If you can help with an LZ duplex timing chain please email me at datrats@aapt.net.au. This is all I need to start putting my LZ together.
MY LZ PROJECT PARTS ARE LOCATED AT THE BOTTOM OF THE PAGE.
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NISSAN LZ ENGINES LZ Engine Development Datsun LZ twin cam heads were developed in the power hungry, early 1970's. The LZ head was designed to give a power boost to the tried, tested and incredibly successful Datsun L series engines. The obvious way to increase output of the very strong L series bottom end was to improve its breathing.
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By taking information gained from racing the very successful S20 twin cam engine used in Skylines and Z cars, Datsun engineers designed the LZ twin cam 16 valve head. As with the S20 design the engine had two camshafts and four valves per cylinder. The included combustion chamber valve angles were quite shallow. This helps to minimise gas flow interference and allow high lifts to be used at large valve overlap periods.
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LZ18 1/4 VIEW
TS210 LZ14 Sunny GX 5. It is shown as a concept car at the 20th Tokyo motor show in October 1973. The vehicle weight is 830kg and powered by an LZ14 DOHC of 1428cc. The engine made 200 PS and would push the car to 230 kph.
Regrettably, Nissan marketing messed this opportunity up. They opted to push for the Silvia (S10) rotary engine model. The S10 was an uninspiring failure, and died rapidly from lack of interest. The sunny excellent is still a cult car today.
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The LZ engine was to form the basis of legends in many forms of motor sports, due to its superior design and versatility. Using the L series bottom end, allowed it to be used in so many different capacity variations. Crankshaft strokes available for different variations of the L and Z series engines that could be used with the LZ head are : - 59.9 mm L13, 66 mm L14, 73.7 mm L16, 78 mm L18, 86 mm L20B, 89mm Z22, 92 mm Z24. Bore sizes can be varied from 83 mm to 90 mm. This allowed the engine to be raced in most capacity categories including : -
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| The Sunny Excellent LZ engined race car was raced in 1428, 1600 and 1770 cc capacities in Japan during 1973 through to 1978. |
The PB110 L twin cam 4V mechanical EFI engine
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The first time the engines were used in Australia, were in the 710SSS cars used in the Southern cross rally of 1975.
"In a concerted bid to win the rally away from Mitsubishi the Nissan team returned at full strength for the 1975 event. They had a team of three 710's for Aaltonen, Kallstrom and Fury. By the end of the second night all three had retired with engine failure" Text taken from http://www.amsag.com.au/amsag/cross.htm
Apparently the cars failed due to a new design of con rod bolt that was not up to the punishment. With typical Datsun engineering dedication, the engines were taken back to Japan and improved for 1976.
"The 710 made another appearance the following year and saw a ding-dong battle for outright honours between Fury and Scot Andrew Cowan. Fury led for three days and was equal with Cowan on the final day when the Datsun's differential broke not far from the finish. 'Third time lucky' wasn't part of the script in 1977. Again in a 710 Violet, George was third for most of the event and was attacking for the lead behind Aaltonen and Kallstrom, but on the very last stage of the final day, he rolled out of the event and out of the placing's. It was a bitter pill to swallow after such a dogged drive." Taken from "Rally sport news "issue 4 published 11/5/2002. http://www.rallysportnews.com.au/cms/A_20201/article.html |
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710 on the Isle of man? Click to enlarge
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In European rallying, the 710 was also used and had some considerable success in events like the Acropolis rally and 1000 lakes in Finland.. |
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The LZ engine was gradually used in more areas of motor sports and gave good performance in every application. The performance advantage was largely due to its valve train design, that allowed it to rev very freely. The car on the left is an FP Falcon chassis with LZ14 from the 1978 Formula Pacific series. Formula Pacific was the Asian equivalent of the international 1600cc Formula Atlantic that was in in operation in 1977. At that time (for Formula Pacific) common regulations were drawn up by countries in the Pacific area, including Japan, Macao, New Zealand, Australia, Canada and USA. In LZ14 Formula Pacific form, the engine made a conservative 205ps @ 10200 rpm in endurance form. Higher figures of approximately 240PS @ 11000 rpm were achieved in actual use for qualifying and non endurance events. This naturally aspirated engine had a 66 mm stroke and 87.8 mm bore. This configuration gave a very conservative piston speed at the rated output.
In the 1978 Formula Pacific season, the engine dominated and filled the six top positions for the formula in 1978. http://fndc.hp.infoseek.co.jp/1978JFP.htm The Formula Pacific series finished up in 1982 as result of logistical problems resulting from having to move the cars to each of the member nations. The idea was also helped along the way to an early death by "the total domination of NISSAN LZ14 and Toyota 2TG engines" appearing in the top positions each race. http://www.oldracingcars.com/results/racelist.asp?CategoryID=JP The series was "side stepped" and ended in 1982 and replaced with F2 due to small fields. |
| Shekar Meta also gained two of his five African "Safari" rally wins in Violet GT's powered by LZ group 4 engines. |
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The LZ20B turbo engine was also used in the "March" Le Mans cars
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In Japan, there are three LZ engined "special" cars that are remembered with much affection. These cars used the LZ20BT turbocharged engine.
First is the Diet Coke/Canon Bluebird. (I am trying to find out more about this car)
Second is the "White Lightning" S12 Silvia coupe driven by Kazuyoshi Hoshino. This car had 500 ps @ 8000rpm. Hoshino inspired a generation of Japanese Motorsport fans with his brave and very talented driving style. Hoshino drove in Australia at the 1982 Bathurst James Hardie 1000 with Masahiro Hasemani and came a credible eighth in the single cam Z18T powered Nissan Bluebird taking out first in class B that year.
Third is the Tomica/GTR works Skyline R30 car driven by Hiro. In this vehicle the LZ engine produced 570PS at 8000 rpm in the "Car that makes long flames " This was the works car prior to the iron mask FJ20T vehicles.
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'83
NISSAN SILVIA
S12 Group 5 Number 23
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Australian rallying saw the famous Portman Bluebird that was also powered by a large capacity LZ engine. |
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In Victorian (Australia) state series sports sedans, Barry Bray's Gazelle has been on the track since the mid 1980's? and is powered by an LZ20B turbo. This car still keeps the top Victorian Sports sedans honest today! |
With thanks to the Australian sports sedan site
and Justin Maher |
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This LZ20B was used with much success in the Australian "Under 2 Litre Sports sedan" series in the mid 1990's Click to enlarge
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In Victoria a Datsun 510 sedan ran in the "Under 2 litre sports sedans" series in the mid 1990's. This car was devastating to the opposition and dominated the series in the time it was competing. |
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LZ CONSTRUCTION The LZ engine uses a conventional L series block. The LZ cam drive mechanism is sandwiched between the timing cover and the block. The head timing case cavity has a 5mm lengthened front section to cater for the drive thickness. The main differences between an LR20B (Nissan terminology for the conventional two valve engine) and the group 4 A10 LZ20B are shown in the tables beside. |
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click to enlarge |
Early engines had cam gear
bearing problems and the bearings required changing frequently. Better
quality bearings reduced this problem.
In the pictures left the taller gear set if for L20B and the shorter one for LZ14, LZ16 or LZ18 engines
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| Camshaft drive starts with a slide on gear
on the crankshaft that meshes with the lowest gear in the cam drive
assembly. The assembly gears are mounted in an alloy frame that
bolts to the front of the block between the timing cover and block. At the top of the gear drive a duplex
chain sprocket is used to drive the short cam chain and camshaft
sprockets. Chain tension is by regulated by an external adjuster.
The duplex chain drive for the two camshafts has a unique pitch and roller diameter. I have been unable to obtain any of this chain after 3 months of hard searching. The alternative to the original drive system appears to be manufacture of a new drive with half speed idler gear then manufacture two cam sprocket to suit more commonly available chain. |
Diagrams and tables above are from the Datsun A10 competition tune up manual published by Nissan export service department. click to enlarge |
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click to enlarge |
One major visible external difference between
conventional L series and the LZ engines is the cylinder head.
It is often thought that the L14 and L18 twin cam series of engines use OS GIKEN twin cam heads. This is not so. The OS head (as shown left) has the inlet and exhaust on opposite sides and use different design combustion chambers and ports. The cam boxes do look similar. The exhaust ports exit straight from the head face the same as the early LZ heads. Later LZ heads exhausts are upswept. The OS head is also an excellent twin cam for the L Series bottom end, but the high price of the kit limited the amount of these beautifully hand made cylinder heads that were sold.. |
| The LZ is most commonly
mistaken for the FJ family of engines.
The FJ24 engine used in the S110 240RS rally car. This engine was completely different to the LZ, although it could be argued it was a design evolution from the LZ. There are common components including valves. |
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click to enlarge
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There appears to be three generations of the
LZ cylinder head made over approximately a 15 year period. The first engine
to use the head was referred to as the L14 twin cam. There was no mention
of Z in the title.
This engine was used in the 1973 Sunny Excellent as shown in the pictures left.
The Excellent twin cam was used in the 1973 Fuji raceway (6 hour
race) driven by Kitano. Thanks to the Pitroad site for this picture http://www.pitroad-ts.com/tuning-page/tuning-5.htm.
The Pitroad site is an excellent site for A and L series engine history
and parts.
This engine had flat exit side exhaust ports, the early 12 bolt rocker cover and the coolant discharge on the inlet side of the head. All early twin cam engines appear to have the 14 bolt rocker cover (6 for the cover and 8 for the bolt in plug holders). Later engines use the full flat cover with six bolts to secure it. The engines in both pictures have an early mechanical fuel injection system (base components were Lucas? or Kugelfischer from 2002 Tii BMW). Also of interest is the Mikuni flat slide throttle body. This system was also used on the Datsun A12 factory race engines of the day. The lower picture is again a 12 bolt rocker engine showing the flat exhaust ports of the early engine and the coolant rail on the inlet side. I think this may also be the same type of B110 Sunny Excellent engine or maybe an early 710SSS. |
| The picture on the right is of an early
carburettor twin cam L engine, again with the 14 bolt rocker cover and
coolant pipe on the inlet side.
This photo is credited as the engine being used in the A10 Violet GT in the 81 Safari Rally. If correct, this is unusual as by this stage the six bolt flat rocker cover head engine was being used. Maybe this older 710 Violet engine was dragged out at the last moment? If anyone has information on this could they please mail me to help sort it out! datrats@aapt.net.au Regardless of model application this is an excellent example of the L series twin cam engine. Check the exhaust headers! This engine appears to have the earlier flat exhaust ports. The extractors are curled up in the engine bay to give a longer primary, while remaining protected rather than being exposed under the vehicle. A very nice package. |
picture thanks to http://www.datsunhistory.com/home.html
click to enlarge Note! Michael Stanborough pointed out the bonnet hinge design suggest this is a 710 LZ not an A10.
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click to enlarge
THIS LZ20B GROUP4 IS IN THE NISSAN ENGINE MUSEUM
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The second version of the L series twin cam
became the LZ This engine had revised port designs and coolant
flow path. Valve sizes are 2 x 33 mm inlet and 2 x 29.5 mm exhaust.
Inlet ports were angled to give the best possible path into the combustion chamber and the exhaust were made the same way to give the best exit for the exhaust gases. Both inlet and exhaust systems have a cast flange surface for connection of the manifolds. When the engines are run with carburettors they use a 300 angled inlet manifold as an interface to this mounting surface. When run with injection the inlet tract is run straight of the mount. Engine coolant was routed out of the head casting into the external coolant gallery. Early engines had the coolant exiting on the inlet side of the head and on later engine from the exhaust side. The later version has the coolant passing the exhaust valve guides to provide extra cooling and increased exhaust valve reliability. The 6 bolt rocker cover was introduced on later post 1977 engines. The covers came in blue, red, green and black. I have been told there is a colour coding system used to determine colour of rocker cover. If you can confirm this from any literature please mail me. |
| The third evolution of
the LZ head was developed for the LZ20B
turbo.
This head apparently has larger valves again and larger port castings. This is the head used in the RS skyline turbo and the March 83G Lemans cars. These engines had the dark anodised (Black) TURBO rocker cover. I am currently searching for more information on this engine in its final evolution.
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MARCH 83G with LZ 21T engine from 1985 LeMans
MARCH 85G with LZ 21T engine from 1986 Le Mans click to enlarge |
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The bottom end of the engines use L or Z
series blocks with the crank, pistons, and rods used decided by the
application. There is such a wide variety of engine parts used in the L
series engine through the years that a choice of suitable components from
a range of engine models is possible.
Some examples of engine components used are the Nismo 8 bolt flywheel crankshafts. These were available for a range of stroke sizes, Titanium or high strength steel connecting rods (Cosworth?) were options, and a range of forged pistons. The LZ14 formula pacific engines and some others are fitted with 6Al4V titanium connecting rods to reduce reciprocating mass and inertial loads. An LZ titanium rod is shown left top and a steel competition (Cosworth?) rod below. Both rods use multi point aircraft style bolts with lock washers and have dowelled caps
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LZ head with Motec T/B's |
LZ head with Motec T/B's |
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Tuned length extractor exhaust with 2" primaries and hand made collector |
214N stainless valves in new seats |
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New guides with K-line inserts are fitted. Head has been rehardened to T6 |
The gear drive to the camshafts |
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Assembled L20B gear drive cover. |
The turbo engine uses lower comp pistons but is identical in all areas apart from the rocker cover. These engines made 500 hp in race trim in Silhouette class cars in Japan and also the Le-Mans cars. |
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Well we have been busy and found some more bits for the LZ project, an alloy LZ20B dry sump and ancillaries. Some maintenance work needs to be done on the windage tray. With a bit of cleaning it will be like new.
You can see two suction tube strainers for the scavenge stages of the dry sump pump.
Above the strainers is a baffle plate to keep oil around the scavenge pickup filters.
Above the scavenge baffle is a two stage windage tray
Scraper reliefs in the windage tray, allow the oil to pass through two levels of tray to the baffle below.
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As part of the deal I also purchased an option part dry sump oil
reservoir. These reservoirs were used in a number of works
cars. The reservoir contains 5 litres of oil for the dry sump lubrication system.
Inside the reservoir there are a series of mesh screens in layers to seperate any air from frothy oil. Notice the classy click locking lid on the filler cap :) |
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And finally the Tsubakimoto (dual scavenge stage and single pressure stage) dry sump pump and mounting bracket. Its gradually coming together. |
A NISSAN SPORT PARTS MANUAL FOR FORMULA PACIFIC AND LZ18 4V &LZ20B-4V ENGINES
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