Recommendation: Engine cleaning

Does anyone have recommendations for a machine shop to get my disassembled engine parts cleaned? Preferably acid dip on the engine and then glass media blast on the gearbox? Some place reputable.

I know we’ve got the Vapor Hone but it isn’t loaded with glass media and instead has a more aggressive media (aluminum oxide I think). I’d be willing to swap glass in for my own use if it’s allowed, but when I’ve asked if that’s possible I’ve never gotten a direct answer so I don’t know if that’s even an option. Aside from that I don’t believe we have the ability to acid dip the engine :grimacing: That sounds equally risky and expensive.

I could always forgo getting it cleaned, but I’m shooting for a full repaint and need the water jacket cleaned. It’s a small delicate engine for a 998cc Classic Mini (currently on a pallet in personal storage, but not for long)

I’d tag Automotive, Metal, and Machine but I’d rather not spam several groups at once :upside_down_face:

I’d tag that Tom guy @TLAR since European metal is his jam (and since Mini has been incorporated into BMW, more so).
And I’m 99% sure it’s “vatted”, which is a caustic solution, not acid. Acid eats metal. You don’t want that. You want caustic (basic, the opposite of acid) which eats fat (grease, oil, etc.).

Sorry I don’t have a recommendation.

You could PM Jim and/or Tim and ask about the media thing on the vapor hone… but face-to-face usually works better for this kind of discussion, if you can coincide schedules…


I’m less familiar with the correct terms and specifics, so thank you for explaining the difference. I’ll see if either can be around the next time I’m at DMS to deal with the engine. I’ll PM them just in case though.

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City Motor has a burn off oven to clean engine parts, they are right down the street. You might check to see how much they charge. Also might check transmission shops, they may have burn off ovens. I know a friend of mine had one as his.


Are those safe to use on alloy parts? My gearbox is aluminum whereas the rest should be steel, I think

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RE: Vapor Hone

In water, the aluminum oxide is less aggressive than when used in dry blasting. It’s very popular for restoration.

However, you need to be cautious about water getting left in places when it comes to more complex objects. You can run some scrap material through it and get a feel for it.

In terms of swapping media, I meant to reply to the other thread and I apologise if I didn’t. We don’t have a rule against it, however it is quite an involved process and difficult to do solo. I’d suggest stopping by a committee meeting and seeing what it entails. We usually do it every or every other meeting depending on what the status of the water and media is. Metal shop meets on the first saturday of every month.



No worries! I’ll endeavour to make it to the next meeting. I figured it was an involved process after watching the company’s videos on the topic, hence my asking and not just assuming I could walk in and swap it :sweat_smile: I try not to ask the same question too many times in case I stumble into a touchy subject.

Could any of the ovens we have be used to bake out the moisture after cleaning? That might allow for rust ingress though with no oil to protect anything. Probably worth letting a shop do the work. City Motor is indeed around the corner now that I look @TBJK. I also see Kip Motor Co. and they seem to specialize in British Autos. I’ll have to give them a call and see if their rates fit my budget. Ideally I’d love to do everything at DMS to showcase a project and of course make the most use or if my membership by learning everything I can with this rebuild. Not to mention keeping expenses as low as possible!

Hope those bolts worked out @hon1nbo :slight_smile:

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Of course. The water actually has some Hold Tight in it which helps mitigate immediate flash rust. I toss stuff in the oven all the time after the vapor hone. Engine parts will release oil and grease, so expect it to smoke out a bit. Cast parts might as well be a sponge.


Would you mind sharing what your plan/ goal is with your Mini Cooper Classic’s engine is?

To answer your question above :

Typically you would have a traditional “engine machine shop” handle that task.

They would “vat” the bare block in a high temp bath (think giant dish washer). The same goes for the bare head and misc larger parts. Better equipped shoppes would tumble valves(for those that are re-using valves) and other small parts (non ceramic media). Time is money to machine shops so if you have them just “vat it” then it has to be a bare block. Keep that in mind. Leaving something attached by mistake and it too gets a high temperature bath.

If you go this route - please make sure that you (you) use compressed air to blow out all the passages and nooks and crannies and let it “air dry” thoroughly before you start to assembly anything. The LAST thing you would want on a fresh rebuild is a chunk of FOD(foreign object debris) lodged in an oil passage that could block a bearing or a follower and ruin your day. Cleanliness and Patience are the keys to engine rebuilding success stories.

This is a good time to have said machine shop “mic” your block, crank, rods, etc (anything that you plan keep in the rebuild). It is not a good practice to re-ring pistons or install new pistons into a clean block that has not been checked thoroughly by an automotive machinist. (no sense in driving a round piston into an oval hole or later finding out the mating surface for the head is not flat - within themanufacture’s spec’s.

You have an iron block - magnafluxing it for cracks is an ancient art(old fashioned NDI)

Machine shops do head work the “right way” - I don’t suggest doing it at the Space.

Head gaskets only come in so many thicknesses(or not at all) before other problems arise.

Machine shops also offer balancing of the rotating assembly.


My main goal with it’s removal was to address any damage that resulted from a severe overheat, take a peak inside my gearbox to check for wear, and in general do a full gasket replacement on everything. The overheat happened when I opened the heater valve while cruising down 635 :grimacing:. Either an air lock or an obstruction prevented flow. When I flushed my radiator tonight, I found a few chunks of rust and other debris, so likely more is still in the system. The engine died when I got off at the next exit and stopped at the intersection. It sat, then I managed to crank it several times to limp it home very slowly watching the heat. The heater valve still operates cleanly, so that’s not the point of failure. The sounds it made as I limped it home, parking lot to parking lot cooling down between, sounded like a blown head gasket (evidenced by oil in my coolant) and possibly also a failed water pump. I couldn’t get the engine started, though it turned over, the day I brought it to the space for removal.

I’ve never had to bring anything to a machine shop before, so I don’t have a clue where to start looking if I need one.

NEED: check the head and block for flat, test compression, and clean the water jacket of rust and debris. Probably more if you have suggestions

WANT: get everything super clean while it’s apart to repaint the block and head, upgrade some parts, lap valves, “rebuild” the engine by replacing bearings and other consumables, maybe delete my heater (maybe not)

I of course have a budget, so a full rebuild might have to wait and I’ll do the “needs” I mentioned to get everything back in running order, but stop short of going too deep into my want list.

While the engine is out, I’m also planning on converting to right hand drive, and repainting the engine bay (off site of course) since the job is much easier in this state. Some of the LHD components are in such high demand that they’ll finance half of this project with their sale, plus I like it better. Thankfully Minis come with holes to simply move everything over, steering column/master cylinders/et , but that’s another topic of conversation. :man_shrugging:

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Iaian MacLeod works at Kip Motor and is my buddy and former neighbor. :+1:


It has been decades since I last worked on a real Mini (and no the BMW ones are not ‘real’ Minis) plus yours is new by comparison to what I last serviced…

I understand being on a budget - that is what make a place like the Makerspace even more appealing but some tasks are better left to the folks that have the proper gear to measure, inspect, and or correct issues before assembly.
Compression yes.
Too late to do a cooling system pressure test tho - or more difficult. This is the test where you would remove the spark plugs and pressurize the cooling system with low pressure air and if a head gasket was blown or worse the head or block was cracked the air pressure would push coolant out the spark plug hole or holes…fairly depressing for Mercedes and Ferrari owners back in the day.

Sure you can lap the valves - I’d be happy to bring in my hand held egg beater style lapper for you to use (old school), but what if the seats need to be cut? What if the guides are worn out? A real valve job on that head is probably not going to be worth your time or the guessing later if you did it “good enough”

Cast iron is tougher than aluminum but overheating is not a good thing - so I suggest you keep the heater so if you experience another time when the coolant temp is climbing just turn on the heater and dissipate some of that heat into the cabin(it is not a solution but it may get you off the roadway etc).


Is he a welder that is over 7 ft tall by chance?

I’d also recommend getting your block & heat magnafluxed, dye pen test or pressure tested.

Many moons ago I did a head on a Mazda. We thought the head gasket was blown. After replacing a subsequently running we found that was not the case. I pulled the head again and had it tested. There was a hair line crack in the head.

I can understand the budget portion. But nothing worse than getting it back together to find an unsuspecting crack just to pull it back apart again.


Nope. He’s a big fan of hockey, mechs, and star wars, but is average height.

So, considering the above, where would you guys recommend that would be capable of doing those checks? And what do those jobs cost on a little four banger like this?

I found coolant in my oil, and oil in my coolant btw, and it sounded just like another vehicle I killed in the past that blew a head gasket :unamused: , so I can assume that with some certainty. Once I get the head off I’ll have a better time looking at things for blow by and cracks.

Stuff like the valves and so on, if they need new seats, then I won’t be the one doing that work of course, but I will have to stretch the project out so it has the least amount of impact to my wallet as possible.

I’ll reach out to Kip to see what their services will run to determine if I need to save up some cash in advance for this work or not.

I will follow up and say, if I can get the engine running again for now, I can get it fully rebuilt later when I have the budget. I walk to work, so I don’t NEED to drive it all the time, and my wife has the other car.

Just got a quote from Kip and I don’t think I can afford what they’re asking for a teardown, failure analysis, machining, & rebuild. As much as I respect the professional level of work and labor costs involved, I may as well buy a new engine, which I also can’t afford. I’ll have to do as much as I can myself and then if things need machining, I’ll stomach those costs if necessary. In other news though… I got my flywheel puller in from the UK :smiley:


Would you mind posting their detailed quote?
(I hope it was detailed and not just one line).

I would recommend you take the head off your engine and take it to a local machine shop that does engine work.
This does not have to be one that specializes in a certain brand of vehicle.

It was an over the phone quote for a best case scenario, single line of you want to call it that. $3500 for teardown, failure analysis, machining, & rebuild. Or $600 for teardown and failure analysis.

Yeah I’ll at least get the head looked at somewhere. It looks like I could do a home dye pen test to find any cracks, but beyond that I’ll need a professional.