Questions About Built Blocks/Supercharging
 

Hey, owner of an early build (affected by valve spring recall) 71K mile 2013 FR-S here. Sunday, my engine started knocking (bottom end) while cruising on the thruway, and partially seized due to heat as I put the clutch in and pulled over.

Backstory:
First things first, I had it tuned by a friend who has done plenty of other applications, they basically put in a little timing and messed with the air/fuel targets to smooth out the torque dip and take advantage of the intake/exhaust I had put on a few months back. This was about three weeks ago. I use the car mainly for autocross and sometimes for track days, mostly Toronto Motorsports Park when the border is open. Once or twice a year for the track, multiple weekends for autocross. I ran the car at autocross with the tune for 8 runs and had no issues, this was on the 4th. I've done regular oil changes and owned the car since 15K miles four years ago. I daily it. The oil was full when it started knocking, no engine lights illuminated, no oil light on, nothing.

Questions:
This sounds like an oil starvation issue to me, seeing as I wasn't putting the car through anything I normally wouldn't on a weekend or track day. My local Toyota dealership is currently tearing the car down, but it looks like I'm looking at replacement. They stated it idles (poorly) and needed throttle at first to keep running, and there's a bottom end noise.

My long term goal with this car was to supercharge, but rather than spending $16K on a new stock assembly, I'd like to go built. I'm seeing a few options out there so in regards to that:

Does compression ratio matter on a stock/street tune? I won't be supercharging it just yet. The car normally runs at 12.5:1 obviously, if I throw in a 10:1 ratio block, will the car perform poorly without forced induction? I can turn a wrench pretty well and know how a car works, but more technical stuff like tuning escapes me. I know what compression does, I've just never changed compression on a vehicle before, so unknown territory for me.

I know I'll need more than just the short block, do the stock heads and front cover suffice for built applications or should I source/upgrade that stuff as well? I'll have the dealership source any lines or miscellaneous parts that can't be reused from the old engine, so I'm not on an endless hunt.

I'll know the full story tomorrow, looking for feedback so I can start ordering the right parts and get the car back on the road sooner rather than later.

TIA!

Honestly I'd just throw in a used engine and supercharge that one. If all you want is the same power everyone else is making then it should hold up ok. If you do want it built, reduced compression allows you to run more boost/timing, therefore more power. You will have less power in the mean time but I couldn't tell you how much.

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Agreed, you can find used motors for $3500-$4000. Unless you have a dedicated track car I don't think it's worth it.

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In my experience, it will perform poorly in comparison unless sufficient boost is used to negate the loss in compression.
Again, INMHO a supercharger is limited in sufficient boost. Turbos can give higher boost and would be more appropriate.

Jackson superchargers give more power and torque quicker with stock compression, but can hurt non strengthened innards.

In the last 9 years have seen several stock blocks blown from excessive track use, as well as the supercharged or turbo'd unbuilt motors (and over boosted BUILT blocks, one blown several times !).

Has anyone built a block with stock compression ratio or used custom pistons at 11.5 to 1 for HP of more than 275 to 300 (split the difference so to speak) ?
- Something I have yet to see on our tracks.
:cheers:

Element Tuning seems to have things worked out pretty well.

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Greatest non answer and advertising since V.P Pence answering the moderator of the Harris debate LOL !

:laughabove: :laughabove: :laughabove: :laughabove::

Do you run an oil cooler?

If not, do you monitor oil temperatures while tracking?

Based on everything I have read I would be cautious building an engine, at that point I think an engine swap becomes a viable plan and you will end up with a better platform. Our engine IMO is not bad, there's just better out there if you're going to invest the money in a build.

Swapping is incredibly expensive. If you just want a little more power, the built engine is a better option. If you have more goals than 300hp then swapping becomes more practical

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Outside of the in-car temperature gauge, I don't really monitor anything. Although I have access to the ECUTek info, I only ran one event with it and it was about 60F out that day. Didn't figure I would need to without forced induction in the picture.

Great information, thanks! I mean wayyy down the road, I may go for something more aggressive. But I basically want this to be a summer daily with an autocross/track focus. I live in the Northeast and have driven it year round for my entire ownership, oil undercoating and such to ward off salt and rust. My end goal here is probably in the 300whp area.

I'll look in to this, but I'd prefer not to throw in a used motor with an unknown history.

Side note, I'm seeing lots of short blocks, and to make this as easy as possible, it looks like I basically need the whole long block. The accessories off my car can all be used - A/C, heater elements, etc.

Any suggestions on companies retailing fully built units like this?

I went with an IAG short block stage 1 which is good for 550 hp. I’m staying NA for now but have much more confidence in the motor when I’m on track. Not sure if I’ll go FI but good to know I’m set up for it.

Yes, but why build for only 300hp? Building you're still looking at an easy 5k and more if you upgrade transmission etc etc. I Just feel like building to run 300whp when stock blocks are reliably running 250-270whp doesn't seem like it's worth the effort.

The consensus seems to be that an oil cooler is needed for track driving even while stock. If you drive enthusiastically on back roads you can easily get oil temps into the 220+ range while stock. What weight oil did you use?

Exactly. If that's all the more you want then building isn't all that necessary

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If this is stupid, forgive me, but I want the reliability/durability of not pushing a stock block and internals to their max, and the potential to go further if I get crazy somewhere down the line, or want to change a pulley for more boost and not have to change a block while I'm at it. The cost difference isn't that much for me, as I'm looking at a full long block replacement anyway. My employee pricing (I work for the dealership group I sent my car to) got me a low, low quote of $16K for a new, stock unit, not including labor. Stock long blocks online can be had for $7K according to a buddy of mine, so if I spend $7000-9000 on a built long block, I'm happy.

I used 0W-20 as recommended. Always full synthetic, usually Pennzoil or Mobil1.

It's not stupid. It's just an unnecessary expense IMO. You can get 2 used motors for that price. If you plan on more than 300hp, which it kinda seems like you do, then building is pretty much a necessity

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