Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Nicolas Aristodemou on January 16, 2021, 18:43:11
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Is the installation of cylinder liners in the 130.983 280SL engine block (liner wall thickness 2.5mm -approx. 100 thou of an inch) feasible or would the limited thickness of the casting between cylinders prohibit that?
I am considering this versus a rebore to 1st oversize (87.00mm) because I already have a new set of standard pistons (86.50mm).
Any views on such liner use or should I go for a rebore and the purchase of oversized pistons?
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I have no experience with liners for an M130-983 but my concern always is, how large you have to bore for liners and the stress that occurs on the remaining walls when pressing them in. May not be an issue at all.
But as you have to bore anyway, why not go to 1st oversize. You will gain a little compression and maybe a hp or two 8) ;D
You can always go larger bore for liners down the road.
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I tried that idea last spring and quickly found that it wasn't possible. Standard-sized 280 pistons make good wall mounts, unfortunately. I have a set of 87.00 mm flat top pistons in stock.
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I will try and swap my unused set of 86.50mm Mahle pistons with an 87.00mm set from my parts supplier. I am also afraid of any damage that can be done when pressing the new liners in the thin cylinder walls. I am also having trouble convincing my machine shop who insist that sleeping is feasible.... thanks for the suggestions and advice anyway. :) Dr Benz could you please PM me on the cost and make of your 87mm piston set?
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I have lined 280 cylinders without issue. Just requires a very skilled machine shop.
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True, but wouldn't liners be the sort of option to which one would resort when a good sound block has been bored out to its maximum possible safe overbore due to multiple rebuilds? It doesn't seem that the original poster's block has reached that point as yet.
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True my block is still in its original state with standard pistons. Two cylinder bores are just outside limits with about 0.5mm of wear, the other 4 cylinders are between 0.3 to 0.4mm of bore wear. Therefore if I didn’t have the standard set of pistons available I would have gone for the 87.0mm oversized pistons and the corresponding cylinder rebore.
In view of the fact that I have the standard pistons already what my machine shop proposes to do (with a high degree of confidence as they claim) is to use sleeves of wall thickness 1.25mm, hence the existing cylinder will be rebored to 89.0mm and the new sleeves will be pressed in.
They propose to make a step at the bottom of the existing cylinder bore - by stopping short the rebore just before the end of the cylinder and also cut the sleeve short so that it will fit into this recess which will provide support at the bottom of the sleeve, the cylinder cylinder head providing the upper support and the sleeve will be rigidly anchored at both ends.
Having looked myself at the available metal between the cooling water slots on the block between cylinders I am also of the opinion that the sleeves will fit without creating any problems. I am glad that stickandrudderman has had a positive experience with sleeving the M130 engine.
I will make a final decision tomorrow and if I will go ahead with the fitting of cylinder sleeves I will post photos of the overhauled block by this weekend.
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Not so sure. From your personal info, I gather you have a the "later" 280 engine with the added cooling slots between the cylinders. There is less room than with the others. I would seriously check
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Speaking as a lifelong mechanic I would start looking into the cost of shipping your block from Cypress to England to someone who has done it before.
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My block last spring was already maxed overbore and .005" past that. Seeing as it was already beyond repair we opted for an early engine and mixed and matched parts to make it work. The car was OK but far from the original so it all worked out OK.
My machine shop told me they couldn't fix the old block and the cylinder head was 83.5 mm thick so aside from the crank and IP, there was little we could use. I had to keep the block and the head together as a unit so this was an easy executive decision.
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If the sleeve thickness, of 1.5 mm, is not more than the difference between standard and max overbore pistons, then it should be fine to use them?
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If the sleeve thickness, of 1.5 mm, is not more than the difference between standard and max overbore pistons, then it should be fine to use them?
My machinist told me that there's a minimum thickness of cylinder liner used. My application wasn't going to work.
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I had the liners inserted today in the block. They have a wall thickness of 1.25mm and the original bore (86.5mm) was bored out to 89mm to accommodate the new sleeves. A small part of the original bore (around 3mm) at the bottom of each cylinder was left without boring it out to provide a supporting base for the new sleeves. I have 2 photos of the work done attached. Block top and block from underneath showing the lining and its securing “step”
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Looks good, please report back on the actual experience of running in your fresh engine.
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Just an update on the engine rebuild process.
Engine was reinstalled last Thursday, all ancillaries and accessories fitted on Friday and yesterday, Saturday engine was started and set up timing, linkages and mixture. Engines runs well and have driven the car for about 50 km in town. At the moment all seems good. I didn’t rev the engine more than 3000 rpm, I will run it in for about a 1000km. Today I will do some highway motoring.
Thanks to the group for all the views and support on the cylinder liner issue.
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"1000 klm today" !? Quite an ambitious drive on a fresh engine.
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I think the "1000km" and the "Today" are in two different sentences..
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Exactly, running in period would be until car covers 1000km. I never said it would be done in a day :)
In any case I have now done 250km since rebuilt mixed city and highway runs. Engine is gradually loosening up.
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My mistake, sorry for the confusion.
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Just as closing remarks, the car has now run in and covered just over 1200 miles in a period of 6 weeks. Running in was done at both city traffic and highway driving never exceeding 4000rpm. At 600 miles I changed the engine oil and filter, retorqued the cylinder head bolts and adjusted the valves. My general comments are the following:
1. No measurable oil consumption vs the 1 liter/ 200miles that I had before.
2. No engine oil leaks
3. Engine runs cooler by about 5-10 deg C and definitely feels more powerful.
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I think I would be very careful about the engine temperature. If it ever overheats I would shut it off immediately.
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What I had stated was that car is running cooler after the overhaul....