Ain't no substitute for cubes
Words: Rich King

 

What do you do when you've got a need for more than the output of your stock Evo lump, but don't especially want to shell out for a TwinCam88.

S'easy really. Talk to Custom Chrome

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Obviously stylistically based upon the outgoing Evo lump, RevTech's 88 and 100-cube motors have been designed to be better than their illustrious stock predecessor in many respects. After years of living with, and gradually improving Harley's big twin with a huge range of aftermarket parts, RevTech were able to virtually redesign the basic concept when they came to build their own motor. The most obvious change of course is the cubic capacity, those extra cubes alone allowing the motor much more low down grunt, but allied with many other technical improvements, both externally and internally, the Rev Tech does look a winner. On the performance improvements side, the stock RevTech – compared to the stock 80-cube – boasts a Mikuni HSR42 carb allowing more performance and a better spread of power than a poor strangled Keihin 40 set up to meet the emissions laws of many countries, and mates to the heads via a redesigned manifold which is claimed to allow better mixture flow. At the other end of the combustion cycle Rama chose to fit an Arlen Ness 2 into 1 exhaust system which breathes a hell of a lot better than stock too, and "D"-shaped exhaust ports from the head have been designed to allow greater velocity than the 1340's round ports. The RevTech engine features, as standard, a 495" High lift cam, featuring less emission-friendly timing, allowing for a good spread, and plenty of torque, and a Thunder Heart high-performance ignition, while the heads come tapped ready for 2 plugs per head. On the reliability front, the motor features more and longer cooling fins to aid the engine cooling process ... ably assisted by a RevTech oil pump which keeps plenty of the vital fluid on the move. Meantime, weak areas like the familiar weeping head and base gaskets, for instance, have been treated to O-rings. High stress areas on the original have been tackled simply by adding more meat – the meat in the case of the RevTech being 356-T6 cast aluminium, which is claimed to be stronger and is used throughout the casings. Also stronger are the redesigned horizontally locked liners for the cylinders, as well as the flywheels – forged from 4340 steel – and the main bearing inserts.

Built in Taiwan, the RevTech Engine comes complete ('just add oil' is Custom Chrome Europe's proud boast) with a 2 year/22,000mile warranty. And – here's the good bit – because the motor is built in Taiwan, they're not overly expensive, and they come complete, ready to fit, either from Custom Chrome Europe's catalogue or from Custom Chrome dealerships:

Custom Chrome Europe:
Planinger Strasse 154
D-55543 Bad Kreuznach

(calls welcome to find your nearest dealer)

Tel: +49 (0) 671 888888 0
Fax: +49 (0) 671 888888 29

www.custom-chrome-europe.com
email: info@cceshop.de

Motors available:

88 cubic inch:
Cat No. 58-500 Black wrinkle finish
Cat No. 58-501 Natural aluminium finish
Cat No. 58-503 Limited edition high-polished finish

100 Cubic inch:
Cat No. 58-505 Black wrinkle finish
Cat No. 58-506 Natural aluminium finish
Cat No. 58-508 Limited edition high-polished finish

All motors include the following chrome bits:
Rocker box covers,
Lifter blocks,
Cam cover,
Pushrodcovers,
Oil filter and mount,
Oil pump cover,
Air cleaner

2 Year or 20.000 mile limited warranty on all engines.

Features include:

  • Increased cooling fin area, some are longer too.
  • High temp o-rings rather than gaskets
  • Computerised ignition
  • Compatible with original equipment and custom frames that accept Evo big twin lumps
  • Flywheel features one piece halves and shafts, forged from 4340 steel
  • Engine cases are constructed from 356-T6 cast aluminium with added material in high stress areas. They feature removable press in/bolt in bearing inserts and removable sump plates
  • Cylinders feature steel liners which are Perma-locked to the alu outer casing. 100 motor features forged pistons.
  • Cylinder heads feature D-shaped exhaust ports for improved flow and a wider spaced bolt pattern for increased strength.
  • Oil pump is late style external
  • Carb is a Mikuni HSR42 manifold and port closely matched for flow
  • Cam is a RevTech 50 featuring .495 lift for good torque throughout rev range

Am-V Comments
Both 100 cube engines Am-V have so far test ridden, a more or less 'stock' one in the CCE bike, Tribal Iron, and a hotter version in Rama's 'Bikers Lust seemed to perform beautifully. Almost silky smooth, they both showed breathtaking torque throughout the rev range and promised a real 120mph top end with high cruising speed capability. Docile at low speeds, carburation was spot on so trickling was almost as good as anything Milwaukee has produced. Clutch was effective, if a tad heavy, the 6 speed box appeared perfectly ratio'd and snicked up and down through the gears very well indeed. If all their Taiwanese-built engines are this good them RevTech should be on a winner.