So I’ve decided to save the sohc. It’s intended to be a track-ready daily driver, so big power isn’t the goal. But before I jump the gun and buy all these parts I want some opinions on the parts (since this is my first build).

Block
Nippon PM6 Pistons (bumps compression from 9.6:1 to 10.5:1)
Forged Rods
ACL Bearings
OEM Oil pump (ported and shimmed)
1mm overbore
Micropolished crank
(Possibly knife edge crank)

Head
Gatestiming belt
Adjustable cam gear
ARP Headstuds
Cometic headgasket
ported d16y8 manifold

Fuel
AEM E85 320lph Fuel Pump
Decapped LS Truck injectors (about 800cc)

Turbo
Cx racing gt28r
cast manifold
Knockoff Greddy BOV
and of course all the miscellaneous turbo kit goodies

let me know if there’s anything I missed or parts that don’t compliment each other. Thanks y’all ✌🏾

 

Sounds like your build could be a lot like mine or TXdragon's. You should read through our threads if you haven't already. Do you have a horsepower goal (a number), and what fuel are you planning to run?

Make sure you also consider:
New OEM gaskets and seals
Budget for machine shop work
MAP sensor
ECU
Dyno session with a professional tuner
Crank case ventilation
Engine cooling
Exhaust
Ignition system with appropriate spark plugs
Clutch

Here are my opinions:

 

DAX and TxDragon are the ones to listen to on this topic

 

With this setup I’m shooting for mid 200’s at the wheels. But no more than low 300’s (that’s if I were to max out the turbo). I’m planning to run 94 pump (maybe flex fuel down the road, hence the fuel pump).

As for the pistons, aren’t the Nippon PM6 pistons equal to the Nippon vitaras (as far as strength goes)? I just figured it wouldn’t be worth going forged pistons for my power goals

And I got the BOV in a trade, so I figured why not use it.

 

Those numbers were the goals I started with, but that changed over time, and likely will for you too. The way I see it, spend the extra $350 to get real forged pistons now so you aren't having to ask yourself how far you're willing to push a cast piston and risk damaging your rods, crank, block, head, etc. if they fail. It's your call though.

I have not used an aftermarket cast piston for a forced induction engine, so I can't comment on the strength of the Nippon PM6's.

 

get Speedfactory no-notch rods and Vitara pistons instead. That's what I have in mine. If you are referring to the Greddy "Type S" BOV, go with one from NGR. They actually purchased the license from Greddy to make their version of this particular BOV. The diaphragm is an upgrade from the original one (Greddy).

 

Vitaras have too low of compression for my liking, even with the SpeedFactory long rods. That’s why I wanted to go with PM6 pistons, but after reading up on txdragon’s experience with cast pistons I’ll steer clear of them. I’m now looking into some CP forged pistons. And I just checked my BOV, it’s From CX racing. I’m aware that it’s not ideal (and it sounds like a HKS layered with robotic-metallic **** if u ask me) but I practically got it for free so I can’t complain for now.

 

I bought my rods and pistons through Real Street Performance. They knock off some $ if you buy rods and pistons together, but you don't see the discount until you add both rods and pistons to the cart. I think I paid $880 for my rods and pistons.

 

Below is one of 2 Nippon PM6 pistons that cracked after a slight contact with valves due to a timing belt slip. It only jumped 3 teeth while using a comp 59300 cam. Spend some money on forged pistons or possibly face this happening..

Edit: I see now you read up in my thread. Lol! You can do ok with a CX turbo kit to learn on but, don't expect it to last long. When I revamped last year, it looked like the turbo was on the way out the door anyways. Your proposed build list modified by DAX is good advice to follow. NVturbo has a good SOHC setup as well. I hope we can see this build through, it's good to see more folks wanting to save the single slam!


Nippon PM6 piston

 

Nippon Racing version of Vitara pistons yields higher compression ratio compared to YPC, because Nippon Racing designed it to be a -11 dome. Personally I’m going with Speed factory no-notch rod & Nippon Racing Vitara Pistons on my d16y8. I’ll be right about at 9.5:1 which is perfect for daily driving.
Hand down the best way you can spend $500 on a turbo D series in 2020... Hopefully LOL

 

I did a deep dive years ago trying to find out if the Nippon Racing PM6 was the same quality and manufacturing process as their Vitara. No real conclusion. Just confirmed that the Vitara was made using the same casting method Mitsubishi had used on their factory turbo pistons. Unsure if the PM6 is. I’ve only scene pictures of both Nippon Racing’s PM6 & Vitara side by side.

Honestly, I would trust their Vitara one up to probably way past what you want. However I’m not sure what head you’re using (combustion chamber volume) or if it’s ever been machined (decked), or head gasket thickness. Kinda sounds like you want you compression higher than 10:1...?

 

Even though the YCP Vitara pistons yield a lower compression ratio than stock/factory, it will run better. I drove N/A with those pistons for about 2 months and it felt stronger than stock pistons/rods.

 

1) d16 = ycp pistons end of story(search on ebay @ d16 custom length rods ycp. Thank me later)
2) Dont get a chinese turbo, wait 1 month to save some cash and get the cheapest garrett borgwarner holset what ever. The_shodan here or go autoworks might help you with a cheap genuine turbocharger.(example https://www.ebay.com/itm/Garrett-T3-...Condition=1000
Another example, you save on using internal wastegate but it might creep if it doesnt creep you saved 250$ on the wastegate https://www.ebay.com/itm/NEW-Garrett...Condition=1000)
3) youll need a genuine turbosmart / tial wastegate.

 

I have dug deeper and I think the most cost effective way to get my desired compression (about 10.3:1) would be the speed factory long rods with cigars pistons. To get the compression I’ll have my head milled about 0.034 inches. And FIY its a Y7 block with a Y8 head

 

As much as I’d hate to say it, I think you’re right about the turbo. It makes no sense using all these quality parts just to slap a china turbski on it. I’m going to leave the turbo for one of the parts to get. Hopefully I’ll see an increased income soon because I’m becoming an apprentice electrician. If all goes as planned it’ll be quality parts head to toe 💪🏾

 

I was reading that the custom length rods bring the combustion up to the top of the chamber which is what “increases its efficiency” opposed to the oem length rods.

 

Milling the cylinder head that much is a really bad idea. I suggest you get the compression the correct way... proper piston dome/dish volume. Head milling introduces three SERIOUS mechanical issues: 1) It is more difficult to properly set the timing belt tension; 2) Quench area in the combustion chamber is reduced and thus diminishes uniform flame-front propagation; and 3) Valve reliefs in the piston top are not indexed properly with respect to the cylinder head and will need to be opened up to eliminate valve-to-piston contact.

 

you reckon it should be fine if I clay the motor? I see people running up 0.06 on these D’s. I know I’m naive but I see people saying they mill much more than I intend to and they don’t even have issues

 

Yes, people mill off ridiculous amounts of material, but as JRCivic1 said, it's causing other issues. Don't go through all that trouble when you can just buy a set of 137mm rods and forged pistons and not have to worry about milling lots of materal off the head. Not to mention it ruins the head casting for future use on a "regular" build.

 

https://bfy.tw/Oxbn

 

after all my revisions I’ve decided on no notch rods and NRP vitaras. Cheapest way to get high-ish compression. And against everyone’s advice I’m still gonna mill my head because I’m only going 0.02 inches (the rod and piston combo brings compression high enough that I don’t need to mill a stupid amount). And if my head gets screwed up? It’s only 80 bucks from a scrapyard

 

.002 should be ok. I had that much total removed between decking the block and resurfacing the head. Watch the rods though, make sure they are the Vitara length and you'll be OK there. Otherwise, standard sized rods are gonna be a disaster.