Engine Restoration and Manufactory

Engine Restoration:

If you want your Guzzi engine restored, HMB-GUZZI is your first adress. Its almost 25 years of experience, that we bring in to an engine restoration of a big V2 engine from Mandelle del Lario. And ist is not only our experience, but also custom engine parts of our own production that bring major improvements.
Every engine is dismanteled, cleaned, glass blasted, recleaned, and then completely restored with new bearings etc. To make it short, the condition is like new, in many ways even better. Factory tolerances apply, in many cases we can get even superior, by using our custom precision engine parts, such as main bearings, oil pump and other crucial engine components. These parts also make us independent of low quality far east spares, thus ensuring quality along tho whole way. In tuning, we do not only see increased power, we also see increased quality and lifespan of the engine. Our valve drive kits are a good example for this, ensuring more torque and power, without shortening the lifespan of your engine. Combustion chamber rework ist not only necessary to adapt big bore cylinder kits, it also compensates (sometimes severe) factory tolerances to ensure a smooth engine, without excessive vibrations. These vibrations are rarely caused by a badly balanced stock engine.
No matter what engine you may have (or you may ask us to build), you always get a carb setup that suits your engine. Not only for tuned engines, stock bikes can also profit from this, as 70ies and 80ies factory setups were far from perrfect. This completes the experience of a upgraded, steadfast, powerful and smooth engine, without higher fuel consumption.
To keep costs transparent, we always make an estimate, as soon as we have the engine here. Usually, this estimate contains things that must be done, and also the "nice to haves". We then get back to you to discuss the scope of work to be done. Cost is of course dependent on engine condition, but also on custumors whishes and upgrades.

25 years of exclusive Guzzi involvement are the fingerprint in these builds, making us to one of the best adresses worldwide for fine Moto Guzzi engines.More powerful, steadfast, more energy-concious, simply better... This also appllies to gearbox and final drives.

Please ask us !

Examples of things that can be done:

  • Combustion chambers rework
  • Squishband optimization
  • Compatibility for  unleaded fuel
  • HMB CNC oil pump and CNC main bearings
  • Automatic chain tensioner, HMB type
  • Cylinder head restoration with durable material and high quality valves. Also for larger carb conversions.
  • Valve drive kit to suit engine type, with correctly calculated  valve spring forces and lubricated lobes in camshaft
  • Correct carb setup
  • Round or square fin look (square engines only)
  • Intermediate oil sump ring, either with front or rear filter, or oil cooler adaption.
  • Twin Spark (optional
  • Pauter CroMo conrods (optional)
  • Big bore kit (optional)
  • Electronic Igintion system (optional)
  • Valve enlargement (optional)

If you have any questions, please ask us !

Manufactoy Engines:

We are often asked, why we do not offer reconditioned engines. There are several reasons for this, one being that there are too many variations of Guzzi engines, the other that some engines are not rebuildable, because of availability of spare parts. Especially in the case of the round engines, useable spare parts like cylinder heads may be a problem. Who would want to have broken out cooling-fins in a rebuilt bike...Others just want to keep their original engine unopened, or do not have an exchange engine at all.
From now on, we offer optimized rebuilt engines, without the need for an old engine in exchange.
We use the reliable Guzzi concept, refined with special parts from our own production. All our manufatory engines are based on a 1100  cc square engine, which can be machined to look almost like an old round one. This has many advantages, as the square engine housings were sturdier, the fin surface of heads and cylinders are larger and we can acommodate 92mm bores without changes to the housing. Nigusil coating of the cylinders and larger fin surface keep temperarures low. Spare parts are easy to obtain, as we stick to stock parts as long as possible.


Example: Round look, polished valve covers T3 type, intermediate ring with front oil filter

Included improvements and upgrades:

  • Combustion chambers reworked
  • Squishband optimization
  • Compatibility for  unleaded fuel
  • Camshaft plasma nitrated, with correctly calculated  valve spring forces and lubricated lobes in camshaft
  • Automatic chain tensioner
  • Crank drive assenbly balanced
  • Valve drive kit to suit engine type
  • DLC or reworked valves
  • Round or square fin look
  • Intermediate oil sump ring, either with front or rear filter
  • Twin Spark (optional
  • Pauter CroMo Conrods (optional)

More tuning information can be found here

There are 3 basic engine builds to choose from.

They may seem different, but they share the same quality parts and the precise workmaship of the rebuild. By balancing the complete crank drive, and by equalizing differences in the combustion chambers we achieve a steadfast engine with low vibration.. Mechanical noise is kept at a minimum by a correctly calculated camshaft- valvespring combination of the valve drive kit.
The interaction of all the modifications involved, will provide a smooth running, powerful engine with low fuel consumption.
Talking of fuel consumption... We have had many "tuned" bikes in our workshop with a consumption of up to 9 litres per 100 Km. Tuned engines do not necessarily have a higher fuel comsumption, easily explaind with the higher efficiency due to the changes made.

With HMB, you will get a correct carb setup for exactly your engine. Either by obtaining a set of carbs with your engine, or by setting up your carbs. No guessing here, setups were made on our dyno, and in countless hours on the road.

1. Torque engine for touring models
This engine is ideal for touring, similar to a California 1100 engine.The modifications sum up to additional 8 PS and 10 Nm in comparison to the stock engine. Homogenous power across the rev range.
For 36mm carbs, or the smaller throttle body of the California models.
Bore: 92mm, Stroke: 80mm, Valve size: 44/37mm, Camshaft: HMB D-8.1, Compression Ratio: 9,5:1

2. Torque engine for models with a sidecar
This engine is specially suited for sidecar models. Similar to the tourqe engine for tourung models, but with a few changes due to the additional burdon of a sidecar engine. The modifications sum up to additional 6 PS and 8 Nm in comparison to the stock engine. The small reduction of compression reduces oil temperature, connections for an oil cooler are supplied in thes version.
For 36mm carbs, or the smaller throttle body of the California models.
Bore: 92mm, Stroke: 80mm, Valve size: 44/37mm, Camshaft: HMB D-8.1, Compression Ratio: 9,0:1

3. Wideband engine
Basically, this is also a tourqe engine...But on a higher power level. This engine is meant for sportive drivers, similar to V11/1100-Sport engines. The optimizations result in an additional 3 PS and 5 Nm in comparison to the stock engine, without the unfamous torque losses at low and mid revs.Twin spark conversion should be considered, as these engines have a high piston dome.
For 40mm carbs, or the  larger throttle body of the 1100-Sport i.e. oder V11 models
Bore: 92mm, Stroke: 80mm, Valve size: 47/40mm, Camshaft: HMB L-7.9, Compression Ratio: 10:1

Engine selection here