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Discussion Starter #1 (Edited)
I have reached critical mass on my project! The "built" motor needs the valve lash set, otherwise it is ready to be installed. I mocked-up the system this afternoon and took a pic:
IMG_1074.JPG
I have shots from other angles if anyone is interested in a specific detail.

The red Uni filter seems like MCX's idea of a joke for a machine that will be driven primarily on dirt. I've already purchased a Donaldson swirl-separation style filter.

Some details on the motor:
ARP head studs
JE +2mm 9.5:1 forged pistons (993 cc vs 951, so not a huge increase)
Kibblewhite dual spring valve springs w/ titanium spring retainers (probably an over-reaction to breaking an OEM spring retainer at Glamis)
SwainTech coatings on the combustion chamber, exhaust ports and pistons
Jet-Hot coatings on the turbo header and downpipe

Things I've done to the motor:
Matched the intake manifold to the cylinder heads
Matched the heads to the exhaust primary tubes (AC builds the motors with a significant mis-match here)
Cleaned-up the bowls under the valves and the ports
Put a blended multi-angle valve job on the valves
Removed forging marks & semi-polished the back of the valves (lots of flow across the intake valves here)
Rounded the top edge of the exhaust valves (minimizes the turbulence caused by the OEM right angle)
Smoothed the combustion chamber ledges where they approach the valves

IMG_1059.JPG IMG_1060.jpg

I think the intake manifold matching deserves some extra discussion. The manifold will index to the cylinder heads via the wide-head Torx screws in the upper positions. Matching the port to the manifold was tedious, and I nearly talked myself out of finishing it since any deviation in how the cylinders go on the engine case or how the heads go on the cylinders could totally screw-up the way the manifold has to go on. Even a too thick or too thin head gasket could mess things up. In the end, the manifold pulled down pretty much as it was when I matched the ports, so I think this was worthwhile.

My piston ring compression tool is far too big to assemble the pistons to the rods and then slide the cylinders over the pistons and into the engine case. There is room to install the pistons into the cylinders, slide the bottom of the piston out of the bore and install the wrist pins. I've done both engines this way, and like it a LOT better than what the Factory Service Manual (FSM) shows. I blocked the gap between the piston skirt and the engine case so that an errant wrist pin retainer clip did not find it's way into the crankcase. And obviously it is a good idea to install the chain side clip before the piston goes into the cylinder, so you don't have 4 clips to install on the engine, and so that you are working on the clip that is more easily accessed.

The way MCX merged the front and rear exhaust was decent, but there was a notch where the rear pipe didn't quite meet the hole in the flange. The turbo casting is quite thick at the flange, so I took some material off of the header flange and turbo casting to improve flow into the turbo.

I'm pretty happy with how everything is coming together thus far. The "spare" engine will be coming out of the Wildcat later this week, then I'll have to make a decision about the built motor. The conservative approach would be to install it without the turbo system and put some break-in miles on it. The WTF, just go for it approach would be to install the engine and turbo all at the same time, but I'm not going there.

I'm wondering how much boost the turbo would make with the wastegate wired wide open. I "think" it would be minimal, maybe 3 or 4 psi, and that I could probably break-in the engine without much risk that the MCX tune, which was developed on a 2012 Wildcat, wouldn't be close enough at low boost on my X engine.
 

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If I tried this I'd have to keep a spare machine handy (probably with a trailer to put the pieces in). Good luck with the build, sounds like you've covered the bases.
 

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Hey Mark, congrats on the build and looks great so far. I would install the entire turbo and just stay off the gas. I believe its a low boost turbo so if you baby the pedal, there is little to no boost so you should be able to get her broken in easily and try to find flat areas to ride so you wont have to build too much boost. Thats only my 2 cents as your an expert compared to me lol. I just installed mine and drove it lol. See you in Glamis with that beast!
 

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Discussion Starter #6
I've had one additional thought that is shaping my decision about installing it with the turbo: I want to use a non-synthetic break-in oil to benefit the piston rings, but I don't like the thought of running that through the turbo, even if it isn't making any boost. I'm also a little curious to see how much power I've lost by lowering the compression ratio. I'm leaning towards leaving the turbo kit off for the first tank of gas.

Izom, that's my '84 Royale RP-37. The class is called Sports 2000, powered by a Pinto 2l (the actual engine spec was the European Capri GT, but over here we just call it a Pinto). It is built like a light plane, with a folded, glued and riveted aluminum tub under the fiberglass body. Weight with driver is 1335 lbs. Fast, fun roadracing car. I've owned it since the early '90s, but can't justify the expense to race it now that we are both retired. The Wildcat gives me the same sort of preparation and driving satisfaction, but we both get to ride in it. My wife only got to experience the Royale on my checkered flag laps.
 
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I like the idea of fossil oil for the 1st ride. Just make it an easy ride with little boost or load and a full range of rpm. Maybe give it a few minutes cool down time before you cut power. Then switch to synthetic
 

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I had a 2014 4x Ltd with an MCX Turbo running 8 lbs of boost, had 30” mongrels and STM primary and Secondary clutches installed. It ran strong, but kept overheating always pissing antifreeze out of the overflow hose and throwing the code on the display. Also was hard on belts, but I did install a powered clutch fan which helped with the belt issue. I ended up selling the machine as I could never get the over heating issue figured out and the fact that the 14 motors were notorious for twisting the crank. Hope all goes well for you and you have better luck than I did, the motors on the 15’s are better for sure.
 

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Here are some pics of the 14 4x Ltd I had, forgot to mention it was also piped and had a 6” super ATV suspension lift on it.
 

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Discussion Starter #11
Great write up for your AC. What is your background?
Life-long car guy, figured out how to afford to go road racing in the late '80s, but only if I did all of the prep &, eventually, repairs. I was tied to the manufacturer for everything until I needed a new front upright (AC would call it a knuckle) and every single detail had changed or was inaccurately machined. That told me I was on my own, and that turned out to be liberating. I started re-designing and building my own parts. Learned a bit about welding, machining, fiberglass repair and making new design fiberglass parts from scratch. I would study cars in other classes or even different disciplines and incorporate concepts that worked. On the Royale, I learned how to repair the aluminum tub with help from an acquaintance that was a certified airframe mechanic. The go-fast engine mods I just picked up along the way from maybe 50 different sources. Away from the track, I learned about turbocharging and ECMs on our Mazda Miata.

It turns out that I was a good driver and an even better setup guy. At one time or another, I held lap records for my class at 6 different tracks. Some will be permanent, as the track has closed or the class has morphed into something different.

Work-wise, I was in manufacturing management most of my career, then started training and consulting in support of a couple of ERP software packages, so not much transferred to my hobbies. I found it to be very therapeutic to go out in the garage and spin the handles on my combo late/mill after spending the day managing people. My wife and I are both retired, and for the first time I have a proper shop. I previously did everything out of a slightly oversized two car garage.
 

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Discussion Starter #13
... It ran strong, but kept overheating always pissing antifreeze out of the overflow hose and throwing the code on the display.
Doing the coatings was more about controlling heat than trying to make more power - I'm already worried about my rear diff. The combustion chamber coatings should keep some BTUs out of the coolant. The header coatings should keep the air passing through the radiator a little cooler.
 
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I had a 2014 4x Ltd with an MCX Turbo running 8 lbs of boost, had 30” mongrels and STM primary and Secondary clutches installed. It ran strong, but kept overheating always pissing antifreeze out of the overflow hose and throwing the code on the display. Also was hard on belts, but I did install a powered clutch fan which helped with the belt issue. I ended up selling the machine as I could never get the over heating issue figured out and the fact that the 14 motors were notorious for twisting the crank. Hope all goes well for you and you have better luck than I did, the motors on the 15’s are better for sure.
Sorry to hear you had issues, if you had joined the forums sooner you would have gotten a solution on how to get rid the heat by having a racing radiator installed for about $200. I understand your Car is alot heavier then a 2 seater and can imagine 4 adults riding in it, def will get hot. 2 seater are not that bad, I had to mod my plastics to get better air flow but even in hard duning my temps never climbed above 200. If I recall shut down was temps over 230???
 

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Hey Mark, look into an alternate temp gauge if you have not done so yet. Pain in the ass to go into diagnostic mode just to check temps on these kittys. I like mine but for some reason Its a 15 degree difference hotter reading the OEM temp so I've grown accustomed to it.
 

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Discussion Starter #16
Good advice! I have a Koso Wideband AFR/Boost/Temp combo gauge coming, with the intention to put the temp sensor in the thermostat housing next to the OEM sender. The Koso has alarms on each reading. I don't know if the AFR alarm is going to be useful unless the Koso can somehow differentiate between closed-throttle-lean and dangerously lean while making power. Boost alarms are "meh", but I'm gonna like having an alarm on the coolant temp.
 
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I did a lot of fighting with high temps under sustained load. Used the $200 mod with the over-sized alum tanks and 2 cross spacer. that helped but I wanted better and sandwiched 2 stock radiators together. That worked.
Options i considered was an oversized oil cooler and/or putting a 2nd small aux radiator/fan up front.
 

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Discussion Starter #18
Sand-n-Sea, if I had your welding equipment and skills, I'd be building a copy of your "double-stuff" radiator. That was inspired and impressive.
 

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Discussion Starter #19
I had an "Oh, shit" moment today while installing the low compression motor. I thought I had threaded new spark plugs into the heads previously. When I went to tighten down the first one, I hit a little resistance and put a little more torque to the ratchet, thinking I needed to compress the sealing ring. The plug sheared, right at the top of the threads. Fortunately, I have a good selection of easy-outs and an impact driver. The impact driver is really handy anytime you need to turn and push at the same time. So a few minutes later, I had this:
IMG_1089.JPG
Whew! That would have been a lengthy detour.
 

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Discussion Starter #20
We put about 80 miles on the Wildcat today. My expectations going into this engine build were that it would be noticeably down on power to a regular compression ratio X motor. Instead, it feels just as healthy as the "new top-end" engine that just came out.

I did a little research and the internet experts think 1 point of compression ratio is worth about 4%. JE says the pistons are 9.5:1. My impression is that the stock ratio is 10.5:1, or perhaps as high as 11:1. I've not found an "official" specification. So I lost around 4 or 5% to a lower compression ratio and gained 4.4% in displacement. So no surprise that the "built" motor feels a lot like the stocker that came out.

You might think this pleases me, but my honest reaction is "Hmmmmm - this thing might break too many parts once the turbo goes in".

More to follow. Tomorrow I will clean up the Wildcat and start stripping it down for the turbo installation. I'll also be installing a combo wideband, boost and temp gauge (Koso) that will require lengthening all of the various wiring runs, so I have a bit of work to do. I'm guessing the turbo Wildcat will draw it's first breath by Friday.
 
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