Future magazine articles III
09-19-2002 | 03:46 PM
#1
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Future magazine articles III
This is a future magazine article for FAMILY AND PERFORMANCE BOATING MAGAZINE. It will appear with two other articles in the Feb.2003 edition. Please read it and give me your opinions bfore I turn it in to the editor.
Dennis Moore
SPECIAL REPLACEMENT EXHAUST MANIFOLDS FOR 305 AND 350 MERCRUISER ENGINES
By
Dennis Moore
Performance boaters are always looking to improve their boats performance and family boaters are always looking to save a buck. When repairing or improving our boat engines and drives we will have the option of buying original equipment parts (such as those manufactured by Mercruiser) or aftermarket replacement parts. Many times an aftermarket parts manufacturer will produce a part that is advertised to have certain improvements over the original equipment part or produce a part that is advertised to be an exact copy of the original part but at a much lower price. I have heard parts sales people telling customers “just bolt them on, they are an exact replacement for the original” when in fact some are not. One of the biggest headaches that boaters have is buying an aftermarket part and finding out that the quality of the part is less than expected or that they may not fit as well as the factory original equipment parts.
Most aftermarket parts are good quality parts and will work as advertised, either improving the performance/reliability of your boat or saving you some money. The key to buying aftermarket parts is to pay close attention to what you are about to purchase. It is helpful to remove the original equipment part and bring it with you to the parts store to compare it with the new aftermarket part.
One of the most popular aftermarket parts available to boaters is the marine exhaust manifold. The factory original equipment exhaust manifold is expensive to replace and can be improved upon as far as performance and reliability. This has opened a window of opportunity for many aftermarket parts manufacturers to supply the boating industry with replacement exhaust manifolds. These replacement manifolds are less expensive and (sometimes) better performing than the original equipment manifolds.
If your goal is to purchase an aftermarket manifold that is an exact replacement of the original equipment manifold, remove the original manifold (drag it with you to the parts store) and compare it to the new aftermarket manifold. Sometimes the difference in quality is quite apparent!
Although there are many aluminum high performance manifolds on the market they are not a direct replacement for the stock original equipment manifolds. Most aluminum high performance manifolds require a certain amount of fabrication and customizing to the engine before you can install them. We at FAMILY AND PERFORMANCE BOATING (being performance boaters and do it yourselfers) would like to supply you with information about a couple of interesting aftermarket exhaust manifolds that you may want to consider purchasing instead of stock replacement manifolds. These are manifolds that have certain advantages over the stock manifolds and are a direct replacement for 305 and 350 Chevy/Mercruiser original equipment manifolds manufactured between 1982 and 2002.
The first manifold is manufactured by Glenwood Marine in Gardena, California (323-757-3141). This is an exact copy of the stock Mercruiser cast iron exhaust manifold but is made from aluminum. The savings in weight is astonishing when comparing them to cast iron manifolds. If you have a light weight boat (especially with twin engines) these manifolds will be an excellent direct replacement for the stock manifolds shaving several hundred pounds off the back of your boat. The castings are excellent, very smooth with very little core shift, and are available either polished (for a custom look) or hard anodize coated (to protect them from corrosion). When the anodized manifolds are painted Phantom Black (Mercruiser black) they look much better than the (rather rough looking) stock Mercruiser manifolds.
The second manifold is manufactured by GLM Products in Monrovia, California (626-357-0077). Externally these manifolds look identical to the 1982 – 2002 Mercruiser 305 and 350 exhaust manifolds but there are many improvements that have been made to the GLM manifold that the stock manifold doesn’t have. The manifolds are made from cast iron (like the Mercruiser manifold) but are manufactured using the modern “Lost Foam Casting Process.” This process is the most advanced casting process for manufacturing with cast iron. One of the most common problems with cast iron manifolds is that when they are manufactured in the traditional sand casting method (such as a Mercruiser manifold) some core shift will result. Core shift will sometimes leave thin or porous sections (slight defects) in the casting. Water cooled marine exhaust manifolds will have intricate water cooling passages that will eventually corrode through (the number one reason for replacing exhaust manifolds). Thin or porous sections will be the first place that the manifold will fail. The “Lost Foam Casting Process” will have very little casting core shift, (almost) never leaving thin or porous sections in the castings. When visually comparing a sand cast manifold to a GLM lost foam casting manifold the difference in casting quality is apparent.
After the GLM exhaust manifold is cast and machined it is sent through a “Hot Dip Galvanizing Process.” This means that the manifold is submerged in hot galvanizing (for corrosion protection) and then painted black. The GLM manifold is arguably the best manifold available for protection and durability in a corrosive environment (salt water).
The exhaust passages inside the GLM manifold are where the advantages of the precise lost foam casting process becomes apparent from a performance aspect. Special runners have been cast inside the GLM manifold to direct the exhaust gases out of the manifold; this is much better than standard exhaust manifolds that simply collect the engines exhaust in an open chamber allowing the exhaust gases to reenter adjacent exhaust ports. When the manifold is used on the port side of the engine there is a distinct separation between the #5 and the #7 cylinders and when used on the starboard side of the engine the #4 and #8 cylinders are divided. A performance increase can be found when installing the GLM exhaust manifolds.
The final advantage to the GLM exhaust manifold is the price, they are less expensive than buying an original equipment manifold from Mercruiser and are competitively priced with other aftermarket replacement manifolds. They are much less expensive than an aftermarket aluminum high performance manifold.
Dennis Moore
SPECIAL REPLACEMENT EXHAUST MANIFOLDS FOR 305 AND 350 MERCRUISER ENGINES
By
Dennis Moore
Performance boaters are always looking to improve their boats performance and family boaters are always looking to save a buck. When repairing or improving our boat engines and drives we will have the option of buying original equipment parts (such as those manufactured by Mercruiser) or aftermarket replacement parts. Many times an aftermarket parts manufacturer will produce a part that is advertised to have certain improvements over the original equipment part or produce a part that is advertised to be an exact copy of the original part but at a much lower price. I have heard parts sales people telling customers “just bolt them on, they are an exact replacement for the original” when in fact some are not. One of the biggest headaches that boaters have is buying an aftermarket part and finding out that the quality of the part is less than expected or that they may not fit as well as the factory original equipment parts.
Most aftermarket parts are good quality parts and will work as advertised, either improving the performance/reliability of your boat or saving you some money. The key to buying aftermarket parts is to pay close attention to what you are about to purchase. It is helpful to remove the original equipment part and bring it with you to the parts store to compare it with the new aftermarket part.
One of the most popular aftermarket parts available to boaters is the marine exhaust manifold. The factory original equipment exhaust manifold is expensive to replace and can be improved upon as far as performance and reliability. This has opened a window of opportunity for many aftermarket parts manufacturers to supply the boating industry with replacement exhaust manifolds. These replacement manifolds are less expensive and (sometimes) better performing than the original equipment manifolds.
If your goal is to purchase an aftermarket manifold that is an exact replacement of the original equipment manifold, remove the original manifold (drag it with you to the parts store) and compare it to the new aftermarket manifold. Sometimes the difference in quality is quite apparent!
Although there are many aluminum high performance manifolds on the market they are not a direct replacement for the stock original equipment manifolds. Most aluminum high performance manifolds require a certain amount of fabrication and customizing to the engine before you can install them. We at FAMILY AND PERFORMANCE BOATING (being performance boaters and do it yourselfers) would like to supply you with information about a couple of interesting aftermarket exhaust manifolds that you may want to consider purchasing instead of stock replacement manifolds. These are manifolds that have certain advantages over the stock manifolds and are a direct replacement for 305 and 350 Chevy/Mercruiser original equipment manifolds manufactured between 1982 and 2002.
The first manifold is manufactured by Glenwood Marine in Gardena, California (323-757-3141). This is an exact copy of the stock Mercruiser cast iron exhaust manifold but is made from aluminum. The savings in weight is astonishing when comparing them to cast iron manifolds. If you have a light weight boat (especially with twin engines) these manifolds will be an excellent direct replacement for the stock manifolds shaving several hundred pounds off the back of your boat. The castings are excellent, very smooth with very little core shift, and are available either polished (for a custom look) or hard anodize coated (to protect them from corrosion). When the anodized manifolds are painted Phantom Black (Mercruiser black) they look much better than the (rather rough looking) stock Mercruiser manifolds.
The second manifold is manufactured by GLM Products in Monrovia, California (626-357-0077). Externally these manifolds look identical to the 1982 – 2002 Mercruiser 305 and 350 exhaust manifolds but there are many improvements that have been made to the GLM manifold that the stock manifold doesn’t have. The manifolds are made from cast iron (like the Mercruiser manifold) but are manufactured using the modern “Lost Foam Casting Process.” This process is the most advanced casting process for manufacturing with cast iron. One of the most common problems with cast iron manifolds is that when they are manufactured in the traditional sand casting method (such as a Mercruiser manifold) some core shift will result. Core shift will sometimes leave thin or porous sections (slight defects) in the casting. Water cooled marine exhaust manifolds will have intricate water cooling passages that will eventually corrode through (the number one reason for replacing exhaust manifolds). Thin or porous sections will be the first place that the manifold will fail. The “Lost Foam Casting Process” will have very little casting core shift, (almost) never leaving thin or porous sections in the castings. When visually comparing a sand cast manifold to a GLM lost foam casting manifold the difference in casting quality is apparent.
After the GLM exhaust manifold is cast and machined it is sent through a “Hot Dip Galvanizing Process.” This means that the manifold is submerged in hot galvanizing (for corrosion protection) and then painted black. The GLM manifold is arguably the best manifold available for protection and durability in a corrosive environment (salt water).
The exhaust passages inside the GLM manifold are where the advantages of the precise lost foam casting process becomes apparent from a performance aspect. Special runners have been cast inside the GLM manifold to direct the exhaust gases out of the manifold; this is much better than standard exhaust manifolds that simply collect the engines exhaust in an open chamber allowing the exhaust gases to reenter adjacent exhaust ports. When the manifold is used on the port side of the engine there is a distinct separation between the #5 and the #7 cylinders and when used on the starboard side of the engine the #4 and #8 cylinders are divided. A performance increase can be found when installing the GLM exhaust manifolds.
The final advantage to the GLM exhaust manifold is the price, they are less expensive than buying an original equipment manifold from Mercruiser and are competitively priced with other aftermarket replacement manifolds. They are much less expensive than an aftermarket aluminum high performance manifold.
09-19-2002 | 03:57 PM
#2
Official OSO boat whore
Joined: Oct 2000
Posts: 6,157
Likes: 0
From: Mequon, WI
So, I take it that GLM is a major sponsor of the magazine. I find that very disapointing as your articles are on the verge of sounding like a paid endorsement. I feel that that really discredits a writer and the publication. I'd prefer a publication/article that told it like it is. No holds barred. If the product was great, tell us. The product was...well you know...then tell us! That's why WE pay you!
09-19-2002 | 04:25 PM
#3
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Joined: Jul 2002
Posts: 1,322
Likes: 1
From: Maximo FLA
I feel like Cord after reading all 3 of them, but if you only read one you lose out on good info. I would like to see "than an aftermarket aluminum high performance manifold." tested also on the 2 article, like the Stainles Marine. To see witch has the best bang for the buck. I guess I am tryng to say more diversity. Charlie
Last edited by ragtop409; 09-19-2002 at 04:46 PM.
09-19-2002 | 04:42 PM
#4
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I read LOTS of magazines. LOTS! Hot Rod, Car Craft, OFF ROAD, Four Wheeler, Hot Boat, Powerboat, and yes, Performance and Family Boating, among a few others. I can tell you, Dennis`s article is no more advertising than any thing you read out there. I get from the article that he truly liked the products he wrote about. I have seen in many magazines, articles describing poor fit and sub-par quality of different products. So it is not "all good".
09-19-2002 | 05:37 PM
#5
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Good Stuff
Thanks for the input Cord! I gotta be honest with you, if I test something and it isn't any good I will not do an article about it!
There are so many consumers out there that become emotionally attached to a product that they have purchased and installed on their boat. Even if the product didn't perform as advertised (after the installation on their boat) these people still get all bent out of shape if we report something negative about it!
It seems like some people don't want to admit to their friends that they purchased and installed a bad product. Some people are also very offended if they have to change their mind about the quality or effectiveness of a product!
If all we had to do was worry about advertiser being mad it would be a piece of cake! The consumers are extremely loyal (many times irrationally so) to the products whether it is good or bad, just ask someone that has installed an aftermarket CD ignition!
Dennis Moore
There are so many consumers out there that become emotionally attached to a product that they have purchased and installed on their boat. Even if the product didn't perform as advertised (after the installation on their boat) these people still get all bent out of shape if we report something negative about it!
It seems like some people don't want to admit to their friends that they purchased and installed a bad product. Some people are also very offended if they have to change their mind about the quality or effectiveness of a product!
If all we had to do was worry about advertiser being mad it would be a piece of cake! The consumers are extremely loyal (many times irrationally so) to the products whether it is good or bad, just ask someone that has installed an aftermarket CD ignition!
Dennis Moore
Last edited by Dennis Moore; 09-19-2002 at 05:56 PM.
09-19-2002 | 06:43 PM
#8
I hate the winter!!
Joined: Jul 2001
Posts: 2,707
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From: long island, new york
I liked what you wrote. I understand that your article targets manifolds, but I feel that you should also have included something about the other major culprit of leaks and engine damage RISERS. For the average boater who doesn't understand much about how things work, he may feel that his problems will be solved by changing to aftermarket manifolds alone. Just my thoughts...
09-19-2002 | 10:38 PM
#9
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Joined: Feb 2001
Posts: 513
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From: Abita Springs, La.
Mr. Moore-
I read the article and you backed up opinions with facts- about the galvanizing and casting methods, etc.- Good job.
I don't know if you have focused yet on exhaust valves and the importance of using inconel, but that's an idea for you and a subject that could be a logical continuation of articles on exhaust manifolds.
And thanks for posting!
Bulldog aka Ronnie
I read the article and you backed up opinions with facts- about the galvanizing and casting methods, etc.- Good job.
I don't know if you have focused yet on exhaust valves and the importance of using inconel, but that's an idea for you and a subject that could be a logical continuation of articles on exhaust manifolds.
And thanks for posting!
Bulldog aka Ronnie
09-20-2002 | 02:22 AM
#10
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Joined: Oct 2000
Posts: 4,541
Likes: 107
From: Western Michigan
Dennis,
Great article and very informative. I wanted to point out that most people cannot take there existing stock exhaust manifolds to a parts dealer for comparison because most dealers don't even keep one brand of aftermarket exhaust manifolds in stock for prospecting customer to compare, let alone several different brands to compare to. This is probably due to pricing and because it's a specialty item. At least if the dealers did have these items in stock they would most likely have them on display for potential customers to see. At least in this part of the country (Michigan) I sure don't see that too much.
Enjoyed your article though and thanks for your contributions---you are an ASSET to this forum!
Mark
Great article and very informative. I wanted to point out that most people cannot take there existing stock exhaust manifolds to a parts dealer for comparison because most dealers don't even keep one brand of aftermarket exhaust manifolds in stock for prospecting customer to compare, let alone several different brands to compare to. This is probably due to pricing and because it's a specialty item. At least if the dealers did have these items in stock they would most likely have them on display for potential customers to see. At least in this part of the country (Michigan) I sure don't see that too much.
Enjoyed your article though and thanks for your contributions---you are an ASSET to this forum!
Mark
Last edited by KAAMA; 09-20-2002 at 02:26 AM.
