IJSBA · Engine

Aftermarket camshafts, IJSBA

Cam timing and cams themselves are governed separately in the stock tiers.

This page is IJSBA only, and the bodies do not agree. The same part under IHRA and UIM. Which one applies to you is decided by whoever sanctions the race you enter.

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This is one body's answer, not the sport's. You are bound by whichever body sanctions the event you enter. If you race more than one series, build to the stricter answer. The differences are set out in the rulebook comparison.

Where it stands, class by class

14 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.

What each answer below means

OEM part required

This comes off. Only the part the manufacturer fitted is allowed here.

Legal

Keep it. The rules permit this part in this class.

OEM part required 3 classes

Camshaft replacement prohibited. Only bearings, timing changes and adjustable sprockets allowed.

• Fixed Steering Ski Stock · FSSK.3.3
• Ski Stock · SSK.3.3
• Four Stroke Ski Lites · FSKL.3.4

OEM part required 3 classes

Camshafts must remain stock; timing adjustment allowed.

• Runabout Rec Lites · RRL.3.4
• Runabout Naturally Aspirated · RNA.3.4
• Runabout Stock · RAS.3.4

OEM part required 1 class

Camshaft stock. Timing may be changed and adjustable sprockets fitted in the 1101-1500cc category.

• Ski Modified · SKM

Legal 4 classes

Aftermarket camshafts are allowed if the original number of camshafts, the original bearing type and dimensions and the original method of valve activation are kept, and cam timing may be changed.

• Ski Superstock · SKSS.3.3
• Freestyle · FREST.7.3
• Ski Grand Prix · SKGP.6.3, SKGP.7.3
• Sport GP · SPGP.4.3

Legal 2 classes

Camshafts may be modified or aftermarket.

• Runabout Limited · RAL
• Runabout Superstock · RSS.3.9

Legal 1 class

Plus aftermarket cam gears, tensioners, chain or belt. Camshaft COUNT must match original and conversion to solenoid actuation is prohibited.

• Runabout Open / GP · ROP

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Aftermarket camshafts: if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.

Every IJSBA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.