Basic engine checks

[paul_GB]

I have Just acquire a replacement engine for my 64 230SL.. after searching for quite a few years (!). It was apparently removed from a 1965 car imported from the USA to the UK, but the body was too rotten to restore so the guy decided to break the car down and sell the parts. It's complete and has FIP, steering pump, manifolds, alternator etc all attached. Clearly it's been running recently. The seller mentioned he thought the cyl head had recently been refurbished in the last 5k miles but didn't know any more of its history. Overall there are no signs of oil/fuel leaks and the engine is relatively clean, with black painted block. Although a closer look at the block revealed no serial ID plate stamped in the usual place.. which alarmed me!! The flat area has a piened finish and no evidence of an ID plate. On trawling through some excellent data on this site it suggests the block may have been an MBZ replacement at some point (or maybe I'm convincing myself). There are some numbers cast into the side of the block.. I think one is '8080'. I might need to recheck that I read it right though. Ideally I don't want to completely strip the engine if it is a sound working unit but I also don't want to instal it and then find it has a major problem. I've carried out a compression test (cold engine, plugs out) and got readings between 155 - 171 PSI. I am hesitating at giving the engine (with ancillaries removed) to a local engine specialist for him to maybe remove the sump and check the bottom end. But it might be the way to go. Appreciate any guidance and thoughts would be very helpful..

Sorry for the lengthy post...

Paul

[Benz Dr.]

The engine number doesn't mean that much and since any dealer was cleared to punch in the old number on a replacement block, it may mean even less.  What it can tell you is which engine version you have since there are three different 230SL engine types. The main differences are pistons and connecting rods but there are a few other things as well.

155 - 175 is normal compression. I always test engines cold because that's the amount you have for starting in cold weather and that's when numbers count.
It depends on how much the seller wants. I would think anything under 5K would be a decent deal. Rebuilding would be twice that much.

[Cees Klumper]

I'd go ahead and install the engine. Chances are it's fine, most of the time issues are with the ancilliaries (cold start valve, FI pump, warm running device, ignition, fuel pump). Taking it back out is a bit of a hassle but not too bad. Also you run a risk of a mechanic not knowing quite all the intricacies and disturbing what could be just a fine engine. It sounds like it's a factory replacement engine without the metal tag that identified is as such. Would be good to confirm through the head casting numbers that it is indeed a 230 and not a 280 or 250 engine.

[Benz Dr.]

When I bought my car, over 20 years ago, it came with a 250SE engine in it. While I was really only looking for a 5 speed, the fact that it came with a more powerfull engine didn't bother me a bit. In fact, it still doesn't bother me.

[paul_GB]

Thanks Dr B and Cees. I did already buy the engine (it cost me £3k.. so not far off the $5k mentioned). The bonus is it came with all the ancillary parts.. so I was lucky there. I have now (today) removed the manifolds, FIP and other ancillary parts to get them cleaned and a better view of the basic engine. There is general grime but no obvious signs of leaks (water or oil).. the crank front seal seems ok, I can't get to see the rear one. My thoughts are to do the following, I think I can tackle them myself :

Change plugs, filters and thermostat
New rubber hoses and clamps all round.
Change timing chain and re-tension
Have the injectors cleaned and tested
Install Ignition123 from my old engine
General clean up and nut/bolt tighening

I will leave the 'heavy duty' mechanicals alone. What could possibly go wrong  .

With the FIP off I can now see the block casting numbers (they are all on the FIP side of the block). At top centre there is '1270110801', at the lower edge just above the sump there is '31C64' and at the rear lower edge 'CR'. Does this shed any light the type of block I have..?

Note, the head is '1270104220' with the numbers 8-9.3 which I assume is the compression ratio.

Cheers
Paul

Yes, more power would be nice 

[Benz Dr.]

The thing that makes any engine pull hard is compression. A worn 280SL probably wouldn't be as fast as really strong 230SL. There's only about one second difference between a 230 and a 280 from zero to sixty.

[paul_GB]

I have always wanted to get a correct 230 engine back into my Pagoda (it has had a 230 head/250 block for the last 25 years Ive owned her).. finally I have one sitting in my garage. Ive cleaned it down ahead of doing a few jobs (as mentioned earlier) in prep for installing in the UK autumn. Its almost sparkling and a thing of beauty!

Currently the car is in for a respray at a local workshop.. a refresh of the original dark blue (altho I was very tempted for Anthracite grey). They wanted a lot more money to repaint the engine bay (for obvious reasons) and I cant afford to stretch that far. So I'll do my best to repaint that myself during the engine swap process in autumn. For some reason the engine bay is black and I gather it should be colour-coded to the body. Hence with the car away at the moment I have a nice clear garage.. with space to work on the replacement engine .. a luxury!

Paul