This RRD COMPETITION crankshaft is a long stroke model, the only electronic cone to be released for Peugeot 103, not to be confused with long connecting rods, the stroke represents the stroke of the piston, if we offset the crank pin by 1.5mm this offers 3mm extra stroke, as an example:
Ø46mm kit in 39.1mm stroke (original) = real 64.98cc
Ø46mm kit in 42.1mm RRD stroke (this crankshaft) = actual 69.96cc
PARMAKIT Ø50mm kit in 39.1mm stroke (original) = real 76.77cc
PARMAKIT Ø50mm kit 42.1mm RRD stroke (this crankshaft) = real 82.66cc
This crankshaft therefore offers additional cubic centimeters of displacement, an enormous gain in torque, while bringing you closer to the so-called "square" engine with your large kits! This model is intended for large kits. The connecting rod remains original size (76mm), it is not impossible that in the future we will release a long stroke version / long connecting rod fitted with an 86mm connecting rod. This crankshaft is cut in the best special case-hardened steels and has undergone 3 treatments, case-hardening.
This very high quality crankshaft has been fully studied, designed and tested in our workshops. It is made of high-end materials in Europe. This crankshaft offers many advantages:
-Course increased to 42.1mm instead of 39.1mm, which offers an increase in displacement, the race also makes it possible to approach again the square race (46X42.1) and to have better behavior engine in relation to a base race 39.1.
-Specific crankshaft balancing for the average piston weights of large kits, calculated on an average MALOSSI / POLINI / AIRSAL ...
- Ultra reinforced connecting rod placed on a 16mm diameter crank pin, ultra reinforced head and foot cage, improved head lubrication.
-On some housings, it may be necessary to mill lightly or to pass a blow of abrasive roller type DREMEL for the passage of the small end. A distance of 0.5mm is required between the crankcase and the big end as a precaution.
* Mandatory milling on MALOSSI housings (band to pass the head)
* Mandatory milling on POLINI housings (band to pass the head)
- The price has been lowered for small, limited quantities, with a very high quality of materials and workmanship!
-Cage of connecting rods in 12X16X16mm
The 3mm increase in stroke will require you to use a base shim of around 1.5mm), we sell 1.0mm shims with an original type base, to be aligned with your engine transfers. Next, play with your base gaskets to obtain the desired compression ratio (also to be defined according to your diagrams). The PMB piston goes down an additional 1.5mm, ideally you will align your lights to the PMB. Attention, do not use this crankshaft with a kit already prepared with very large diagrams on a normal race, the diagrams would end up being too high ... We recommend at most, diagrams of 196 / 133. Attention, check that the piston closes the exhaust port by at least 0.5mm at top dead center (TDC). On some kits, it is possible that the piston does not close the light. It will not adapt over a long run! Originally, the ignition of the electronic 103 is set at 0.9mm before TDC. You can put 1.1mm to 1.2mm ahead of this long stroke (on a normal stroke, you can go up to 1.3 to 1.4mm before TDC).
Attention for the Ø50mm PARMAKIT kit it is necessary to change the piston and to start for example on the top performance Ø50mm TPR (also exists in ITALKIT for TPR AM6 50mm kit) because the exhaust port is not blocked at top dead center. In addition, the cylinder head must be reworked to respect the angle of the piston head, etc ...
Compression Ratio : Once you have aligned your cylinder to the PMB and with proper diagrams ... Machine your cylinder head so that you have a nice compression ratio. On air cooled engine, we recommend a squish of 1.00mm with a compression ratio of 12 to 12.6: 1 MAXIMUM. On liquid cooled engine with pump, a 0.6mm squish can be used with a compression ratio of 14 to 14.5: 1. On a 50mm diameter air cooled parmakit with our long stroke, we will recommend a chamber volume included. between 7.5ml and 7.2mm. On a Ø46mm kit, we recommend instead between 6.3ml and 6.08ml for air cooling or between 5.38ml and 5.18ml for liquid cooling!
