|Article number:||11106-58020 AM|
|Availability:||In stock (20)|
These are high quality, affordable, stainless steel pre-combustion chambers to replace cracked and broken chambers in engines that are being rebuilt.
• Please pay careful attention to the machining and fitting requirements, as outlined in the Factory Service Manual, of the cylinder head and block when replacing combustion chambers.
• When using composite head gaskets, cylinder heads of the B family of engines should be re-torqued once (and only once) after being run-in and fully warmed up and then allowed to fully cool down.
Made from 310 Stainless Steel. 310 is an austenitic (non-magnetic) stainless steel containing high amounts of chromium and nickel for use in high temperature applications.
Please read the attached document provided by Engine Australia.
Fitting Pre-Combustion Chambers (Engine Australia)
Important Notes: The number 1 failure points of combustion chambers in Toyota B series engines are from A) localized overheating in the pre-combustion chamber - too much fuel relative to the air supply and/or a poor injector spray pattern, especially when running a turbo; B) generalized overheating of the engine - usually the result of a poorly functioning cooling system or a compromised head gasket - which lets combustion gases into the water jacket which pushes out the coolant... and without coolant you will get a faulty coolant temperature reading and a loss of engine cooling. And, C) a poor/loose fitting pre-combustion chambers in a worn or previously overheated cylinder head.
Overheating your B series diesel even once is enough to cause serious damage, and that damage may not show up right away. This is commonly experienced as "dropping a pre-cup" - which causes severe engine damage.
Overheating is more common in older diesel engines commonly due to very poorly functioning radiators (internally or externally plugged up), which prevents the center portion of the radiator from getting hot, reduces the cooling capacity of the radiator to keep the coolant adequately cool, which in turn means there's not enough hot air passing through to activate the fan clutch... and that leads to a type of cascade failure.
The factory coolant temperature gauge is not accurate at all, and can only be used as rough indication of operating temperature. DO NOT rely on either the factory coolant temperature gauge or the factory oil pressure gauge to monitor your engine's cooling requirements.
It is almost impossible to monitor for localized overheating. What you can do is monitor EGTs before the turbo, and keep these in a very reasonable range: never exceed 1250F on measured on a fully heat soaked engine, and try to keep EGTs below 1100F during normal operation. The effects of localized overheating can be tested for after-the-fact (the metallurgy and harness is affected), but this gets expensive and it's usually pretty obvious to the trained eye that you overheated things.
If your engine was tuned at a lower elevation, as you start to go up in elevation you may see a very large increase in EGTs at engine loads that previously yielded acceptable EGTs. If this is happening to you, you need to back off the throttle, shift down a gear, and/or adjust your injection pump to reduce your fuel delivery volume for the elevation (some B series engines have rudimentary altitude compensation, others do not). If you are seeing black smoke from the tailpipe, you are running too much fuel - and excess fuel means you are heating up your combustion chambers.
Generalized overheating of the engine can be sort-of monitored with a good quality coolant temperature gauge, however it is entirely possible to overheat your engine while the coolant temperature gauge is saying you're mostly in the normal range.
It is also possible to see completely normal or even low coolant temperature readings yet your engine is suffering from localized overheating due to excessive combustion temperatures. It is critical to monitor Exhaust Gas Temperatures (EGTs) - preferably pre-turbo - and drive in a manner that does not create excessive temperatures.
If you have taken the time and money to install a turbo system, then you also need to spend some money ensuring you have new Denso injector nozzles in place with a perfect spray pattern and the crack pressure at the top end of the specification, and that your injection timing is set correctly according to the Toyota Service Manual for your application.
• Get your radiator re-cored with a good quality high-density 3 core rad.
• Replace your fan clutch with a new Japanese (Aisin or NPW) fan clutch.
• Consider installing the slightly lower temperature 82C thermostat vs the original 88C thermostat.
• Make sure your fan shroud is in place, and that you have proper air flow in your engine bay (for example there should be a foam strip between the front of the radiator and the front rad support to prevent recycling of hot air).
• Electric engine cooling fans will never move the same amount of air as a good engine driven fan...
• With a turbo, you should be running a 2.5" exhaust system with minimal restrictions (mandrel bends).
• If you are planning on consistently running a boost pressure of 10-12 PSI or more then an intercooler is strongly advised.
Replaces Toyota pn:
B and 2B engines use part number: PCTO700
**NB: see technical details of this particular part in the images.
Engineered in Australia - made in Taiwan
2020 09 29
keywords: pre cup, pre comb, combustion chamber, precombustion chamber, pre-combustion chamber