• Home
  • Magazine
  • News
  • Tech Center
  • Products
  • Management
  • Shop Solutions
  • Engine of the Week
  • Ride of the Week
  • Catalogs and Literature
  • Buyers Guide
  • Advertise
  • Subscribe
  • Contact Us
Engine Builder Magazine Babcox
Engine Builder Magazine Babcox
Hot Shot’s Secret Announces NHRDA World Finals VIP Trip Giveaway

by Engine Builder

First STEM Days Opens Eyes for 94 Fifth Graders to the Engine World

by Engine Builder

Sponsored Content
Custom Pistons 101: Everything You Need to Know!

by JE Pistons

COMP Performance Group Names Director of Product Development and Adds to Sales Team

by Engine Builder

BMW’s Twin-Turbo 3.0L Diesel to Become Marine Outboard Engine

by Engine Builder

Elgin Industries Looks Good in John Deere Green

by Engine Builder

Jobs of the Week – April 16-20

by Engine Builder

DAYCO Announces Dan Sheehan as VP of Aftermarket Sales

by Engine Builder

Motovicity Picks Up BLOX Racing

by Engine Builder

Motovicity CEO Announces SEMA Board of Directors Candidacy

by Engine Builder

Engine Builder Job Fair

by Engine Builder

Centroid Announces its A590 5-Axis Engine Shop Machining Center

by Engine Builder

7 Hot Rodders of Tomorrow Teams Qualify at UTI/NASCAR Technical Institute

by Engine Builder

Schumann’s Announces 2018 OER Program

by Engine Builder

Lubrication Specialties Inc. Announces Brian Merz as Director of National Account Sales

by Engine Builder

STA-BIL Celebrates 60 Years of Keeping Engines Running Smoothly

by Engine Builder

Tenneco Signs $5.4B Agreement to Purchase Federal-Mogul

by Engine Builder

Engine Builder Subscriber Pens Historical Aviation Novel

by Doug Kaufman

Motovicity Unveils Facility Renovations to Improve Workplace Productivity

by Engine Builder

Dayco Aftermarket Operations Relocated

by Engine Builder

Join PERA for a Piston Alloys and Coatings Webinar

by Engine Builder

Engine News/Cometic Gasket
5 months ago

GMS Racing Engines’ S&S-Based Evolution V-Twin Voted 2017 Engine of the Year

Share Tweet
Print Print Email Email
Greg Jones

Greg Jones,Managing Editor

View bio

  • Bio
  • Recent Posts
  • Popular Posts

Greg Jones joined Babcox Media in January 2014 and currently serves as managing editor of Motorcycle & Powersports News and Engine Builder magazine. He is also content specialist for Speedville.com.

632 cid Big Block Chevy Engine

434 Small Block Chevy w/ All Out Package

365 cid Dodge R5P7 NASCAR Engine

Kamikaze Chris' 566 cid Big Block Chevy Engine

Video: Engine of the Week – 481X Top Sportsman Engine

465 Small Block Chevy Engine

Kamikaze Chris' 566 cid Big Block Chevy Engine

434 Small Block Chevy w/ All Out Package

365 cid Dodge R5P7 NASCAR Engine

Video: Engine of the Week – 481X Top Sportsman Engine

We first met Gregg Dahl of GMS Racing Engines, located in Uniontown, PA, at the 2016 PRI Show. Fast forward a year to the 2017 PRI Show, and we met with Gregg again. This time we were awarding him for his engine, a S&S-Based Harley-Davidson Evolution V-Twin, which was voted the 2017 Engine of the Year.

Dahl was presented the award at Engine Builder magazine’s 2017 PRI Party at Rock Bottom Brewery in Indianapolis on December 6. His V-Twin engine made it into the Top 10 most popular Engine of the Week engines from the past year where it was then voted on by Engine Builder readers on our website and social media channels. The Engine of the Week series is sponsored by Cometic Gasket.

Gregg Dahl hoists the Engine of the Year trophy built by Ray Banyas of Victory Engines in Cleveland.

The contest was neck and neck between Gregg’s V-Twin and Jon Kaase Racing Engines’ Boss Nine. But in the end, after more than 800 votes, the V-Twin came out on top, earning Gregg Engine of the Year honors and a custom trophy built by Ray Banyas of Victory Engines in Cleveland.

Below are snippets of the Engine of the Week article featuring the Evolution V-Twin engine…

Gregg Dahl of GMS Racing Engines – GMS stands for Gregg’s Machine Shop. Photo by Ed Hinchey, Thunder Roads

The engine highlighted in this week’s Engine of the Week was built for a customer up around the Toronto, Canada area. The engine is a S&S-based Harley-Davidson Evolution V-Twin, and is going to be in a Fast Bracket Race drag bike.

“The engine is built to stay together for a long time and provide a lot of runs,” Dahl says. “The compression is only 13.8:1. The engine makes around 200 hp at 190-200 lb.-ft. of torque on the rear wheel. Honestly, it’s a simple, basic, great big engine. The customer is shooting to run 8.90s at the track.”

To start, Dahl used basic cases from the S&S 145 tribute motor from about 10 years ago. “We had to do some work inside the case to get the big stroke to clear so the rods would clear,” he says. “All of the parts are all hand massaged to fit together. In the heads we put a 2.300 and a 1.800 exhaust valve. Being that the RPMs of the engine will be shifted around 6,800 – 7,000, if that far, we don’t have to run killer valve springs because of the real stiff valve train parts we have. Valve spring pressure will be around 275-300 on the seat and about 800 open.”

The Engine Builder and Cometic Gasket team pose with Gregg Dahl.

GMS Racing Engines did a lot of machining on the heads since those came from S&S as unfinished castings. This is also a flattop piston engine because of the 151 cu. in. size.

“It’s such a big engine we didn’t have to put domes in it,” Dahl says. “We were able to mill the heads down to get the correct cc to get the compression up to about 13.8:1. At the same time, milling the heads down that far also unshrouds the valve on such a big bore. When we milled the heads down we actually see the flow bench result a little bit, especially in the low lifts because the valve is hanging down out from underneath the head a little more.”

Gregg Dahl and Stacey Bortz at the Engine Builder booth at the 2017 PRI Show. Gregg builds engines for Stacey’s drag bikes.

When GMS gets the cylinders for the engine from Axtell, those are also not finished. Dahl finishes those here at the shop.

“We have our own torque plates that we made up and we use the actual fasteners in the torque plate that will go in the motor, and we use gaskets with them,” he says.

That’s not all he does on this engine. There’s some breather timing that Dahl does where he machines or grinds the window that the rotary breather gear runs in to get the breather timing correct. He also degrees the cam and scoots the drive gear around on the cam to get the timing where he wants it before welding the timing gear to the cam so it doesn’t move. He also trues up the flywheels.

“We also had to do some work for valve clearance,” he says. “Being that we are trying to achieve this compression with a flat piston, there was a lot of piston machining. We had to make the valve reliefs a little bigger but not deeper. We had to cut the rear piston for the front piston to go through it at the bottom of the stroke. The pistons are gas ported and we run light-tension rings.”

Photo by Ed Hinchey, Thunder Roads

This Evo engine has a 4-3/8″ bore and a 5-inch stroke, and has a laundry list of top-quality parts involved. The Red Shift 715 cam closes the intake at 71 degrees at .053” lift. It has S&S special application engine cases. It has a S&S billet HVHP (high volume high pressure) oil pump. It has a set of GMS’s own proprietary lifters, which are modified from Hylift Johnson. The cylinders are finless ductile iron from Axtell. The pistons are from JE. The heads are S&S B2’s that GMS custom finishes. The shop used Pac springs and the engine also has Victory 1 valves and all the valve train hardware is Victory 1.

Photo by Ed Hinchey, Thunder Roads

“We use Smith Brothers push rods, which are really cool because they are adjustable and are 7/16″ tapered down to 3/8″,” Dahl says. “They’ve got to be real stiff because they are 12-inches long. We use S&S billet rocker boxes and our own GMS 4.140 chrome moly rocker stands. We use rocker arms from either S&S or R&R Cycle. We send all the valve train out to Hekimian Racing Engines for cryogenics.”

GMS uses Cometic gaskets on all its engine builds, and this Evo is no different featuring Cometic on the head and base gaskets.

Photo by Evan Sanders.

The Evo got Cometic’s MLS gaskets and has ARP fasteners throughout. The engine has S&S 5-inch stroke flywheels in it and S&S 8.5-inch aluminum connecting rods. It also has a single S&S Super D carburetor on it.

This Evo V-Twin engine is very similar to the ones Dahl and GMS build for their drag bikes, which boast a 15:1 compression ratio and 260hp at the rear wheel. It should be one heck of a bike engine!

Engine of the Week is sponsored by Cometic Gasket

  • Tags:
  • Cometic Gasket
  • Engine of the Week
  • Engine of the Year
  • GMS Racing Engines
  • Gregg Dahl
Search for:
Show Full Article
Copyright © 2018 Babcox Media, Inc. All Rights Reserved
  • Privacy Policy
  • Home
  • Magazine
  • News
  • Tech Center
  • Products
  • Management
  • Shop Solutions
  • Engine of the Week
  • Ride of the Week
  • Catalogs and Literature
  • Buyers Guide
  • Advertise
  • Subscribe
  • Contact Us
Racesaver Sprint Car Engine Part 1 – Developing the Program

by Bobby Courtwright

465 Small Block Chevy Engine

by Greg Jones

Sponsored Content
Custom Pistons 101: Everything You Need to Know!

by JE Pistons

Kamikaze Chris’ 566 cid Big Block Chevy Engine

by Greg Jones

434 Small Block Chevy w/ All Out Package

by Greg Jones

365 cid Dodge R5P7 NASCAR Engine

by Greg Jones

Video: Engine of the Week – 481X Top Sportsman Engine

by Greg Jones

Sponsored Content
Custom Pistons 101: Everything You Need to Know!

by JE Pistons

Racesaver Sprint Car Engine Part 2 – Engine Block Selection and Prep

by Bobby Courtwright

632 cid Big Block Chevy Engine

by Greg Jones

FRAM Launches Innovative Website for Better User Experience

by Engine Builder