Author Topic: Engine Delima  (Read 4180 times)

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Offline Indy72

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Engine Delima
« on: January 27, 2015, 06:33:08 PM »
My son bought a CB350f for $700.00 that ran but obviously had been abused cosmetically and mechanically (list too long to go though here). He's not mechanical at all and he didn't consult me about it prior to purchasing. I agreed to help him work on it. My problem is I'm a bit of a perfectionist and it's his money (or lack of) were using to do this project with. So after tearing down the engine because it was severely weeping oil and I noted it had more than a one loose and or stripped out bolt in cam cover, head and case, I'm seeing that the cam and journals are in pretty bad shape and the valves have major carbon build up. The pistons and rings were replaced recently and it looks like the cylinder walls have been cross hatched. I haven't taken any cylinder measurements yet but the cam journals and lobes are in tolerance, albeit with a some deep scratches. The rockers look horrible.

So with very little budget to work with at least right now (he's still in college) and assuming the cylinders and pistons are OK (big assumption)
Where would you spend his limited funds, or maybe I should just put it back together as is, re-gasket, fix the stripped out bolts and let him ride it until it needs attention. I'll probably end up throwing some of my money at it too cuz I'm enjoying the project and this bike was basically my first bike (CB400f) while in High School.

'72 CB350F

Offline 750cafe

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Re: Engine Delima
« Reply #1 on: January 27, 2015, 07:03:25 PM »
I would see if someone on this forum had some good used rocker arms, Ebay, this place: http://www.hondabikes.com/fiche_section_detail.asp?section=2555996&category=Motorcycles&make=Honda&year=1974&fveh=132737 or Z1 Enterprises.
Perhaps you could even find a good complete cylinder head just to use for parts.

Eric
« Last Edit: January 28, 2015, 07:59:15 PM by 750cafe »
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline Indy72

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Re: Engine Delima
« Reply #2 on: January 28, 2015, 04:16:45 PM »
Digging deeper reveals more issues. Not unexpected though. The PO used a dremmel tool on the deck. >:(
'72 CB350F

Offline Vinhead1957

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Re: Engine Delima
« Reply #3 on: January 28, 2015, 05:34:06 PM »
Gougamatic   Might be able to shave a little off

Offline Lostboy Steve

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Re: Engine Delima
« Reply #4 on: January 28, 2015, 06:42:29 PM »
Yes, I would try to find someone to deck that ever so slightly.
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Offline Indy72

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Re: Engine Delima
« Reply #5 on: January 28, 2015, 07:07:16 PM »
Would this crack worry you? It looks like a crack in the case where the Clutch anchors to the case and it seems to go all the way around the mount.
« Last Edit: January 28, 2015, 07:10:55 PM by Indy72 »
'72 CB350F

Offline 750cafe

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Re: Engine Delima
« Reply #6 on: January 28, 2015, 08:01:40 PM »
Yes, I would try to find someone to deck that ever so slightly.

Ever so slightly??????   ::)
At LEAST .05" has to come off of that surface to make it CLOSE to flat.   :(
Who was using that deck as an anvil?

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline Indy72

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Re: Engine Delima
« Reply #7 on: January 28, 2015, 08:17:29 PM »
So, I guess Id be time and money ahead by buying a new (used) case?
'72 CB350F

Offline 750cafe

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Re: Engine Delima
« Reply #8 on: January 28, 2015, 08:35:38 PM »
You will have to pull the pistons/rods out along with the cylinder studs to get that decked. Then, you will have to get a custom made lower end gasket made by Cometic Gaskets to fill in the missing material to maintain the same deck height. Cometic does not charge much for the custom gaskets. The machine work will cost much more though. I would be inclined to find another parts bike that hasn't been destroyed like that one myself.

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline lrutt

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Re: Engine Delima
« Reply #9 on: January 29, 2015, 04:41:17 AM »
Got to say, this is a money pit. If it was a 400f maybe, but not so sure a 350f is worth the effort to be honest.
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Offline Indy72

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Re: Engine Delima
« Reply #10 on: January 29, 2015, 01:56:03 PM »
Pretty much any vehicle from the 70's that I chose to restore is a money pit, but I think for $700 dollars plus a few hundred more in parts is worth the time my son and I will spend working on this bike together. We aren't going for a concurs resto, just want it to run a couple years til he graduates from med school, Then he will buy whatever he wants and hopefully will have  learned a few things about bikes to.

I can get a whole crankcase for around $100 with head bolts. That sounds like a better option than taking it to a machinist. I think those guys though worth the money can be a bit pricey.

Thanks for your input, Im sure youll be hearing from me again soon.  :)
'72 CB350F

Offline Bootsey

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Re: Engine Delima
« Reply #11 on: January 29, 2015, 02:34:53 PM »
Hard to tell from the picture, but that crack near the clutch, looks like a casting mark.

Offline Indy72

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Re: Engine Delima
« Reply #12 on: January 29, 2015, 02:45:39 PM »
Yea your probably right. Ill know once I get it apart. The case I see for sale has the same mark. Right now I'm expecting problems given the bikes condition. I'm strongly considering buying another case because of the deck issues and the bolt that's broken off down in the lower half. Ill decide once I get it apart and see the crank races and such.
'72 CB350F

Offline przjohn

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Re: Engine Delima
« Reply #13 on: January 29, 2015, 02:51:44 PM »

So with very little budget to work with at least right now (he's still in college) I'll probably end up throwing some of my money at it too

Ya think?

 Just kidding, we have just finished off with that "C" Word expense, thank God. I wish you the best on your project and am sure you will have some great time together with getting this bike going. They are all money pits but time spent together on a project like this, well, you can't even put a price on that stuff. Good luck and keep the pics coming.
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Offline Indy72

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Re: Engine Delima
« Reply #14 on: January 29, 2015, 05:12:36 PM »
Irutt,

I'm interested in why you think a 400f is worthy but a 350f isn't? Ill agree the 400f is a nicer bike (I had one), but I'm not aware of the major differences that would make the 350f a bad choice. Is it the availability of parts or some know issues with the 350f?

Regards,
'72 CB350F

Offline Indy72

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Re: Engine Delima
« Reply #15 on: January 29, 2015, 05:21:02 PM »
BTW,

I still haven't cracked open the case yet (which I should probably be doing instead of writing emails) but I may need one head tower bolt. I haven't been able to find one online anywhere yet. Anybody have a good source?
'72 CB350F

Offline scottly

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Re: Engine Delima
« Reply #16 on: January 29, 2015, 05:47:42 PM »
Digging deeper reveals more issues. Not unexpected though. The PO used a dremmel tool on the deck. >:(
The damage doesn't look that bad: remember, a paper gasket is used there, so a precision surface isn't near as important as at the head gasket. As long as it doesn't leak oil, you're good. ;)
Don't fix it if it ain't broke!
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Offline 750cafe

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Re: Engine Delima
« Reply #17 on: January 29, 2015, 07:09:21 PM »
The damage doesn't look that bad: remember, a paper gasket is used there, so a precision surface isn't near as important as at the head gasket. As long as it doesn't leak oil, you're good. ;)

No reason at all for it to be flat.  ::)  Are you NUTS????? :o :o :o

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline scottly

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Re: Engine Delima
« Reply #18 on: January 29, 2015, 07:27:25 PM »
Those gouges are no way .050" deep, and should be within the compression range of a stock paper gasket. To the OP, check the surface with a straight edge. Irregularities of .005" or less are acceptable, at least for a budget rebuild.
Don't fix it if it ain't broke!
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Offline 750cafe

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Re: Engine Delima
« Reply #19 on: January 30, 2015, 09:13:47 AM »
OP, always remember that advice on the internet is FREE and often worth every penny.
Good luck with your leaker if you choose to follow the bad advice from some members with little to no engine building knowledge.

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline 750cafe

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Re: Engine Delima
« Reply #20 on: January 30, 2015, 10:08:56 AM »
Here is a tiny little imperfection that I filled and milled just a few weeks ago. Strangely enough, it is FLAT.



Carry on...

Eric   ;)
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline Indy72

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Re: Engine Delima
« Reply #21 on: January 30, 2015, 11:45:57 AM »
Thanks,

Im an Electrical Field Engineer by trade (Controls and Drives) and have learned to welcome all opinions and then use my best judgment to derive a hopefully thought out and with any luck informed plan of action. I enjoy and welcome all comments, try not to let it get personnel. :)

So I was curious about the relative depth of the gouges in question. Based on my inexact quick measurement I would say Scottly got this one. That being said everyone would agree that Flatterer is Beterer ;D. I also would note that the PO used a paper gasket on surface in question and the best I could tell it really didn't seem to be the source of the leaks. But I'm with you Eric, I'm not sure I am able to live with that surface. I'll decide as soon as I get a look at the rest of the case. Also if I'm able to extract that broken bolt! >:(
'72 CB350F

Offline strynboen

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Re: Engine Delima
« Reply #22 on: January 30, 2015, 12:22:13 PM »
if the sealing serfase are flat. so the silenderr bloch   stands stabile lined up.its not a problen there are some holes,, just use bond..it vill fill the lover parts..and make it seal fine...but..it have to be overall straight..so the cilenders  lining not are get stressed..

at a top gasket there are pressures and streses and temperature differenses..betveen the parts in game..and the surfase must be perfekt..

.but not a expert.(.specily not in english komuikasion)...but im machining parts and building parts together. as a maskinist .

its not so hard to mashine the top of engine...but think it are vaist of money
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
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Offline Indy72

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Re: Engine Delima
« Reply #23 on: January 30, 2015, 03:25:51 PM »
I cracked the egg, so to speak. now to get that bolt out, (looks doable) ???.
So I know I said this is a budget build, but.... are crank bearing races available and how much? I'll be looking myself but if you know....
'72 CB350F

Offline Indy72

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Re: Engine Delima
« Reply #24 on: January 30, 2015, 03:36:26 PM »
Well crap, I don't own a welder and the bolt is 3/16" below surface. :(
'72 CB350F

Offline 750cafe

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Re: Engine Delima
« Reply #25 on: January 30, 2015, 05:01:09 PM »
Add your favorite brand of PENETRATING oil (Not WD-40) and allow it to soak over-night.
Use a spring-loaded center punch and mark the dead center of that broken bolt.
Heat the area surrounding the threads with Map gas until nice and toasty without setting fire to your shop.
Allow it to cool with more PENETRATING oil applied after it no longer bursts into flames.
Drill it out using LEFT-HAND drill bits. Starting with about 1/8" and work your way up in size until it unscrews itself.
Report back on your success.

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Offline Indy72

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Re: Engine Delima
« Reply #26 on: January 30, 2015, 05:03:42 PM »
That works for me, thanks.
'72 CB350F

Offline scottly

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Re: Engine Delima
« Reply #27 on: January 30, 2015, 05:19:49 PM »
Thanks,


So I was curious about the relative depth of the gouges in question. Based on my inexact quick measurement I would say Scottly got this one.
Thank you
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline scottly

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Re: Engine Delima
« Reply #28 on: January 30, 2015, 05:28:37 PM »
I cracked the egg, so to speak. now to get that bolt out, (looks doable) ???.
So I know I said this is a budget build, but.... are crank bearing races available and how much? I'll be looking myself but if you know....
Those bearing shells look almost new?
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline Indy72

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Re: Engine Delima
« Reply #29 on: January 30, 2015, 05:39:43 PM »
What is recommended to reseal the case. I noticed there wasn't a gasket there?
'72 CB350F

Offline stevep

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Re: Engine Delima
« Reply #30 on: January 30, 2015, 05:59:52 PM »
hondabond.