NSX broke down while driving
- Thread starter Formula 170
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Replacing the engine seems like an extreme response. How confident are you in the competence of the shop? I am thinking that the shop is more into parts replacement than having to deal with machine work on an engine that they may not be familiar with. I would ask them how they diagnosed the spun rod bearing - just to be confident about the diagnosis before you go through the hassle of engine removal.
A rod bearing failure is not a small deal; but, should be repairable for a lot less money than trying to find a 'good' replacement engine. Regardless of which repair option you pursue: replacement engine, repair your engine or a J swap, the engine is coming out of the car. The big cost variable is do you machine the crankshaft or replace it if you are not confident about the quality of the machine work that you can get. A new crankshaft is going to be approaching $3000 so that is not a trivial decision. Maybe you will be lucky and the spun rod bearing did not damage the bearing journal. You won't know that until it is inspected.
My suggestion is to have the engine removed and separate the heads from the block. Inspect the lower end for the amount of damage. Depending on the amount of damage you can make the decision as to whether you want to try the repair locally (especially if there is no crank journal damage) or do you just box up the complete shortblock and ship it to somebody like SOS with instructions to 'make it better'. Of course, that presumes that you can find a local shop amenable to doing the engine R&R and having the car sit around taking up space in the shop while the short block is off being fixed.
I thought I saw an engine on sale recently with spun rod bearings as well. Is this just coincidence? https://www.facebook.com/groups/437986923023014/permalink/1272981112856920/
There is also https://www.facebook.com/groups/7990613243/permalink/10156715214423244/
I think John (MotorMouth93) and Procar also recently had ones for sale, if you want modified. Posting a WTB in the facebook group or Prime can always get you some leads.
There is also https://www.facebook.com/groups/7990613243/permalink/10156715214423244/
I think John (MotorMouth93) and Procar also recently had ones for sale, if you want modified. Posting a WTB in the facebook group or Prime can always get you some leads.
I sold a bare block recently but not a full motor. If I ever finish my engine build I'll probably sell the stockish (head studs, MLS gaskets, top end rebuild) motor thats currently in my car but realistically that won't be until like June 2021.
Thanks everyone for the kind words and good suggestions. I’ll look into having a shop remove the engine and see what’s going on internally. We’ll see how bad the damage is. Just have to find one that won’t mind the car sitting for a bit as Old Guy suggested.
Also, what’s the all in cost w/ motor for a j swap?
Also, what’s the all in cost w/ motor for a j swap?
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I am going to estimate between $7,500-$10,000. The J engines are cheap, in many cases under $1,000. I haven’t seen a full on kit for sale, but check in the builds section for at least piece parts and what it takes. I have mixed emotions on the j or k swaps, but they can can be done efficiently and when done properly can be reversed when the time is right to go back to a C engine. I believe a J series engine is much like a small block Chevrolet, very compact, versatile, plentiful and cost effective. Not as exotic as a C series DOHC, but from what I’ve seen, a very good engine for an NSX.
https://m.facebook.com/NSXJswap/
Good luck.
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Keep in mind that the J swaps are probably being done be skilled owners. They are not an off the shelf conversion. I don't think any dealership repair shop would touch it - or even understand what you are asking about. I don't know whether there are any 'NSX specialist shops' who have done a J swap so it is unlikely that you will get any kind of firm estimate if you are looking for the conversion. You are entering loosely charted territory with a J swap.
Might be worth checking out https://www.facebook.com/NSXJswap/ and https://innovativemounts.com/products/90-05-nsx-conversion-mount-kit-k-series-manual .
Just throwing it out there you could talk to Kun about doing the swap. He can give good advice. I am sure he's done it before. However, you'll have to source all your own parts.
Just throwing it out there you could talk to Kun about doing the swap. He can give good advice. I am sure he's done it before. However, you'll have to source all your own parts.
Concur. The link I (and furinax) listed to the Facebook page and the 2 or more threads on the NSX build page provide good info on the swap. I believe the facebook page is by Titanium Dave, a long time NSX guy, and it sounds as if SoS has even looked into producing a kit; the territory gets explored more and more every day.
I’ve been reading about J swaps and it does indeed seem like a do it yourself project. I spoke to GT Automotive and they said it’s not something they do. As I don’t have the ability to manage the care and feeding of a tuner project, a replacement engine (or rebuild) is the better choice for me. When done, I need to be able to take the car anywhere for routine service, including an Acura dealer if desired.
Yes, a very valid reason to stick with a stock setup.
But I will say that as the NSX qualified skill set at the dealer dwindles, I’m not sure if a dealer would notice a difference between a J and a C engine for routine maintenance.
But as I learned many years ago with a fuel injected Monte Carlo I built, sometimes an original carburetor was just as good as fuel injection, and it didn’t need the custom maintenance.
Here’s an oddball question - anyone hear anything about an NSX EV conversion? Has it ever been done?
Not on a NSX, but I'm not gonna lie- this is something that is in the back of my mind too. Depending on how quickly petrol is phased out, it might be in the cards for me too down the line. The fuel tank space could support quite a large battery unit.
https://www.evwest.com/catalog/index.php?osCsid=p1f6j4v25vpolf69r8uld0mtf5, they have an excellent EV conversion market, including Tesla drivelines. From some aspects, EV conversion is simple, less issues with size and fuel lines, etc.
Keep us updated whenever your engine comes apart.
On the parts page, Curren has a block, crank and some other parts available for sale at a pretty good price.
I had another thought. So the original and second generation Legends and first generation RL also had C series engines (SOHC) and they may be readily available at salvage yards. I’m not sure if they would bolt in without mounting modifications, but might be an intermediate solution. A 3.5L would be an interesting engine, more displacement, but less RPM may give lots of bottom end grunt.
I had another thought. So the original and second generation Legends and first generation RL also had C series engines (SOHC) and they may be readily available at salvage yards. I’m not sure if they would bolt in without mounting modifications, but might be an intermediate solution. A 3.5L would be an interesting engine, more displacement, but less RPM may give lots of bottom end grunt.
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It's an interesting idea but not financially feasible unless you want to write a blank check to a custom hot rod shop to install a worse motor in the car for a lot more money than just rebuilding or buying a C30. There's 3 general families of C engines, the FWD transverse engines in 2.0L, 2.5L, and 2.7L flavors, the RWD transverse engines found in NSXs which are 3.0L and 3.2L, then the FWD longitudinal engines that came in 3.2L and 3.5L.
The transverse FWD engines are somewhat similar to the NSX engines and look like you might be able to fit one in without too much trouble - the engine blocks look almost identical including bell housing bolts, intermediate shaft mounts, engine mounts, even the 6 bolt mains - but the wiring would be a mess since these engines use distributor ignition instead of coil on plug. There was a 2.0L turbo C20 in the late 80s though so you'd get lots of points for originality for putting one of those 190hp wonders in an NSX.
The longitudinal FWD engines are wildly different in design and would require a huge amount of fabrication in order to get one to fit.
The transverse FWD engines are somewhat similar to the NSX engines and look like you might be able to fit one in without too much trouble - the engine blocks look almost identical including bell housing bolts, intermediate shaft mounts, engine mounts, even the 6 bolt mains - but the wiring would be a mess since these engines use distributor ignition instead of coil on plug. There was a 2.0L turbo C20 in the late 80s though so you'd get lots of points for originality for putting one of those 190hp wonders in an NSX.
The longitudinal FWD engines are wildly different in design and would require a huge amount of fabrication in order to get one to fit.
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Thanks for the info. I did a quick look online and the C32 and C35 (longitudinal FWD) are super cheap, like $400-$500 complete. I did have an 89 Legend Coupe and I loved that engine (2.7L). Overcoming the differences for things like the distributor would be a fun project. But if the goal of simple and street able, if probably isn’t the solution.
Just my take. Spun bearings are pretty simple, but I wonder if there is an extra charge for expensive cars-lol. The motor comes apart and they measure the tolerances and fix what is out. A K/J swap would be last on my list. I'm sitting on half the project with a built K24 and won't finish it as you need to be that guy who can whittle a car out of a scrap of aluminum, or have that friend who can. You need trans cables made, tranny that bolts to a K/J rebuild it, or an expensive sequential gear box. Then there is engine management for a 4cyl with a nice turbo as it's the only reason to loose 2 cylinders. Exaust etc. I think it would be worth calling Science of Speed as they and rebuild and even enhance your motor. I suppose no matter the route, 5-10k will be the bill.
[MENTION=25953]Formula 170[/MENTION]
Since you've decided on the replacement or rebuild route, I would recommend getting in touch with HQ Engineering and talking with them about your possible options or just to have a second opinion.
Having had a motor that was practically toast rebuilt by them (probably one of their toughest builds ever), they were great to work with especially as I was on the other side of the country from them (like you, but in the south). I feel like they are definitely an asset to the NSX community. Thumbs up to David!
Good luck with your quest! Stay strong.
Thanks for the tip. Yes, I’m committed to rebuilding at this point and all information is helpful and appreciated!
Of all the engines that I had to rebuild due to spun bearings is caused by: 1. Poor oil choice 2. 8K revving up a 3 mile hill for two minutes 3. Clogged oil passages or. 4. Lack of oil. I am curious as to how your motor is knocking at 137k miles (from what I consider still a break in period if driven normally). You had our oil changed 100 miles ago and wondering if they forgot to add oil before starting. How does the oil look? Were there an additives to mask the noise? Any metal shavings?
By far, a rebuilt is your best option. Source the crank and rods from Curren if necessary. You will know more of the damages once bearing caps come off. Unless you are 100% confident of engine damages, you should definitely get a 2nd or even 3rd opinion about the rod knock. Have it taken apart and thoroughly inspect it. A used crank and rods without any scoring is as good as new. Trusted mechanic, trusted machine shop, rings, and new gaskets, etc. will have you a literal brand new engine that should go for 300k as we have seen from stock motors.
By far, a rebuilt is your best option. Source the crank and rods from Curren if necessary. You will know more of the damages once bearing caps come off. Unless you are 100% confident of engine damages, you should definitely get a 2nd or even 3rd opinion about the rod knock. Have it taken apart and thoroughly inspect it. A used crank and rods without any scoring is as good as new. Trusted mechanic, trusted machine shop, rings, and new gaskets, etc. will have you a literal brand new engine that should go for 300k as we have seen from stock motors.
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