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View Full Version : Aluminum exhaust again



ky-donzi
10-31-2007, 12:01 PM
I have recieved quite a bit of info on the GLM aluminum exhaust systems (here and other places). Ive checked the price with Dennis Moore and for about 549.00 + shipping I can get them to my door. I have a 98 classic with the MPI engine. My engine has low hrs on it so I don't want to pull it and put a bigger cam in it, plus this will require reprograming of the computer. I want very un-intrusive upgrades. My thought s are to install the GLM exhaust and replace the cast iron vortec heads with Aluminum vortec heads. The whole package should cost me $1300 +/- and I should lose about 160lbs off the stern. Input please???????

f_inscreenname
10-31-2007, 08:22 PM
Check eBay for the GLM's they were the cheapest 5 months ago when I bought mine.

Newby
10-31-2007, 09:10 PM
I got mine from Dennis through ebay. Aluminum manifolds and risers. They have been in service for a year in salt water without any problems so far. The weight loss was great and performance was similar if not slightly improved (probably from the weight loss).

MOP
11-01-2007, 08:05 AM
The head change with out going deeper is a waste of money, if you are that far into it you will benefit greatly from a cam. Taking each Heads/cam into perspective the cam will give you the greatest gain bar none! And be far cheaper!!!!

ky-donzi
11-01-2007, 08:48 AM
Thank you MOP, i know from experence with auto engines that the cam and headers are the cheapest upgrades, (get the mixture in and out) i guess im just scared of reprograming the computer. I figuared the light weight heads and manifolds would help. I'm probably just going to put the aluminum manifolds on and call it good. I might go deeper in a few years when a full overhaul is nessary.

BigGrizzly
11-01-2007, 08:51 AM
I agree with Phil. I have been doing this for a lot of years and you are not going to get significant gains without going deeper and bigger! You have heard it before," I have hopped up my motor and it is slower than before!". Cam selection and build up with reliability and drive-ability is not an accident. The point is the stock cam is quite good. I have used marine engines in street rods for years with great results. If your expecting! 3 to 5 miles per hour, the heads and that exhaust won't do it. You would be better off propping that unit and buying different props for applications. I have at least 2 different props for each boat I own. Yes there is one particular prop I use most of the time, but it isn't always the fastest depending on the boat. The weight savings will affect the handling more then the speed. I am sure someone will disagree with me, but this is what we have found. I am luckier than most. I live on the lake with a Hydro-Hoyst lift, which makes prop changing easy and fast. 15 minutes and I am back on the water. Oh, one minor detail, I have access to lots of props. If it were me And I was going for $3,000 I would do a good exhaust and forgo the heads this go around. That way you already have them for a future mod. Do not kidd your self those exhaust are not a performance type.

ky-donzi
11-01-2007, 09:11 AM
What exhaust do you recomend?

mrfixxall
11-01-2007, 09:24 AM
I agree with Phil. I have been doing this for a lot of years and you are not going to get significant gains without going deeper and bigger! You have heard it before," I have hopped up my motor and it is slower than before!". Cam selection and build up with reliability and drive-ability is not an accident. The point is the stock cam is quite good. I have used marine engines in street rods for years with great results. If your expecting! 3 to 5 miles per hour, the heads and that exhaust won't do it. You would be better off propping that unit and buying different props for applications. I have at least 2 different props for each boat I own. Yes there is one particular prop I use most of the time, but it isn't always the fastest depending on the boat. The weight savings will affect the handling more then the speed. I am sure someone will disagree with me, but this is what we have found. I am luckier than most. I live on the lake with a Hydro-Hoyst lift, which makes prop changing easy and fast. 15 minutes and I am back on the water. Oh, one minor detail, I have access to lots of props. If it were me And I was going for $3,000 I would do a good exhaust and forgo the heads this go around. That way you already have them for a future mod. Do not kidd your self those exhaust are not a performance type.
DITTO!
EMI or stainless marine....cant beat the emi's for the money..

heres what the emi's sound like..

http://youtube.com/watch?v=dLdeNiyk0Ew

BigGrizzly
11-01-2007, 09:31 AM
I am partial to Stainless Marine. The best bang for the buck. On the dyno they perform almost as well as tube type but a fraction of the cost. They can fit any boat and have been around a long time. I have not compared the Dana to the rest yet, but my guess is not much if any improvement will be attained, according to the gaines people have gotten in the real world. Remember everybody makes claims theirs is the best. With the Glm they still look stock and perform stock after the work and money. On my Criterion I built the motor around the exhaust so I use CMI tube hedders. On the Corsican with the 351 Cleveland I use CMI, because except for log manifolds -at the time-They were the only people who would make them for me. My son with hisw Wipple charged 454 uses the Stainless Marine manifolds with really good results. He put them on before the Wipple and had good results then too. I don't know anyone with a complaint about them.