Doc Talks: Evo Cylinder Stud and Head Bolt Update
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- Опубликовано: 15 окт 2024
- This week, Doc Harley demonstrates the evolution of cylinder studs and head bolts.
Now, here's a brief video summary from Doc;
Allow me to share some lessons I've learned over years of working on Evolution or Evo engines. One common problem customers would experience is failing base gaskets, usually due to issues with the cylinder studs or head bolts.
Early Evos from 1985-1994 used head bolts made of soft metal that was prone to stretching over time. The service manuals at the time did not recommend replacing the head bolts during repairs. This often led to customers needing repeated repairs as gaskets would fail again after a season. These Evos also installed the cylinder studs with a shelf above that the long head bolts could bottom out on. Between the stretching bolts and potential bottoming out, it created problems.
In 1995, Harley made some important changes. They started installing the cylinder studs upside down, which prevents the head bolts from bottoming out on the shelf and provides better clamping force. However, the earlier manuals did not specify this updated installation method. I've also found issues like this on other models, where the manuals were later updated with improved repair techniques learned over the years.
I demonstrate some tips for safely removing old studs and show how to properly install the new upside down studs. Using an old bolt and special Harley bearing tool as an installer prevents bending or damaging the new stud during installation. Following the latest service manuals and updates can help prevent the frustrated repeated gasket failures customers were experiencing on their Evo engines. Proper replacement of parts like this, learned from experience, is key to reliable long-term performance.
#lowcountryhd #docharley #harleydavidson #motorcycles #biker
These are the kind of "tips" I love.
Great to see information on the EVO motors. 🏍💨🏍💨
You the man Doc! A lot of HD dealerships in my area won’t work on evos or anything older than 2009.
Sorry to hear this. We will but you have to wait for me to get to it 🤷♂️…..Doc
@@LowCountryHarleyDavidson I’ll ship mine out to you Doc. Might cost me to fix it more money than a new one cost.
Just joking Doc.
I’ve been doing my own work for over 50 years.
Hell The EVO is a modern engine compared to when I started riding and working on Harley’s…
Thanks for this, I have a '94 FLHS
Going to replace all of the topend gaskets.
This never entered my mind,
As well as it should have!
How many times have we seen 10-20 year old class 8 truck's for sale with the usual;
"Freshly rebuilt engine, just needs a head gasket"
Yea, they reused the same headbolts!!
(I know because I am guilty too)
Your knowledge is so helpful,
Thanx for sharing!
That's great DOC, I have a 94 lowrider I bought new im working on right now, thankyou!
Best too you…Doc
Excellent video Doc
Thank you kindly Victor…Doc
Doc, that is very very important information. Thank you
Thank you Jim….Doc
Nailed it!! Great work brother. SPORTSTER4LIFE ☘️ ☘️ ☘️
Always love to hear from the Irish ☘️….Doc
Hands down,Doc is the baddest Harley mechanic on the planet............
Shhhhhh…let’s keep that a secret…Doc
Per usual great videos Doc! Please keep up the great work. Thank you for sharing your knowledge Sir. Priceless!
Thanks, will do Vinnie….Doc
Years ago when I was rebuilding my FXR the shop owner/mechanic told me to do that.
Awesome News….Doc
Hello Doc! its always a pleasure watch your lessons! I really hope HD values you as much as we do becaue you are a really HUGE SOURCE of knowlege! thanks doc for sharing!
I appreciate your post…..Doc
Another great tip, thank you Doc!
Thanks Jeff…Doc
great tip last couple yrs. getting into the great EVO before flathead /panhead//shovelhead HAPPY TRAILS
Got to keep the Evo running….Doc
I'm glad I save all this videos, you the man Doc !
I appreciate your support….Doc
Thanks what a wonderful tech innovation that we can use and a great way to pass on motorcycle technology history
Our pleasure Richard…Doc
I used brand new head bolts and studs, I don't trust the studs to not be stretched, using Cometic gaskets too. Helping my nephew rebuild his after someone screwed it up. He is learning a lot and I feel good showing him. Another good tip is to remember to put some oil on the flat of the head bolt and some oil, not much on the stud so you get a proper torque reading.
Pass the knowledge on 👍….Doc
This is a great tech tip makes a lot of sense 👍
Thanks Richard….Doc
Sage advice from the sage.
Your too kind….Doc
Good stuff, Mike.
Thanks for your support Roger….Doc
Thanks for this important info on the studs/head bolts! My EVO is ready to reassemble with my next step/task being to install 8 new studs (Colony) and 8 new head bolts shortly after. (Colony too) I picked up the 8860 at Harley. My new studs did not come with Thread-lock already on them, so I wasn't sure whether to use red or blue. Your studs show red in this video. I hope my assumption of using red is not a mistake.
THANKS for all your countless effort & time!
I always look forward to learning from the Legend 🙌
Thanks for watching from the Heavenly island….Doc
What great knowledge you are giving. Thank you. Will remember this tip for sure
Keep up the great work bro
Thanks, will do Frank….Doc
If I ever win the Billion Dollar Lottery..Doc you will be my personal mechanic
I’ll keep my eyes peeled on the Lottery…Doc
Great video! In most cases i have found the rear cylinder on the left side most often leaks. I have also found that the bottom of the cylinder is not always flat, especially on early Evo's. During production the machining tool would slightly deflect causing the surface to not be flat. Harley corrected this later. Sometimes a light machining cut is required to restore flatness. Basically re-decking the cylinders top and bottom.
Ron not disputing what works for you, but in most cases it's literally the deck surface of the engine cases giving the most problems. When I build a engine, I lap the case halves together and then I bolt them together and indicate both deck surfaces and they always need a light skim cut to ensure the surfaces are both parallel and flat.
Thanks for listening Sir.
@@t.s.racing Your suggestion is also a good idea. However I was a Manufacturing Engineer at Harley when the problem of the cylinder base not being flat was discovered. i changed out the tooling to make it more rigid and used a more positive cutting insert to reduce pressure. You can check this on a surface plate, ideally with a hole to fit the cylinder, and using prussian blue.
Thanks for adding your knowledge and experience….Doc
Great information Doc! Experience can make all the difference in the world when doing a job!
Thanks Jeff…Doc
Thanks Doc, excellent tech tip!
Great information Doc. This will come in handy as i am doing a ground up restoring on an 86 Liberty edition FXR.
Sweet project…..Doc
Hello Doc
Thank you so much for all that you do for your us , your students. I am writing as I need your help.
I am restoring a 1989 XLH 883. My head bolts are marked CP part # 16480-92.
I brought this topic up with my local harley service dept. All I received was blank stares and shrugs.
What upgraded head bolts am I looking for.
Chuck
The last year of the air cooled sportster head bolts or S&S sells good head bolts…Doc
Saw this just in time. Was getting ready to do a full top end.
That’s pretty interesting.
Should we replace our head bolt’s every time we take the upper end apart or leave them once we have replaced them with good Harley studs ???
There is no information in the Evo Service Manual for when to replace head bolts. With the new studs I would still replace head bolts with every top end rebuild. It’s good practice….Doc
Sharing is caring
I like those Hi-Tech piston and thread protectors. 👍
Me too…..Doc
great video. hated to click the like but because the count was at 883 which made me smile
Thanks…Doc
great info thanks Doc.
Thanks for watching Tracy….Doc
Thanks for the Info . Enjoy the Videos
Thanks for watching…Doc
Always awesome information DOC! Too bad My dealership in my area Old Glory will not work on any bikes older that 10 years..
Sorry to hear that….Doc
You always have some great tech tips, Thankyou.! Getting ready to teardown my 93 fxdwg.
Take your time, follow the Factory Service Manual and enjoy the journey….Doc
Great info! Thanks!
Very, very interesting video.
Thank you for this tech tip.
Regards from Austria.
Thank you Wolfgang…Doc
Hey Doc ,I have a early 1984 FLHT that needs a top end, I know this has not been apart except the updated lifters. Can I put the updated stud and nut combo on in place of the "upside down" early set up? Any special considerations? Thanks for the knowledge you offer to our community, a true class act.
If you do this you will need head bolt washers sold by S&S that are placed under the head bolts because that year had deeper head bolt pockets….Doc
Always top advice. Thank you.
Thank you….Doc
Great vid Doc. Harley dealers up here in the northeast would not touch an Evo
Sorry to hear that….Doc
Great tip Doc is this the same on sportster's and Buell's or just Evo's
Yes but using Sportster or Buell parts….Doc
Doc, you da man!!
Thank you Peter…Doc
great info.
Thanks, I am about to do base gaskets on a '94 and this is a big help! Doc, should I also incorporate the kit that adds oil gallery sleeves to the cylinders? (The Oil Fix, from Hayden)
I’m not a big fan. I would rather you have someone lap the base flat and check the surface at the top….Doc
@@LowCountryHarleyDavidson Thank you for your reply.
My ‘93 Heritage which I bought new and still have,kept blowing base gaskets under warranty. After the warranty ran out I installed the Hayden oil spigots which solved the problem. I then put over 150k more miles on it before rebuilding the engine. I reused them after the rebuild and so far after 32k miles,still no leaks.
Very informative video, thank you.
There’s experience for ya. 🙏 👍🏻🇨🇦
What size nuts did u use doc??? and also thanks for the great info ...keep doing u
I have an early 84 Evo and it had the stupid studs in it. They didn't use them in 85, the top bolts had the threads on the outside, unfortunately to put the newer headbolts in, the holes in the head had to to be drilled out
Wow! I’ll have to look that up again, thanks…..Doc
My shop teacher taught me that when installing studs, you should not bottom them out - but take them back half a turn. This stops you from risking splitting the housing, afterall the clampload is being achieved by the bolt exerting force down upon the head and the thrreads in the block are what hold it down. You may beg to differ, but it hasn't failed me yet.
I know a few shop teachers with skills and knowledge better than I. I share what I know now….Doc
what if you have stripped threads in lock, can you fill hole in by welding drill & tap new threads
Lovet. Just lovet
Ok doc I have an 09 street bob and a 07 build 08 street glide both now 103 10/1 comp. What manual should I get. I think 13 the bike changed in dyna but 09 for street glide in frame. Thanks Doc u good
I would choose 2017 for both….Doc
Another great tip from the expert. Thanks Doc.
Thanks Brad….Doc
Doc please tell me.. So you can leave the gastank on while pulling top end on fxr i am in the middle of tearing mine down for seals and gaskets.. I have shifter play and need to address that as well as doing base gaskets... and now to top it off i need to take heads in for broken exhaust studs. I have never done top end on a harley new territory for me. Also push rod considerations while removing and installing rockers have found some video about taking time to torque down things as oil channels bleed down. You the man. I have nobody around here that will work on fxr anymore.
Attempting that much work. Take the tank off. Be prepared to take a long time getting the base gaskets off. Yes you should have both cam lobes at the lowest lift…..there is so much more. Get a Factory Service Manual and follow each step
you can use any bearing that will fit in the head bolt.
I was told you need to heat up the case to break the loc tite in order to get the studs out
Wondering what your opinion was ???
Hard to do this safely but yes….Doc
Hey Doc. liked the idea but have another question. Could you stick the head bolts in a lathe and take say 0.030" off of it. What are the bolt strengths, those types of bolts, well nuts actually are seen in industry and are available? Could you buy stronger studs, and these bolts and eliminate the problem for good. You said to trash the bolts after the 4th use, something sounds wrong with me as these studs and bolts should not stretch out that bad that the base gaskets go out that much. Many modern engines use torque to yield bolts so you trash them after first use. Just seems to me someone should have built a better mouse trap by now.
I am not an engineer. Just sharing what I know at this time….Doc
@@LowCountryHarleyDavidson I was just wondering, as this leaking problem seems as if you hit right on the head on what was happening. I can imagine that since it is such a long-stroke engine with those aluminum cylinders and heads, there have to be some rather significant thermal expansion issues. Older Air Head BMW's have a similar issue on older bikes, 4 long studs per cylinder, but they used normal shouldered nuts vice those unusual internal threaded bolt things. They are torqued down to what makes me worry every time, the studs have to be made from spring steel or use unicorn tears and fairy dust in their construction, have seen them break however. A new stud if you tap it with something has a strange ring, like a bell not like a bolt, so there is something strange going on there. Haven't had to get into an oil head yet, thank God, they are typical German design "Insane complex" for absolutely no reason. As for Goldwings, everything is under plastic, absolutely everything. Changing out the air cleaner is an afternoon project, and changing out the rear tire on a double-sided swing arm model, you MUST have a lift with a removable rear tire plate. All Jobs end up with a LARGE pile of plastic on the shop benches, floors, stools, dogs doghouse, at a minimum. Yes normally Wings don't brake often, but when something fails it is an absolute chore to get to, maybe a simple job once you get to the issue but until then, it ain't pretty. Every brand has those Whiskey Tango Foxtrot Oscar, what were they thinking design issues, but it all pays the same.
@Peter Angles I avoid working on Harleys as much as possible, every time I get sucked into working on one I say to myself "Never Again", but you know how that goes. Agree they are not the most reliable machines out there, you're constantly fighting issues that should have been addressed several decades ago, but life is life.
Had base gasket leak chronically. Later found out my oil return had a broken tooth and oil was sumping excessively
I will never dig that far into the bike (I know my skill level), but it sure is interesting.
Thanks for watching Fred….Doc
It's pretty much a garden tractor/ lawn mower engine. Don't be scared
Harley for being #1 sure has lots of problems, bolts, valve guides, cam chain tensioner, head breather going into throttle intake, oil scabbing . You would think AMF is still around. After years of building motorcycles Harley would have have top notch quality!!!
Attend a HOG rally and hear all the positive…..Doc
I have a question about an Evo. I have a 1997 road king 45,000 miles.
It has started blowing gray smoke out of the right side exhaust.
It does not blow gray smoke all the time, mostly on hard acceleration.
Any ideas of what I should be looking at that would cause this? Thanks.
Possibly the beginning of an exhaust valve seal failure. Remove the rear pipe and look inside the port. If you see oil around the valve stem, that’s it….Doc
Hey Doc can you transfer to a HD dealership in So Cal? We need you!!!!!
😆😂….too many rules in your state but love to visit….Doc
@@LowCountryHarleyDavidson …I guess I’ll have to move to you 😃
I really really like that Harley shirt you're wearing!!! Is there some magical way I could buy one? THANKS!
It’s our uniform. Not mine to give…..Doc
@@LowCountryHarleyDavidsonWell pardon me! I didn't ask you to give me the shirt. I asked if I could buy one.....Jeff
How many guys dropped that ball bearing in the engine when they removed the head bolt. Yah I know the bottom end should be covered. But you know it’s happened.
Scary thought….Doc
Love your work Doc 💪
Living The F 🤪 KING Dream
Safe travels 🙏♥️🐾🐾🇦🇺
I have new Colony Cylinder Base studs for my 1993 XLH1200, the say turn the shoulder to the base, the height is different, does it matter?
Yes it matters….Doc
@@LowCountryHarleyDavidson what do I do if FSB said to run the stud shoulder to the base and and I am just below the 4.770 height they call for? Is that sufficient for the head bolts to reach?
Thanks for the good content Doc
Anyone. 1993 wide glide never been apart. All my studs seem to have different threads on one end of the stud, meaning that the factory “cp” 12 point cylinder stud “cap nut” nut will only screw on stud end with the shoulder. What am I missing here? So are the threads different in the engine block where stud screws in than the cp nut. Yes I understand get rid of the cp nuts but I feel I should understand threads first. Yes I understand clamping load and desire shoulder end to screw into engine the engine block and cap nuts to screw on to non-shouldered stud side. For now I just plan to purchase the cap nuts themselves(would replace everything if money grew on trees) as stud kits are big bucks.
Great videos, but wearing a microphone on your person would help with the sound immensely.
The 95 way of installation on those studs seems normal, the earlier way with having to measure the height seems completely stupid.
Hi... why are my head bolts on my evo motor solid bolts ..they're not like yours that are hollow and my cylinder studs are hollow with threads inside for the solid head bolts to thread into the inside of the studs.. ? I can't find any other evoi motor like this. .. do you have any info on this ? .. thanks man.
You have the first edition ( thanks for supplying the year of the bike) of cylinder through studs and male head bolts. You should contact S&S for updated studs and headbolts. Your heads will need headbolts spacers….Doc
@@LowCountryHarleyDavidson thanks doc... I thought maybe I had an aftermarket engine like revtech or ultima or an S&S motor.. because this bike is a stretched out big custom chopper. (it's an unregistered hand built bike so I don't know any year model ) I bought it as an unfinished project bike and I was wondering how I would identify the motor if it's an aftermarket engine. I live in South Africa so I'm a bit limited to resources . Thanks Doc.
When you remove the head bolt from cylinder stud, what keeps the ball bearing from accidentally dropping the bearing into the bottom end?
Your fingers…..Doc
👍👍
Try Arp?
OEM typically
i have a 1990 FXRP i will check it out i got a leaking base gasket now... Thx... that ball bearing looks like trouble if you drop it into the motor... so scary to use...
There had to be an engineer somewhere back in a dark corner of the engineering department's lab who designed these studs with the ring flange, or whatever the nomenclature is, to serve some purpose. Now what comes to my mind is why would anybody want to install them in the upward location. Like, what purpose would that serve? Apparently nothing since at the later date they were installed downward which makes sense as the ring flange would then serve as a stop against the engine case and establish the correct installed height. I am sure that some non-thinker mandated the upward position, and the rest of the flock followed along until one day someone with big brass ones challenged the concept and made things right. Another turd from the MoCo? You bet. But that has finally been rectified. Now, let's go for a ride.... RooDog....
Typical ''Management '' in most work places ,''Why are we doing it this way ? doesnt make any sense '' ,''The boss said to do it this way, so thats the way we are doing it '' .sometime later ''We have to change the way we are doing it '' , ''Why ? '' , Because the boss discovered it doesnt work this way, and now wants it changed '' GAWD we knew that all along !!!!!!!!!!!! hmmmmmmmmmmm
Me with a '93: 😭😭😭
That doesn`t jive with what I recently read about harley dealers refusing to work on anything over 10 years old.
What’s the conflict?
599
???….Doc
@@LowCountryHarleyDavidson im like 599th to like this video
Good trick with the ball bearing. Now if that ball bearing makes it past the rag into the crankcase is another story. 😒🤢🤮
My Evo is an '84 with actual grade 8 head bolts, ( not head nuts ) Never an issue with base gasket leaks. Harley got it right in '84 but has done it wrong since '85.
Man,,,I’m starting to miss my metric that never had such issues!
Wondering why your watching….Doc
lame lame lame
What’s “Lame”?…..Doc
Lol BS, thread is different on both sides. One side for bolt has more lose thread while the other side is mutch tighter.
Excuse me ☝️. Be careful what you post…..Doc
ARP studs.. you really can't go wrong..
Outstanding! Keep up the good work and thanks for all info. Regards from Sweden
Alway great to hear from Sweden 🇸🇪…Doc
Aren't those an "interference thread" or a "zero tolerance thread" ?? You really shouldn't ever reuse an interference style thread whether it be a nut bolt or stud..
I can’t answer your question Cody…Doc
Thanx 👍