Machining Services

Triumph / BSA / Norton Motorcycle Machine Services
I know a lot of you are working on your vintage Triumph, BSA and Norton motorcycles and may need some machine work done. I would like to offer up some information on these services from Wes White over at Four Aces Cycle. He is the mechanic in the Triumph 650 Rebuild DVD as well as the English 101 DVD, and is an expert Triumph mechanic. Rather than rely on a local shop who may have no experience with vintage British motorcycles, you can ship your head, cylinders or crank to Wes at Four Aces Cycle quite inexpensively and be sure you are getting top level work you can be confident in.
To inquire about machine services please contact Wes via email click here.

Head Work
A friend
of mine always says that the top end on a British Bike is "where all the excitement is." I am not sure about that but a good valve job is paramount in any good running motor. We ofer cylinder head service for all British bikes, but of course we specialize in Triumphs, Nortons and BSA's. We can do a 500cc or 650cc Triumph, BSA or Norton head of any year, cast iron or alloy. Exotic stuff does not scare us, but parts availability for uncommon makes and models can be difficult sometimes.

If you are rebuilding your motor and are unsure of your valves, guides and springs (and you should be concerned about them), you can send them to us for full inspection and repair and replacement of worn parts. So much goes into a valve job, it is sometimes best left to a good shop. Correct reaming of guides, correct packing of springs to insure maximum performance, correct valve height and of course a perfect seal between the valve and the seat are of the utmost importance. We use quality Rowe products in most of our cylinder head jobs, but can source more exotic materials if need be. Each head is going to be a little different, but here are some of the prices for the labor and parts.

Labor: $200
Includes full inspection of existing components (the head itself, valves, guides, springs, seats), three angle valve job, including driving in new guides, reaming the guides, replacing valves and grinding/lapping of the new seat.

Guides: $50 - $75
For a set of four (sometimes a little more if your guide holes are worn out badly).

Valves: $100 - $200
For a set of four. Price varies depending on stand or a more exotic valve like Black Diamond Valves.

Springs: $35
For a set of 8 pieces. Quality American-made springs packed to the correct height and tension.

We also take a look at both sides of the head and check for flatness. This prevents head warpage and blown head gaskets, it also prevents leaky rocker boxes. If you head is warped or damaged we can fix that with a good surfacing. This is done the old fashion way on a piece of marble with emory paper, not with a mill, so as not to take too much material off.


Helicoil Services
Prices are about $10 - $20 per helicoil, depending on whether you have Whitworth or American threads. We will inspect your spark plug holes as well and repair them if need be. This usually runs about $25.

Cylinder Boring
Send us your barrel and we can check it for you. Proper clearance of piston top and skirt to bore is paramount. I can check out your pistons and rings for roundness and advise as to whether you need new ones or not.

We offer a variety of pistons, both English and Taiwanese as well as a selection of rings (American, Taiwanese and English). Prices range from $150 - $250 for a full set with rings depending on what you want. Boring your cylinder is done at a flat rate of $175.

Crank Grinding
We also offer Crank Grinding services when your crank is out of spec from use or damaged due to use or impurities in the oil. Crank grinding is charged at a flat rate of $175 for both journals. We can supply you with new shell bearings if needed as well.

Crank Balancing
Balancing of your crank, which is not always necessary, ranges from $125 to $175 depending on the complexity of the job.