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Cost to bore and hone an inline six

E28 technical advice asked and given! Troubleshooting, modifications and more.
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turbodan
Posts: 9366
Joined: Jan 09, 2007 10:19 PM

Cost to bore and hone an inline six

Post by turbodan »

I got a quote the other day for $350. It's been over 10 years since I had one done, can't remember if that's reasonable. 

What does the peanut gallery think?
Mike W.
Posts: 27514
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: Cost to bore and hone an inline six

Post by Mike W. »

turbodan wrote: Mar 22, 2025 11:52 PM I got a quote the other day for $350. It's been over 10 years since I had one done, can't remember if that's reasonable. 

What does the peanut gallery think?
Sounds high to me. IIRC when I had a 89 bore M30 bored out to 92MM, it was around $200. That was back around '98 though, but I am in Sonoma County Calif which is one of the most expensive cost of living areas in the country, and I believe you're in NM which is low. My machinist charged a considerable premium, although I don't recall exactly how much, for such a large overbore. He called it a triple overbore due to being an eighth of an inch. I wouldn't call your quote an "on crack" quote, or stupid expensive, but it sounds high. Not way high, just high.

But... IMO the most expensive machine shop is the cheapest one. Money be damned, paying more upfront is cheaper than trying to fix or redo things later. Let alone the cursing, screaming and swearing that goes along with it.

And lets face it, all they really want to do is V8s.
stuartinmn
Posts: 9585
Joined: Feb 12, 2006 12:00 PM
Location: Minneapolis

Re: Cost to bore and hone an inline six

Post by stuartinmn »

I'd be more worried about the quality of the work than how much it will cost.  The question revolves around how much time will the job take?  Shop rates these days is probably going to be in the range of $125/hour; $350 will get you less than three hours, and that doesn't include any required materials or supplies.  Of course you can always get a second quote from another shop.  
I'm no machinist but I think machining on a straight six will require less setup time than a V8.  They'll only have to position the block in their machine one time, rather than having to do four cylinders, then reposition it to do the other four.
austin8753
Posts: 1518
Joined: May 16, 2010 1:37 AM
Location: Portland, Oregon, USA

Re: Cost to bore and hone an inline six

Post by austin8753 »

i had an M10 bored 1mm over in August of 2024. i think i remember it being $100/hole just to bore + hone it. probably another $150 to set it up on the machine and have it resurfaced. client paid the shop directly or i'd have the receipt to reference.

automotive machine shop rates out here are around $200/hour, so that checks out.
szacsi72
Posts: 344
Joined: Nov 13, 2022 3:41 AM
Location: Hungary

Re: Cost to bore and hone an inline six

Post by szacsi72 »

Sounds fair to me.

I live in Hungary, and 0.25mm over bore + honing + decking (if you are there...) would set me back roughy 150-200$ in most shops.
The average pay and the cost of everything is roughly 1/3rd of the US, so I don't think that's too bad.
 
athayer187
Posts: 1627
Joined: May 10, 2006 11:27 AM
Location: Cheshire, CT

Re: Cost to bore and hone an inline six

Post by athayer187 »

In my area (CT), that's cheap.  Good machinists are getting harder and harder to find.  I'd expect to pay $100/hole here.
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