Exhaust manifold recommendations for a 383

[Mckillop]

So the engine for our 18C is finally going into the dyno this week, and we are now getting the last pieces of the puzzle put back together. I am wondering what you guys would recommend for this application. It is a built 383 stroker, however we stayed somewhat mild with it for longevity and reliability reasons. We are not going to be using a silent choice system, we are just going to go straight thru with muffled tips. We have been looking at the Stainless Marine as well as some of the EMI stuff. Any opinions or other systems I should keep my eye open for?

[Jraysray]

When I bought it from Forrest.

http://www.donzi.net/forums/showthread.php?t=65279

[osur866]

If price is no option, CMI makes a nice set for the smallblock for around 2,700
I'm running stainless marine on my Whipple 383 and have had them for about 4 years and have been very happy with them, at that time the smallblock CMI's where way pricey at that time. Do you boat in salt water or fresh water?

[pipnit]

I'm in the process of putting in a 500+ hp 383 in an 18 footer. I opted for the stainless marine solution. It's a pretty slick setup and from talking with people who know much more than I do, it should be a good match.

[Mckillop]

If price is no option, CMI makes a nice set for the smallblock for around 2,700
I'm running stainless marine on my Whipple 383 and have had them for about 4 years and have been very happy with them, at that time the smallblock CMI's where way pricey at that time. Do you boat in salt water or fresh water?

Both, but majority fresh. Probably looking closer to the sub $2k ones. I don't think I could go wrong with either Hardin, EMI or Stainless. Probably leaning more towards the Stainless Marine

[osur866]

Both, but majority fresh. Probably looking closer to the sub $2k ones. I don't think I could go wrong with either Hardin, EMI or Stainless. Probably leaning more towards the Stainless Marine

Out of those 3 I prefered the stainless and that was what I went with, I've had my stainless manifolds and risers on and off countless times for just working in the bilge, I can have both sides off in about 20 mins easier to just take them off than work around them in the tight bilge of an 18! As info you will save yourself exactly 83 lbs going to the stainless stuff over the factory cast iron manifolds, that helped mine plan quicker and fly flatter by just changing those.

Steve

[Ed Donnelly]

Stainless Marine,,,,,,,,,,,,,,,Ed

[Mckillop]

Just out of curiosity, does anyone ever just add stainless risers to the stock Merc. manifolds? The only reason I ask is that we have brand new Merc manifolds that have been powder coated to match the engine, and then we decided to change the exhaust around.

[pipnit]

Just out of curiosity, does anyone ever just add stainless risers to the stock Merc. manifolds? The only reason I ask is that we have brand new Merc manifolds that have been powder coated to match the engine, and then we decided to change the exhaust around.

I know in my case, that wasn't an option since I had logs. I doubt that the stainless ones will work with anything other than stainless manifolds, according to flange and band clamp design. I imagine that the stainless marine ones are a better flowing manifold anyhew. I'm 99% sure that they will custom powder coat the manifolds or you could do that too.
As someone pointed out, this system will be nice because you can unclamp a pipe and have it off in a matter of minutes to get to plugs, etc.
Also, Jerry, the owner at Stainless is a heck of a nice guy and very good to work with.

[MOP]

The SM's and Gil's are very similar "both" contrary to what some think have aluminum lowers, Gil has both S/S and aluminum risers. The Gil's in the link above were a steal at that price, mine on my 383 are five years old in salt and are still like new. I had the risers checked this spring as a buddy has a metal shop with sonic testing, said they were fine and some thick.

[Mckillop]

I know in my case, that wasn't an option since I had logs. I doubt that the stainless ones will work with anything other than stainless manifolds, according to flange and band clamp design. I imagine that the stainless marine ones are a better flowing manifold anyhew. I'm 99% sure that they will custom powder coat the manifolds or you could do that too.
As someone pointed out, this system will be nice because you can unclamp a pipe and have it off in a matter of minutes to get to plugs, etc.
Also, Jerry, the owner at Stainless is a heck of a nice guy and very good to work with.

Hardin makes a nice stainless riser with standard Merc. mounting holes, just curious if anyone has ever gone in that direction.

[8318]

I have a like new set of stainless marine that came off my 383.
I went with custom headers when I built my 400 that is in the 18 now.
Give me a call I wiil sell these for short money
Dave 508-965-2005

[zelatore]

Hardin makes a nice stainless riser with standard Merc. mounting holes, just curious if anyone has ever gone in that direction.

I've seen them on a couple of non performance boats. Looks nice enough, but I couldn't tell you about installation, performance, durability, etc.

I certainly wouldn't expect any performance gain.

[Mckillop]

I've seen them on a couple of non performance boats. Looks nice enough, but I couldn't tell you about installation, performance, durability, etc.

I certainly wouldn't expect any performance gain.

Good point. I was just curious.

[Mckillop]

I have a like new set of stainless marine that came off my 383.
I went with custom headers when I built my 400 that is in the 18 now.
Give me a call I wiil sell these for short money
Dave 508-965-2005

Thanks Dave, I'll be in touch

[mike o]

I have a like new set of stainless marine that came off my 383.
I went with custom headers when I built my 400 that is in the 18 now.
Give me a call I wiil sell these for short money
Dave 508-965-2005Hope your bringing it up to the Winni poker run. :hyper:
Last Saturday of this month..........:yes: Love to run with you :kingme:. Should be a bunch of us running, from the Thursday before.

[wagspe208]

How much camshaft can a guy get away with before reversion/ water becomes an issue?
Do the aftermarket manifolds help/ prevent this? Or do I need to buck up and buy some CMI pieces? (which I am not very interested in)
68 18' barrelback. Old hot rod style piece. So, it needs to sound cool.
Thanks
Wags

[osur866]

How much camshaft can a guy get away with before reversion/ water becomes an issue?
Do the aftermarket manifolds help/ prevent this? Or do I need to buck up and buy some CMI pieces? (which I am not very interested in)
68 18' barrelback. Old hot rod style piece. So, it needs to sound cool.
Thanks
Wags


Wags, what's your cam specs? Stainless Marine offers long risers and I'm pretty sure if you want them to do a set of dry all the way out the transom they'd do pretty much anything you want.

I'm running a comp cams xm276hr with stainless marine and captians call and short tails and haven't had a issue with reversion yet after 40 hrs, it does idle at around 800 rpm tho.

Steve

[wagspe208]

No camshaft yet. This is a work in progress. I just want to be positive no mattter what camshaft I get.. will be cool with marine issues. Seen guys time and time again struggle with this issue.
Wags

I have a set of SB2 heads I'd like to put on it, but then my choices are ceretainly limited, so I'll probably just settle with a set of darts.

[donzidenis]

I called, no reply. Are they painted, powder coated, polished?

[Ranman]

Imco makes a nice SS riser that fits stock Merc Manifolds. GLM makes aluminum Merc replacement manifolds (much lighter than Mercs and an improved runner design). Rootsy ran these on his modded 350 @ 80'ish in his 16 Classic.