap (wares mount all off to one side), used on Bosch distributors on various (presumably very cramped) little Citroens and Renaults. Had to get it on UK eBay. Then the 'roof' of the crab cap was lower, so I had to trim the shaft of the distributor, and shorten the rotor slightly by slicing off some of the base. Then it fit fine. The cap barely has room to slide off, the distributor itself can't come out with the head on. But then again it doesn't really need to.
3) Timing belt. One of the issues you end up with using a 16V head on an 8V block (in exchange for not worrying about motor mounts). On a B234 the tensioner mounts on the block (there are two versions, 700 series uses an 8V style tensioner mounted low on the block, 900 series uses a pivoting arm on the head with a hydraulic tensioner mounted on the block). And on an 8V, the tensioner mounts on the head. When you put a 16V head on an 8V block, there's no place to put a tensioner. There are a number of different ways to skin this cat, including a nice (but spendy) all Volvo solution using Penta AQ171 parts - since the Penta DOHC motor was basically a 16V head on an 8V block. I used a little kit made by Josh (yoshifab.com) which uses an 850 tensioner, 960 idler, and 850 belt. Nice bolt on solution.
4) Intake manifold. 700/900 series cars have wider engine bays, and even then they need a skinny flat brake booster to move the master cylinder back enough to make room for the bulky 16V intake manifold. On a 240, that won't even help much (could possibly mount the brake master cylinder straight to the firewall and use a remote brake booster, but who wants to reengineer the brakes?) and it ends up with the throttle body pointing *RIGHT AT* the master cylinder, with barely any room to spare. Plus there is some anecdotal evidence that the 16V manifold flows unevenly under boost, so I didn't even grab it at the junkyard when I got my head. Instead, I went with an adapter plate (again, Yoshifab.com) that allowed me to bolt my 8V intake manifold to the 16V head. While the adapter fixes the different bolt pattern problems, there's still the issue of round runners in the manifold vs. oval ports in the head. I spent an evening porting to blend the shapes together, wirking in a couple of inches on either side. Then, when I got the engine in the car and munted the intake manifold, I found that there was *still* some clearance issue. Because the 8V manifold was stuck out a fwe inches farther on the 16V head than it was on the 8V head. Uncomfortably close to the master cylinder still (although slightly better than the 16V manifold). Solution was to go to the junkyard and pick up an 850 throttle body which is a couple of inches shorter (and larger throttle valve as a bonus). Took some work to fit it to the 8V manifold's unusual 3 bolt pattern, but it worked and I had room for an elbow. Then I noticed that the accelerator cable brackets and throttle spool stuck up too high now, apprarently the 16V head also angles the manifold up more. I spent some time reworkign those to lower them.
5) Exhaust manifold. Volvo only made a few 16V turbos (in Italy, and a few other Euro markets where they sold a 2.0 liter B204 turbo for tax purposes) and you really can't realistically expect to get your hands on one of those manifolds. There's a guy who makes beautiful tubular turbo manifolds over on turbobricks, but he seeemd to be bookd for months, and I wanted it done sooner. So I got a log manifold kit from jgsturbo.com. ~$300 and it was here in 2 weeks. I got the vesion that was all the runners welded up, it just needs the turbo flange located and welded on. I found a place where my turbo (GT3076R) would fit and welded it up. Made a downpipe.
All in all, it's not a bolt on, trivial sort of swap. It's the sort of project that will stretch on a pretty long time because you've departed from parts swapping and ventured into the world of actual custom engine building. It's easier now that guys more clever than I have pioneered the way, and peopple like Josh are making parts that would be difficult for shade tree mechanics like me to create with limited machining ability.
Here's a thread I did over on turbobricks with a fair number of pictures.
http://forums.turbobricks.com/showthread.php?t=166061
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'63 PV544 rat rod, '93 Classic #1141 245 +t
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