Custom Sleeves

Custom Sleeve Production Policy

Darton is the leading producer of sleeves on a quick turn, small lot basis for the performance industry. Our normal production time after receipt and confirmation of an order is, on average, 15 – 20 working days. During peak periods of the year production time may extend from 20 – 40 working days. Production time estimates can only be given when all details of an order are known and discussed with Darton Customer Service.

Production days estimated on any particular order begin when: The blueprint is signed !!! and approved by the customer and accepted by Darton. Advance payment has been received by Darton. Production times do not include shipping days. For a custom order to be accepted for processing the following steps must be accomplished:

  1. Darton issues a written quotation.
  2. The customer accepts the quotation and signs the quote approval.
  3. Customer is advised and acknowledges production or lead time estimates.
  4. Payment has been received by Darton.
  5. The blueprint is accepted and approved by customer and Darton.
  6. There are no exceptions to this process!!!

Engineering And Blueprinting Policy

For sleeves of simple shapes and standard tolerances, Darton employs “Basic Sleeve Blank” forms for general dimensioning of bores O.D., I.D. flange dimensions, and flats. Use of these “Sleeve Blank” forms with fill in the dimension slots is the easiest and simplest way for the customer to design a unique sleeve and provide Darton with an approved print. These print blanks are available on request and this service is free of charge. Darton maintains a full engineering and CAD drawing department to provide additional services for customers. These services are:

  • Reverse engineering from samples
  • Creation of professional CAD blueprints

Reverse engineering from samples is a service we charge for. When we reverse engineer a sleeve, using standard shop measuring tools, the charge is $150.00 and includes a CAD blueprint. When reverse engineering is more complex where shapes, precision and tolerances are beyond the capabilities of measurements with standard shop measuring tools, Darton will employ a CMM (Coordinate Measuring Machine). The charge for this service is $100.00 per hour with a 2-hour minimum, plus a CAD drawing charge based on time.Customers may provide their own blueprint provided it meets the following conditions. Darton requires minimum specifications and call outs on customer supplied prints to include: All required dimensions, angles, chamfers and radius callouts

  • Tolerances on all dimensions
  • Surface finish specification
  • Mechanical specifications
  • Material specification
  • Hardness

Darton will not manufacture any sleeve from a customer blueprint unless:

  • All of the minimum call outs are present.
  • The print is legible.
  • And the customer has signed a print approval form.

Or Customers may elect to have Darton create a production blueprint. Blueprinting is a service we charge for. Initial drawings, re-drawing of customer drawings or sketches, drawings derived from reverse engineering, and/or other CAD services are charged at a rate of $75.00 per hour.

  • When Darton is required or requested to provide blueprinting services for an initial print, or correction of customer’s prints, such services may take up to two weeks. No production can begin without approved blueprints.
  • No order!!! can be processed or production begin unless an approved blueprint has been supplied and accepted by Darton.
  • Unresolved blueprint issues or lack of blueprint approval delays!!! production.
  • No blueprinting will be accomplished by Darton unless an order has been confirmed and payment issues resolved.

Custom Manufacturing Expedite Service

Darton offers a manufacturing expedite service for an extra cost.

  • Service A: Delivery within 10 working days, part cost plus 25% surcharge
  • Service B: Delivery within 5 working days, part cost plus 50% surcharge
  • Service C: Delivery within 2 working days, part cost plus 100% surcharge

Note: Expedite service is not available at all times or for all quantities of parts desired. Check with a Darton Customer Service to determine availability of this service.

Darton is the leading producer of custom sleeves in the world. If you can come up with the specifications we can make the sleeve you need and if you can’t we can help you. Darton covers a wide range of applications like tractors, motorcycles, marine engines, vintage race cars and many more race and street applications. We can even make the most complex sleeves like ones used in Ferrari, Alfa Romeo, Peugeot and Porsche to name a few. We can do short runs or larger quantities of your sleeve depending on your needs.

We can make sleeves ranging from bore sizes of 2.800” – 5.200” and lengths from 4.000” – 10.500”. Darton can make sleeves like the basic re-sleeve to 2 and 3 body diameter sleeves and even water jacket sleeves. We can also add special features like fire dams, multiple o-rings, undercuts, flats, special chamfer or radius and crank notches.

Reverse engineering is also available should you not be able to measure the sleeves you need. For an additional charge you can send us a sample sleeve and we will do the measuring for you. When we reverse engineer a sleeve we use state of the art measuring equipment and create a blueprint of the sleeve you need us to manufacture.

You can contact Darton and we will even supply you with blank prints to fill in the specifications of your sleeve or you can get the prints off our website,, under the custom sleeve section. Once we receive your print or the part we are reverse engineering we can give you a quote and estimated production time.

Darton makes it easy to make those difficult and often hard to find sleeves for almost any application. All of our custom sleeves are made of our superior strength Ductile Iron used on all of our regular production sleeves and high performance sleeves like Top Fuel and Funny Car. For more information contact Darton Sales.