Oil su carburetor
In the race carbs we run no oil in the SU carbs, we're not much concerned with idle to on throttle acceleration, once the car is on track it's never near a idle, most of time not even below 5000 rpms, however on the street, the weight of he oil controls how fast the piston rises, if the piston rises too quickly from idle to acceleration, you'll get a momentarly too lean condition, which normally results in a stumble in acceleration. They sell 2 types of oil – “SU Damper oil” which is straight SAE 20 monograde oil # BDR125S and “SU Dashpot oil” # BDP125S for pre-war SU’s without a damper ( SAE grade unspecified). The bottle shown in the test is labelled “SU Damper oil” so it should flow like any other SAE 20 at normal temperature – say 70 degrees Fahrenheit. In the middle of the suction piston there is a well with the "carb oil" in it, kinda like a water well. There is a smaller piston, for lack of the technical word, that hangs in the well on a rod that is attached to the black plastic caps you see on the outside top of the dome. As the suction piston rises the oil in the well is forced past The first is SU Damper Oil, which is a straight 20 grade and comes in a handy 125ml bottle. This oil is for use where the carburetter is fitted with a damper inside the piston and can be used on all SU, Zenith and CD carburetters. The second type is SU Dashpot Oil, which is for use in earlier, pre-war, The delay enriches the mixture briefly when the throttle is opened suddenly. SAE 20 engine oil is the correct grade to use when you top up. On older SU carburettors, which have a vent hole in the screw-in plastic top of the dashpot, the oil level should be i in. (13 mm) above the top of the piston tube. SU DAMPER OIL is a Mineral based oil containing anti-corrosion and anti-wear additives for the lubrication of pistons and dampers in SU and Stromberg carburettors. Application SU DAMPER OIL is suitable for post 1940 vehicles using SU and Stromberg carburettors incorporating a damper in the dashpot assembly. Su Carburetters are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares.
The delay enriches the mixture briefly when the throttle is opened suddenly. SAE 20 engine oil is the correct grade to use when you top up. On older SU carburettors, which have a vent hole in the screw-in plastic top of the dashpot, the oil level should be i in. (13 mm) above the top of the piston tube.
Wrong! The oil is for the purpose of dampening the open of the slides when the throttle is opened quickly. This effectively richens the mixture. It's the constant velocity carb equivalent of an accelerator pump. I'm not sure what weight oil belongs in them, to some degree its a matter of tuning. SU Carburetor butterfly closed When the engine speed is constant the air velocity (vacuum) past the jet is directly proportional to the volume of air passing between the bridge and piston, ie. piston height regulates the air speed over the jet, and piston height is proportional to engine vacuum. SU DAMPER OIL is a Mineral based oil containing anti-corrosion and anti-wear additives for the lubrication of pistons and dampers in SU and Stromberg carburettors. Application SU DAMPER OIL is suitable for post 1940 vehicles using SU and Stromberg carburettors incorporating a damper in the dashpot assembly. The damper assembly is attached to the cap and can be seen when the cap is removed. The SU carburettor is simple to strip. It has only one jet (except in a few special types) and very few moving parts. It is very reliable, but it can become dirty and choked — and some parts wear out. The most common type of SU is the HS. The HIF, overleaf, differs in some ways. They should be removed from the engine for cleaning. Su Carburetters are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares. Page 1 of 3 - Su Dashpot Oil Choice - posted in Problems, Questions and Technical: I am going to use an SU HIF 44 to fuel my 1380 engine when it,s rebuilt, i,ve read in various publications that a 5W type synthetic oil is best for the dashpot. I used some 5W 20 synthetic oil that i was given by my neighbour who has a motorbike and thought this would be alright. But a friend who used to race
oil type to top su carb Dedicated to You! The Classic Zcar Club is a not-for-profit group dedicated to the purpose of preserving the classic Datsun/Nissan Z and other similar cars from Japan. All information if free to browse and use for research purposes. We are here for the sole purpose of preserving restoration and drivability of classic
Reportedly, Hitachi licensed the SU design, but I have yet to see a reference for that (Nissan manual, etc). The lighter oils tend to run the carb on the lean side. Results 1 - 48 of 2431 GENUINE SU CARBURETTOR DASHPOT OIL 125ML CLASSIC MINI METRO CARB HS2 HS4 HIF 44. £8.60. + £11.13 postage · CRK254
No casting marks but is an SU HIF carburetor. Took carb off & apart, cleaned it up , left most settings the same, added damper oil to the top of the
Retailer of classic SU and Zenith carburetters, fuel pumps and components. Located in Salisbury, UK. SU Dashpot oil - manufactured for the specific application of SUs in STANDARD applications. That is on engines that are completely standard as the manufacturer produced them. It is a little on the thin side, but the whole engine tuning data for each engine is based on using this oil. In the race carbs we run no oil in the SU carbs, we're not much concerned with idle to on throttle acceleration, once the car is on track it's never near a idle, most of time not even below 5000 rpms, however on the street, the weight of he oil controls how fast the piston rises, if the piston rises too quickly from idle to acceleration, you'll get a momentarly too lean condition, which normally results in a stumble in acceleration. They sell 2 types of oil – “SU Damper oil” which is straight SAE 20 monograde oil # BDR125S and “SU Dashpot oil” # BDP125S for pre-war SU’s without a damper ( SAE grade unspecified). The bottle shown in the test is labelled “SU Damper oil” so it should flow like any other SAE 20 at normal temperature – say 70 degrees Fahrenheit.
Retailer of classic SU and Zenith carburetters, fuel pumps and components. Located in Salisbury, UK.
Su Carburetters are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares. SU Dashpot oil - manufactured for the specific application of SUs in STANDARD applications. That is on engines that are completely standard as the manufacturer produced them. It is a little on the thin side, but the whole engine tuning data for each engine is based on using this oil. oil type to top su carb Dedicated to You! The Classic Zcar Club is a not-for-profit group dedicated to the purpose of preserving the classic Datsun/Nissan Z and other similar cars from Japan. All information if free to browse and use for research purposes. We are here for the sole purpose of preserving restoration and drivability of classic SU Carb Dashpot Oil. The purpose of the SU damper is to retard the rapid upward movement of the piston on the rapid throttle opening associated with acceleration. This delay in piston movement causes a momentary decrease in pressure at the throat, thus achieving a momentary increase in richness much the same as with an accelerator pump. Wrong! The oil is for the purpose of dampening the open of the slides when the throttle is opened quickly. This effectively richens the mixture. It's the constant velocity carb equivalent of an accelerator pump. I'm not sure what weight oil belongs in them, to some degree its a matter of tuning. SU Carburetor butterfly closed When the engine speed is constant the air velocity (vacuum) past the jet is directly proportional to the volume of air passing between the bridge and piston, ie. piston height regulates the air speed over the jet, and piston height is proportional to engine vacuum.
SU DAMPER OIL is a Mineral based oil containing anti-corrosion and anti-wear additives for the lubrication of pistons and dampers in SU and Stromberg carburettors. Application SU DAMPER OIL is suitable for post 1940 vehicles using SU and Stromberg carburettors incorporating a damper in the dashpot assembly. Su Carburetters are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares.