What type of exhaust bolts to use?

[jmeydenbauer]

I'm replacing the exhaust manifolds and risers with some Barr replacments for my OMC 235hp (ford 351) motor. What type of bolts should I use ... grade 5, grade 8?? Also, should I put some grease on the bolts to help prevent rusting and make removal easier next time (boy was it fun this time ) hor should I use anti-sieze? I thought that I read somewhere not to use anti-sieze on marine motors but I'm not sure about this. These are cast iron manifolds not aluminum.<br /><br />Thanks,

 

[Bondo]

Re: What type of exhaust bolts to use?

I recommend Studs,+ Nuts, If you have the Space to work........<br />If you use bolts,<br />Gr5s will work... Gr8s Are Better......<br />And,<br />Yes, Lots of Never-Sieze..............

 

[biloxiriver]

Re: What type of exhaust bolts to use?

The mfg of my new manifolds says to use at least a grade 5, and to only put red thread lock on the bolts; they specifically say not to put anti-seize or anyother type of thread lube on them. Since not installing per mfg instructions can void a warranty, I am going to follow their instructions.

 

[yoced]

Re: What type of exhaust bolts to use?

Using Never-Seize will be ok on your _manifold_ where it bolts to the head, as you are only risking an exhaust leak if the bolts back out. However, you will be voiding manufacturer's warranty if you user the slick stuff on your riser bolts.<br /><br />Stick with the thread-lock compounds or some gasket sealers if you think you must use something on your riser bolts.<br /><br />Keep in mind that you need to decrease the torque values you are aiming for if you are lubricating your threads. <br />Never-Seize is good for about a 20% reduction. In other words, if you were going to be torquing a 3/8-16 zinc plated stud or bolt to 33 foot-pounds, you now need to aim for 27 foot-pounds.<br /><br />If you were planning to use 18-8 stainless studs on your head, you would be lowering your torque from about 20 foot-pounds to 15.

 

[Bondo]

Re: What type of exhaust bolts to use?

And,<br />Yes, Lots of Never-Sieze..............

I guess I should Clarify this.......<br />It's been My Experince that the Problem is the Manifolds Rusting to the Bolts, Rather than the Threads Rusting into the Heads...........<br />I also lube the Threads with Never-Sieze,+ torque to Standard Values.......<br />I've Never Seen a 3/8ths bolt that Wouldn't take 35lbs torque..... Wet, Or Dry.........

 

[giniustflord]

Re: What type of exhaust bolts to use?

whats wrong whith using stainless steal<br />????

 

[cjflanagan]

Re: What type of exhaust bolts to use?

What's wrong with spell checking before posting?

 

[Danny_Ocean]

Re: What type of exhaust bolts to use?

whats wrong whith using stainless steal<br />

Stainless Steel bolts are not as strong.<br /><br />D. Ocean<br />Pompano Beach, FLA

 

[Danny_Ocean]

Re: What type of exhaust bolts to use?

What's wrong with spell checking before posting? <br />

What's wrong with grammar checking before posting?<br /><br />Should read: What's wrong with spell checking prior to posting a response? (still an incomplete sentence).<br /><br />D. Ocean<br />Pompano Beach, FLA

 

[crazy charlie]

Re: What type of exhaust bolts to use?

Welcome to English 101 kids Happy St. Patricks day!!!!!Erin go braless!!!!

 

[giniustflord]

Re: What type of exhaust bolts to use?

i thought this was about boats not english <br />ow well guess ill get 2 leason in one

 

[roscoe]

Re: What type of exhaust bolts to use?

Just curious, what is a "GINIUS" ?

 

[james082273]

Re: What type of exhaust bolts to use?

I worked in a muffler shop while I was going to school and we never used anything but Grade 8 bolts on manifolds. It is surprising how easy it really is to twist off an old 3/8 grade 5 bolt.

 

[giniustflord]

Re: What type of exhaust bolts to use?

well whith a name like roscoe dont know if id ask<br />however its like most others hear jest a call sing for the net roscoe hehehe some would also call it a parodox considering the word genius means very inteligent yet obiously it mispelled :] hehe<br /><br />by the way iused stainless steall olts on my exust manifold they worked jest fine dont see you guys point and mine dont carode used sealent too to asist gasket

 

[roscoe]

Re: What type of exhaust bolts to use?

This is roscoe. I just use my pets' names as my user names, on various sites. <br />

 

[yoced]

Re: What type of exhaust bolts to use?

Ginius: I'm glad everything is working out for you. But, stainless does have its problems like everything else, and an informed decision about it at least lets you take responsibility later on when things either go your way, like they seem to be now, or, which may (will) happen eventually, not. <br /><br />The manufacturers of the exhaust systems will often recommend against stainless, especially as used with risers. Using it when they say not to may give you warranty headaches later.<br /><br />Stainless is softer, and stainless does not hold a torque as well. Stainless, because of its most excellent property, is also not coated - it is therefore prone to galling when the threads are engaged while dry. <br /><br />Also, stainless does not corrode. You may have noticed this fine point. Keep in mind that when any two different metals are in contact in an ionic environement (salt water or mist counts) there will be an electrolytic reaction - one of the metals will start to dissolve. If the stainless is not corroding, what is? In this case it is the iron that the stainless is in contact with. The reaction is very slow in the case of a stainless to iron connection, but it is there none the less. <br /><br />Stainless is a wonderful alloy. But keep in mind that using it entails compromise - a trade off, if you will. There are no free lunches.

 

[jmeydenbauer]

Re: What type of exhaust bolts to use?

Thanks guys, it looks like I'll go with Grade 8 studs and nuts on the heads and bolts for the risers. They should be here today ..yea!<br /><br />Now I just need to find some OMC blue paint for them. I bought a can of "Old Ford Blue" but that was way off.