posted by
someone claiming to be Hugh
on
Mon Apr 4 16:55 CST 2022 [ RELATED]
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Hello All,
I am in the process of having the engine rebuilt on my 1996 850 GLT Wagon - non-turbo with a 5-speed manual (It has 430,000 miles on it). The garage that is rebuilding the engine told me it is having difficulty in obtaining the 10 connecting rod bolts. Volvo doesn't sell them anymore. Can anyone direct me to a source where I could obtain these bolts? Thank you to all who respond. Separately, doesn't anyone know if these bolts were manufactured for Volvo by an outside company, say Mahle? If "Yes" that information could be helpful.
Hugh
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posted by
someone claiming to be Tim
on
Fri Apr 15 09:34 CST 2022 [ RELATED]
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IPD shows the bolts on their website as available.
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Hi,
Can you provide a link to what you found?
I probably don’t know how to use their site.
I don’t see where IPD lists anything earlier than 1993 for 850s. He says His car is a 1986.
I have no idea when Volvo started making FWDrives when they said early on of the worlds rush to go that route, they wouldn’t. That was a big set of misstatements!
I gather one would or could “assume” that earlier and later lower ends, of both engines, might be kept the same.
Assuming is dangerous though!
Phil
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posted by
someone claiming to be Tim
on
Sun Apr 17 05:56 CST 2022 [ RELATED]
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https://www.ipdusa.com/products/16681/Engine-Connecting-Rod-Bolt-Genuine-Volvo-1271900-236399
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Hi thanks!
I see my mistakes now. It helps to get the right year into the old noggin.
Phil
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Hi Chris,
Thanks for your input and I'm in the same boat as you as I'm neither of those mentioned too.
I'm in no way as knowledgable as Klaus with these all aluminum engines and Volvo models.
But bolts, to me, are to be as a standard as they can get everywhere. Limits are mostly cost driven with a dose of physics thrown in to keep it real.
There are so many types of fitted joints and stress analyses with or without heat related applications, that the bolts are the least of the problems.
I have seen high speed camera films of engine heads actually moving around on the head gaskets from all the combustion "banging." They don't call engines "bangers" for nothing.
They were furnished by Caterpillar diesels for my classes in machine tool metalworking back when I was an instructor in the eighties. Stationary engines with bores that you could stick your head into.
Things like casting the head and the block poured as one piece was thought up a long time ago and is another story all by itself!
When we start having to use gaskets mediums for containments of gases, fluids and what have you, then bolts or rivets, are your choices for fasteners.
As we know with home products, Rivets can make many things a non repairable throwaway? Luckily they haven't gone that far... yet?
In the case of those rod bolts, it's ludicrous to pay $20 a piece for them IMO. I believe they are even made of stainless steel so since I'm in the boat like you and being an old salt maybe ARP 's special steel might be an option someplace on that? 304 stainless is not so exotic but still very affordable. If, you don't go crazy with extra chromium for rust resistance and nickel for heat resistance in a 250 degree environment of an oil bath?
Talking about down there in the sump and crankshaft and rod loading from combustion down forces over side thrust of the crankshaft against exiting combusted gases and creating vacuum is probably why they are only using those small headed (external torx) bolts as you see in the package the poster provided.
Are they after a weight reduction or selling more tools?
I guess Volvo uses them there? I have no clue about it.
I have read about those newer engines having special tricks and tools.
Oil seals that are put in from the backside of housing enclosures, so you have to pull it. Nuts! But I bet they reuse the bolts.
Another rule of thumb I learned, in being an unofficial machine shop to engineering liaison, is that the bolts diameter is used in calculating or limiting the thickness of joint plates. There is a relationship in that marriage.
The rod cap only needs to be so thick and the calculation goes back and forth to reason things out.
Everything was prototyped that we used today and lots of it was trail and error or "lucky we got it to work longer that time."
(:-)
Yep, a 240 man, without a car or mechanic payment since 1978.
I take aspirin, if I get new car fever and if that doesn't work, I buy a quality used one!
Phil
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But bolts and screws are as important as anything in a machine! Sure a con-rod screw may be a little simpler to spec than the con-rod itself since they are, as you suggest, built to a standard, but there's a lot that goes into it.
Lucky for us engineers they're usually cheap, readily available, and strong fasteners available (Grade 8s are mass produced and wicked strong). I don't know the struggles of a Volvo engine designer sitting in Gothenburg in the 1980s, why exactly they couldn't spec an off-the-shelf screw, but perhaps in their world it is just that.
I work in a role where I get to design bolted joints fairly often. Bolts and screws are fun! (Nuts not so much) Making sure they meet the customer specs, finding the balance of size, material strength and number of, making sure they fit and can be installed (and not loosen), material interactions, corrosion issues - It's a good time! Even more fortunate for me, it's low-volume and cost usually isn't a driving factor. In one particular application, backed into a corner requiring high strength and corrosion resistance, I saw a five-figure price tag for just the material to make a custom screw. A lot of mother-may-I went into that one.
Even further off-topic, look into "Superbolts". They're pretty wild.
-Will
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XC60 / Odyssey
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Hi Will,
I know we are story telling and it’s off topic, but hey, it’s a reading entertainment site isn’t it!
Well, I looked into those super bolts. There are wild like you said.
Using a tapered body sleeve to take up the clearance around the bolt left to get them assembled.
That makes for a very interesting fastener system to lock the joint from creep.
Using several smaller bolts to “jacking” them into its stretch mode without the twisting torque on a
fastener was interesting too.
That reminded me of what I did to keep a thief from stealing another generator off my Harley back in the mid seventies.
I drilled and tapped only one hole into the head of bolts and into the engine casing.
I Installed a set screw that went into the case and along side and engaging the body of the bolt with its threads.
In effect, it’s keyed the bolt into the case at its torqued up value.
One has to shear a hardened set screw by trying to shear it. The bolt head that will not even begin to move a speck to rotate loose or tighter to snap.
No thief’s, in the pocket hand wrench can do that.
I never wanted to try a breaker bar to see if I could get it started either. It’s an unproven idea.
50 years and a hundred thousand miles later, I never had another “easily stolen” one from my bike though.
I do have to remember to use an Allen wrench, as it’s not easily seen either! (:-)
A lot of changes from the mid eighties with my temporary position with Southern Cal Edison Power Co. overhauling steam turbines.
Brutal work using 5” slugging hex wrenches and 20 lb. sledgehammers for disassembly.
These through studs had a deep hole from one end.
We depth micro measured before and after we used 1-1/2” drive air impacts to set the initial tightness.
Then when heated the stud by inserting Cal rods. We then rotated the nut X more degrees of turn.
Measured again after it cooled to read the amount stretch.
Redo the ones to make them all the same within a tolerance.
I never found out how much or what tolerances they shot for.
They were good at hitting what they told us to do, first time, on lots of those fasteners.
Yep, I decided I didn’t want to become part of the traveling Steam Division, nicknamed “Animals” with Edison.
Some generating plants are in the deserts and they have to keep their wrenches in buckets of water, so they can handle them.
Other plants are nuclear and those guys got to volunteer to “glow in the dark” for the over time money.
Those guys, Live in their own pull behind trailers and ate lots of bologna sandwiches.
This is in the mid eighties.
Very very loyal and hard working employees but they did make two thousand-plus dollars, for a minimum of seven day week, after week.
Oh yes, Many were divorced too!
In the seventies, I used to machine gear boxes as big as a VW car would fit inside of.
On those we used 1-1/2 standard bolts and a hydraulically driven torque device.
They were far smaller and didn’t have the heat that a 1200 pound steam system has.
Did you also see the reinvention of the “Bellville” washer system by the Swedes?
Tapered serrated teeth on the faces along with the spring action. Anti-rotation and maintaining tension inclusively. I noticed the doubling down to do it too!
You are correct about very wild “patents” happening.
I also loved your statement to those bean counters, against the designers, while saying, “Mother-may I”
Use this? (:-)
Phil
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You Sir, have so much more practical experience with all of these things than I! Sounds like interesting work (but work nonetheless). There's a reason they call it "work" and not "fun".
That was nice of you to provide a replacement generator for that Harley driving thief all those years ago. I'm sure they appreciated having a proven tested part at hand when they needed it most. ;-)
-Will
--
XC60 / Odyssey
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“…. I also loved your statement to those bean counters, against the designers, while saying, “Mother-may I” Use this?…”
Real life story (well maybe):
The company finance manager and the chief development engineer are having a heated argument over the design of a new product. Unable to convince the finance manager of the need to spend more money on the new design, the engineer yells “What the heck? You’re just a damn bean counter!” The finance manager calmly replies “ You’re right. And you’re just one of the beans.”
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ARP seems to be the go-to for any high strength engine assembly bolts, Volvo or otherwise.
https://arp-bolts.com/kits/arpkit-detail.php?RecordID=5104
Price seems high for 10 little bolts, but 220ksi tensile strength material for specialty applications doesn't come cheap I suppose.
Best,
Will
--
XC60 / Odyssey
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Hi Will,
I have to agree with your thoughts on the cost of those bolts for the application that the company has spotted a possible market and it being a little bit ridiculous.
I bet Volvo never even got close to requiring bolts like those or their per unit pricing!
I read on into their spiel for the “non engineer” about metallurgy with their special steels provided to NASA.
I saw let them being made with stainless steel with a grade of 10, of which, from my experience means a certificate of the metals batch origin is required on some contracts.
The key word here is the sales pitch for “Racing” and the lure for those bottomless money pockets!
No matter what you do to a production car, that is made for any number of populist customers!
This car is a street level Volvo!
It’s not going to be treated like a military jet engine or on a top end speedway for a few hundred miles, while only requiring a left hand turns!
Like I said, in my earlier post, those bolts only keep the rods from flying off the crankshaft.
The whole TTY (Torque To Yield) thing is being over emphasized as ruining bolts!
It is a method of applying a maximum strength stretch or torque with a margin of safety built in!
Ultimately you don’t want to break a bolt on installation and you have to consider its environment.
Head bolts get more heat than the rod bolts will ever see and still get used twice!
All torque methods apply stretch rated to the thread capacity related to its engagement into a material used. A rule of thumb, used in my relationship with engineers of my era, is that the maximum strength of any thread is achieved at a specification of engagement. It is the diameter is multiplied by 1.5 time to give its length needed to have the “bolt head to snap off” before the threads strip out!
Machine taps are made alone those lines too!
Bolts are made with some longer threads mostly for the application of nuts or it’s considered an adjusting screw! In the case of the 240’s alternator adjustment screws.
This company’s bolts are being used in aluminum here and the aluminum cap of the connecting rods cross section, is thinner than the bolts are of stainless steel!
When or how does the bearing cap going to get that much tensile strength forces applied?
Does Volvo use even stainless steel to begin with?
Most bolts on cars are grade five.
Farm tractors and commercial equipment use grade eight. In some cases with giant torque wrenches!
On steam turbine cases, that have 3” diameter studs, that get heated internally and nuts turned so many degrees and remeasured. Another torque method that doesn’t ruin threaded bodies!
Their used over and over for many many years!
Again, safety factors are reached by laboratory tests!
ARP has to have to have their own in house reliable certificates for NASA or government contacts!
I doubt a 850 owner wants to go that far, but the moon is 240,000 miles away!
I feel that the pocket book is more down to earth in this case! (:-)
Thanks for the sites technical reading material, even for ordinary folks that like a racing sales pitch!
Phil, a 240 man!
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I tend to agree with you that a bit much is made to do about TTY fasteners but perhaps not in applications such as this, a relatively small screw in a highly stressed application. Indeed head bolts/studs are subject to heat and stress cycles but so are the connecting rod bolts - plus bending loads.
This is exactly the type of application where you want to ensure that fasteners are installed to a prescribed torque that yields (haha) a preload that will never be exceeded during the life of the bolted joint. Otherwise there's a chance that the cyclic loading will cause that preload to lessen and the joint to become loose.
Now, looking at ARP's installation instructions, they seem to throw much of that out the window when they say if you don't have a stretch gage, just go ahead and torque to 50ft-lbs. I suppose that's more than Mother Volvo's 15ft-lbs plus 90deg. Which would account for their NASA grade superalloy...
1.5 times the nominal thread diameter is a good rule of thumb for thread engagement to ensure that the fastener fails before the tapped hole (which is always what you want; a screw is more easily replaced - except maybe in the case of a 1996 Volvo 850 connecting rod!) The formulas governing that calculation can be found in Fed-Std-H28. The driving factor is the material strength of the internal vs. external threads. A mismatch such as we have here, a high strength fastener and a relatively weak aluminum connecting rod will require a longer engagement to develop the full strength of the screw.
I find it odd that the Volvo online parts catalog lists zero engine fasteners. We must be missing something. I think a call to the parts desk would be in order. I wonder if, although they don't list it for the 850, it is the same as any of the later white block rod bolts. The connecting rod prescribed for the 850 is also listed as applicable to 42 other Volvo models, including 4, 5, and 6 cylinder versions up through 2005. The connecting rod bolt Volvo PN 9125471 cross references to many of those models. That might give the OP's local dealer parts desk something to start from. Or if not, it may be, like ARP's installation procedure, close enough.
Will, currently a Honda Odyssey man!
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XC60 / Odyssey
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Hi again Will!
I say it’s nice to have a conversation with someone that is quite a “litterateur” of technical nomenclature. (:)
Apparently, you have your sources that I have none of.
I’m aware that connecting rods can flex or bow but bending of the rod end cap within its joint in particular means we are running an engine way up at the top of its mechanical limits. Racing does that.
You have another valid point on a worn engine where the crankshaft might be able to shift itself longitudinally, due to worn thrust surfaces of the crankshaft journals.
Maybe “pounding” of a clutch at high RPMs can contribute to that bending of the connecting rods laterally. Even In this case, I still doubt that the bolts are breaking first.
I have seen broken connecting rods with caps still on the cranks or at least the bolts were still in their holes. The rods gave out in some other ways, like lack of lubrication and twisted themselves into two or more pieces!
Now, if they are now putting too small of bolts in the application then who gets to replace the $19 bolt, ARP? I bet, not, if it’s still in one piece!
I wonder if they ever get any warranty claims?
Is there a racing clause down at the bottom, in fine print? I just don’t see the need for a mass produced street engine to have those NASA bolts.
You are correct about the buying power of Volvo or any other engine manufacturers and their part vendors supplying bolts.
42 other Volvo models alone, Wow!
Those bolts should be as plentiful as popcorn kernels in a bag and about as cheap.
For whom … is another question!
Yes, I’m sure they want to have them being replaced, in the future, if current engines are supported.
Now missing replacements or not having an equivalent part number reference, just might help scrap out those cars quicker.
It wouldn’t call it a “Better Business Bureau” decision but a bureaucracy is close enough.
In his case or mine, I would put them back in.
As I’m sure a rebuild warranty, of 90 days or a year at best, than those used but proven to be good, bolts have already done?
You can tell I have a problem with those bolts being ruined coming out of a working engine.
I have used too many junkyard items to say I have gotten stuff not reusable.
Maybe a length gauge call “vernier calipers” can rule out the excessively long ones.
Does anyone have the specifications on them new or some comparison reference to judge them by?
Even New bolts have the “propensity” to be like popcorn kernels, as those don’t always “all” pop either.
You see, there’s something weird about nature and the whole idea of pushing limits and throwing it away.
IMHO we are treating everything, including us, with the same mind set.
I just told the wife that I have been reusing her for 47 years and she said, “likewise” back. (:-) (?) (?)
Good cars are hard to shake loose, when they continue to be affordable! (:-) ha ha!
Phil
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Just a thought. Head bolts are NOT reusable, yet they are not subject to constant banging. I am sure if they were reused, they would work quite well - for a while.
It is trust we are after, not someone's say so. An engine that falls apart is almost as dangerous as wheels falling off while moving. Neither of which is acceptable.
Find new connecting rod bolts! They exist for ALL 5 cylinder engines and are the same strength as far as I know.
--
Keeping it running is better than buying new
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posted by
someone claiming to be Hugh
on
Thu Apr 7 22:21 CST 2022 [ RELATED]
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Klaus and everyone else who responded,
I want to thank you for your replies. I was able to confirm that Volvo no longer makes these bolts. The garage that is rebuilding the engine, was able to buy a set of bolts from APR. I think the cost for the 20 bolts was just over $200. I am thankful these bolts are available. I hope to be getting my red 850 GLT wagon back soon.
Hugh
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Will, Phil,
Been reading the thread with a bit of interest. I'm neither a degree'd engineer nor a metallurgist, but I think there should be some consideration given to any upward thrust of the piston/rod assembly applied against the rod cap that may occur anywhere within the 4 cycles.
When the piston/rod assembly is within the last 90 deg of the exhaust stroke and the first 90 deg of the intake stroke there is significant deceleration and opposite acceleration at play. Something has to keep the piston and rod from continuing right out through the head. And when the crank starts pulling the p/r assembly downward for the first half of the intake stroke there is continued load against the rod cap.
So the question - is this upward load against the rod cap significant enough to warrant all the fuss over bolt strength? It might be. Someone smarter than I would have to calc all that piston/rod/wrist pin mass times stroke length times acceleration......
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Hi,
You have made me curious about these front wheel drive engines now?
Why can you not reuse the bolts that were in the engine?
There is probably a reason why Volvo doesn’t offer them, because of, no demand being one!
Wanting to sell more cars could be another one? But, if they were really that critical that would only work up to a point. Bolts are too available, so, Not so, IMO?
On the 240s you can reuse the head bolts, but only twice.
I wasn’t aware that the connecting rods bolts could ever be put under the stresses that the head bolts can get.
The bolts only hold the cap on that makes up a journal’s circle.
The actual thrust of the piston is transferred onto the upper end of that journals circle.
The cap only holds onto the rod and the piston assembly as a unit from being flung off the crankshafts journals.
If the mechanic is worried about those cap bolts, what does he think he is going to do about the crankshafts bolts? They have to hold the whole lower end together from the hammering from above!
I might be a little behind the times here but I wouldn’t worry about those cap bolts.
I would worry more about him not keeping the rod caps attached on to each rod as that the cap came off of the crankshaft.
And changing out those cap bolts could be a mistake! IMHO
You see, In today’s engines the rods could be made from sintered metal forgings or not?
A whole newer technology may have been used in there? I have no idea about the 850s but Ford was into that with their cars.
If these rods are like those mentioned above, the big ends of the rods are intentionally made to be completely machined first!
At First the bolt holes are drilled and tapped to remove material.
Then the cap is broken off from the rods big end!
When it’s broken away from the rod itself and the split line is a matched set to that connecting rod only!
The bolts are then installed and then the big bore is machined so they are a set!
On earlier engines the split line had to be machined separately and then assembled.
The rods are weighed and gathered as a group set for balance along with the pistons! Everything but the bearing inserts are there and heck, they might even be weighed from the manufacturers as a set, for all I know?
On the 240’s the upper “camshaft” has numbered caps in a sequence from front to rear when the cam journals are “line bored.”
I have never opened the bottom of a Red Block, but I can only imagine a similar thing is done down there!
It is one of “many reasons” why those engines are named as close to “bulletproof” as you can get because the Swedish know or knew their metals too!
With the 850’ and other later types of engines, Volvo started shaking many different hands!
In fact, all of their cars, like many other production cars, they shopped over many vendors!
Like the 240 they get a little bad, with a lot of good, if done wisely!
So with that, I would question, why not used everything in that engine the way it came apart!
I liked the idea, that the whole engine has done a lot of spinning.
So the ingredients are still there and proven to be in harmony!
It has gone many miles!
Don’t mess with success.
Sometimes, new parts don’t meld without some teething!
You only want to replace metal that has wore away and those bolts don’t wear in this case!
Just my opinion for what ever it’s worth?
Phil
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