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HELP: identifying nsx-r na1 engine
- Thread starter tanth85
- Start date
I am thinking that you are purchasing some hype! Honda did not specify any hardware / parts differences between the engines in the R and non R NSXs. The final drive ratios were different on R cars. However, there is lots of internet opinion about the R engines having a more careful final assembly. Take that for what it is worth. Unless somebody has wrecked an R, it would be extremely unusual for an engine / transmission from an R to become available. Because of their value, I suspect that any R that has been involved in an accident is likely to be rebuilt unless it was wadded up in a ball following a high speed collision with something immoveable.
If the engine is really from an R, ask the vendor to provide the VIN of the donor chassis. The VIN will tell you whether it is an R type and you can search the VIN to try and find out whether the car is still in existence or whether it is a fabricated VIN (at least on NA cars Honda uses a check sum digit to confirm that the VIN is legitimate). If the car is still in existence, I can bet that the engine you are purchasing is not from an R. You will have to use a Japanese market VIN decoder since the JDM VIN arrangement is different than the NA VIN arrangement. I don't know whether the transmission number identifies the final drive. That is something else that you could check into.
I would bet money on this engine and transmission not being out of a legitimate R.
If the engine is really from an R, ask the vendor to provide the VIN of the donor chassis. The VIN will tell you whether it is an R type and you can search the VIN to try and find out whether the car is still in existence or whether it is a fabricated VIN (at least on NA cars Honda uses a check sum digit to confirm that the VIN is legitimate). If the car is still in existence, I can bet that the engine you are purchasing is not from an R. You will have to use a Japanese market VIN decoder since the JDM VIN arrangement is different than the NA VIN arrangement. I don't know whether the transmission number identifies the final drive. That is something else that you could check into.
I would bet money on this engine and transmission not being out of a legitimate R.
For the transmission, you could put it in 2nd gear and count the number of turns it takes for a full rotation of the diff.
For an NA1 Type R transmission (short gears, short FD) it would be 8.25 turns. For a US market transmission (long gears, long FD) it will be 7 turns. For a normal JDM transmission (short gears, long FD) it will be a 7.9 turns. For a US market transmission with R FD it will be 7.3 turns.
This isn't 100% though as those parts can be swapped into any NSX transmission.
The engine is trickier to tell and I'm not sure if there are any external identifiers. But frankly there isn't a good reason to pay a premium for an R engine over a standard C30.
For an NA1 Type R transmission (short gears, short FD) it would be 8.25 turns. For a US market transmission (long gears, long FD) it will be 7 turns. For a normal JDM transmission (short gears, long FD) it will be a 7.9 turns. For a US market transmission with R FD it will be 7.3 turns.
This isn't 100% though as those parts can be swapped into any NSX transmission.
The engine is trickier to tell and I'm not sure if there are any external identifiers. But frankly there isn't a good reason to pay a premium for an R engine over a standard C30.
A few more points:
For the engine, it will be difficult to determine with 100% certainty. Honda may have an internal list of matching engine serial #'s to VINs for the NSX-R (due to the limited production), but such a list has never been made public. Thus, getting the VIN might not tell you much. You could try asking Honda Japan about the engine serial number and see if you get an answer (Acura will have no idea what you're talking about). Mita Motorsports may be able to help with this.
The NSX-R engine will be nearly externally identical to a regular NA1 NSX. The only cosmetic difference is the top cover plate, which can be easily purchased from Honda and placed on a regular NSX engine. The other difference is that many of the wire harness plugs on the engine will have additional heat shielding/rubber covers. If the engine comes with a harness, I would ask for pics. This will be a dead giveaway.
Another thing to check is the ECU. If the engine comes with an ECU, get a picture of its part number. The NA1 NSX-R ECU has the following part number: 37820-PR7-J22
As for the transmission, I agree with the other posters here with counting the rotations and/or checking the speed at a certain rpm. Other than the final drive ratio and differential clamping force, there is nothing really "special" about the R transmission.
How interesting. Is the engine in the States? If so, how on earth did it get here? Pulled from a wrecked R in Japan?
Hi
The engine is actually in Australia. A wrecker brought the whole wreck in 20 years back and sold everything. Now whats left is the engine, ecu and transmission, which he claimed he wanted to keep it for auto to manual conversion.
