RevTech engine facility at Harley-Davidson

After many kilometres and after an important breakdown caused by the wear of the internal components we have reached this point where it almost costs the same to repair the engine or replace it with a new one, equipped with the latest technologies in manufacture. We finally opt for this important renovation: we will replace the heart of our machine, the engine, with a new unit.

The opportunity
Usually when you comment on the possibility of replacing the complete engine of a vehicle with another new one, a certain catastrophic sensation comes to mind, intuiting a very expensive procedure.
In reality, if we analyze the situation coolly, it is more an opportunity to renew and at the same time improve a component that has reached the end of its useful life cycle, because romanticisms apart, the motor does not cease to be a set of movable metal pieces that interact among them millions of times, causing wear and permanent deformations that moreover the manufacturer has predicted, but to some extent: there comes a moment where there is so much wear and tear that even if they are renewed certain internal components by new ones, these will see their life shortened prematurely, forcing us back to an early change. Explained in a simple way: from a certain amount of kilometers or wear it comes out more economical in the middle and long term to replace the complete engine. (The one who doesn't believe this to pick up a calculator and ask some friend with "old" engine how much money has invested in keeping it running in recent years).
A decisive factor that helps to understand all of this is how manufacturing procedures have changed in the last 10 or 15 years: thanks to technology it is now manufactured with lower tolerances and better materials, and most importantly, at a much lower price than a few years ago. On the contrary, the specialised labour force is becoming more expensive, which leads us to the following conclusion: "Before the pieces were expensive and the cheap labour force, now it is quite the opposite".
With this data when for some reason we have to perform a great import repair on an engine with many years or kilometers it is very practical to consider the option of the change.

Choice of engine
Today there are many options in the market to obtain a new driving unit at a reasonable price, from the Motor Company itself to reputable manufacturers such as S&S, TP Engineering, Ultima Products, RevTech, Jims ...
Explaining the steps to follow in choosing the right engine for each need would take a full article, we will only remember the most important keys:
-Try to acquire a product of a recognized brand, that will assure you continuity in obtaining spare parts in a future. If your engine lasted more than 20 years, it should last more than 30 years, so you'll need parts for future repairs.
-Choose well the size (and character) of the engine based on its use. For the day to day in a big city and sporadic trips do not urge a "monster" with excessive compression and displacement.
" Report. Read, ask, consult professionals and draw your own conclusions, the more information you get the most criteria you'll have to make a good decision.

A practical case
We will proceed to change a complete engine in a Harley-Davidson Softail model of 1995, with many kilometers and fairly punished by several owners and little "orthodox" mechanics.
The original engine is an Evolution of 80 ci (1340cm3), and has been chosen as a better choice for the specific needs of the current owner a RevTech unit of 88 ci (1442 cm3), with substantial technical improvements, such as greater compression, joint technology used in Twin Cam models, reinforced crankshaft and mounted by the modern system, larger cooling fins , reinforced crankcase and a long etcetera of technological improvements, which place our new "EVO" at the same level as the latest HD engines, maintaining the essence of the '80s.

Mounting
This would be the summary mounting sequence, as always following the specifications, procedures and tightening torques of the service manual and the engine manufacturer itself:
1. Empty the oils and disassemble the fuel tank.

2. Disassemble and extract the crankcase and primary transmission.

3. Let go of the bolts that attach the engine to the chassis.

4. Extract the original engine and insert the new engine into place.

5. Align the motor and tighten the clamping bolts in order.

6. We make all electrical connections and install the oil ducts.

7. After putting oil we start the engine and adjust carburetor and ignition, we are ready to roll again, for many kilometers!

Frank Burguera

#mecanicaharley