Engines: WTF Thread, I need help

[AceInHole]

So, today was the season opener for NER SCCA Autocross (Solo).

9 runs in with the car, it develops an ignition cutout. An hour later, with a new rotor, it drives fine, and then blows up. I just got back to my apartment, so no pics of damage yet, but there's a good hole or two in my built KA's block. I'm tempted to say it must've been instantaneous oil starvation, as there wasn't a huge amount of warning before everything went to hell.

Anyways, here's the kicker: I need a new engine, and I have a few options. Regardless, it has to be running, tuned, and race-able by June (DC Pro is the first major event).

1. Build up my spare motor with stock bore pistons, h-beam rods, and acl bearings.

2. Buy an S14 SR20DET and do something completely different (my GT2871 and SARD injectors should swap right over).

3. Pop in the spare motor as it is and pray it survives till winter, when I can source a VQ setup.


Option 1 is currently most likely, since I don't have to re-tune anything, and it guarantees I'm ready in time to race with a setup I can put some trust in.

Option 2 is tempting because I've always wanted to try the variable cam thing, and I can drop a bit of weight going to the aluminum block shizzle.

Option 3 is really seeming more and more like a hail-mary play that doesn't make sense for this year....

Thoughts, comments, suggestions, and random quips welcome!

[jmauld]

If you intend to do a VQ, don't dump any more money into any intermediate steps. Go ahead and get the VQ and bum rides into the swap is done.

[Def]

I don't think you can make enough power on a VQ setup to really hang with a good turbo motor.

As much as I like the SR, I think your S14 is heavy enough to benefit from the extra KA torque.

[AceInHole]

There's a couple things I still need to consider with the VQ, though. AFAIK, people hack the front crossmember to get it to fit. I'm not sure that would be SM legal. I'm also still debating on if I want to run the VQ in the end, as well. Overall, it's a LOT more money to achieve the same power levels as even my current KA24DET.

The thing that has me intrigued about the SR20DET is that I did a few drives in my co-driver's Evo. I really have to admit: that 2L engine is pretty nasty. It makes me wonder if the S14 SR can do something similar (not sure how much VVL makes a difference, but the S13 SR's I've driven didn't strike me as impressive in the past).

As for the weight: I'm currently at 2680 (1/8th tank) with a stock hood, heavy front wheels, and lots of misc. parts that I need to replace with lighter counter-parts. I'm confident I could hit min. weight with the KA (2560), which pretty much leads me to believe I could hit min weight with the SR (2480).

[Matt93SE]

Oh, you can build TONS of power in a VQ.. just not NA. Actually I've seen 300whp NA out of a VQ30, but that's on a $$$$$ SCCA GT-spec build.

A VQ30DE-T with stock bottom end will put down 300+++ hp reliably. Maxima guys have been doing it for years. I've seen 400+ on stock bottom end, but they don't last terribly long.

Either way, it's whether you want to go through the hassle of swapping right now.. If you have to have it up and running by June, throw in your stock KA that's sitting there and de-tune the thing to get you through until you're ready to do the VQ.

Personally I'd just go straight for the VQ swap and bum a ride for an event or two if you have to.

[AceInHole]

VQ turbo would be out of the question (I'd have to add way too much ballast weight). The more I look at my budget, the cost of going high HP NA is less and less tempting.

As for bumming rides, it'd either by my own G35 coupe or my co-driver's Evo 9, neither of which would be as competitive for the DC Pro as they currently are (in any eligible class). Buying fresh tires for either car (although we have take-offs for both cars) would be more than building up my spare motor, and still wouldn't guarantee a decent setup against cars that have a few seasons worth of development.

[a_ahmed]

I'm sorry to hear you got engine issues... but I'm glad you're back, I missed seeing you on the forum haha...

Forget NA VQ, it's gotta be totally derestricted, tuned and on race gas and will be loud as **** to get anywhere far in power. Awesome yes, but crazy. I was just on track today, Sasha from SG-Motorsports/CCTCC 06 champ.... his koni challenge 350z has a VQ35DE putting down 300whp: totally awesome and the loudest car I've ever heard... with his custom straight through header, exhaust, etc... he makes 300whp, it's responsive, goes crazy, but... think about it.

I doubt you'll be able to match a ka-t with an NA anything.. other than an LS1 I'm guessing you're not allowed to go that route (plus it's a money pit which I think you're not thinking ofn ow)...

The guy i got my KA 4-2-1 race header from Adam Hutchinson (I forget if he registered here) races an LS1 S13, he raced a KA-t for something like 6 years and after numerous engine failures he just said screw it and went LS1... he said never looked back and loves it, didn't do anything to motor all stock but hauls ass.

I wish you best of luck though and welcome back to nrr, you've been missed

[veilside180sx]

For auto-x the torque of the KA, really is hard to beat over an SR.

The S14 SR doesn't have VVL, it's a cheesy version that isn't truly effective.

[Def]

Yea, VQ35DE/HR can do 300 rwhp with lots of bolt-ons/cams/tuning, but that's about $2-3k in just go-fast engine bits.

You really think an S14 could hit 2480 and be SM legal? Possibly, but that's probably a lot of composite parts.

That 80 lbs in less weight is pretty big at that weight level. You're talking about losing 3% of the mass of the KA-T car, and a lot of it will be up front where our cars need to lose weight.

Not sure what kind of S13 SRs you've ridden in, but mine is pretty violent on high boost above 3k RPM as far as being able to get the car moving in a hurry.

As long as you think you won't get caught out in sub 3k RPM corners, the SR sounds like a good idea IMO. I personally don't think VTC is that big of a deal when you shoot for more than 300 rwhp due to the changes in powerband you must make, but it does help a small amount. I'd look into how high S14 SRs can rev though, because I've always known them to not take higher redlines well, and stock I think it's 7200 RPM. One of the benefits of the SR is being able to gear the car down and rev it out with some valve springs(SM legal IIRC).


All this weight talk reminds me that I need to weigh my car. It'd be neat if I were somewhere below 2500 lb now.

[Def]

For auto-x the torque of the KA, really is hard to beat over an SR.

The S14 SR doesn't have VVL, it's a cheesy version that isn't truly effective.

It's VTC - same thing as VANOS on a BMW(varies intake valve timing). It works pretty well on stock cams, but go to big cams and it doesn't seem to matter that much.

[Matt93SE]

250hp with a NA-VQ is easy. 300hp is doable with bolt-ons and high compression pistons and a tune. I'd say you can probably do it for $3000-4000 total and have a damn reliable NA engine with 300hp.

not sure what your KA is putting down though......

[AceInHole]

The KA on low boost was dyno'ed at 280rwhp (340rwtq). I never dyno'ed high boost, which was 10psi higher.

Basically, SM allows me to run any Nissan/ Datsun engine with any internals or modifications. I could get an SR for now, and stroke it to 2.2L later (which was one of my pipe dreams when I first got into 240's). It's possible that the early SR setups which were hacked together and poorly running are what turned me off (never sat in one properly done, I guess).

Anyways, here's my logic for weight:
Part: Weight Savings
-------:-------------
CF Hood: 25lbs
Flywheel: 15lbs
Driveshaft: 10lbs
PassAirbag (proposed removal): 10lbs
AC Core removal: 5lbs
Lightweight Wheels (currently 30lbs each): 20lbs
Lightweight Pulleys: 5lbs (still have the weighted stock crank pulley)
Lightweight Fans (currently Alty fans): 5lbs
New sheet metal intake (get rid of the cast stocker): 5lbs

That's roughly 100lbs of weight there, with other possibilities still out there for the future (titanium exhaust, or even titanium control arms [hey, titanium prices could drop someday....]). I'm sure we'd all lose some weight if Rich made aluminum shock housings :P 2480lbs is definitely possible, just costly in the long run (but less damaging if you can chip at it slowly).


There's also this notion that the only place I can beat the Evo's is by going as light as possible, while nearly matching their power (get up to speed and stay there). Daddio's Evo ran something like 27psi to the tune of 450awhp if memory serves, and the Hoops/Leiber Evo probably isn't far behind (if not faster... dude had a titanium manifold just to play with).


Right now, the $900 KA24DET rebuild (rods/pistons/bearings) is looking like it's in the lead, unless I can source a decent SR and tranny for less than $1500.

[ecugrad]

Right now, the $900 KA24DET rebuild (rods/pistons/bearings) is looking like it's in the lead, unless I can source a decent SR and tranny for less than $1500.

That's the option I would choose.

[Matt93SE]

The KA on low boost was dyno'ed at 280rwhp (340rwtq). I never dyno'ed high boost, which was 10psi higher.

Right now, the $900 KA24DET rebuild (rods/pistons/bearings) is looking like it's in the lead, unless I can source a decent SR and tranny for less than $1500.

I highly doubt you'll be able to source a good condition SR for that kind of money.

The KA output is impressive. Didn't think there'd be that much torque at 10psi.

So where do you get rods, pistons, and bearings for $900? Last time I looked, good rods and pistons were in the range of about $650 per set, then add bearings onto that.
My NA build might happen a bit sooner if I can find parts for that kind of price!

[AceInHole]

I was gonna run the cheaper side of things: CP pistons, Eagle rods, ACL bearings. Add in a dealer discount in some cases where I can get parts through "sponsors", and it should be roughly that much (maybe a bit more).

The update to the situation is that I can get a used drift engine from Jeff at 240sxMotoring for a good price (slightly less than I was expecting to pay to rebuild my other motor). He'd been keeping it as a spare for his time attack car, so it's running CP pistons, OEM rods and bearings (new pumps, seals, and everything else). It was good enough for 366rwhp at 18psi on his turbo, so it should last me a season of Solo. I'll probably pick that up, and spend the extra time re-doing things I've been meaning to, such as running hard lines to quick disconnects for turbo coolant and oil (can get the valveless setups pretty cheap).

This'll kind of work out, as I'd definitely rather be tuning suspension and aero than worrying about a totally new and untested engine setup...