Future magazine article II
#1
Guest
Posts: n/a
This is going to be a companion to the first article (appearing in the same edition). Give me some feedback!
Dennis Moore
FAMILY AND PERFORMANCE BOATING MAGAZINE
SMALL BLOCK EXHAUST MANIFOLD TEST
By
Dennis Moore
The real fun in owning a boat is ripping across the lake at top speed. Even if you aren’t the fastest boat on the lake the wind in your face makes it feel like you’re really free! We at FAMILY AND PERFORMANCE BOATING MAGAZINE know that not everyone owns a fast boat but most of use would like to go a little faster than the stock boat we purchased. We used a typical boat to write this exhaust test article to see if a simple improvement could make much of a difference in the average boater’s setup.
The boat we used belongs to a local car drag racer in southern California named Kevin Houmard. He gets his kicks from tearing up the ¼ mile in a nine second supercharged big block Camaro. When he goes out boating with the family he likes to take it easy and just cruise. Kevin owns a 21 foot Eliminator open bow boat with a 350 Magnum/Alpha sterndrive.
We took the little Eliminator out to a southern California lake called Lake Elsinore. If some of you have heard of Lake Elsinore I wouldn’t be surprised, it has a section marked off in the middle of the lake for high speed boat tests. Most of the hottest factory prototype boats in California have been tested here (sometimes on the same days!).
The morning we arrived it was typical southern California weather, clear blue skies and around 80 degrees. The lake was very smooth. Bob Carpenter and I were really enjoying ourselves on the lake that morning testing the speed of the little Eliminator with a radar gun. We made many passes across the lake that morning recording a speed of 49 mph with occasionally seeing the radar gun flash a 50 mph reading. There was no doubt in our minds that the boat had a top speed of 49 – 49 ½ mph.
We came equipped to change the manifolds at the lake. We pulled the boat up onto the trailer and headed for the launch ramps picnic grounds. Because it was a week day we had the place to ourselves except for a few retirees. We found a cool, shady spot and removed the stock Mercruiser exhaust manifolds and elbows. We installed some replacement GLM exhaust manifolds and elbows. The installation was an absolute bolt on affair, there were no installation problems. These manifolds have the exact same external dimensions as the original manifolds. The difference between these manifolds is all internal, (as you will read elsewhere in this magazine) the inside exhaust passages are tuned to separate exhaust pulses within the manifold.
After cooling ourselves off with a few soft drinks Bob and I launched the boat and under almost the exact same conditions (maybe the outside temp at the lake rose a few degrees) we tested the boat as thoroughly as we had with the stock manifolds. This time we consistently hit 51 mph with the radar gun occasionally hitting 52. There was no doubt in our minds that the Eliminator was now going 51 – 51 ½ mph!
Many of you may be saying to yourselves that an increase of two mph is not much! But in a small boat like our little Eliminator two mph is a real treat. Let’s put this into perspective, the GLM exhaust manifolds are a replacement exhaust manifold/elbow combination. This means that they are less expensive than the stock Mercuiser (manufactured) manifolds. If you are replacing your manifolds/elbows on your engine from simple wear and tear you can purchase these high quality manifolds for less money and find an increase in performance!
After talking to the people at GLM we found out that they had also run similar tests and found as much as 4 mph difference in top speed and an increase in timed acceleration tests performing the manifold switch on a similar family style boat.
If it is time for replacement manifolds or you just might like to improve the performance of your engine the high quality tuned GLM exhaust manifolds are really an excellent product!
GLM Products
Telephone 626-357-0077
www.glm-marine.com
Dennis Moore
FAMILY AND PERFORMANCE BOATING MAGAZINE
SMALL BLOCK EXHAUST MANIFOLD TEST
By
Dennis Moore
The real fun in owning a boat is ripping across the lake at top speed. Even if you aren’t the fastest boat on the lake the wind in your face makes it feel like you’re really free! We at FAMILY AND PERFORMANCE BOATING MAGAZINE know that not everyone owns a fast boat but most of use would like to go a little faster than the stock boat we purchased. We used a typical boat to write this exhaust test article to see if a simple improvement could make much of a difference in the average boater’s setup.
The boat we used belongs to a local car drag racer in southern California named Kevin Houmard. He gets his kicks from tearing up the ¼ mile in a nine second supercharged big block Camaro. When he goes out boating with the family he likes to take it easy and just cruise. Kevin owns a 21 foot Eliminator open bow boat with a 350 Magnum/Alpha sterndrive.
We took the little Eliminator out to a southern California lake called Lake Elsinore. If some of you have heard of Lake Elsinore I wouldn’t be surprised, it has a section marked off in the middle of the lake for high speed boat tests. Most of the hottest factory prototype boats in California have been tested here (sometimes on the same days!).
The morning we arrived it was typical southern California weather, clear blue skies and around 80 degrees. The lake was very smooth. Bob Carpenter and I were really enjoying ourselves on the lake that morning testing the speed of the little Eliminator with a radar gun. We made many passes across the lake that morning recording a speed of 49 mph with occasionally seeing the radar gun flash a 50 mph reading. There was no doubt in our minds that the boat had a top speed of 49 – 49 ½ mph.
We came equipped to change the manifolds at the lake. We pulled the boat up onto the trailer and headed for the launch ramps picnic grounds. Because it was a week day we had the place to ourselves except for a few retirees. We found a cool, shady spot and removed the stock Mercruiser exhaust manifolds and elbows. We installed some replacement GLM exhaust manifolds and elbows. The installation was an absolute bolt on affair, there were no installation problems. These manifolds have the exact same external dimensions as the original manifolds. The difference between these manifolds is all internal, (as you will read elsewhere in this magazine) the inside exhaust passages are tuned to separate exhaust pulses within the manifold.
After cooling ourselves off with a few soft drinks Bob and I launched the boat and under almost the exact same conditions (maybe the outside temp at the lake rose a few degrees) we tested the boat as thoroughly as we had with the stock manifolds. This time we consistently hit 51 mph with the radar gun occasionally hitting 52. There was no doubt in our minds that the Eliminator was now going 51 – 51 ½ mph!
Many of you may be saying to yourselves that an increase of two mph is not much! But in a small boat like our little Eliminator two mph is a real treat. Let’s put this into perspective, the GLM exhaust manifolds are a replacement exhaust manifold/elbow combination. This means that they are less expensive than the stock Mercuiser (manufactured) manifolds. If you are replacing your manifolds/elbows on your engine from simple wear and tear you can purchase these high quality manifolds for less money and find an increase in performance!
After talking to the people at GLM we found out that they had also run similar tests and found as much as 4 mph difference in top speed and an increase in timed acceleration tests performing the manifold switch on a similar family style boat.
If it is time for replacement manifolds or you just might like to improve the performance of your engine the high quality tuned GLM exhaust manifolds are really an excellent product!
GLM Products
Telephone 626-357-0077
www.glm-marine.com
#3
Guest
Posts: n/a
Don`t let the "Family" in the title fool you. I am an avid reader. It is my favorite of the boating mags. These guys do a lot of performance / speed oriented articles. I would compare this mag closely to "Hot Boat". Lots of West Coast style boats featured.
#4
but not to sure how the standerd reader of "FAMILY AND PERFORMANCE BOATING MAGAZINE " is about speed
#8
WOW! Real world testing.
Some people would balk at the expense for just an extra 2mph. But a 4% increase in speed with just a maifold change is fine by me. Maybe even more if he swapped to the aluminum manifolds for the weight savings.
This is the type of atricles I like. Taking the product out into the field and testing back to back.
BTW went to GLM Products website and couldn't find any listings for exhaust manifolds only the gaskets.

Some people would balk at the expense for just an extra 2mph. But a 4% increase in speed with just a maifold change is fine by me. Maybe even more if he swapped to the aluminum manifolds for the weight savings.
This is the type of atricles I like. Taking the product out into the field and testing back to back.
BTW went to GLM Products website and couldn't find any listings for exhaust manifolds only the gaskets.
Last edited by Iggy; 09-20-2002 at 09:52 AM.




