Honda CB750 Sandcast

The Restoration Shop => Engine Mechanical => Topic started by: markb on December 16, 2011, 05:02:53 pm

Title: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 16, 2011, 05:02:53 pm
I've been mulling this over for a while and now that I'm sorting through everything for plating I should make a decision on whether or not to replate my studs.  For #5383 and my K0 I used the APE heavy duty cylinder studs and the head gasket and o-rings as recommended in Honda Service Bulliten #42, http://data.sohc4.net/SB750/750_42.pdf, (http://data.sohc4.net/SB750/750_42.pdf) to improve my odds of not having an oil leak.  So far, so good on those.  But on #97 I've taken great pains to keep everything as correct as possible like the 10mm rotor bolt on the crank, stock bore, etc., so would I be making a mistake by installing the heavy duty studs?  Another way to ask it may be would you pay more for it with or without the HD studs, gasket and 0-rings?  I've said this before, I probably won't be putting a lot of miles on it so maybe the oil leak thing is a moot point anyway.
Thanks,
Mark
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: kp on December 16, 2011, 05:07:10 pm
Mark
You know this answer cos your anal like me.  ;D  I might concede with the gasket and O ring though  ;)
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: Wayne on December 16, 2011, 11:41:55 pm
I wouldn't have a problem going with HD studs, as a matter of fact I'm going to. If your bike is "perfect" in appearance for the "judges" who's to know? I have never really seen anyone "tear down" a vehicle in a show. Certainly tear downs are done on the competitive racing circuit. Perhaps I'm not up on the lastest in show judging?  ???

If like me, you had to use vice grips or similar and heat to get yours out, re-using them is out of the question. Next comes the challenge on where to find NOS. A quick search shows:

90033-300-030 Discontinued

Part number 90034-300-020
has been superceded by
Part number 90034-300-030

So there's my 2 cents. I don't see it as a show stopper. For me I like peace of mind and a leak free, reliable engine.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 17, 2011, 11:04:42 am
Mark
You know this answer cos your anal like me.  ;D  I might concede with the gasket and O ring though  ;)
Coming from you, I'll take that as a compliment.  ;)

If like me, you had to use vice grips or similar and heat to get yours out, re-using them is out of the question.
If the vice grips didn't slip and chew up the stud, why would this be an issue?  I wouldn't think that using a propane torch with the heat concentrated on the case would put enough heat into the stud to hurt it.  Anyone else have an opinion?
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: Steve Swan on December 17, 2011, 09:20:33 pm
If the stud has not been stressed in any way, i.e, not twisted, gouged and overly heated, i don't see what's wrong with reusing them.  These studs are not subjected to any force dis-similar to other bolts, except connecting rod bolts or perhaps cam shaft bolts.  In racing applications (which i have experience with) connecting rod bolts were replaced due to stretching, generally every other teardown.  These cylinder head studs are not subjected to forces anyting like rod bolts.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: cb7504 on December 18, 2011, 08:00:06 am
If the original integrity of the stud has not been jeopardized in any way, reusing them should/would not be a concern. The following common reasons to discard them would be (twisted, bent, gouged, heated, etc:) Marty K.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 18, 2011, 04:04:40 pm
Not trying to be a wiseguy here but I guess that's another way of saying "if they've never been removed".  I've always had to use heat (propane) and a vice grip to get them out.  Usually the vice grip doesn't slip (I wouldn't use those for sure) but there's always teeth marks.  So it kinda brings me back to my original question, "Would heavy duty cylinder studs be OK for a "correct" restoration or would it devalue it for you fellow collectors.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: cb7504 on December 18, 2011, 05:05:37 pm
Mark:
 Have you ever used a stud removal tool they work great without leaving any marks. Marty K.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 18, 2011, 08:26:48 pm
This is the tool I use to install studs. 
(http://cb750sandcastonly.com/coppermine/albums/userpics/10002/DSC032895B15D.jpg)
I tried using them for removal but they don't have enough grip.  I have a feeling you're talking about something else.  I looked through my stash and have a some with no marks on them.  I must have been able to get them out by double-nutting them.  Plus I have a case I can pull the studs out and get enough if you can steer me in the right direction.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: Steve Swan on December 18, 2011, 08:58:06 pm
I have 2 sets of different sizes and jaw types of Vise Grips.  One set is has "plain" steel jaws.  The other set, i made copper covers for the jaws, the copper covers prevent scarring of what i am gripping on to. 

I don't see how using non-stock cyl.studs could devalue.  Who would ever know non stock studs were inside the engine, unless the engine was torn down ?  Anything to make the engine more secure against oil leaks makes sense to me. 

I use a set of Mac stud removers, they are pretty much all the same, such as these - http://www.aztecbolting.com/stud-removal-tools.html (http://www.aztecbolting.com/stud-removal-tools.html)
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: cb7504 on December 18, 2011, 10:49:40 pm
Mark:
       The one i am talking about is a cam lock version.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 19, 2011, 08:37:49 am
Thanks guys!  One never stops learning around here.
Mark
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: Riccardo on December 19, 2011, 01:54:30 pm
Sincerely i think that  the studs are solid....why change?...why unassemble?

The only problem can be the outer aspect, the refinishing.

Ok, if they are assembled on the upper cranckase you dont zinch them,  but you can paint them with high temp. paint.

Another, as some guys says, during the chrome or zinch procedure the old metals goes in sufference and they are not hard, after, as in origin.




Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on December 19, 2011, 04:21:38 pm
Good question, Riccardo.  I removed them because my original intention was to replace them with the heavy-duty studs.  Now I'm thinking I should have the originals and probably should have left them alone.   ::)
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on January 12, 2012, 07:01:10 pm
I have kind of a good news/bad news story.  I've been think about using standard studs instead of heavy-duty.  The good news is I found a source for the short (discontinued) studs.  While I was at it I bought a whole set.  Now the bad news.  The short ones look good but the long one look pretty rusty.  I’m not sure I want to use them.
(http://cb750sandcastonly.com/coppermine/albums/userpics/10002/DSC07985.JPG)

I have another concern too.  I compared them to two sets I took off two engines and there are different diameters.  One set is about .220” (5.6mm) and the other is about .240” (6.1mm).  I’m not sure which engines they came from.  Is anyone aware of different diameters?  The ones I just bought are the smaller diameter.  I’m thinking I’ll at least return the rusted ones but if the early VIN’s have larger studs I might return them all.  Any thoughts?
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: Wayne on January 17, 2012, 03:32:35 pm
Mark
I checked the studs that came out of 576 (E748). They are in the 5.6 to 5.7 mm range as well.
Title: Re: Heavy Duty Cylinder Studs OK On "Correct" Restoration?
Post by: markb on January 21, 2012, 01:18:10 pm
I think I’ve decided that I will use correct studs.  In my quest to find some I’ve run across some interesting (I think) differences.  I’ve started a new thread for discussion.
http://cb750sandcastonly.com/smf_forum/index.php?topic=725.07 (http://cb750sandcastonly.com/smf_forum/index.php?topic=725.07)