I wanted to see if this forum can help me out. I have an '05 MCS with about 130k miles on it. I noticed I was down a quart of oil and I seem to be blowing black smoke out of the tailpipe when I get on it. I did a compression test and my numbers were low, between 105 and 110. I then did a leak down test and I am hearing air through the dipstick, and intake valve. The car is in good condition, and I just did a large maintenance project last year where I took the subframe out to change the control arm bushings, hit all of the seals where oil could leak, changed the SC oil, clutch, etc.

I am going to see if I can find a reputable shop in Phoenix to take the car and get a second opinion by having them perform the same tests.

The question;
If the piston rings are worn and require replacing. Is it better to rebuild it yourself, buy just the bottom end, or buy a full crate motor. I have rebuilt motors before (a long time ago) but not sure with the newer cars if that's such a good idea or not. I love the mini coopers, and even have a classic mini so it's not just another car in the family. It is family. I am looking for some opinions while I get a second opinion and determine what I want to try and do.

Thanks for your help.

 

For a DD, it really depends on if it would require honing or just a simple scuff up.
If it requires honing you might want to look into a complete motor, since you'd be adding head work into the cost as well.
But if it's just a scuff up, rings and rod bearings & bolts, that can actually be done with the motor still in the car, and isn't very difficult.

I wouldn't even consider making a decision without pulling the head first, you may be pleasantly surprised, 130k is barely half life for a well maintained lower end with original parts.
When I pulled mine apart it was only showing 110psi avg, across all 4, but the cylinder walls were pristine, and that was with 212k.

 

Typically the bottom end being all forged is usually in good shape including the bearings, the problem is usually found in the head on leak down checks so check your valve train----130thou is not considered high mileage for the motor internals.

 

Yeah, I'd look inside and get a second opinion on the motor. Hopefully the cylinders are fine, and you can re-ring it for peace of mind and throw a performance head on it. I want to say that most people that have head's go bad usually find it more cost effective to find another head than rebuild the one they have.

If you do need to rehone it, maybe it's worth looking into sneeds 1.7L kit, and having the engine bored out. it seems like that might be a decent way to refresh the block and put some more power into it while you're at it.

 

Thanks, I am going to take it to a shop and have someone do the same tests and see what they come up with. If the shop shows it low as well, I will take the head off and see what I am working with. I will be disappointed if the bottom end needs rebuilding at 130k, but it is what it is. When I did the work last year, I changed the oil pan gasket and didn't see any metal shavings or anything that would cause concern about something failing. I didn't go much further than a visual check at that time though.

I will start looking at options too. If the cylinder walls are good, and I decided to go with just rings, should I change the crank and rod bearings out?

I did see the Sneed engines and the 1.7L rebuild kit. A little more power would be cool!

 

Also wanted to post the compression numbers here to see what people think.

Cyl 1 2 3 4
Dry 104 103 104 105
Wet 135 136 130 120

Happy Turkey Day!

 

Unless it's showing signs of issues I wouldn't worry about the crank at all, for crank bearings you'd have to pull the motor, rod bearings you wouldn't. And The only reason you'd want to do the rod bearings is from pulling the Pistons to do rings, it's not normal to "need" rod bearings.

 

Thanks for your help.

I guess the bottom line is to take the head off to get some measurements and see what state the cylinders are in! Looks like that will give me an idea of whether it will just be the rings and rod bearings.

If not, I may opt for the 1.7L kit from Sneed since the block would probably need to go to a machine shop for the honing/boring process. I am sure I can do that but would leave that process to the professionals. We will see which route I will want to go.

Don't want to invest a ton of money, but if I do rebuild, I wouldn't mind building in a little more power. The fully assembled engines from Sneed do look nice though. Will call them tomorrow and see what options they have for kits in preparation.

 

Hey Guys.

So, it was a gray weekend here in Phoenix, so I tore down the motor to see what was going on. I am attaching some pictures of the head and the motor. I took the head down to a local machine shop to have it redone. The valves had carbon build up caked on the exhaust side on cylinders 1 and 4. Cylinders 2 and 3 weren't as bad.

I haven't checked the clearances on the cylinders yet, because I need to go buy the tools for that work, or seeing if I know someone who knows someone who might have them. The cylinder walls look to be in good shape though, still see the factory hatching on them which is a good sign. I plan on taking the oil pan off and popping the pistons out to see how the Rod bearings look. I do have some carbon built up around the top edges of the cylinders. Just take a chisel and hammer to that? Just kidding guys! I already cleaned one cylinder to see if it still had a small lip.

I am still on the fence on whether the motor will still come out to rebuild the whole bottom end. I would hate to get all this way, then have something else go. The machine shop said they would clean it up for $200, and reminded me I was already 95% there...

I am probably going to purchase the Sprintex Supercharger too and bolt it on. My supercharger is leaking oil again. I had already refilled the reservoirs a year ago and only about 3k miles went on the car this year. I am going to swap it with the Sprintex instead of a factory replacement and then fit the Eaton to my 74 classic A series... That should be fun!

 

Have you had the head checked out? Are any of the valves leaking?

If it was my motor, and the head was in good shape and the valves were all sealing good....I would probably just pull the pistons/rods out the top side, cover the crank up really good, run a ball end hone down into each bore to put a nice cross-hatch pattern on the cylinders, put new rings on the pistons, drop them back in, put new rod bearings in, bolt it all back together....and motor on

 

The machine shop is going to call tomorrow with their findings after they tear the head down. I did a leak down test with the intake and exhaust off before I took the head off as another check before removing the head. As suspected, it was still leaking into the crankcase. I did hear some air out of the exhaust valves on cylinders 1 and 4 so those are the ones I am worried about.

I think I caught it before causing any major issues.. Trust me, I am contemplating seriously just getting a set of rings and connecting rods and calling it a day. Just don't want to be in a position a year from now where I should have done "something" while I was in there type thing.

Attached is a pic of the cylinder. I still need to clean up the carbon build up on the top edge...

 

Might not be a bad idea of doing everything while its apart. Like you said, you would be kicking yourself is 1-2 years down the road, another issue surfaces.

Think of all the extra miles you will get from the MINI then? hehe

Eager to see how this plays out.

 

The crosshatching in those cylinders looks great! Clean up the carbon on top, put new rings and rod bearings in...and call it a day

 

Ended up pulling the motor and will rebuild the bottom end. I sent the head off to have it rebuilt by Way and will finalize my parts list. The head was certainly in need of rebuilding and it will be topped with a nice mild cam. The rod bearings were a little worn down, and the Mains, as expected, were in good shape. I started thinking of the things you should do, "while you are in there", even if I did just the con rod bearings, and I just decided to go the rebuild route. Hoping the car will give me some really solid years ahead. The block is going to the machine shop tomorrow and will get cleaned up so I have a clean start.

I will let you guys know when I get everything back together. There are a few more things I need to find. Torque pattern and torque values for the crank bolts. I found a thread saying the M10's are 60/44 and the M8's are 35/26 (nm/ft). They don't say anything about doing this in two stages though, or if you have to turn them another 90 degrees, or similar.



Michael

 

Hi Liquid. Good luck on the rebuild and please ask if you have any questions. You still have your Classic Mini? Would love to see some pix.

Drive Hard. Drive Safe. Keep Grinning.

 

I do still have the classic! Awesome little car and is a great addition to the family. Changing the suspension is on my project list for it once I get the '05 back down on it's wheels. I will keep everyone informed on the progress here.



Michael

 

Great pic with the classic and LY!

Any updates? How are things progressing?

 

Agreed! Great pix, the BEST of both worlds! Congrats!

Drive Hard. Drive Safe. Keep Grinning.

 

I need some history on your classic. It looks exactly like the one we sold a few years back.




IMG 1458

It looks like you decided to do the rebuild. I finished one last spring, take a look at my thread here

Basically your engine is looking very similar to mine when I rebuilt it. I redid everything, but in reality, with the cylinders looking like yours, likely all you need is a ring job. I suspect that oil rings are gummed up. I still had original hone marks at 365000 miles and probably could have gotten away with just a ring job.

good luck,

Nik

 

Hey Guys (and any Gals!),

So, this has been a journey. Thanks for checking in on my progress.

First off, on the classic, it's a '74 but it has a 1275cc motor that was manufactured in 1989. It's Single Point Injected, so they converted it at some point. I wish I had a lot more history on the car. It came over from New Zealand about 12 years ago. The owner before me had it that whole time in the states, but he was selling to buy a house. Great little car, and my wife and I thoroughly enjoy it. I like the light bar on the pic you had, and I wouldn't mind sticking some turn signals on the side above the wheel arches too. Like I may have mentioned, the new suspension is sitting in my garage itching to be put on the car.... Next project!

Okay, onto LY, I finally got all of my answers as to the state of the block and head. Unfortunately, I had a cracked piston, my head was cracked, and the cylinder bores were a bit tapered. With all of that leaving me with a few options, I ended up going with a new long block. Way really helped me through this process, and he found me a smoking deal on a JCW long block. I know he's in Georgia, but it almost seemed like it fell off the back of a truck! I did a side by side comparison, and by the time I got the machine work and all of the parts I needed, it seemed to be a quicker path to getting the car up and running again.

I should get the motor next week. I had a mild cam put in, will get a new header, and with all of my other mods it should have some giddy up. I will have some parts for sale if you know anyone looking to start a rebuild. I will post something after I get everything sorted.

Truly appreciate everyone's assistance with trying to help me figure out what should be done. I will post a reply when the motor is back in and the car is running around AZ again...

Michael

 

Glad to hear you found an option that works! Kudos to Way for assisting!

Pics pics pics Would love to see the process if you think of it. Hope everything works out.

 

Hey everyone. The motor arrived and is in the garage. I am going to start getting the car back together this weekend. Should go together smoothly...

I will certainly take pictures along the way and let you all know the progress. Looking forward to getting the car back on the road again. Miss driving it!

Michael

 

Good luck with your new engine. Let us know how it is going and if you needed to retune the engine computer.
As you know, We love pics and your journey to get your baby back on the road!
Good Karma to you!

 

Those that have not driven a Mini just don't know about the smile effect produced during driving.

 

Well, I'm jealous. I used to have a LY/B, also located in Phoenix, like yourself and CooperSAZ, until it got hit while stopped at a red light late in November on Mill Ave in Tempe.

Unfortunately LY was a bit out of my price range, so I bought a new DS one in Cali last week...of course the owner was a cheat and it blew the head gasket on the way home. Turned out it was shoddily repaired, so I had the head milled properly on Sunday, so I'll be rebuilding mine this weekend, as well. By the way, the guy I found was really good and washed/milled my head for $75, I can share his details if anyone wants.

It seems there's a few more of us R53's popping up in AZ. Maybe in these coming few months once our poor cars are alive again we could go on a cruise...