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FAQ's
General
Things to know before purchasing a Rotary
Problems and Fixes
Yes! We can ship internationally.* Please drop us a message if you would like to make a purchase to be shipped internationally and we can provide you with a cost for shipping.
*All money exchange, taxes and duty fees to be paid by customer.
Please note we are unable to ship to the following countries; Afghanistan, Azerbaijan, Armenia, Belarus, Burma (Myanmar), China, Democratic Republic of Congo, Egypt, Eritrea, Republic of Guinea (Conakry), Guinea- Bissau, Haiti, Israel, Iran, Iraq, Ivory Coast, North Korea, Lebanon, Liberia, Libya, Russia, Sierra Leone, Somalia, South Sudan, Sudan, Syria, Tunisia, Ukraine (Crimea/Sebastopol) and Zimbabwe.
No. We hope you can understand at the end of the day we are a small business who needs to make money in order to be able to offer our customers great products and services. This is not and will never be an option in the future.
Up to a 50% deposit is required to secure your booking on all major works, this is none refundable but can be transferred to a later booking date if required.*For large projects or conversions, this is slightly different. Parts are paid for upfront, and the labour payments will be broken down into segments. The final amount is to be paid upon completion of the job.*Please provide 48 hours notice if you require a rescheduled appointment.
No. 😊Sorry. 😉
Sometimes referred to as a ‘Large Street Port’ or an ‘Extend Port’, this is essentially a regular Street Port but with even more aggressive port timing.In an Extended Port, the ports are open for a longer duration which will cause the power band to climb up the rev range. In an RX-7 engine an Extended Street Port will begin to introduce the rotary’s, almost signature, rough idle, though it will not give a full ‘Brap’ effect at idle. In an RX-8, the idle is unaffected due to the staged intake. However, coupled with basic intake and exhaust modifications, the engine will be able to produce slightly more power in the higher part of the rev range, over a normal street port.Bridge-porting was developed in the 1970’s for racers who were banned in their various race-series from running a full peripheral engine port. Rules such as ‘Must retain original intake manifold’ were easy to add to a rule book, with the intention of sniping the then new-rotary engines initial successes. The design of the rotary engine prevents the engine builder from being able to extend the existing ports in either direction towards the e-shaft (or the housings) because of the oil seals and the necessity for a track used by the corner and apex seals of the rotor to run over. Early racers needed more port area without impacting on timing too much, and so they introduced an eyebrow port over the existing ports leaving a ‘bridge’ for the seals to run over, preventing them from falling into the port. This strip of metal was later coined the term ‘Bridge Port’.Introducing ‘the eyebrow’, means that at bottom dead-centre, both the exhaust port and eyebrow port are fully open resulting in an intake exhaust overlap, this overlap creates the rotary’s characteristic lumpy idle or ‘brap’, but as a side effect sacrifices low-end driveability and power in place of bigger gains higher up the rev range.Half-Bridge PortA ‘half-bridge’ refers to when only the secondary ports are bridged. By only cutting an eyebrow over the secondary ports, which remain closed at idle and low RPM’s, we avoid inducing overlap at low throttle positions and so can retain much of the drive-ability and power at lower RPM’s whilst still gaining some benefit from the extra port overlap at higher RPM.Note, that some rotary engines do not isolate the primary and secondary runners. And in these cases, the benefits of having a half-bridge over a full-bridge in terms of low RPM driveability are simply diminished.Full Bridge PortWhen cutting a Full Bridge Port an ‘eyebrow port’ is cut over all of the intake ports (primary, secondary and in six-port configurations, the auxiliary ports as well).This type of porting brings with it all of the benefits and short-falls of bridge porting; high RPM increases in power but poor drive-ability in the lower RPM ranges. The effects are much more dramatic in RX-7 and earlier engines, but still present in the RX-8’s Renesis Engines. Also with RX-7’s, idle speed must often be increased to as a much as 2000 RPM in order to develop a stable idle. Due to the Side Exhaust Port configuration on the Renesis Engine, the overlap quite minor by comparison, and the idle speed only requires slight elevation (1200 RPM just to idle, but 1500 RPM for a consistent brap). Note that these types of ports are strictly race only, and therefore engine longevity may be compromised. Using this type of port on a road-going vehicle will reduce low-end driveability in light duty driving. It affects emissions, and may not pass UK MOT test standards. Please carefully consider the purposes of your vehicle before opting for this type of porting.Semi-Peripheral PortThis type of port requires some careful machining into the Rotor Housings, and a means of sealing the new intake passage to prevent coolant ingress, usually by means of epoxy or resin. This creates a direct airway into the engine for a great homogenous charge of fuel and air. It is used in conjunction with your typical side port intake arrangements (where the intake ports are on the irons). The benefit of this is more intake opening area, without affecting timing. Almost equivalent to a high-lift cam on a piston engine. Although this type of port requires some clever fabrication of the intake manifold to accommodate it, the gains are quite significant, particularly in turbo or supercharged applications. Peripheral PortPerhaps the ultimate form of porting in the rotary world; the Peripheral port is a large intake area port provided directly from the housing. Much like the Semi-Peripheral Port, the housings are machined to provide a passage into the engine, and the passage is sealed within the water jacket. The side intake ports are no longer used, which means the intake charge from the intake manifold is unhindered. Coupled with the peripheral exhaust ports found on all previous generations of Mazda rotary engines, this allows for some major overlap, which is far more effective than any other port configuration. This is all-out motorsport porting, so there are some huge sacrifices to any drivability below 4,000 RPM. Peak torque is usually very close to the end of the rev range in naturally aspirated applications. Coupled with boost, you will find that there is a huge surge of power the higher the revs climb. It goes without saying, these ports will require the most work in terms of fabrication, and there are many sciences that will affect peak power as a naturally aspirated engine, from intake/exhaust runner length and design, injector placement, port timing and scavenging effect. These matter less with a turbo or supercharger, as the dynamics change quite significantly. The Peripheral Port is strictly for track use only, as it will never conform to emission standards, nor will it have particularly good road manners, fuel efficiency or reliability.
For the average customer we estimate turn around time to be 2-3 weeks for a standard rebuild, on the basis that the engine is in good serviceable condition upon inspection after the teardown.
Additional time is required for;
Porting
Machining/Balancing
Secondary parts orders (please note we are unable to know if there is any damage to the engine's internal component's until the it is removed, stripped and inspected.)
Tuning
Additional works while the vehicle is on the premises
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