Lister Engine Forum
How to / DIY => Engines => Topic started by: scott p on August 27, 2019, 07:31:03 PM
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Looking to rebuild a Lister SL1. I sent the crank off to the shop. They say the crank is off by .002. They couldn't find the tolerance limit for this engine and suggested that being off that much would kill the oil pressure. I wonder if with a new bearing that .002 would be acceptable.as far as the oil pressure is concerned.
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Aw they are too smaaall, I can't read them and I don't have the imagination to deal with it.
Seriously, I need the crank and connecting rod journal diameters when new so I can get this rebuild on the road. The machinist says he has to have that information in order to get his tolerance to a half a thousand. It's a SL1.
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G'Day scott,
When you say it is "off by 0.002" do you mean that it is 0.002" undersized or running out (bent) by 0.002"?
If it is run out then he should be able to correct that in a press. If it is undersized then look at oversize bearings to make up the difference. 0.002" would make a big difference to oil pressure so getting the correct tolerance will be good.
Sorry, I don't have any specifications for a SL1, but do a search here on this Forum for a workshop manual or do a Google search for one (this is how I got my manual for the SR2 or buy a manual online to get you tolerances. Your engineering shop should have a fair idea of what the tolerances should be.
If worse comes to worse either get him to use a set of bearings from a similar engine and hone them to suit the new crank size after machining. Or have a set of bearings made to suit. Not sure where you are but there are a few places here in Oz that make bearings to order.
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What did broncodriver99 reply with?
All I can see is 4 little dots like this >>>> ....
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Had a look in the book and it gives no tolerance information at all. The spare parts section shown undersizes as O.010 020 and 0.040. Be aware the main bearings are different materials in each half so genuine would be the way to go if you can get them. Old part nos Crankshaft bearing top 201-12910 bottom 201-12920
Conrod 201-10040 camshaft bush 201-10190 and 201-10181.
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What did broncodriver99 reply with?
All I can see is 4 little dots like this >>>> ....
I replied with what I remembered as far as clearances and went searching but could find no specifications to substantiate so decided against posting up clearances that I could not verify so I deleted them. The .... was just a way to replace the text I had written as one cannot delete posts.
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I went through a couple of Lister manuals that I have. I do not have one for an SL but have LT/LV, ST, TS/TL, and HR manuals and they all read the same. They all call for a wear limit of .003-.0035" and a max clearance of .005-.006". I cannot imagine that the SL would deviate much from those specifications as they are in the same ballpark as most engine recommendations.
I am not sure where you are located Scott, but one thing to consider is British vs American engineering practices. The Brits tend to spec a nominal size, say 2.5" for a journal diameter and then remove the needed clearanace from the journal diameter. They would spec a 2.5" bearing ID and a journal diameter of 2.498" whereas American engineers tend to do the opposite by specifying a 2.5" journal diameter and a bearing ID of 2.502". If you are in the US that may be something to consider. I will keep looking around for an SL manual but hopefully that helps.
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Hello gentlemen, always glad to hear from you. The machinist did not specify what he meant by .002 out but I'm pretty sure the crank is out of round by .002 and not bent.
Based on what broncodriver99 posted .002 out of round is acceptable ?? I am still soaking in the different methods of measuring the crank British versus US .
I sent a email to realdiesel.co.uk asking them about the tolerance information. They sent me this JPG.
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Sadly that doesn't offer much help. Lister is specifying a 2.5" main journal diameter as well as a 2.5" crankpin diameter. There are no tolerance limits listed in that chart, most likely they are on the next page of the manual. Is it the main bearing journals or the connecting rod journal that is .002" out? The rod journal would be easy to check with plastigauge. The main bearings on the other hand can only be measured before assembly. Can the machinist provide you measurements of the different journals on the crank?
You would want as little out of round as possible but if it is within the wear limits you can likely get away with it. As far as the different ways of measuring the crank, they aren't different. The measurement would be the same, ie. micrometer reading. The difference is in the engineering/spec practices. Brits tend to undersize the crank diameter for clearance whereas Americans tend to oversize the bearing ID. Both ways accomplish the same clearance value, .002-.003", but the difference is in which part is smaller or larger than nominal.
Where are you located BTW?
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Going by this comment,
They all call for a wear limit of .003-.0035" and a max clearance of .005-.006".
If your journal is out of round by 0.002" and if you machined this to being round you would be at your maximum recommended tolerance before needing a rebuild. That being the case check all the journals sizes then source the next size bearings first before machining. So in order to maintain good oil pressure this is your only option especially if the engine is going back to work. If it is just to be a rally engine and run 6 times a yeareither re-use your existing bearing or buy a set of standard ones and use them. Not the ideal fix but should work.
I had a Pommy vintage tractor that was running 10 - 12 lbs oil pressure cold and drop to 5-6 lbs hot. for doing tractor treks this worked for a couple of years and I even screwed up the relief valve on the oil pump to help things out. In the end I bit the bullet and bought all the new parts from UK to do a full engine rebuild as nothing remotely made here in Oz would fit. So ahppy I did this as it now is a very reliable toy and can do a plough day when ever I want or drag a sled along the track to really test it out.
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Hi Scott
If you PM me your email address I will send you the SL1 manual in PDF
P
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I am in Washington state US.
I sent the JPG to the machinist and he ground the crank .010 under on all the journals. When I asked him about the UK way and the US way of reading the specs he seemed to know about it.
Not sure what PM means Johndoh. Is that a special private place to go ?
Thanks for the input all you.
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It means private message Scott. I will send you one and you can reply with your email address.
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Gentlemen:
Thanks Johndoh for the SL manual the resolution is good at 100%.
All in all it seemed best to have the crank turned. It is now .010 undersized The SL is going to be a backup for a Hydroponic system I am planning. Want it to be like new as much like as possible.
My next challenge will be to get the old bearings out and the new in. I was advised (strongly advised) not to attempt to do it in any other way but to use the Lister Main Bearing removal and installation service tool. I suspect the only timely way get that tool would be through Sleemen/Hawkin and I can imagine there would be a hefty outlay of cash for that.
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https://www.youtube.com/watch?v=Q9yyYGPmjKo
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my last post was interrupted. The reason given to me about removing the bearings was that there was a high risk of distortion and or galling of the bearing when the tool was not used.
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I cant imagine Sleeman's will be cheap for a one off special tool. I would be inclined to leave the parts in a machine shop and they will fit it for small money. Plus if they fcuk it up they will have to do it again gratis.
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Well said Johndoh and very true.
I have always had a DIY mentality, at times a shoot yourself in the foot out come but that's how you learn. I watched the you tube video and looked at the picture of the special bearing removal tool in the manual.
I turned up a plug that fits the SL1 and was able to extract the bearings and reinsert them so maybe I will be able to proceed.
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Thats the spirit Scott! Improvise experiment and occasionally improve.
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Well done Scott
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thanks guys: That was good for a chuckle Johndoh.
Yes, occasionally improve, add a few years to that and you might amount to something.