GLM Aluminum manifolds vs. stock Merc's......

[Donziweasel]

Alright, I guess the general consensus is that actual hp gains from a aftermarket exhaust system on my 355 cid is going to be minimal at best. Now looking at weight savings. Full 350 with all Merc exhaust is pretty damn heavy. I found the GLM aluminum exhuast manifolds and elbows, but can not find a weight on them. So, my question is, how much do the stock Merc exhaust manifolds and lebows weigh vs. the GLM aluminum ones? All I could fins was that the GLM's weight 65% less, but no real numbers. I feel pullin 100 plus pounds off the ass end of my boat can only help, especially with high end chine walking!

[ky-donzi]

I don't know the real numbers, but unless you plan to do the swap right now.... I would watch ebay. I bought a new set of eddie marine manifolds and risers cheaper than I could have a set of GLM. I plan on doing the swap this winter. If you need something right this minute you might look at the GLM because they will be alot lighter, like you said. Just my 2cents

[blackhawk]

There is a new set on ebay:

http://cgi.ebay.com/ebaymotors/Mercruiser-GLM-Small-Block-V8-5-7L-Manifold-Set-59235_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el12 47QQcategoryZ31285QQihZ005QQitemZ150242997695QQrdZ 1QQsspagenameZWD1V

[mjw930]

Alright, I guess the general consensus is that actual hp gains from a aftermarket exhaust system on my 355 cid is going to be minimal at best. Now looking at weight savings. Full 350 with all Merc exhaust is pretty damn heavy. I found the GLM aluminum exhuast manifolds and elbows, but can not find a weight on them. So, my question is, how much do the stock Merc exhaust manifolds and lebows weigh vs. the GLM aluminum ones? All I could fins was that the GLM's weight 65% less, but no real numbers. I feel pullin 100 plus pounds off the ass end of my boat can only help, especially with high end chine walking!

The shipping weight for a SBC GLM exhaust is 56lbs. The shipping weight for the cast iron equivalent is 141 lbs, that's an 85 lb weight savings.

You can get it here every day cheaper than that ebay link: http://www.ebasicpower.com/mm5/merchant.mvc?Screen=PROD&Store_Code=eBasicPower&Product_Code=GLM59235

[blackhawk]

The shipping weight for a SBC GLM exhaust is 56lbs. I believe the stock exhaust, with risers weighs well over 150 lbs, probably close to 200 lbs.
You can get it here every day cheaper than that ebay link: http://www.ebasicpower.com/mm5/merchant.mvc?Screen=PROD&Store_Code=eBasicPower&Product_Code=GLM59235

Nice find!

[mjw930]

What I've noticed about them is always check ebay first. When I bought my BBC kit it was ~$550 on ebay but $699 on their site. Same part, same company, different price......

[Donziweasel]

Nice find!:nilly:

Now the big question, will I notice any difference? Handling, speed, etc...?

[BUIZILLA]

look at it this way... if you lost 85# would you handle better??

[BigGrizzly]

Because of where the extra weight is you should notice the difference in handling and plaining. I am not a particular fan of the GLM, but they are lighter and in theory every 5 pounds is a horsepower. I usually go for weight and performance. After 325 hp on a small block horse power gets expensive for the real life returns. Notice how I worded that.

[Rootsy]

how about this...

http://www.donzi.net/forums/showthread.php?t=34205&highlight=glm+weight

and this

http://www.donzi.net/forums/showthread.php?t=34358&highlight=glm

[Donziweasel]

Never used an aftermarket exhaust before. Everyone said wieght savings but no real hp gains. I plead innocent!:hangum:

[osur866]

DW, I put Stainless Marine on my 18 and weighed the cast iron stuff and it came in at 83 lbs. weight savings over the factory stuff, thats on a late model set up and yes the boat did handle better flew flatter and I gained 80 rpm's on a stock 6.2 maybe 3/4 mph to 1 but noting real noticible but the handling did improve along with fuel economy! Steve

[Trueser]

I had a set of GLM'S on my 22 and they were great.

[The Hedgehog]

DW, I put Stainless Marine on my 18 and weighed the cast iron stuff and it came in at 83 lbs. weight savings over the factory stuff, thats on a late model set up and yes the boat did handle better flew flatter and I gained 80 rpm's on a stock 6.2 maybe 3/4 mph to 1 but noting real noticible but the handling did improve along with fuel economy! Steve

Yes, an answer from the Shorty mythbuster.

I need to stay out of this before I end up ordering something for the X-18.