× 1-800-946-2642 Home My Account Social / Forum Articles Contact My Cart
Shop Now
Select Your Car Type Sale Items Clearance Items New Items
Ultra light "adjustable" steel duplex timing gear and chain set. The innovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

The line boring of motors is becoming increasingly necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.

'A' Series BMC

IMPORTANT

Supplied are 2 screws. Replace the original bolts with screws after modifying cover plate.

Manufacturer's Statement:

Rollmaster are C.N.C. machined, high tensile steel sprockets using double row O6B-2 chain. Care must be taken to inspect key & keyways & shafts for damage before fitting. Do not use pin punches as damage will occur. Use a drift such as a pipe or sleeve. Machine to suit the boss area.

No responsibility will be taken for improper fitment or usage or damage incurred.

Mini Cooper Camshaft timing chain kit

0 STD cam timing
A keys to left of STD mark will adv cam timing
R keys to right of STD mark will rtd cam timing
2 2 degrees Keys at crank will give a value of 1,2,3,4 degrees ADV or RTD at the camshaft. The ratio is 2:1.
4 4 degrees
6 6 degrees
8 8 degrees
Classic Mini Steel duplex timing gear kit various applications

Classic Mini Steel duplex timing gear kit various applications

Classic Mini Steel duplex timing gear kit various applications

Classic Mini Steel duplex timing gear kit various applications

Classic Mini Steel duplex timing gear kit various applications

Ultra light "adjustable" steel duplex timing gear and chain set. The inovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

 

The line boring of motors is becoming increasing necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.
If you are working on your engine and you want to do it right then you should consider how you are going to drive the camshaft. People often spend a lot of time picking the camshaft and then ignore the exact reason they spent so much time picking the cam. Driving the cam and controlling the timing relationships between the cam and the crank is what camshaft drive systems are all about. It makes no difference what the cam does if it does not do it in sync with the crank and pistons. The stock system on many 848, 948, 998 and 1098cc engines is a single chain drive between the crank and cam. The 'S' and some 1275 have a much better "duplex" chain. But even those do wear out! The best judge is to check it while you are taking it apart. With the timing cover off the engine rotate the crank a slight amount back and forth. The camshaft must move the exact distance at the same instance!
The least expensive but better than an old one is a stock cast gear and chain set, This budget standard cast duplex gear and chain set is the next step up, for road use only.
Fitment of an uprated cam drive system is essential when building a performance engine. Timing scatter induced by the standard set up can reach up to 15 degrees once the single row chain has stretched, which it does after only a few miles. This scatter not only affects the cam timing, but also the ignition, the distributor being driven by the camshaft. Power loss suffered by this phenomenon is substantial. Replacing the standard single row (simplex) system with a dual row (duplex) system greatly reduces the problem; use of a toothed belt system all but eliminates it. The belt system vastly reduces valve train noise and also helps damp out some of the odd harmonics generated by the 3 main bearing 'A' series engine. It is also extremely important to time any cam in to its required setting to obtain maximum performance, especially with performance cams. The 'dot to dot' method can, because of manufacturing tolerances, be out by as much as 15 degrees. Anything above 2 degrees out and power suffers -- most noticeably in small bore engines. In race engines you probably lose 1 hp for every degree the cam is out, more when over 6 degrees!

Ultra light "adjustable" steel duplex timing gear and chain set. The inovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

The line boring of motors is becoming increasing necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.
If you are working on your engine and you want to do it right then you should consider how you are going to drive the camshaft. People often spend a lot of time picking the camshaft and then ignore the exact reason they spent so much time picking the cam. Driving the cam and controlling the timing relationships between the cam and the crank is what camshaft drive systems are all about. It makes no difference what the cam does if it does not do it in sync with the crank and pistons. The stock system on many 848, 948, 998 and 1098cc engines is a single chain drive between the crank and cam. The 'S' and some 1275 have a much better "duplex" chain. But even those do wear out! The best judge is to check it while you are taking it apart. With the timing cover off the engine rotate the crank a slight amount back and forth. The camshaft must move the exact distance at the same instance!
The least expensive but better than an old one is a stock cast gear and chain set, This budget standard cast duplex gear and chain set is the next step up, for road use only.
Fitment of an uprated cam drive system is essential when building a performance engine. Timing scatter induced by the standard set up can reach up to 15 degrees once the single row chain has stretched, which it does after only a few miles. This scatter not only affects the cam timing, but also the ignition, the distributor being driven by the camshaft. Power loss suffered by this phenomenon is substantial. Replacing the standard single row (simplex) system with a dual row (duplex) system greatly reduces the problem; use of a toothed belt system all but eliminates it. The belt system vastly reduces valve train noise and also helps damp out some of the odd harmonics generated by the 3 main bearing 'A' series engine. It is also extremely important to time any cam in to its required setting to obtain maximum performance, especially with performance cams. The 'dot to dot' method can, because of manufacturing tolerances, be out by as much as 15 degrees. Anything above 2 degrees out and power suffers -- most noticeably in small bore engines. In race engines you probably lose 1 hp for every degree the cam is out, more when over 6 degrees!

Ultra light "adjustable" steel duplex timing gear and chain set. The innovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

The line boring of motors is becoming increasing necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.

Ultra light "adjustable" steel duplex timing gear and chain set. The innovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

General: Camshaft Drive Systems
See AEA587 for new counter-sunk screws)

The line boring of motors is becoming increasing necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.

 

Ultra light "adjustable" steel duplex timing gear and chain set. The innovative 'multi-keyway' sprocket means that you can easily adjust timing in 2 degree increments. The matched paired spockets give precise chain fitment.

The line boring of motors is becoming increasingly necessary as engines age and as the demands on them continue to rise. And while this process does provide a lot of needed benefits, the only downside is that it moves the crank closer to the camshaft which means that even a new sets of gears and chain will not be tight enough to accurately control camshaft timing. These special gear kits are designed with very slightly oversized gears to compensate for this distortion. Available in different increments to accommodate various line bores.

'A' Series BMC

IMPORTANT

Supplied are 2 screws. Replace the original bolts with screws after modifying cover plate.

Manufacturer's Statement:

Rollmaster are C.N.C. machined, high tensile steel sprockets using double row O6B-2 chain. Care must be taken to inspect key & keyways & shafts for damage before fitting. Do not use pin punches as damage will occur. Use a drift such as a pipe or sleeve. Machine to suit the boss area.

No responsibility will be taken for improper fitment or usage or damage incurred.

Mini Cooper Camshaft timing chain kit

0 STD cam timing
A keys to left of STD mark will adv cam timing
R keys to right of STD mark will rtd cam timing
2 2 degrees Keys at crank will give a value of 1,2,3,4 degrees ADV or RTD at the camshaft. The ratio is 2:1.
4 4 degrees
6 6 degrees
8 8 degrees
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Related Technical Articles:
Removing Slack In A-Series Engine Timing Chains
Created: March 01, 2018
Watch Our Video - If you've got too much slack in your A-Series engine timing chain, Mini Mania now has Rollmaster timing gear sets in stock to take up that slack! These oversized gear sets come in three offset options.
Timing Chain Replacement for A-Series engines
Created: February 28, 2018
Building an engine is very much like most things in life- the more attention to detail you give an effort the more likely you will get the results you were looking for. Whether you are installing a new stock or performance camshaft or even simply rebuilding your motor with the stock camshaft getting the valve timing correct is one of the more important things that you can do.
How-To Set Valve Timing on a Classic Mini 1275cc A+ Block Part 2
Created: August 15, 2016
VIDEO: How-To Set the Valve Timing on a Classic Mini 1275cc A+ Block Part 2
How-To Set Valve Timing on a Classic Mini 1275cc A+ Block Part 1
Created: August 15, 2016
VIDEO: How-To Set the Valve Timing on a Classic Mini 1275cc A+ Block Part 1
Did You Know? December 3, 2015
Created: November 25, 2015
Did you know how important it is to get your cam timing correct?
Choosing The Right Timing Set For Your Engine
Created: March 25, 2014
Choosing The Right Timing Set For Your Engine with an quick review of timing chain tensioners. Camshaft selection can be as complicated as you like, but for the ultimate performance, even if that means best gas mileage, the decision requires that you consider the entire envelope that the camshaft will work within.