Originally posted by TRiv
Will keep you guys posted on the 87 conversion to the 85 T Riv engine,have about 2/3rd of parts needed, though the 85 Riv engine and trans I am converting is going into a mid engine custom, a few issues I see will apply if done to a Riviera, Will post in a few days what I am finding.
Well days has turned into weeks, but here are a few brief notes:
*The motor I am upgrading, an 85 turbo Riv motor,trans,frame section (from boneyard) is actually going into a custom mid engine, but I am looking to see how to convert with my driver 85 T Type Riv.
*It's not cheap, if we didn't already know that, even when getting good prices on the parts, it adds up quickly, just over $1600 now with a few small things to get.
*Wire harness first big problem, while same firewall connectors are used Riv,GNs, the wire pin outs are not all in same location, plus the Rivs have almost twice as many wires going to firewall with engine harness. While they can be made to match up if connector is reconfigured, it is no plug and play. My solution was to get entire 87 GN harnesses front to rear, but that won't work in the Rivs.
*Intercooler will fit as GNs, it gets mounted to the engine block by two brackets, however because of the funky front motor mount in the Rivs, the brackets have to be modified to work, one out of the three bolts will go in no mods,but bottom ones need mods.
*87 GN passenger header fits, mounts the turbo, but driver side 87 can't be used, it points down and 87 crossover goes down under between oil pan and trans. Have to use original Riv driver header and crossover because of th325-4l trans , but the crossover needs a little tweak to bolt up to 87 pass header, it's real close but has to fit better. Probably best to use Riv crossover as pattern and custom bend a pipe, besides, the flange on Riv crossover for turbo would have to be blocked.
*Downpipe from 87 turbo is going to have a real tight squeeze past heater and engine.
*Power steering is different on 87, has no provision for Rivs Hydroboost brakes.
*Turbo oil drain hole needs to be put in front of engine block.
*Everything else so far bolts up fine, manifold, engine accessories etc, need to measure and make sure 87 turbo location clears the hood, looks like it should.
That's it for now, at this time my thought to convert, the easier route would be keep the car as is, upgrade to 87 ECM, MAF,ignition coil, manifold/plenum/throttle body.
Use Riv turbo in stock location and fab (looks pretty easy) simple flange/bracket to mount the turbo to 87 manifold bosses for where ignition coil goes, reclock turbo to point towards front of motor and plumb to intercooler, again 87 cooler brackets will need mods to fit around the funky motor mount. Plumb intercooler to TB as stock 87. I did fit fit the parts up this way on engine stand and will work, the one tricky part to make will be turbo to intercooler pipe, could keep Riv turbo pointing up as stock and use elbow pipe as to clear the intake plenum.
If I find more I'll let you know.
