Rat-a-tat-Dat

Double checked the measurements with another micrometer and found the first instrument readings were out. Thanks! All parameters are within rated specifications. No need for machining or boring. Phew! Now to order the standard replacement parts. Although if I do order, tell them it's for an L20B and everything will be fine? Grateful for your knowledge.

Here's a twist in the panties with Datsun/Nissan transitioning back in the day. My very first post indicated that I had a 1979/1980 vehicle. Ever since then identifying parts, especially when the appropriate year mattered, became contentious. Another example of that fact is the Haynes manual I possess does in fact cover 1980 thru 1997 pick-ups and pathfinders. Unfortunately, those specs are exclusive for the engine. The memory forgets these small details and neglects to focus on the obvious. Hence, a search for the proper year of corresponding text and specifications are necessary for my dilemma. It pays to have a little foresight and in doing so I had managed to acquire a 'Chilton's' repair and tune up guide a while ago when purchasing other needed parts ( let's just say my library is a little messy, lol ).This book covers 1970 thru 1984 US and Canadian models of L16, L18, L20B, Z22, Z24 and SD22 & SD25 engines. So, with that, I'm definitely on the right path and will knowingly focus on these earlier engine criteria's when ordering replacement parts. It still need the experience of anyone who can verify if the con rod diameter requires standard or oversized bearings. Appreciate you all, thanks.

I finally had time to remove the engine and tear it down. Checked and recorded all the necessary items for referral and came across a couple of interesting things. One, looks like the main journal readings are not the same or for that matter even close to the book. According to the 'Haynes' specifications for an L20B it varies between 2.1631" to 2.1636". My measurement reveals a 2.368" micrometer reading. Can someone check this out for me please, and confirm what should be correct, thanks. Two, the connecting rod journal diameter should be (Haynes) 1.9670" to 1.9675" and I come up with 1.9647" so does this means it's been already machined? As for the block, the cylinder bores are 3.346" across the board, top to bottom with maybe a 0.001" variance. Piston ring grooves check out with no signs of fatigue anywhere. The thrust sides have minimal wear and wrist pins are pristine. Appreciate any feed back, thanks.

Can you elaborate on what "Ring selection dictates what cylinder finish you hone to" means? If I have a block and its cylinders are within 85mm to 85.050mm, wouldn't I just need a standard ring set? Thanks

Removed cylinder head and found very little tell tale signs of cause. wtf? The area in question had the usual soft spot and bypass on gasket but cannot find the reason behind it. Possibly a weak head bolt, stretching? Will clean up the block surface and straight edge for unevenness. The head too, of course. Found a little wear ( scoring in number three pocket ) but within specs., 3.345" If I were to replace the pistons, say with flat tops and bore each hole 0.010" over, is there going to be any issues moving forward? Should I keep the old pistons? How much can I get away with? What will work in a L20B with a W58 peanut head? Previous pistons are slightly dished but I'm not sure about the flat tops, especially for valve movement. Don't want piston slap. I'm doing the bottom end at this stage of the game, it just makes sense. Thanks ya'll.

The sad part about this experience, it's the second time I'm repairing this motor for a head gasket issue. In the beginning; I tore the head off, removed the existing exhaust port liners, sand blocked the head, ported intakes and exhausts, new valve guides, new valves, new springs, timing chain set and related items. The block itself was within tolerance specs. and I did a mild scrub around the cylinder bore themselves ( took away the lip ). After which the assembly followed. Some other mod's continued as to help with improved engine performance, attached peripherally in nature. I did not dive into the bowels of the engine, nor needed too at the time. Internal components felt tight and without any visual concern. A satisfactory Bill of Health. As I try to stay positive, the outcome of Helios is wavering to be a complete reconstruction and upgrade. I thought about a transplant but there is no need to overcompensate his abilities. Perhaps refreshing some internals and/or adding a larger lung capacity my be all he needs to perform slightly better. I'm interested in all ideas that may help but without going extreme, if you know what I mean. Cheers.

Great! thanks. For those reading this, I have continued my conversation on my Datto Project. Cheers

Well, I thoroughly enjoyed Helios this summer. Lots of driving, with not too many hiccups, was bliss. The occasional mishap happened with a no start but sorted that out as an ignition issue, a poor connection at the matchbox terminal. The climate here, I found, compared to where I was before seems to be more humid and harsher on electronic connections. It wasn't until the late fall heading home, just before I bedded down Helios for the winter, that he made a loud unhappy noise. Not even a kilometre from home the engine temperature gauge max'd out and all I could do was baby him home, making sure the movement of air would keep the temps down just long enough. Eureka! home at last. Stopping and looking behind me my eyes followed a trail of coolant showing where I had come from. I didn't like the looks of this past. After opening the hood and letting the steam out, I proceeded to investigate our dilemma. At first I was hoping it was just a coolant leak coming from an old deteriorated hose. Not so lucky, a second closer look indicated otherwise and pointed to the cylinder head gasket. Oh dear! I let Helios rest and later feed him four litres of refreshment prior to leading him to the stall.

I don't want to high jack this thread and go on about my issues so should I start a new thread or just add my questions to my existing project?

Bystander question, curious to know if these L20B engines are prone to head gasket failures? I'm on my second since procuring this vehicle.

I'd like to be in the reserve if this thing flys again. P&T. Put me down for two. Much appreciated.

So, the worst possible dilemma occurred all because I trusted a guy whom happened to own a Datsun 510 truck. Albeit he was going to restore the vehicle and had a collection of parts to install, but who are I kindling, right? I am the one that happened along and spotted these rims in the back of his truck during a walk through a neighbourhood. I am the one who insisted on buying these rims. So naturally, I am the one to take full responsibility. For all you Datsunites and followers, never take for granted any parts that are NOT attached to a vehicle. Measure and double check all your specifications regarding proper fitment to the vehicle those said parts are going to be attached to. Case in point, I picked up these rims and imagined 'they' would look real good on my Datsun truck. Even though 'they' had been IN not ON a Datsun truck and 'they' also had the 6 stud holes matching the description of a Datsun rim. This doesn't necessarily mean they will be a perfect swap over. I found out the hard way, meaning, I bought new rubber for these cleaned up and polished rims, dismounted all four existing tires, swapped over the old to new shoes and when it was time to remount them it became apparent that these rims were never going to fit no matter how hard I tried to push them on, lol. Palm of your hand smacking yourself in the forehead moment. Turns out the bolt pattern is for some GM SUV models, like the Trailblazer and Envoy. Very limited, apparently, 6 x 5" or 6 x 127mm. You guessed it, I have some rims for sale, lol. Have a gr8 day everyone, cheers!

Here's a blunder I'd like to share. Each time I drove Helios, I'd complain about the continuous and constant poor performance of the Webers. No matter how many attempts to correct or tweak the carbs, the same result came back ( carb linkage sticking after it warmed up ). I put up with it for far too long. I finally parked him and neglected to drive him for quite awhile. So after a long absence, I decided that the carbs probably needed a major overhaul, right? and was ready to do it. Started the process of removing the carbs when I came across the throttle sticking even before the engine had been started. New problem? or maybe this time I get lucky and find the actual issue. Yup, as far as I was concerned the carburetors were in fact the problem. How many tries and attempts of having a normal running engine had been accumulated? Enough to frustrate the hell out of me, that's for sure. Meanwhile, a clear fault and oversight on my part could have been avoided so easily ( hindsight; wink, wink ) by a simple twist or rather a not so firm twist of a fitting on one of the carb linkages. These dual carbs are linked with one pull rod that attaches to each individual carb throttle. So naturally the heim-joint connection points are critical, especially with synchronizing the idle and performance aspects. Each bolt carries two flat washers, one on either side and one ny-lock nut to keep them firmly in place. They're not very big but very important. I thought I had just snugged them up, not with too much pressure. There are four of them to deal with and every time I made an adjustment to the carbs I had movement in each one. Easy, nothing to see here! I even lubricated them too at one point. Nope, when all things seem too easy you can even miss the obvious. Case in point, by just releasing the nut on the sticky carb connection, a hair or two, the throttle linkage was free from sticking. What a revelation, what an idiot! I was even preparing to rebuild a new heat shield to go under the carburetors too, if it came right down to it. Reset the carbs and they idled smoothly, burped the engine and Helios revved with a new anticipation before descending back to a smooth idle again. Even after running him for quite some time, no more stickiness. Problem solved! Blunder worth sharing, I hope.

Well, you're in good fortune my friend. One of their many branches across Alberta is actually in Edmonton. Its location is in the northwest and goes under the name of All West Glass. They expedited it for me the very next working day. When you pick up the parcel it'll be wrapped only once in perforated cardboard. Definitely bring a blanket with you to ensure its safe journey home. My windshield part number was FW00413, dimensions are 55" x 25", for a 1980 720 King Cab. You can purchase separately and DIY or have them install for you for an additional cost. Either method is realtively inexpensive.

An update, with regards, to the obligatory windshield. ( The exiguous and somewhat non existent component ) During my travels back in Alberta, an unprecedented stop at a glass shop emerged and I had a conversation with the office attendant. Despite the reason for my visit, I couldn't resist the temptation to inquire about aforementioned windshield. With little luck ( no conclusive findings ), as expected, we exchanged contact info. After returning to the Island a few days later, a serendipitous incident occurred. I received, via that Glass Shop, an actual place and location to which confirmed the availability of a windshield. OMG! Thank you for your diligence office staff attendant. So now I'm focused and excited to obtain this item. I then called the business to which I had been directed and was disappointed when I heard of their location, too far away to make another immediate trip. Further conversing lead to an alternative plan that would be more doable. It was delightful to know they had other branches across Alberta but only in said Provence. A plan was formulating. With a contact I have near one of their locals, I proceeded to acquire the parts for replacement and ordered them. Given the timeline and nature of my return to that area, we managed to arrange a day where we both could pick up the new windshield and seal. Done! Only one acute disruption interfered with it being in my possession back home, I had flown to that destination. No big deal, it just meant a further delay in repairing the truck. The windshield was mildly wrapped in perforated cardboard and therefore subject to any incidental accidents. Simple enough, with plenty of access to materials, I constructed a wooden crate that surrounded the glass. This prevented any minor mishaps and gave it an external perseverance with easier handling capabilities. Unfortunately, my contact lived too far away as well, closer yes but still in Alberta. Oddly, the path of the crate continues, as a transferor accepted responsibility to retain my illusive but well traveled package. This other contact stepped up and it now resides somewhere in central BC, still too distant a trip, some 600 km away. Please don't judge. I'm not in any hurry. Sure, putting it on a transport and expediting it here would be the norm but I enjoy the basic, fundamental execution of a journey, with little to no overcharged transactions, I control the costs. Besides, everyone loves a great storey. Am I right?! Early October is in the works...