Exhaust advise??!!!???
 

Many of you know I have been working on my Scarab for a couple of years. I have now gotten to the point where I am fixing all the shortcuts I have taken in the past. The biggest mistake so far had been the exhaust- when I built the engines a couple of years ago I cheaped out on the exhaust- I had to cut corners somewhere- so I blasted the stock manifolds and painted them which was a bad idea. Now I am asking this question- yes this is a performance boat, but, I am not looking to go faster, I am just looking to go. So now I have to replace my exhaust and I am looking at all my options-

Here is what I did to the engines a couple of years ago-

4 bolt main blocks, balanced, with forged pistons, bored 60 over, rec port heads with air gap manifolds and 750 holleys. For ignition all I have is pertronix flame thrower coil and a mallory unilite distributer. Do I need headers, is it really worth 4 grand, or even a couple of grand? Or should I just buy GLH stock replacements and call it good? Does anyone have any experience with these? Big difference in $600- but I also know you do get what you pay for. Any advise is always appreciated:hitfan:

Scott..
Buy some used 496ho exhaust manifolds...They will work great and bolt right up...Plus they are much lighter than your current exaust. Should be able to buy a pair for about $300 a set. This IS the route I am going to go next year when I replace mine....

PS..they look cool and the stanless riser can be polished out
Also they can be ported to pick up a few extra ponies
eddie

You should have let me buy the beer in Havasu- call it a consulting fee!!! :D Next question- where do I get a couple of sets?

They show up all the time in the classifieds...Or post in the general boating section that you are in need of them...I just hope there is a couple of pairs left when I am looking for a set next year:)

I was lucky and found Gils on the site for about the same price, but I understand they aren't a favourite amongst the salt-water boaters...plus there are risers on eBay for 496 exhaust for $200/pr....good luck!

I got mine by posting in the "wanted section" , also seen a few sets on ebay in the last couple months
i'v heard the GLM manifolds have issues with the castings , dont bolt up flush without a little help , but thats just what i'v heard
i do know the 496 manifolds are a great improvement over stock , if you take the restrictor plates out of them (they call them turbulators or something like that) they sound fantastic too
next project is to buy an extra set of risers and see if i can polish em up for that aftermarket look

Scottie 150 - What year are your engine blocks? I ask this because I too would like to upgrade and the 496 manifold and riser option sounds pretty good. My boat is a 1989 Scarab Excel 31 with the stock 454's. I like the idea of both engines with new exhaust for a grand and not 4 grand! Sounds like there needs to be a few pair for sale now that we all may be looking. You have first dibs on any that come up for sale I will be looking in the fall and next winter.

Mine are early 80's Mark IV- I found a set of 496HO manifolds and risers on my favorite place(EBAY) and bought the other set from Teague Custom Marine. I will let you know how it comes out- should have one of the sets this week. I think I found a place to get some more- but I promised Westcoast he could be the broker- :D

Roger That

I just finished mine last month , i think it came out great
its a gen 4 454 , the exhaust sounds great and really kicks up the midrange power over the stock cast iron
not to mention it looks really good with the shift bracket and ign module relocated off the engine
make sure you go for the aluminum if you can , might as well drop weight too

Attachment 342990

better pic

Attachment 342991

:cool-smiley-027:Very nice - lots of room to work with - do you run mifflers?

Not yet , its not too loud till you get around the docks , i was thinking about some switchables but its not real high on my list o things to do , unless a great deal comes at me

:cool-smiley-027:Yeah, I have to be quiet by law.

I found these on eBay for $400. Don't know how quiet they will make it, but it gives me the appearance of caring.

:cool-smiley-027: Must be your lucky day - http://cgi.ebay.ca/ws/eBayISAPI.dll?...E:B:SS:CA:1123

I have a set of 496 HO takeoff manifolds in MI

MattBMiller - I live in Leonard, right next door to Romeo. PM me.

I've been looking on e-bay and have seen a few of the 496 risers on there. What diameter is the outlet on the riser, are they 4"? They appear to look smaller.

4" outlets on the risers

MattBmiller -give l me a call on my cell phone at 586-917-3135 regarding the 496HO manifolds you have. This is my work phone and can't always answer it if I am in a meeting. Leave a message with price and your phone number and I will get in touch. Are the manifolds you have aluminum or cast iron?

i'v seen those on there before , even watched when he had both sets up for sale , but there nothing with out the air actuators , lines , pump ... , money money money , each week i top off my tank and put a fresh 18 pack in the cooler , if they end at the opening bid i'll buy em , but i'm not getting into a bidding war for something that i'll probably just take off when i realize i love the rumble of my engine
:) , good looking out tho
know anyone thats looking for big tube headers / bravo1 tails that need some TLC ?

What do they need done to them and whats the price. May know someone.

one riser needs to be rebuilt , its rusted and leaking in the center of the collector , not leaking into the exhaust side , just outside , aside from that there good , 4.5 inch tails completely dry , small bung at the tip of the pipe for cooling water , if you want pics i'll snap some for you
looking to get 500 bucks , not bad for headers / risers / tails

Enforcer24- Can you tell me how you routed your water lines? Is your exhaust wet or dry?

Scott

IT'S wet , i used a crossover system , but that really doesnt change much , water comes from the sea water pump to my crossover , thru the engine and out the thermostat housing to the bottem of the manifolds and out the exhaust , if your running a circulating pump on the engine (water pump) , the only change to your system is using 2 "T"'s to eliminate the water lines that would run to your risers , sending all the water to the bottem of the exhaust manifolds
or buying a thermostat housing that has only the 2 lines out for water to the manifolds
let me know if theres anything else i can help with

I bought 2 sets of GLM exhaust a few months back, what a joke. They went straight back. I bit the bullet and bought Stainless Marine.

I havent heard much good about the GLM's , theres no doubt that if you can afford stainless marine manifolds there the best before stepping up to true headers like CMI or Stellings , but not everyone can afford that kinda stuff

If you want GILS, I have a customer who just upgraded and has a couple sets for sale.

PM me for his info.

Jeff

Stainless Marine was out of my comfort price range, until someone pointed out the ease of the dry joint riser removal. My engines are so tight in the boat, that I have to remove the inside risers and manifolds to get to anything. The fact that my life will now be so much easier was worth the extra cost. They also make custom risers to your application to prevent reversion issues should you ever want to go to a more radical cam.




A few pics of the GLM that I reccieved.....yes all 4 manifolds came in that little box.:eek:


for the reccord, I dont have an axe to grind with GLM, I just dont want to see anyone else get stuck paying very pricy return shipping becase they expected a lot higher quality.:party-smiley-004:

Picture # 2 holy crap , how could they send things out looking like that ? , with the almost guarenteed water leak your gonna have at that riser fitting , wonder if there paying for many replacement engines ?

GLM= China crap

The funny thing is, a friend of mine travels to China on a regular basis and has seen the lost foam casting process in action. He says its generally very accurate and was supprised with theese manifolds.

I will pass the word along and let you know if he wants tofool with fixing them. Thanks

So I think I have 2 pair of 496 HO risers purchased that I found from a guy who has them as new take offs. Will find out shortly when I receive them, $85/pair. I will let everyone know how easy or not they are to polish too. Unfortunately he doesn't have the manifolds anymore. What is a fair price for manifolds only, offer $200/pair maybe?

I paid 300.00 for mine , so that sounds about right
i'm really curious about the polishing , that would look awesome if you get em to shine like chrome

The going price seems to be around $350- everyone I called seemed to be stuck on that number for some reason.

i have 2 complete gil systems with pipes, cheap.

I wish I would have seen this last week. I posted a question in the SONIC forum about replacement manifolds and the GLH replacement exhaust. No feedback so I bought and installed the GLH manifolds without much difficulty or visual defects in the castings. Looked good and boxed well unlike some comments here. But I do have an exhaust leak on the starboard side I did not have before and no time to check yet. Are there problems with casting and fitting flush aginst the heads?

Yes-there is problems...however I would look first at the supplied gaskets. If they were the green ones then I would first try to get ahold of the factory merc ones...The silver ones. Also make sure your surfaces were really clean. On the block side it is easy to miss a chunck of old gasket material. Also if there was any pitting on the head surface that can be a problem. On the manifold side I always like to remove the paint on the riser surface and the exhaust gasket mating surface. Glm really puts the paint on thick. lastly make sure you go back and re-tourqe. If all has been checked then it is possible that you got a bad set from GLM.

I do have the silver ones that were supplied with the set. I checked with a straight edge for trueness from one port to the next as well removed the paint from the mating surface. When it comes to getting the head clean and all gasket material off, I did the best I could, I think. I will recheck torque first, then other areas behind and below the silent choice. All else fails, I will remove and reclean the head surface and keep my fingers crossed. I gave the manifolds a good once over, considering the cost, before I installed. Sucks doing a job a second time. Thank you for the advice. I love this sight.

Hey WestCoast, I didn't get anytime to play with boat this weekend, spent too much time in DOVER. I hate Kyle Bush. I want to check the torque first, I set them at 30ft/lbs. when I installed the manifolds. I got the specs out of a Mercruiser manual, is that what you would recommend?