On my 76 h30 I have a yse12 which I rebuilt 7 years ago. I also replaced the mixing elbow then. Yesterday I was trying to remove the hose from the mixing elbow and upon exerting a small pressure the elbow broke in two right at the top of the 180 deg. bend. I was then able to examine it very well on the inside and noticed it was about 20% plugged. I'm not paying $170 or more for a new one made from cast iron. I think that was the problem. There is a large temp. graident across the elbow and that induced the cracks. My new one will be SS. Hopes this helps somebody.
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S.S.?
Royce: Where are you going to get one of these made from S.S.? I doubt that it will last for 7 years with the heat that is generated by a diesel engine but we will be interested in finding out more about it. Just a note. You DO NOT see autos with S.S. exhaust systems gas or diesel. I believe that this is because they will rust out MUCH faster than cast iron. The mixing elbow for your boat was $170? The one for our engine was only $90! We have had our elbow on our 2gm20f for 15 years and no cracks. I replaced mine last year and have the old one cleaned and ready to go back into service.
Royce: Where are you going to get one of these made from S.S.? I doubt that it will last for 7 years with the heat that is generated by a diesel engine but we will be interested in finding out more about it. Just a note. You DO NOT see autos with S.S. exhaust systems gas or diesel. I believe that this is because they will rust out MUCH faster than cast iron. The mixing elbow for your boat was $170? The one for our engine was only $90! We have had our elbow on our 2gm20f for 15 years and no cracks. I replaced mine last year and have the old one cleaned and ready to go back into service.
Price Seems High
The price mentioned seems high. This spring I replaced the elbow for a 3GM30 for just under $130 from a marine store in Seattle - www.docfreemans.com. Also had the replace the stainless threaded coupling for nearly that much, around $115?? The threads had gauled together with the cast iron mixing elbow. The mixing elbow was 13 years old and had started to crack through the side about midway around the elbow. This was the third time it was off for cleaning. The passage was probably 70 percent clogged!! Recommendation to others: If it appears the engine is overheating, a fair amount of vapor is comming out of the exhaust, if the raw water system is not clogged it's a good guess the mixing elbow needs cleaning. When reassembling the double threaded coupling use a little anti-sieze compound like Never Seze.
The price mentioned seems high. This spring I replaced the elbow for a 3GM30 for just under $130 from a marine store in Seattle - www.docfreemans.com. Also had the replace the stainless threaded coupling for nearly that much, around $115?? The threads had gauled together with the cast iron mixing elbow. The mixing elbow was 13 years old and had started to crack through the side about midway around the elbow. This was the third time it was off for cleaning. The passage was probably 70 percent clogged!! Recommendation to others: If it appears the engine is overheating, a fair amount of vapor is comming out of the exhaust, if the raw water system is not clogged it's a good guess the mixing elbow needs cleaning. When reassembling the double threaded coupling use a little anti-sieze compound like Never Seze.
Stainless is a great choice
royce is right on the stainless selection and from what i can see it will be an easy fabrication using a 180 degree elbow. Most cars since the 1980's have stainless exhaust systems up through the convertor, and the convertor is usyually made of 410 or 411 SS. Problem with these grades is that they are low in chrome and appear to look like black iron. terry -
royce is right on the stainless selection and from what i can see it will be an easy fabrication using a 180 degree elbow. Most cars since the 1980's have stainless exhaust systems up through the convertor, and the convertor is usyually made of 410 or 411 SS. Problem with these grades is that they are low in chrome and appear to look like black iron. terry -
Mixing metallurgy
I don't think there are any circumstances where stainless steel will corrode faster than cast iron. SS is the material of choice for most of the chemical industries. Re: cars. I've had two cars with stainless exhaust systems. It's too expensive for econo cars. One was a Mazda with rotary (Wankel)engine. This needed SS due to very high exhaust temperatures and bad chemistry. The other was a Toyota Supra -- just plain expensive and first class everything. I drove the Mazda for 7 years and the Toyota for 13 years without needing to replace any SS exhaust system component. This was in Toronto, where the mayor's cousin owns the winter road salting contract company (just kidding!) and the road salt is applied so deep I've actually skidded on it. Very corrosive environment.
I don't think there are any circumstances where stainless steel will corrode faster than cast iron. SS is the material of choice for most of the chemical industries. Re: cars. I've had two cars with stainless exhaust systems. It's too expensive for econo cars. One was a Mazda with rotary (Wankel)engine. This needed SS due to very high exhaust temperatures and bad chemistry. The other was a Toyota Supra -- just plain expensive and first class everything. I drove the Mazda for 7 years and the Toyota for 13 years without needing to replace any SS exhaust system component. This was in Toronto, where the mayor's cousin owns the winter road salting contract company (just kidding!) and the road salt is applied so deep I've actually skidded on it. Very corrosive environment.
Get from Hunter
Allthough many peoples opinion of Hunter does not match mine, one thing nobody can argue about is their retail parts pricing. They sell all parts at net cost. Call them, we always do and parts are almost always 35-50% less. Their in the book in Alachua, FL. As for Mike in Retail parts. Same comments about S.S. lasting long term. Doug
Allthough many peoples opinion of Hunter does not match mine, one thing nobody can argue about is their retail parts pricing. They sell all parts at net cost. Call them, we always do and parts are almost always 35-50% less. Their in the book in Alachua, FL. As for Mike in Retail parts. Same comments about S.S. lasting long term. Doug
cough-- sputter-- ehhh!
mr england A lot of us folks, down here in the sates, are just not fortunate enough to be able to drive these highly sophisticated precision machines from japan you mention. And as you most certainly are aware us folks from the michigan and ohio area will never be able to step up to the plate when it comes the construction techniques utilized by the real carmakers of your opinion. However I know of no domestic "econo cars" that do not have stainless exhaust headers and converter devices. I do keep a 1987 blazer s10 "tool box" that I bought new in 87 for 8K, it seems to have 350,000 miles on a 4 popper engine and still has the original stainless steel exhaust header it came with. Can you imagine that ? ehh!
mr england A lot of us folks, down here in the sates, are just not fortunate enough to be able to drive these highly sophisticated precision machines from japan you mention. And as you most certainly are aware us folks from the michigan and ohio area will never be able to step up to the plate when it comes the construction techniques utilized by the real carmakers of your opinion. However I know of no domestic "econo cars" that do not have stainless exhaust headers and converter devices. I do keep a 1987 blazer s10 "tool box" that I bought new in 87 for 8K, it seems to have 350,000 miles on a 4 popper engine and still has the original stainless steel exhaust header it came with. Can you imagine that ? ehh!
Never Seze????
I am surprised about the recommendation to use "never seze". After replacing the SS double threaded connector I could not get it tight enough to stop it from backing out due to vibations. It would back out in less than 15 minutes of running the motor. I finally had to use some kind of "lock tight".
I am surprised about the recommendation to use "never seze". After replacing the SS double threaded connector I could not get it tight enough to stop it from backing out due to vibations. It would back out in less than 15 minutes of running the motor. I finally had to use some kind of "lock tight".
Retailer Recommendation
The Never Seze was a recommendation from the dealer (Doc Freeman in Seattle)where I bought the mixing elbow and stainless steal threaded connector parts. The reason I had to buy a threaded connector is because my old one galled up on the cast iron elbow and I cracked the elbow getting the two apart and the connector threads were buggered. When talking to the guy at the parts counter he said that the stailness threadded part should not be tightened too tight in the cast iron elbow; tighten only until one starts to feel the two parts start to bind as this is when the galling starts to occur. With regard to thread compounds, the other thread compound I had, which I thought would be better, was one designed for use on aircraft sparkplug threads which is a very high-heat environment but the parts guy said not to use it. Assembly difficulties: It was very difficult to install the double threaded coupling to the two cast iron parts (mixing elbow and manifold elbow) in the manner described above, i.e., don't tighten too tight. For those without the hands-on experience here, the coupling has both left and right hand threads. Perhaps some Loctite would be a good idea to keep the coupling from unscrewing itself. Next time.
The Never Seze was a recommendation from the dealer (Doc Freeman in Seattle)where I bought the mixing elbow and stainless steal threaded connector parts. The reason I had to buy a threaded connector is because my old one galled up on the cast iron elbow and I cracked the elbow getting the two apart and the connector threads were buggered. When talking to the guy at the parts counter he said that the stailness threadded part should not be tightened too tight in the cast iron elbow; tighten only until one starts to feel the two parts start to bind as this is when the galling starts to occur. With regard to thread compounds, the other thread compound I had, which I thought would be better, was one designed for use on aircraft sparkplug threads which is a very high-heat environment but the parts guy said not to use it. Assembly difficulties: It was very difficult to install the double threaded coupling to the two cast iron parts (mixing elbow and manifold elbow) in the manner described above, i.e., don't tighten too tight. For those without the hands-on experience here, the coupling has both left and right hand threads. Perhaps some Loctite would be a good idea to keep the coupling from unscrewing itself. Next time.
I stand corrected
Terry, I didn't know that newer American cars had stainless exhausts. And I had no intention to offend. I was responding to another post where the author claimed that there are no cars made with SS exhausts, and that cast iron corroded less that SS. I was just giving my actual experience with cars I have owned. I'm no automotive expert. As for driving "precision Japanese machines", that was before I got married! Now I drive a '93 Chrysler and hope it holds together from day to day. Bob.
Terry, I didn't know that newer American cars had stainless exhausts. And I had no intention to offend. I was responding to another post where the author claimed that there are no cars made with SS exhausts, and that cast iron corroded less that SS. I was just giving my actual experience with cars I have owned. I'm no automotive expert. As for driving "precision Japanese machines", that was before I got married! Now I drive a '93 Chrysler and hope it holds together from day to day. Bob.
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