Tuning su carbs book

I offer this comment based only upon contemplation of how they work. Nov 10, 2015 our moss tech hans deciphers the world of su carburetors. Su carb history su books available tuning and adjusting sus. If it lands with a clunk, the jet is correctly centered. The stromberg cd carburettor, like the su see adjusting an su carburettor, is a constantdepression carburettor, hence the cd. It is a process that when followed correctly does not normally require repeating. My car is a 1974 tr6 frame off restoration, engine modifications. Tuning and adjusting datsun 240z su carburetors zcarguide. Also check the level of oil in the dashpot the domed piston chamber at the top of the carburettor. Although i have stripped and overhauled many su carbs i have almost no su tuning experience.

I was surprised how easily the car started with no choke and the slow running screws had no effect whatsoever. Comments on su hs4 carburetor tuning did you find this article useful. While attending a jane su carburettor workshop, gary hagopian supervised us. Tuning of carbs is confined to correct idle settings 3. This book is out of print and shows up from time to time for over a hundred bucks. You will experience a huge increase of power, mileage, and less breakdowns. When someone says that they cant tune their sus i guarantee you that they mean they have set the idle and simply trusted that the needle was right throughout the driving range and it wasnt and no amount of tuning with that needle is going to make it right. It has some very clear explanations of the principles of operation and a lot of information on the various models. The following is a simple stepbystep guide for tuning your su carburetors using a different method from that usually suggested in the various books published by bmc, haynes, su or burlen fuel systems.

We are the worlds sole manufacturer of genuine su carburettors, fuel pumps and spares. The method listed below seems to work best for dual carb xks that i have worked on it is not cast in stone. It is the intention of this article to help clarify those principles in the hopes that many owners will be able to tune and maintain their su carburtetors. I think it was peter burgess that states in his book that there are more fuelling points on an su than in a fuel injection system. The fuel system of the mgb is adequately covered in the factory workshop manual, and the choice of carburetter needle and spring seems to be just about right.

Su carburetors have a minimal number of moving parts and are easy to tune, providing of course you understand the operational principles. The su carburettor high performance manual speedpro series hammill, des on. Setting hs4 carburetters comparison of two manuals by gerry threlfall ah workshop manual 1. Please message or ring for a pricewhy spend hundreds on a head, and not sort the carb and manifolds if you want the power to win you have to. The main reason that an su carb appears to go off tune is because the engine condition changes or there has been a change in the fuel used, maintenance is poor or the temptation to fiddle has not been resisted. Bre custom high performance engines and carburetors. While the same general tuneup principles apply to the type hs unit, detail differences exist which make the purchase of an s. Need help figuring out which skinner union su needles you need to keep your car running right in all throttle conditions. Nov 08, 2008 i approach su tuning from the point of view of an engineering understanding of what the carb is trying to achieve together with highly successful practical experience on an mgc 3ltr staight six. Make sure all components of the ignition system timing, plugs, points, and wires are properly adjusted and working well, and that the valves are adjusted to specification before trying to adjust the carburetors. I created my own pdf after someone sent me what i thought was a xerox of the actual book but is more than likely a printout of the more common pdf. Tuning the su carburettor on the tseries mg totally t. Su carburettors the su carburettor is a relatively simple design but has proved to be very effective.

Sep 18, 2007 watch john twist of university motors tune hif carbs. The trick to tuning su carbs is to understand that there are two things you need to get right. Rochester carburetors detailed instructions and 650 illustrations show you how to rebuild and tune your rochester carb. Thats the core of everything we do at book racing ent. Thats because, just like you, we live and breathe performance. It suggests to have a tuned piston needle damper assembly with a slimmed down needle, weakened spring and no oil in the damper which will have a very close performance to a weber but very heavy on fuel. Wayne knows what he is doing and he wont lead you up the garden path. Its the definitive guide to installing, calibrating and tuning weber carburettors. A few years back, a genius over at developed a handy charting and searching tool for just that purpose. Weber carburettors tuning tips and techniques by john. Bring operating temperature to the normal running temperature, turn off engine 2.

Leave a rating or a comment below, and get instant reply notification via email if you have a long question, or a question not directly related to this article, please start a new topic in the discussion forums. Had a look in the archives and found a link to tuning su carburetters by by speed sport motors so far i have followed the procedure including slackening off the throttle links to the two carbs. From stock small block engines to rwhp blowthrough carbs, from pump 98 to methanol and anything. Although it is not specific to the hitachi su carburetors seen in the 240z, the basic design is the same. Su s work on the principle that fuel is let into the engine in response to the level of suction in the inlet manifold. The other carb book covers 4 very different carbs and as a result has less information on the su. Most engine problems are caused by incorrect timing or points out of adjustment.

Details about su carburetters tuning tips manual carb carburetor su fuel pumps new book. It just goes to show that you shouldnt believe all you read especially on the interweb. Our moss tech hans deciphers the world of su carburetors. It can be a good way to get aquatinted with how su carbs work. Su carburetters tuning tips manual carb carburetor su fuel. One carburetor draws far more air than the other make sure the pistons are moving freely, and when dropped hit the bridge with a distinctive clank. Su carburettors featured a variable venturi controlled by a piston. Ztherapy 240z su carburetor spotters guide this is not a carb it is a boat anchor. Su carburettors are very simple to adjust, but please resist the temptation to fiddle with them unnecessarily. I cant recommend him highly enough for all your old school repairs, builds and carb tuning. If you have these carbs on your 240ztrash them and get ztherapy su s. Su carb mods for track days mgb tips mods and maintenance.

The b 20 b engine in the l20 and 140 models is fitted with two horizontal carburettors of type su hs 6. Su carbs modified to david vizard spec austin morris rover. How to make su carburetors perform almost as well as sidedraught webersdellortos. The su carburettor high performance manual speedpro series. Righthand steered 1800 cars are also fitted with this type of carburettor. Covers tuning tips and techniques for su carburetors as well as all su fuel pumps for numerous classic cars, including the mini cooper, sprite, bentley, jaguar etype, jaguar mk 2, daimler v8, land rover, mgb, rolls royce, tr4 and tr7, spitfire, rover and volvo 1800. These are great carburetors and so much easier to tune than webers. Mechanical or ignition problems will greatly complicate you tuning efforts and may make tuning the carburetors impossible.

Su carbs modified to david vizard spec austin morris rover if you would like a pair or a single su or triples modified to dv spec. Drawings, dimensions and part numbers of all emulsion tubes available. This book is extremely helpful in understanding the functional principles behind the su carburetor. Anyhow, this book is an excellent resource explaining how to tune your carbs, repair them, and how to get the most out of them. The often underrated su offers good versatility and reliability.

What is the correct amount to raise the piston, 120 book suggests 14, others. It is assumed that your carbs have been properly rebuilt and the jets centered. Follow the instructions in the tuning guide for establishing a base line, make sure linkage is loose and reset idles making sure that the fast idle screws are clear of the fast idle cam. The oil is there to slow the movement of the piston. Tuning your datsun 240z s su carburetors can be extremely tricky, but when armed with a proper understanding of their functionality, the right tools, and a little patience, you will be able to get them running smoothly and delivering the appropriate amount of power under all engine circumstances. Before attempting to install or tune your new carburetors you must make sure that all engine systems are in good repair. Tuning includes mixture adjustment, idle speed adjustment, and synchronization. How to balance su hs6 carbs and adjust the fuel mixture.

Ztherapy 240z su carburetor spotters guide this is not a carbit is a boat anchor. Instead, go study one or more of my posts on su rebuilding, starting with. It is essential, particularly where vehicles are equipped and tuned to comply with engine emission control regulations, that the carburetters are tuned in accordance with the vehicle manufacturers tuning data. All of these things can affect the setting of the carbs, which should be done last, if at all.

Do you have a question or comment about this article. Ok, this section is more about the upgrades than trying to help you set the carbs. Youll know how to identify and measure the size of your su. All of these things can affect the setting of the carbs, which should be done last, if. Someone set a needle specification from the factory maybe years ago. The su tuning tipstechniques book is the best of the three for learning how an su works. Performance carb tuning 149 callaway street, wangara 6065 rated 4. When you tune sus according to the book all you are doing is synching the air density between the two carburetors and then setting the idle mixture. The idiots guide to tuning su carburetters centering the jet first determine if your jets need centering. Su carburettors can theoretically perform better than modern computer controlled fuel systems.

Since the needle is tapered, as it rises and falls it opens and closes the opening in the jet, regulating the passage of fuel, so the. This is due the su being analogue and the vast array of needle profiles available. Tuning su carburettors speed sport motor books 1968 scribd. To do this, remove the piston dampers and the air cleaners, so you can access the pistons.

With this book, i was able to tune these carbs to very acceptable performance level. Slacken the actuating arms on the throttle spindle innerconnection. Identify the carburetor in your british classic car youtube. The author is an engineer and a professional race engine builder. A basic method of adjusting the air flow and fuel to a su carb. The su carburettor high performance manual speedpro. Classic car hub articles guide to setting up and tuning su. Anyone who runs twin su hif carbs and finds them tough to tune should have a read of this from barrie jones.

Now with your finger flip the piston up and let it fall back. Su carb the worlds sole manufacturer of genuine su parts. This book is for those people who wish to tune su carburetors themselves, irrespective of how many carburetors there are on the engine or what type of engine it is. Su carburetor tuning manual factory workshop manual for su carburetors and fuel pumps. The su meters fuel according to airflow by maintaining a constant vacuum over the jet by allowing the piston to rise or fall, and simultaneously working the lovely little tapered. Text is only available in english language lists thousands of weber part numbers by carburettor type. Nov 01, 2019 an interesting paragraph in the excellent book in the picture about tuning su carbs for the track. Oct 04, 2015 today i will discuss tuning of su carburetors. Su carburetters are the worlds sole manufacturer of genuine su carburettors, fuel pumps and spares. Before proceeding to synchronize your carburetors and for best results, some preparation is in order. Ive been meaning to write this up for some time, ever since i did the su performance tuning 101 a few months ago. Your carburetors should be in peak condition with no play in the throttle shaft bushings.

He throws in some zenithstromberg information as well. The aud xxxx numbers are the designations for the different components which can change. This piston has a tapered, conical metering rod usually referred to as a needle that fits inside an orifice jet which admits fuel into the airstream passing through the carburettor. This paper doesnt try to explain how to rebuild your carburetors, the manuals available on the market do a fairly good job of that. The book says unscrew the throttle adjustment screw to the stop or almost out, then turn down 34 of a turn. If your engine is not running correctly, always check your ignition system first of all as this is the problem in most cases. This one is more like basic su adjustment for happy driving. Carburetor books in order to reduce the download time, and hence the time that you spend waiting for all the data and images to download, we have reduced the maximum number of items per page to 24. Its an absolute must have for anyone continue reading. Tuning your carbs need help figuring out which skinner union su needles you need to keep your car running right in all throttle conditions. The two work in much the same way, but the stromberg differs in having an air valve commonly called the piston surrounded by a rubber diaphragm in the dashpot. Please use our product search boxes below to find your carburettor, fuel pump or spare part for your vehicle or have a look around our store to find a range of accessories to fill your needs.

If you own a vehicle with a carbureted engine and are looking for ways to save on maintenance and repairs, the carburetor repair manuals and guides available at the motor. Setting up and tuning su carburettors classic car hub. Tuning su carburettors speed sport motor books 1968 free download as pdf file. Its just a good book that will be irreplaceable for the old car fiddler. June1972 240z to all 260zs us flattop hitachi evil things, these square mouthed carbs. This can mean that the item that you are looking for is located on a next page. Its all about speed, speed that comes from performance. Instead, go study one or more of my posts on su rebuilding, starting. The size and type of a stromberg are given by numbers and letters. Tuning su carburetters including full needle charts triumph.

Comments on how to blow through an su did you find this article useful. We hope that this book will serve as a trusty guide to millions of motorists running cars with. Invaluable rebuild procedures for different types of sus. The b 20 b engine in the 1800 model and in cars intended for usa and canada is fitted with two horizontal. Complete guide to modifying sus for highperformance applications. Im assuming this was a typo and not what they actually do when tuning the carbs at cmc. Covers quadrajet, twobarrels, monojet, 4gc and computer controlled carbs with complete rebuild instructions, mixture settings, basic adjustments, tuning for street or strip and tips on manifolds and fuel systems.