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1971 Series IIa 88" Overhaul

mikeau said:
The old ones you have look better than the new, so unless there is wear that we cant see on them I would use the old sprockets.
I would definitely buy the best quality chain you can find as that will be the part that wears, stretches and breaks.
I dont ever recall hearing of an engine being junked because of failed timing sprockets/gears, its always the chain/belt that goes.
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The crankshaft sprocket doesn't look too bad but because the chain was so worn that the tensioner had extended out to far and was cocked off at an angle, the idler wore funny. The really bad one though is the cam sprocket. For some odd reason the peaks of the sprocket teeth are all smashed off and it looks like crap. It might still work but I really don't want to put it back in the engine.
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I tore apart the working but very grungy starter last night and cleaned it up. The commutator, bushings, and brushes all look great so I just lubed and reassembled it. And a coat of paint of course. Funny thing: the interior absolutely reeked. Mouldy rotten socks describes it well. Definitely the worst smelling thing on this project so far. I think the gasket under the brush cover band was the source. It got replaced...
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My engine parts order from John Craddock arrived today in good condition. Genuine main bearings, King rod bearings, aftermarket tappet brasses & rollers, Santana valve spring cups & keepers, and Britpart camshaft, valves, and oversized pistons.
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Disappointingly I learned of Turner Engineering just after I had placed this order or I would have gotten the pistons and valves from them instead as they sell "non-Britpart" (read: non-Chinese) parts. Strangely enough the Britpart pieces actually look pretty good. Buying blue-box parts really is a total gamble. The intake valves are stainless and appear good and the exhaust valves are steel and look like they might be older stock as they were wrapped in wax paper. The pistons were my biggest worry but close inspection shows them to be machined well and the castings look nice.
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I did some searching online and couldn't find any horror stories about Chinese pistons so I think I might just use them. Several comments suggested that practically all pistons come from the far east anyway and the remaining suppliers aren't exactly Federal-Mogul quality so what the heck. Like I said, they look pretty good.
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So that's where I'm at currently. I'll finish cleaning up the block tonight and if the planets line up right I'll take it up to the shop tomorrow evening and machine the cylinder bores.
 
I don't like to grease drive dogs on starters. They eventually get dirty, the dirt sticks to the grease...you know the rest.
Some dry lube, like graphite, is a good bet.

You're, once again, brave/crazy with the blue box stuff but they do look fairly usable indeed. It's a Russian roulette!
 
SWBFreeLoader said:
I don't like to grease drive dogs on starters. They eventually get dirty, the dirt sticks to the grease...you know the rest.
Some dry lube, like graphite, is a good bet.

You're, once again, brave/crazy with the blue box stuff but they do look fairly usable indeed. It's a Russian roulette!
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That's good advise with the starter. I went pretty light with the grease on the spline and some motor oil on the gear/spiral thing but graphite sounds better. I might just take it apart and do that.

For me taking the blue box gamble is less about bravery or insanity and more about getting the job done in a reasonable amount of time for a reasonable amount of money. When I can't find anything else then it's got to be Britpart. I'm not particularly thrilled with the idea of putting what might end up being substandard parts into my engine but I also don't want to spend hundreds or even thousands more on this project hunting down genuine parts. I don't know how much better Indian or Italian parts would be anyway. I generally only really trust US, German, or Japanese made parts myself.

Doing all this from a "foreign car" perspective makes it a tad more challenging that it would be for a UK resident as well, where entire spare engines are likely available locally and actual Land Rover stores exist. But then that's part of the fun too! 😁
 
Huge day today. After a 14 hour shift at work I grabbed a burrito on the way home then picked up my block and head and went back up to the shop. Nobody was working in MILL07 tonight so I figured I'd better use this rare opening in our busy schedule to jump on my engine machining. The machine itself is an old YCM SuperMax V-146B vertical machining center (CNC vertical mill) with a lot of hours on it but I think will be fat and sassy enough to handle this job. 😅
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I pulled the current setup off the table (a 3-jaw that I'll have to re-setup later when I'm done...) and managed to squeeze the block between the two vises - another setup I'd rather not mess with.
20240323_204747.jpg

I haven't been on the tools for a while and I've never used this particular machine before so it was all a tad stressful but I did well. I clamped the block at four places around the sump mating surface to hold it to the table. I'd rather have clamped it a bit higher up for more rigidity but this was convenient and I'm not doing any heavy roughing so I went for it. A quick dial across the deck surface showed a paltry 0.005" variance so it's go time!
I dialed in to cylinder #4 and wrote a quick program to make the machine run over to X & Y zero (bore center) and feed a Kennametal "Mod-Bore" boring bar and head down through the cylinder, stop the spindle, and rapid back up and home. It took a couple of dry runs in the air to debug my program (its been a while since I've done this okay?! 😆) but soon had the bar making chips.
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These Mod-Bore's are super nice boring tools and being on a #50 CAT arbor, was very rigid so I got perfectly round bores with zero taper. Smooth sailing really. I set up a dial bore gauge to easily and quickly check my progress and settled on one roughing pass at 350rpm and 0.006"/rev feedrate which took the first 0.015" out and another final pass with the same specs taking out another 0.010" leaving the bores clean and 0.005" under. It's a good thing I changed my mind from 0.020" over pistons to 0.030" over as they barely cleaned up at +0.025". Number two bore was especially close. I'll take the last bit out with a borrowed Sunnen AN-604 portable hone for final sizing to each piston.
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Once the first bore was done the other three went fairly quickly. I just redialed X,Y zero for each bore off the relatively unworn top 1/4" of their bores and ran the program again: one rough and one finish pass for each cylinder. Same sizes every time. Damn these are nice boring bars! If I was really going for it and blueprinting this thing I'd have dialed everything to the crank mains but I think this way will work fine for what I need.
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With the bores all done (yay!) I used another bigger Mod-Bore modular boring head to make a fly cutter and took about 0.010" off the top deck surface to make it nice and flat and give the head gasket the best surface for sealing I can give it.
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I cleaned up my area while this cut was running and before I knew it I was back home and my newly machined block was sitting on my work platform. Whew!
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As I said it was a big long day but I'm super happy to have gotten this extremely important step in my rebuild out of the way. The local automotive machine shop quoted me $1500+ and 12 weeks lead time to do this work so I'm miles ahead now doing it myself. I still have to hone the bores to size and skim the head but I should be able to finish that off tomorrow after work, if I'm not too exhausted.
Anyway, hopefully you guys (and gals...) didn't mind my long winded and overly specific description of what I did. I enjoy this kind of thing and as a machinist do get carried away sometimes... 😁
 
Neil said:
That cylinder block looks beautiful and what a handy resource to have available.
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Thanks Neil. This shop is less handy than others I've worked at as they're not particularly keen on employees using the equipment. We run almost around the clock too so it is difficult to find an opening to do this type of thing, hence the Saturday at midnight time frame. Still, as you said, it's a handy resource to have available. Hopefully I don't need to do much more machine work on this project. 🤞
 
SeriesG said:
Huge day today. After a 14 hour shift at work I grabbed a burrito on the way home then picked up my block and head and went back up to the shop. Nobody was working in MILL07 tonight so I figured I'd better use this rare opening in our busy schedule to jump on my engine machining. The machine itself is an old YCM SuperMax V-146B vertical machining center (CNC vertical mill) with a lot of hours on it but I think will be fat and sassy enough to handle this job. 😅
View attachment 526541
I pulled the current setup off the table (a 3-jaw that I'll have to re-setup later when I'm done...) and managed to squeeze the block between the two vises - another setup I'd rather not mess with.
View attachment 526542
I haven't been on the tools for a while and I've never used this particular machine before so it was all a tad stressful but I did well. I clamped the block at four places around the sump mating surface to hold it to the table. I'd rather have clamped it a bit higher up for more rigidity but this was convenient and I'm not doing any heavy roughing so I went for it. A quick dial across the deck surface showed a paltry 0.005" variance so it's go time!
I dialed in to cylinder #4 and wrote a quick program to make the machine run over to X & Y zero (bore center) and feed a Kennametal "Mod-Bore" boring bar and head down through the cylinder, stop the spindle, and rapid back up and home. It took a couple of dry runs in the air to debug my program (its been a while since I've done this okay?! 😆) but soon had the bar making chips.
View attachment 526544
View attachment 526545
These Mod-Bore's are super nice boring tools and being on a #50 CAT arbor, was very rigid so I got perfectly round bores with zero taper. Smooth sailing really. I set up a dial bore gauge to easily and quickly check my progress and settled on one roughing pass at 350rpm and 0.006"/rev feedrate which took the first 0.015" out and another final pass with the same specs taking out another 0.010" leaving the bores clean and 0.005" under. It's a good thing I changed my mind from 0.020" over pistons to 0.030" over as they barely cleaned up at +0.025". Number two bore was especially close. I'll take the last bit out with a borrowed Sunnen AN-604 portable hone for final sizing to each piston.
View attachment 526547
Once the first bore was done the other three went fairly quickly. I just redialed X,Y zero for each bore off the relatively unworn top 1/4" of their bores and ran the program again: one rough and one finish pass for each cylinder. Same sizes every time. Damn these are nice boring bars! If I was really going for it and blueprinting this thing I'd have dialed everything to the crank mains but I think this way will work fine for what I need.
View attachment 526546
With the bores all done (yay!) I used another bigger Mod-Bore modular boring head to make a fly cutter and took about 0.010" off the top deck surface to make it nice and flat and give the head gasket the best surface for sealing I can give it.
View attachment 526549
I cleaned up my area while this cut was running and before I knew it I was back home and my newly machined block was sitting on my work platform. Whew!
View attachment 526548
As I said it was a big long day but I'm super happy to have gotten this extremely important step in my rebuild out of the way. The local automotive machine shop quoted me $1500+ and 12 weeks lead time to do this work so I'm miles ahead now doing it myself. I still have to hone the bores to size and skim the head but I should be able to finish that off tomorrow after work, if I'm not too exhausted.
Anyway, hopefully you guys (and gals...) didn't mind my long winded and overly specific description of what I did. I enjoy this kind of thing and as a machinist do get carried away sometimes... 😁
Click to expand...
Great work there ,it must be so satisfying doing the job yourself..very clever you are sir .all good and well having the machines for the jobs but you also need the brains to do it .👍
 
SWBFreeLoader said:
Really shows how the bores can wear given enough time, those ridges still being there at +25 thou is quite a surprise.
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Very true. I thought it was unusual for the bores to be so worn but the crankshaft almost looking new. Maybe the previous owner was regular with his oil changes but ran no air cleaner! 😆
I also found it strange how inconsistently the bores were worn. Each cylinder was worn more on one side or part and in a different pattern that others. One might think that pistons moving up and down in machined bored would wear similarly but it was quite random. There were some pretty deep scores in #2 and #3 due to broken rings so that probably caused uneven wear. All I know is it's all gone now.
 
SWBFreeLoader said:
Bit of crank whip around the centre main perhaps?
3 main bearings are a bit floppy in the middle :p
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That's quite possible, especially if it was being over revved. Now that you mention it one of the rods has a slightly pounded out wrist pin bushing bore so maybe the piston was wobbling about some. I'm not sure how I'm going to deal with that rod. I bought new bushes but even a new one is loose in that one rod. New rods are pricey so I think I'll rebore it round and press in a custom steel bush. Steel on steel isn't unheard of in racing circles so I'm sure it'll do in my modest little engine.
 
Paul d said:
Great work there ,it must be so satisfying doing the job yourself..very clever you are sir .all good and well having the machines for the jobs but you also need the brains to do it .👍
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Thanks for the positive comments Paul, although one might question just how clever I am for starting this project in the first place... haha! 🤣
 
Guitar Mick said:
Wow , thanks for taking the time to photograph what you were doing. It really gives a good insight to a process not many of us get to see. Lovely work 👍
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Thanks GM. I don't know how they do it in an actual automotive machine shop but this was how I did it with the machinery available to me and it seemed to work well. I think "real" engine shops generally have machines that are specifically designed to do certain functions like a "block boring machine" or a "head grinder" and would likely be easier to use and get the jobs done faster.
 
I stayed after work today and finished up machining operations with skimming the head surface. I used the same big boring tool to single-point flycut between 0.005" and 0.010" off. I don't think it really needed it but I might as well do it while I'm set up for it.
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Work went quickly which was good as I'm pretty tired this evening. I don't have to work again until next Saturday so hopefully I can get a bunch of work done this week. With luck I'll have the honing equipment for tomorrow evening and can size the bores and get cracking on assembly.
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