Beware of production variations of L18 engines!...1974 Datsun 160J SSS KP710 Violet Turbo

According to popular performance books "How to Modify Your Nissan/Datsun OHC Engine by Honsowetz" and "How to Hotrod & Race Your Datsun by Bob Waar" the L18 stock crankshafts should have "more" counterweighting than say the stock L16 crankshaft.

Beware that the info in these two books may not apply to engines fitted to cars destined for other parts of the world or engine made from casting plants in other parts of the world.

Figure 1
Courtesy of Google Images.
Left crank is not fully counterweighted. Right crank has "more" counterweights although some would call it "fully".

What the books meant was that the extra lump of steel added was not the full taper or pear shaped lumps and therefore called "more" counterweight. The factory option crank of both the L16 and the L18 are said to be "fully" counterweighted meaning eight pieces of tapered or pear shaped lumps of counterweights.

The L20B crank seems to come stock with "more" counterweights also. I have never seen a so called "factory option" crank as described by the books for L-series 4 cylinders engines which are said to be "fully" counterweighted.

Figure 2
Courtesy of Google Images.
Crank regarded to have full counterweights. Each piece similar in shape. This looks like a billet crank.

However, my newly arrived used L18 engine had a crankshaft similar to the stock L16 crankshaft's counterweights. It was neither "more" nor "fully" counterweighted. There was a total of four lumps instead of eight. Unheard of? This came from a fuel injected engine. I was not so surprised as production differences do occur depending on model and year of production. Perhaps the magical number for an L18 crank to have eight counterweights is the casting number stamped on the crank. It should read A8740. I need to confirm this myself!

My LZ18 competition crank from 1974 only had "more" counterweights :-). I do have a later model LZ18 of which I will recheck the crank to make another post!

My lesson learnt from the last few days. Always open up the crankcase pan to check the crank before buying to be sure. Also my engine had a punctured crankcase and rust had taken over the inside! I was fortunate to be able to return the engine to seller in this instance!

Delivery of a stock used Nissan/Datsun L18 engine...1974 Datsun 160J SSS KP710 Violet Turbo

It's a beautiful Saturday morning. Yesterday the used Nissan L18 engine arrived. I had gone to several used car parts yards before finding this unit. It was a private sale unit as it belonged to one of the shop owners. My conclusion was that the L18 is quite rare today in 2014 in this city of mine here in Malaysia.

My reason for buying another used L18 engine was that it actually shares the world famous L18 block and crank forging with the LZ18. Yes, but the L18 fully counterweighted(some would say,"more counterweighted" instead of full) crankshaft only has five smaller flywheel bolt holes. I plan to dowel the flywheel to the crank and find suitable ARP flywheel bolts for it.

I may even rebuild back my LZ18 with this crankshaft suitably balanced in Kuala Lumpur. It's a contingency plan I have :-).

Also, on another note, coffeeshop friends have told me that a machining shop was reputed to have stock of many of these L18 crankshafts. The shop attendant's reply was that they would call me back when they have located the right crank in their warehouse.

Power and torque specs Part 2 of the 1974 Datsun 160J SSS KP710 Violet Turbo

A thought experiment...

I had earlier mentioned the power and torque figures of the Datsun Violet Turbo as published by Nichimo in one of their 1/24 scale model of the car (The yellow coloured Datsun Violet Turbo).

A measly 300 p.s. at 7600 rpm and 231 foot pounds (32 kg.m) torque at 5600rpm by 2014 standards?

In 1974 this was state of the art running a non-intercooled turbocharger configuration.

I read further that boost with available petrol then was an invariably low figure of 0.9 kg/cm² or about 13 pounds per square inch (psi). I am reminded that Nissan did actually release a production FJ20ET that was non-intercooled initially boosting only 6-7 psi.

I am very pleased with the above figures. Why?

• I love the fact that this engine produces maximum power at a relatively low maximum rpm.
• Cam timing (to be mapped out later) would, I believe, be of mild road rally style type duration with very reasonable idle characteristics.
• This LZ18 could in 2015 be turned into a good mid-range torquey engine.
• Longer lasting/wearing
• Less cam gear float/wear problems
• L18 stroke is a good low figure of 78mm that would stress this engine minimally.

LZ14s and LZ18s of the normally aspirated versions were very high revving engines and there is an inevitable cost to this. Check the valve gear/cam train often for trouble. I've actually magnaflux checked another later model LZ18's valve train and seen cracks develop across the top of the valve buckets! This LZ18 surpasses 10,000rpm uncontrollably in 1st gear. So now I'm happy with a 7600rpm LZ18 :-).

Late model mods I am considering:

• In 2015, I would replace head bolts with available ARP 200,000 psi items.
• Replace injectors with late model 700 cc or slightly larger type.
• One could custom made high silicone forged pistons for it but I've already got old style Cosworth forged pistons made and bore honed to match with Australia's Argo H beam steel rods ready to work. Piston bore is at 89mm. LZ18s are actually 2-litres in capacity.
• Replace efi to late model speed density with intake air temp/variable fuel pressure.
• Turbocharger could easily be optimised with a Borg-Warner EFR 6258 series unit or a Garrett GTX3071R
• Intercooler
• Late model CDI ignition
• Fuel and ignition via programmable ecu.
• Data-logging of many engine parameters

Power and torque to expect:(This is still a thought experiment)

300-380 ps at 7500rpm

231-380 foot pounds torque at 5500rpm

Max. boost of say 0.9-1.5 bar

The rarity of the L-series 4-cylinder engines in 2014...1974 Datsun 160J SSS KP710 Violet Turbo

My rebuild of the LZ18 awaits for my crankshaft repair work to be completed.

I had a thought.

Wow! It's been a long time since I had gone to survey the used car engines shops/yards in my city the old fashion way. Yup, park your car and walk through the masses of engines. Of course it was a fun thing to do every now and then.

A lonely 6-cylinder L-series...not what I was looking for.

This year, 2014, it was very quiet at these places. I had decided to check out if there were any more Nissan/Datsun L18s left from the 1970s to the 1980s since eBay seemed not to have a single complete long block, short block or even a crankshaft listed as of now!

At one of the used engine yards, this being a big one, there were no L18s but I found these...

An L13...

Another L13...slight valve cover differences...

And an L14...

And that was it...

6-cylinder L-series there were still a couple here and there but no L18 4-cylinders.

I did manage to finally find a complete fuel injected L18 at a different yard and only so because it belonged to the owner who had transplanted a different engine into his car. He kept it under the stairs for some reason and was in very good running conditions and stock, according to him. I will make another post of that engine when I've had it delivered.

My conclusion was that Nissan/Datsun L18 engines are pretty rare nowadays! There were tons of them in the 90s but not now in 2014. I could be wrong but this was so in this part of the world here in Malaysia. I had wanted another L18 engine because it sports a fully-counterweighted(some would say "more counterweighted"....another post on this one day!) crank that I could use in my LZ18 despite the 5 bolt flywheel (Could be dowelled). Also the L18 engine block could double as a spare block. The other reason was in preparation for a possible new OS Giken TC16-C1 kit.

Reference this link: OS Giken's TC16-C1 for L-series 4-cylinders 2014

The other 2-litre L20B on the other hand was one engine that never came into Malaysia in the used engines yard. One reason I believe was that they were as rare in Japan and were perhaps made overseas and meant for the U.S.A and Australian markets. So Japanese used engines importers never really brought in any L20Bs into Malaysia. Although Nissan also makes the rare LZ20B racing engines in the 80s, retrofitting an LZ18 head to the LZ20B may be quite involved due to the different deck height. The LZ20B may have some extra height in the gear mechanism housing to cater for that and I'll not dwell on that now.

Cheerios!

Engine details Part 8: Larger pics of engine dismantling 20th Nov'14 of 1974 Datsun 160J SSS KP710 Violet Turbo

As per my last post, larger pics from now on...no more collages :-)

How I packed the crankshaft for shipping...1974 Datsun 160J SSS KP710 Violet Turbo

Thinking of an environmentally friendly way, I went to my local plumber store and got these...

a portion of 21.5 inches long pvc 6-inch diameter stormwater drainage pipe with end caps after measuring the width and length of the crankshaft to be about 5.5inch and 21 inch respectively...

Oil the crank...spread all over the surface where possible...

Next to cling wrap the entire crank with your kitchen's favourite wrap...

Now to roll the crank up length-wise with some more cardboard to take the slack in the cylinder...

After a good somewhat firm fit is achieved, slot the entire cylinder down and cut two pieces of foam and buffer each end...

Cap both ends and all is left is to tape it up good with some good tape...I need to buy some!

Next to find a good sturdy rectangular cardboard box that will house this cylinder and fill up spaces with newspaper or any other lightweight filler material.

I must remember to write address of sender and addressee with details of the proposed work on a piece of note to be attached on the cylinder before packing it up and heading to my favourite courier agent. Cheers!

Engine details Part 7: Larger pics of engine dismantling 19th Nov'14 of 1974 Datsun 160J SSS KP710 Violet Turbo

Hmmm...I realised that my earlier collaged pictures of engine dismantling could be difficult to view...also they were taken with my phone camera and quality is not the best in slightly darker light of the workshop. So I present here the full individual pics (longest side 2048 pixels):