Need some help?AcceptDecline

Warranty - JBS CNC performance Heads




Please read the following important information

First check your cylinder head against your old one to make sure that you have received the correct type, also please retain the box for the exchange unit to go in. [This does not apply to customers that have had their own head unit reconditioned] If there are any differences please call us immediately, DO NOT fit the cylinder head.


1. If your previous cylinder head failed for any reason you must identify the root cause of your head failure.

2. We strongly recommend a workshop manual be obtained prior to fitting.

3. Before you fit your new cylinder head you must have your radiator pressure tested and flow tested by a radiator specialist. If the report finds the radiator blocked or leaking you must have a new one fitted to validate our warranty terms, please retain the radiator report.

4. Make sure that the top of the engine block is free from old gaskets or dirt before fitting and check for flat.

5. You must replace all gaskets and head bolts with new quality parts [diesel cylinder heads must have the correct thickness head gasket fitted]

6. Use the correct manufacturer's torque specifications

7. Re-time the crank, camshaft and injector pump with the correct timing kit.

8. Check thermostat, all water pipes and heater matrix.

9. Do not hesitate to call us if you are having difficulties. We will be happy to help.


All our cylinder heads are sold on an exchange basis.

Exchange costs are simple and are a standard practice for many automotive parts based on used parts. If you order a head from us, we normally require your existing cylinder head in exchange. We charge the exchange fee in addition to the cost of the new head. When we receive your head and it is checked and accepted, we credit your credit card with the exchange fee. If you don't have a head to exchange we charge the exchange fee in addition to the head price.

Please contact us as soon as the exchange unit is ready for collection. We will then arrange for our carriers to collect it. Please make sure that you put in all the exchange parts in the box and seal it well. If we do not receive the exchange unit with all parts back after four weeks of the invoice date, you will be surcharged 350.00 plus VAT.


We are aware we are dealing with modified engines of various states of tune, built and maintained by people of various skill levels. We will stand by our 12 month warranty but need to impose reasonable conditions.

The purchaser must adhere to all of the warranty conditions to validate any warranty claim.

1] The cylinder head must be prepared and fitted by a competent tradesman using all new gaskets, head bolts and cambelts [where applicable]. Proof of this will be requested upon receipt of claim.

2] An adequate service history is presented by a competent tradesman to include:

3] Oil and filter change

4] Compliance of manufacturers recommended tightening torque sequences.

5] Cam timing, injection and pump timing to comply with manufacturers specifications.

6] The radiator must be flow checked and pressure tested at the time of fitting by an independent radiator specialist and a report issued at that time. If the report states that the radiator is blocked or leaking in any way, it must be replaced immediately. Failure to do this or present an adequate report within two days of this claim will immediately invalidate any warranty.

7] takes no responsibility, nor does it accept any liability for repairs, transport or any other out of pocket expenses unless authorised in writing by us.

8] Should the head need to be returned under a warranty claim, then the purchaser must contact us immediately. Under no circumstances should the cylinder head be stripped internally unless written permission is given us.

9] All cylinder heads carry a 12 month warranty, providing you adhere to the warranty terms and conditions above. If you do have a problem with the cylinder head supplied we will instruct our carriers to collect the unit immediately for us to inspect. We also request that the radiator report and the gaskets used be sent with the cylinder head. The cylinder head and parts will then be put through the following tests to find the cause of the cylinder head to fail.

A] Pressure test to find any cracks
B] The valves and seats tested
C] The cylinder head will be checked for distortion
D] The valves will be checked to see if they were deck heighted efficiently
E] The camshaft will be checked

90% of failed cylinder heads are caused by overheating, incorrect valves / injector timing [diesels], broken cam / timing belts, faulty leaking hoses, faulty thermostat and blocked or leaking radiators.

The cause of the cylinder head failure must be identified before refitting a new unit; otherwise the problem will occur again. If we find that the cylinder is faulty due to our workmanship we will repair the fault free of charge or offer a replacement and cover all delivery charges. Cylinder heads that have failed and are not down to our workmanship will be returned to you and you will be charged a delivery and testing fee.

Please note that all "cylinder head" repairs and supplies cannot be cancelled or returned once work has been started. Your statutory rights are not affected.