[Guest]

It's 12/22 and I have added relevant stuff at the end of this post. read the whole topic and look at the pictures.
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(Written 12/12)--This week, when we were R&R'ing the clutch, we sure felt lucky to get out the two bolts that fasten the exhaust pipe to the manifold. We put the old bolts back in because we hadn't thought far enough in advance to have new replacements for them. They sure seem like odds-on candidates to snap off next time around. So the question is: what do you think the absolute BEST replacement bolt would be for this application? Also, please include the size, length and thread for this metric-challenged guy.
THANKS!

jp

PS--I didn't do a search before posting this topic--30 lashes with a greasy shop towel!

 

[1339]

Re: Exhaust manifold to pipe bolts

In reply to:

S--I didn't do a search before posting this topic--30 lashes with a greasy shop towel!

[/ QUOTE ]

I can't recall this one being covered, otherwise it would be a wet Shop rag...

I can't say about size, but the MFGs theory is to use soft unplated bolts so they rust in place and don't
vibrate out. (poor man's lock tite? LOL) . Ive had good luck with cad plated grade 5 bolts, 8s ive seen
snap in exhaust systems. I dont know if its from viration, Heat or a combination. Similar results with SS.

Youd think SS would be an obvious fit, but my results have been not as good as with cad pated.

You will want to double nut the dang things to insure they don't vibrate loose though.

 

[RRich]

Re: Exhaust manifold to pipe bolts

Easiest bestest way - replace the bolts with studs - then use brass nuts on them -- with anti-sieze.

Then even if the studs do rust in, the brass nuts come off easy even many years later. The brass is soft enough that they won't gall the theads on the steel studs.

Muffler shops have the brass nuts.

Oh, use a flat washer under the brass nut, then double nut it with another brass nut, so they won't come loose.

Lockwashers, like split or star washers only work when it's loose. Think about it - when the washer is compressed, the sharp edges don't/can't dig in.
Nylocks aren't made in brass, and I have no idea where to find splitlock nuts in brass.

 

[341]

Re: Exhaust manifold to pipe bolts

Just use anti-sieze compound, and proper torque. I use it on all exhaust bolt applications.

 

[RRich]

Re: Exhaust manifold to pipe bolts

The problem with anti-seize alone on steel nuts and studs is it eventually evaporates, leaving just the graphite - but the graphite itself doesn't stop the rust.
It's OK if you frequently remove them - like every year, but anti-seize on exhaust - hot, corrosive - doesn't last long.

 

[Guest]

Brass nuts

We just returned from nearly a week in Phoenix. My wife visited with her family while I roamed around looking for Zuki stuff.

Couldn't find brass metric nuts or metric studs either, for that matter. Stopped in several muffler shops and apparently didn't "hit it off" real well with those guys. Once they realized I wasn't gonna fork over big bucks for them to do something to the Zuki they brushed me off. I even ferreted out a muffler dealers warehouse in some unmarked building in an generic industrial park. Got a real nice deal on a stocker Zuki muffler ($35) but no help whatsoever on studs, brass nuts or any insight on the anti-seize debate.

I found a "nut and bolt" dealer who stocks 36" lengths of hardened metric rod. They suggested making my own studs and using hardened nuts to double nut both ends. But they weren't "auto shop oriented" so I really didn't put much stock in their "words of wisdom." They couldn't even tell me the "hardness" of their hardened rod, no pun intended.

Well, anyway, I appreciate the posts on this topic and have tried to put them to productive usage. So far, though, I have come up empty handed and am still scratching my head.

Happy Holidays!

j

 

[1339]

Re: Brass nuts

Many of the better hardware stores are doing much better at stocking metric fasteners. have you tried
there? try your better ACE outlet. I'll see if OSH has them,
if you can't find them, maybe I could ship them to you.

 

[Guest]

The bolt

Well, okie, dokie, I took the bolt off our '88. Our '87 was off with the wife behind the wheel. Here's the two pix URL's:

http://campgroundhost.com/zuki/bolt.JPG
http://campgroundhost.com/zuki/head.JPG

The bolt and spring pic turned out OK. The bolt head pic is blurred. I propped it up with some rocks. But you can see there are no markings on the head.

Anyway, here are the specs for the bolt:

Overall length (top of head to end of bolt) 75 mm
Head size: 14 mm
Head flange diameter: 22 mm
Diameter of threaded bolt: 10 mm
Thread: 1.25 mm
Seat of lower flange to end of threads: 19 mm
Length of bottom of lower flange to tip of bolt: 23 mm
Over length of coil spring: 43 mm
Length of bottom of lower flange to tip of bolt: 23 mm

Heads stamp and/or markings: none visible

I am not used to working with a double-flanged bolt like this one. Before I put it back in, I brushed the threads and then spiffed them up with the appropriate die. The bolt went in fine until I got to the "take up" portion.
Somehow, it sure felt like I stripped the threads. I stopped and got "up top" and looked and could see that the lower flange wasn't seated so I got back underneath and turned very carefully trying to "feel" that flange seat on the manifold. It's a "weirdy" that's for sure.

Well, now that we have the naked bolt on display, what do you think?

j

PS-- I called the Suzuki dealer and ordered two of these puppies--six bucks a pop.

 

[905]

Re: The bolt

Just a thought why not use a 3/8" bolt that is a little longer and will fit through the threaded part of the flange and still use the spring on the 3/8 bolt with flat washers and NOT worry if you strip out the treads on the flange part of the exhaust manifold .?

Just a regular bolt,2 flat washers,1 lock washer,1 nut.

The reason I say this is when I changed the lead gasket that goes there I broke a bolt off in the manifold(the same one you are showing)

NOW I had to remove the whole exhaust manifold and tap and drill the broken bolt out..Put Neverseize on the bolts when I put them back together and STILL broke the other bolt next time I worked on the exhaust system....Why fight that again drilled out the broken bolt and just used a longer bolt that sticks past the flange and put a lock washer and nut on it. Now if it bolt brakes so what I don't have to drill or tap AGAIN