RevTech engine installation on Harley-Davidson

After many miles and a major breakdown caused by internal component wear, we've reached the point where it costs almost the same to repair the engine or replace it with a new one, equipped with the latest manufacturing technologies. We finally opted for this major overhaul: we're going to replace the heart of our machine, the engine, with a new unit.

The opportunity
Generally, when the possibility of replacing a vehicle's entire engine with a new one is discussed, a certain feeling of catastrophe comes to mind, sensing a very expensive procedure.
In reality, if we analyze the situation coldly, it's more of an opportunity to renew and at the same time improve a component that has reached the end of its useful life cycle. Romanticism aside, the engine is nothing more than a set of moving metal parts that interact with each other millions of times, causing permanent wear and deformations that the manufacturer has predicted, but only to a certain extent. There comes a time when there is so much wear that even if certain internal components are replaced with new ones, their lifespan will be shortened prematurely, forcing us to replace them again early. Simply put: after a certain number of kilometers or wear, it's more economical in the medium and long term to replace the entire engine. (Anyone who doesn't believe this should grab a calculator and ask a friend with an "old" engine how much money they've invested in keeping it running over the past few years.)
A decisive factor that helps us understand all this is how manufacturing processes have changed over the last 10 or 15 years: thanks to technology, products are now manufactured with tighter tolerances and better materials, and most importantly, at a much lower price than a few years ago. On the other hand, skilled labor is becoming increasingly expensive, which leads us to the following conclusion: "Parts used to be expensive and labor cheap, but now it's the opposite."
With this data, when for some reason we need to make a major repair on an old or mileage-laden engine, it's very practical to consider replacing it.

Engine selection
Today, there are plenty of options on the market for getting a new powertrain at a reasonable price, from the Motor Company itself to renowned 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 whole article; we'll just review the most important points:
-Try to purchase a product from a recognized brand that will ensure you can obtain replacement parts in the future. If your engine has lasted more than 20 years, this one should last more than 30, so you'll need parts for future repairs.
-Choose the engine size (and character) carefully based on its intended use. For everyday use in a big city and occasional trips, don't install a "monster" with excessive compression and displacement.
-Get informed. Read, ask questions, consult professionals, and draw your own conclusions. The more information you gather, the more knowledge you'll have to make a good decision.

A practical case
We are going to proceed with the complete engine change in a 1995 Harley-Davidson Softail model, with many kilometers and quite punished by several unorthodox owners and mechanics.
The original engine is an 80 ci (1340 cm3) Evolution, and an 88 ci (1442 cm3) RevTech unit has been chosen as the best option for the specific needs of the current owner, with substantial technical improvements, such as higher compression, gasket technology used in Twin Cam models, reinforced crankshaft mounted using 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, while maintaining the essence of the '80s.

Mounting
This would be the summarized assembly sequence, as always following the specifications, procedures and tightening torques of the service manual and the engine manufacturer itself:
1. We drain the oils and remove the fuel tank.

2. We disassemble and remove the crankcase and primary transmission.

3. We loosen the bolts that hold the engine to the chassis.

4. We remove the original motor and insert the new motor in its place.

5. Align the engine and tighten the mounting bolts in the order shown.

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

7. After adding oil, we start the engine and adjust the carburetor and ignition. We're ready to roll again, for many kilometers!

Frank Burguera

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