Transalp Engine Swaps

Swap Candidates

The following engines should swap in with no modifications to the frame:

• Hawk NT650 (known as the Honda Bros outside the US market)
• Honda Africa Twin XRV750 (RD04 or RD07)
• Honda Transalp 650
• Honda Transalp 700

The Honda NT650V and NT750V Deuville motor **will not** swap in, because it's shaft drive. It may be possible to put the head and cylinders onto a Hawk engine. The Deuville EFI throttle bodies may be usable on a 52-degree Honda EFI conversion.

The Rotax-made Aprilia 60-degree V-twin engines **might** be made to fit, but will require frame modifications. To my knowledge, this has never been done. One person on the Hawk GT Forum has swapped a Tuono engine into a Hawk and only mentions modifying the front engine hanger, but there are no additional details or photographs.

Engine Swap Details

Hawk NT650

Exhaust

• This post shows the difference in front exhaust port angles between the Transalp and Hawk engines.

Modification

The Hawk 650 still has great aftermarket performance support. Hord Power is the best known supplier and modifier in the US. Hord Power commented on the Hawk GT forums:

The order of building hp into a Hawk goes:

Stock 47hp

Pipe/3.0 kit/pods 52hp

700 kit/cams 62hp

Stage 1 heads 67hp

Stage 2 heads 72hp

Flatslides +5hp

Stage 3 heads 80+hp and $$$$$$$$$$$$$$$$$$$ and other $$$$$$$ stuff to make it "reliable."

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
• EcuMaster EMU

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. It appears that the NT700V used a fuel pump that provided something like 45 - 50 psi.

Specification 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
Aprilia ETV1000	997.6cc	98 hp @ 8250	71.5 lb-ft @ 6250	97x67.5mm	10.4:1	47mm

Transmission Gear Ratios

	1st	2nd	3rd	4th	5th	6th
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
Aprilia Tuono	2.26	1.63	1.3	1.09	0.96	0.88
Aprilia Caponord ETV1000 / Falco SL1000 / Futura RST1000	2.5	1.75	1.368	1.091	0.957	0.852

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.