Transalp Engine Swaps
From GummyCarbs
General Comparison
| Displacement | Torque | Horsepower | Bore x Stroke | Compression Ratio | Induction | |
|---|---|---|---|---|---|---|
| XL600V | 583cc | 55 hp @ 8000 | 38.8 ft-lb @ 6000 | 75x66mm | 9.2:1 | 2x32mm Keihin CV |
| NT650 | 647cc | 56.1 hp @ 7897 | 43 lb-ft @ 6053 | 79x66mm | 9.2:1 | 2x36mm flat slide carburetor |
| XL650V | 647cc | 52 hp @ 7500 | 40 lb-ft @ 5500 | 79x66mm | 9.2:1 | 2x34mm flat slide CV |
| XL700V | 680.2cc | 59.1 hp @ 7750 | 44.3 lb-ft @ 5500 | 81x66mm | 10.0:1 | EFI 40mm throttle bodies |
| XR750 RD07 | 742cc | 62 hp @ 7500 | 46.2 lb-ft @ 6000 | 81x72mm | 9.0:1 | 2x38mm flat slide CV |
Transmission Gear Ratios
| 1st | 2nd | 3rd | 4th | 5th | |
|---|---|---|---|---|---|
| XL600V | 2.571 | 1.777 | 1.380 | 1.125 | 0.961 |
| NT650 | 2.769 | 1.882 | 1.450 | 1.174 | 0.965 |
| XL650V/XL700V | 2.500 | 1.722 | 1.333 | 1.111 | 0.961 |
| XR750 RD07 | 3.083 | 2.062 | 1.550 | 1.272 | 1.083 |
The XRV's first gear is 20% lower, second is 16% lower, third is 12% lower, fourth is 13% lower, and fifth is 12% lower.
Engine Swap Details
Hawk NT650
Exhaust
- This post shows the difference in front exhaust port angles between the Transalp and Hawk engines.
XL650V
- Thunder Dan's engine swap. He put a 2003 XL650V engine into a 1988 XL600V.
EFI Conversion
Rather than trying to source and/or tweak carburetors, it's probably best to use one of the aftermarket EFI systems that are now on the market.
EFI Systems
- Megasquirt
- Microsquirt
- Ignitech
Throttle Bodies
The 2003+ SV650 uses 39mm throttle bodies. The 2017 model's throttle bodies are redesigned and "slimmer", according to Wikipedia.
The NT700V was sold in the US. It had 81x66mm bores with a 10:1 compression ratio, producing 65hp at 8000 RPM and 48.8 lb-ft of torque at 6,500 RPM. It's in the same 52-degree V-twin family as the Transalp, Hawk, and Africa Twin. Its throttle bodies are 40mm with 12-hole injectors.