RXBeetle Reader
March 5, 2016 7:36 p.m.

This project started about the same as my FB RX7, smokey. I've had my RX7 for 4 years and daily drove it for 80,000+ miles. I bought the RX8 for just over challenge $$ with a blown engine. The RX8 started and "ran" but the engine was toast, likely an oil control ring failure and a bad oil metering pump sensor that kept throwing it into limp mode. I've had a 6-port 13B sitting on an engine stand for years with the intentions of putting it in a few different chassis over the years. I bought the 13B off John Brown, and rebuilt it along with street porting the intake and exhaust.

The goal is to match the power of the Renesis with the ported 13B. I built the engine with the intent of turboing it but that's down the road. The Renesis engine came out pretty easily despite my HF engine hoist being delivered sans caster... wtf

The 13B mounts right up to the trans but after that its time to get creative with the welder. There are some real nice (pricey) mounts for the 13B-RE engine. I don't have an RE but I like the mount design.

Why are there a bunch of welded up holes you ask? I drilled the whole thing backward... weld weld weld, redrill redrill redrill.

I started with some steel angle iron, I'm also running a 12A front cover so the fabbed pan seals that up as well. I made a baffle to cut down on slosh, the oil pan is deeper than the RX8 but shallower than the S4 pan but still holds 4 quarts. Teadplate because why not

The crossmember replaces the stock stamped unit. 2 urethane mounts connect the dots between the pan and the crossmember. After some POR15 engine paint:

It fits!!! Kinda, the header (cheap-o OBX stainless) needed a ~10-deg cut/weld at the flange to get it to clear the crossmember.

A little Tractor Supply black paint on the engine bay before the engine went in. A few more engine details:
-ACT streetlight flywheel and clutch -JW Performance 4 barrel intake manifold -Speedmaster 4 barrel throttle body

I've got some more progress I'll post pics on soon. Lots of little things that eat up hours. injector bungs, throttle pedal, cable, coil mounts, etc.

chandlerGTi UberDork
March 6, 2016 6:58 a.m.

Nice work, looks like fun.

JtspellS SuperDork
March 6, 2016 7:11 a.m.

Nice!! It looks odd to see a carb in an 8 chassis though lol.

RossD UltimaDork
March 6, 2016 7:25 a.m.

Nice work.

RXBeetle Reader
March 6, 2016 6:01 p.m.
JtspellS wrote: Nice!! It looks odd to see a carb in an 8 chassis though lol.

I had a chuckle at it as well. I seriously considered throwing the 12A dizzy and a 600cfm Holley I have on there to get it running but decided against it. I am topping it off with a big round air filter. The 4 barrel stuff makes it cheap and easy and I get more surface area cheaper than a cone filter. The intake manifold clearance is a challenge and the 4 barrel intake clears with just enough wiggle room.

MS3 will run the engine but I have to keep the stock ECU for now to keep the electric power steering and some body control stuff functional.

BoxheadTim UltimaDork
March 6, 2016 6:20 p.m.

Nice work. I especially like the creative use of diamond plate for the oil pan.

RXBeetle Reader
March 31, 2016 12:12 a.m.

Some more no-particular-order updates. Exhaust is 95% there. I'm using a cheap-o stainless OBX header and a magnaflow 6" round muffler, after that it's just the factory RX8 exhaust. I reused the doughnut flange from the stock exhaust. Only problem was the inside was so caked with carbon and oil it ignited when I welded it to the muffler... The header is for an FC and didn't clear the new crossbrace/engine mount. I had to cut the primaries off the engine flange and hack at it with the angle grinder to rock the header up and closer to the engine. I welded in a couple of EGT bungs and moved the O2 bung to the collector.

The coil bracket has taken me way too much time but floating 4 big bricks (FC trailing coils) in space and connecting all the dots didn't turn out too bad. The coils just didn't seem to have a happy place they wanted to be in the engine bay. (Lokar throttle cable poking through the fire wall under the coils)

The pulley alignment was a hot mess. I wanted to use the RX8 AC pump and alternator, but none of this bolts to the FC block. I welded up some monkey bars off the side of the engine to hit all the points which let me move the alternator over to the driver side to make room for some future induction plans.

That all went great but I realized the water pump was way out and the RX8 pulley was too shallow with the FC pump. High rpm and rotary water pumps aren't a good combo so I wanted to stuff the biggest pulley I could in the space I had. I found a Jones Racing pulley that seemed like it would save me from doing any machining, almost... I turned a little sleeve to hold it all concentric and still had to take a mm off the back of the pump housing to get everything lined up.

The intake manifold is a disaster. It's a JW 4-barrel intake and I'm sure it flows a ton but the runners took a lot of cleaning up with the ole Dumore. The flange matches the engine ports well but the hardware doesn't have a finished face to snug against. More buzzing to do there. I poked a couple holes in the secondary runners and welded in some bungs. I have a pair of ASNU 1000cc injectors to fit there, still need to make the secondary fuel rail.

I've done quite a bit of work on the fuel system but need to snag some pics. I have a 340L/hr Aeromotive drop in pump and I'm doing a lot of mods to the fuel module with the goals of increasing the bowl capacity (remove filter and replace with external) and get the siphon jets to flow more (plumb in parallel instead of series. Should I have just picked up the improved S2 fuel module? probably, but I'm stubborn and like the challenge.

Other odds and ends include oil filter bypass (remote filter), mold almost done for an fiberglass air cleaner base, welded up a throttle pedal, and fabbed a crank position sensor bracket. It's getting warm out and I'm getting anxious. As soon as I finish the fuel system it's on to cooling and ECU.

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