General questions and discussion - '87 323 SL

[FE3-323]

Sounds to me like bent valves.

[JKuhn]

Well, I suppose a R1500 (or thereabout) head/valve job would be cheaper than whatever could otherwise be lurking in the block. But it's strange. This wasn't the first time the engine locked like this (fail to start immediately, followed by about half a turn mimicking a flat battery, and then locked). The first time it started again after maybe half a minute. The second time (at a car meet) it was freed up by pushing the car backwards in 4th gear (so turning the engine backwards, there I was told that the starter was sticking in the flywheel). This time it refuses to free up. And it never gave any other signs of anything being wrong. It ran beautifully (as shown on that dyno sheet), no noises apart from what I assumed to be a noisy lifter (seems the distributor clicks, so I suspect that's the real source of the ticking). I literally drove into the yard and parked the car, and the next time I got in it wouldn't start.

The friend who built the engine (and who will help pull and inspect it now) is of course convinced that it's the 5W40 premium synthetic oil I'm running (he believes the car was made for 20W50 mineral although he agreed that 15W40 mineral would be fine). He's afraid of the word "synthetic", and also of the 5W (because 5 is thinner than 15, 20, etc). But mostly he believes that synthetic will destroy this old technology engine "because the engine wasn't made for it".

[FE3-323]

oil grade won't matter.

its possible you have some sort of transmission issues that could be the cause as well. in neutral can you rotate the engine either direction?

I suggest pulling all 4 plugs out and putting it in neutral before trying to rotate the crank
i also only really suggest trying to rotate it in the proper direction of operation. sometimes if your timing system has slop it can cause a tooth to skip by rotating it backwards.

[JKuhn]

The chain didn't seem loose. And the tensioner also looked fine (from what we could see with a cheap scope).

[JKuhn]

I'm wondering, are these actually interference engines? I've always been under the impression that an E5 is non-interference. My friend reckons it's seizure of a main bearing (and if so, it'll be pretty much impossible to convince him that it wasn't caused by the synthetic oil).

I'll start stripping the engine bay tomorrow, and then I'll have another look specifically trying to turn the engine with a ratchet in neutral with the plugs out. I'll also keep the valve cover off so I can keep an eye on the chain. I do know with the plugs in it refused to turn forwards with a ratchet. And the car should be on a trailer by Tuesday or Wednesday, to pull the engine and see what's actually wrong.

[FE3-323]

a different oil type won't make your bearings spin or sieze - end of story out of oil... now thats a different scenario.
i wish you luck in the meanwhile. i hope you come to a conclusion and are able fix it cheaply

[JKuhn]

Unfortunately people here are TERRIFIED of synthetic, thinking any engine that wasn't specially designed for it will be destroyed. Even if I tell them where the fear of synthetic (reactions between mineral and early synthetic, as well as seal issues with early synthetics) comes from.

And no, it wasn't out of oil (I actually checked to verify). It's just slightly below the full mark. Couple hundred km on the current oil to boot.

[FE3-323]

People have Silly superstitions. I believe you that it had oil.

[JKuhn]

Here we go again...



The car will be loaded tomorrow afternoon, then we'll find out what happened and what the damage is. If it is a bearing, the oil pump will be replaced without second thought (since it could have been a bad pump). Hopefully this does not mean redoing pretty much the entire job from 2020 (minus the head recon/porting). And hopefully it's not so expensive that I can't get the engine bay painted (speaking of which, one of the bolts holding the piece below the bumper broke).

[JKuhn]

The engine's been stripped, and the verdict is in.

• Crank good.
• Mains good.
• Bigends good.
• Cam good.
• Head, valves, etc good.
• Cylinder walls good.

Back when we assembled the engine in 2020 the halfmoon for the valve cover vanished without a trace. Turns out it was on top of the crank sprocket, and wedged itself beween the sprocket and chain like a doorstopper. But that's actually a great thing, because there's one thing that was NOT good. And that's the oil pump. The outlet side was actually broken clean off the housing,

I'll post some pictures a bit later of the pump and bearings, but it will get new bearings during assembly. I'm also thinking of maybe putting in some E3 pistons while it's apart anyway (last time we were unsure what to get, so we settled for stock pistons).












And don't worry, everything will be nice and clean when the engine gets assembled. The teardown was done on a garage floor.

[JKuhn]

Update.

I just spoke to the friend who's building the engine, and his supplier said not to use E3 pistons. The head's already been skimmed a bit, and using E3 pistons would bump the CR past 10.5:1. That would require 98 RON minimum, and we only have up to 95. So we'll be going with the less extreme E5S pistons. Kind of a letdown, to be honest, but I don't want to be stuck without the alcohol or 100LL that would be required to blend my own fuel.

[JKuhn]

Big things are happening.

For now it's just the engine bay. I don't have a good place to put the car yet, and I can't leave paint like this in the sun. But the rest will follow at some point.

Pretty much every mounting point is crossthreaded, rusted, overtorqued, or had a damaged bolt in it. And the new paint doesn't help either. So now every single one is getting some attention before I put anything in it. I'm also cleaning up the threads of some temporary bolts, but I'm planning to buy new screws/washers to replace them. That should happen next week, when the shop has stock again.

This might take some work to sort out:

And of course I also had the battery tray, fuse holder bracket, and ignition coil bracket painted to match. Don't mind the white (and black) bolts, as I said those are temporary while I get everything right prior to dropping the engine in. Those brackets will also come out again before the engine goes in.

[JKuhn]

Getting back to this thread.

The engine is in, and now has about 400-500km since assembly. So I've now started to give it higher loads and RPM. I'm also going to get the ignition timing properly tuned soon, maybe as early as this weekend.

I do have one question though, and that's the exhaust. The current one (46mm inner diameter) has served me decently well, but it's built VERY poorly with welds that remind me of how our dachshund looked after a couple hours of barking directly under a hadeda (hopefully that brings the idea across). And of course it leaks regularly. So with the engine no longer stock, what would you folks suggest? I'm currently torn between a 4-2 header (the one I bought earlier didn't fit on my revised engine) and two smaller pipes, or a 4-2-1 header with a single pipe. And I'm unsure what size to go in either scenario, considering the work that's been done to the engine. I do know the current one already made a decent difference when the engine was otherwise bone stock, so I'm thinking a bit larger might be prudent?

[JKuhn]

Let there be life! (Hopefully someone's still checking in)

I bought a used coolant bottle to replace the broken one in the car, and the replacement has a bilingual English/Japanese sticker on it. I'd like to have the sticker replicated before cleaning and installing the bottle, but sadly one corner is torn off (and it just HAD to be the Japanese part) Any idea how I'd be able to find out what the missing text should be? My brother might be able to guess, but I'd prefer something more accurate.



As a side note, it's interesting that the Japanese text says "long life coolant" (mentioned by my brother, and also according to Google Translate).

Lastly, a current photo of the engine bay. Unfortunately I haven't been able to do the rest yet.

[redheddude222]

I'm no help on the sticker, but the car is looking good!