ScaryPony Posted February 8 Report Share Posted February 8 Hi all, First post on this project and on the forum! Datsun rescue I will add pictures as I dig them up. Non-runner from the Chelan area, bought late ‘23. Borrowed a neighbor’s trailer - you know the kind, deck carpeted in moss and tires from the long long ago. Forgot the come-along so we had to tow the car on. Wind gusts to 40 on the ride back. . . just a classic sketchy all-day car adventure. Credit to my other half being super helpful and very patient on the trek back to Snohomish county. Parts car, so boxes of parts, 3 sets of rims, a tote of wiring harnesses, etc. The previous owner also had a grey wagon with a linked rear end. So nice. No work on car until summer ‘24 Sidelined by house projects. Step 1 was patching together a harness out of sections from a few different cars. I sat with the rats nest and wiring diagrams for a weekend. When I isolated a section I checked continuity. Got stuck with the wrong wire to the points. Credit to another neighbor for an assist. We made it live, but it ran like garbage. Quickly identified a leak at the carb (32/36). Wiring time Given the state of the carb I ordered a service kit from Redline and rebuilt my first carb since high school. Ran better but still garbage. Not so bad as to stop me driving around the neighborhood though. Did some interior work, and started replacing rubber components. Welded up an exhaust after some comments about the open header. Threw a couple E28 seats in. Also installed the front coil overs and the ?Maxima? calipers. Started on the dash wiring, rear disc convert. By late fall ‘24 car was on hold again. Busy travel schedule and another house project. Spring of ‘25 started dialing in idle fueling and timing. This helped a lot. Cleaned the tank and ran fresh line/hoses so I didn’t have to drive with a hose through the firewall to a Jerry can anymore. Ran it like this for a while on short trips. Slow, but sounded great. Started to notice bad missing at higher revs. Putting around Sidelined again, other cars and life stuff. Ran every now and then, super Smokey. Oil smelled strongly of gas. Tested compression late ‘25 on a strong hunch and confirmed rings on cyl 3 with wet retest. That brings us to now. Dropped fluids, pulled head. Identified several issues, most notable the fuel pump diaphragm/fuel-to-oil injector. Out of curiosity I put a bore gauge down 2 and 3 with pistons still in block. Taper and out-of-round both around 0.0025”, max piston-bore clearance about 0.004” on a 0.0001” gauge. Borrowing a cherry picker next weekend to pull the block. Currently have a freshly machined A87 closed chamber on the kitchen table. Just installed a reground cam (head and cam came with car) and realized I would need taller lash pads (around .290”). These seem to be tough to find? Now I’m trying to decide my next steps. Basic approach to this rebuild is mostly to get it back on the road, learn the rebuild process, keep the cost down, and improve things where it makes sense. Thoughts, advice, general commentary are welcome. Thanks folks. 1 Quote Link to comment
datzenmike Posted February 8 Report Share Posted February 8 Bore clearance is 0.001 to 0.0018 or roughly 1 to 2 thousands. I think time for an over bore and over size pistons. This will give you a new engine. Miss at high revs could be poor condition of the valve seats. A closed chamber head has a larger combustion chamber so this will drop your compression from 8.5 down to 8.38. I doubt the larger valves and ports on the A-87 will make up for this loss. The cam regrind should. Try the cam on both heads see what the ass dyno says. Quote Link to comment
Slow Loris Posted February 8 Report Share Posted February 8 This spot has been indispensable for me during my rebuild and has a few sizes of lash pads in stock: https://datnissparts.com Quote Link to comment
ScaryPony Posted February 10 Author Report Share Posted February 10 Hey thanks for the info. I ended up skipping the taller lash pads for now. That site is a good find though. Instead I pulled the cam and followers from the old head (W53 closed chamber) and put them onto the ported refurb head in same order. Wipe looked good with the lash pads from the refurb head and tower shims in place. Then I set lash to spec. I would like a hot cam but getting back to enjoying it is more important to me for now. Mike your intuition on the valve seats is right on. Only one of the chambers holds any liquid. Any thoughts on boring up to l18 pistons? Seems like displacement and compression are both improved that way but I defer to you guys expertise. Quote Link to comment
datzenmike Posted February 10 Report Share Posted February 10 You can quick lap them to get a better seal if not interested in re-building them. L16 bored with L18 pistons with L16 head............... 8.83 Be advised that L18 pistons are pretty much NLA. Used would be the only option. The above with closed chamber head.................... 8.48 The above with open chamber head....................... 7.96 The above with L20B pistons and L16 head............ 7.92 the other heads would be even worse. The L20B cam is the same as the L16 SSS cam from the Coupe. Quote Link to comment
ScaryPony Posted February 10 Author Report Share Posted February 10 A quick lap is a good idea. Then I could just run the W53 and save the A87 for future. I’m enjoying the process so a full refresh on the W53 isn’t out of the question. Im open to recommendations on piston selection. I haven’t fired up the Google machine to determine availability. Quote Link to comment
datzenmike Posted February 10 Report Share Posted February 10 If open chamber I wouldn't use either. I don't think L18 pistons are around but There were flattop L24 pistons. If the L16 block bores are worn, overbore to 0.5mm or 1.0 mm and use L24 flattop pistons in matching over bore sizes. An L16 bored to 84mm (1mm over) with matching 84mm L24 flattop pistons would have a compression of ... L16 head........... 9.48 Closed head..... 9.06 This is a nice compression and you get to use the larger valve and port, closed chamber head. Open head........ 8.44 Quote Link to comment
banzai510(hainz) Posted February 10 Report Share Posted February 10 wheres the photos?????????? Quote Link to comment
banzai510(hainz) Posted February 10 Report Share Posted February 10 (edited) On 2/7/2026 at 6:46 PM, ScaryPony said: around .290” .190 I can see .290 I dont believe and a cam I would not want. retainers better hold those in there better make sure the valves springs dont compress Edited February 10 by banzai510(hainz) Quote Link to comment
datzenmike Posted February 10 Report Share Posted February 10 Google Drive for photos..... sux. Stock L20B valve lift is 0.413" or 0.275" of cam lobe height. Maximum before the coil spring is fully compressed and bottoms out is around 0.470" or 0.313" of lobe lift. Quote Link to comment
Slow Loris Posted February 11 Report Share Posted February 11 Need pics have wagonlust. 20 hours ago, ScaryPony said: machine to determine availability. If you go the L18 route you’ll find a lot for L18 on eBay but beware they are probably for L20b with a larger dish. I bought 3 sets for my motor and ended up with only 1 true L18 set with the correct dish. Correct set came from https://www.nzdatsunparts.co.nz/l-series-piston-sets which also has tons of other hard to find stuff, and the exchange rate v. New Zealand dollar makes the prices pretty reasonable for NOS Datsun stuff imo Quote Link to comment
banzai510(hainz) Posted February 12 Report Share Posted February 12 On 2/10/2026 at 6:32 PM, Slow Loris said: Correct set came from https://www.nzdatsunparts.co.nz/l-series-piston-sets which also has tons of other hard to find stuff, and the exchange rate v. New Zealand dollar makes the prices pretty reasonable for NOS Datsun stuff imo Yep the 4cc dished L18 pistons. also good for bumping up compression in L20s most likely get the oversize cause the machine shop is going to want perfect bores Quote Link to comment
ScaryPony Posted February 12 Author Report Share Posted February 12 Hi all, Really appreciate all the input. Quick question, how do I post photos directly? What am I missing? (very much want to share) Quote Link to comment
Slow Loris Posted February 13 Report Share Posted February 13 I think you have to post some magic number of times before unlocking the privilege. Most of those posts will be you responding to people (like me) asking you “where are the pics??” It’s a little game Ratsun likes to play. Enjoy. Quote Link to comment
datzenmike Posted February 13 Report Share Posted February 13 It's just under 30 posts. Try now I added 30 Quote Link to comment
ScaryPony Posted February 13 Author Report Share Posted February 13 hopefully this link works Quote Link to comment
ScaryPony Posted February 13 Author Report Share Posted February 13 wedge the chain they said. . . Quote Link to comment
datzenmike Posted February 13 Report Share Posted February 13 Look on the block just behind the dipstick handle, the engine size is stamped on that flat boss. Quote Link to comment
ScaryPony Posted February 13 Author Report Share Posted February 13 if i can find a pic of the gasket i'll post it. It was in interesting condition Quote Link to comment
datzenmike Posted February 13 Report Share Posted February 13 I'm not convinced that engine is an L18. I see three things that are sort of odd. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.