EMI or IMCO exhaust?

HowardRC · Dec 8, 2016

I am getting ready to ditch the stock manifolds and risers on my 1990 454Mag for some new manifolds and risers. My question is should I go with EMI or IMCO? I do not have much experience with either company so I am looking for some input. Thanks in advance.

Runs2rch · Dec 8, 2016

HowardRC said:
I am getting ready to ditch the stock manifolds and risers on my 1990 454Mag for some new manifolds and risers. My question is should I go with EMI or IMCO? I do not have much experience with either company so I am looking for some input. Thanks in advance.

For a basically stock or mildly modified the EMI's are fine as are the Imco Thumpers. The EMI's are probably less. I have installed both and the results were similar. A lot of people never pull risers to check them. Even running in fresh water after 5 or so years the rust build up is pretty bad.

BDMar · Dec 8, 2016

IMCO.

HowardRC · Dec 9, 2016

BDMar said:
IMCO.

Thumpers or Powerflows? My engine is stock with over 1000 hours, but I do plan on repowering at some point within the next few years.

Uncle Dave · Dec 10, 2016

Imco.

UD

BUSTI · Dec 11, 2016

shunter2005 · Dec 12, 2016

If you are looking to the future, I would suggest IMCO. I went with IMCO Powerflows on my old 454 mag. My boat had a Corsa Quick and Quiet setup with Corsa muffled tips and were power robbers for sure. The new IMCO's were a great change from the original Corsa system. May have added 1-2 mph max, but it sure could breathe better and sounded great.

Reason I went with IMCO, I was looking to the future rebuild. The Powerflows are rated to around 600-650 hp and that was going to be my hp goal. Unfortunately, sold the boat before I modded it.

If you do go with IMCO, and are looking to use their "A" risers, make sure you get a template kit from them to measure and design the risers. I installed the manifolds and then used the template to design the risers. They only charged me $100 extra to custom make the risers and had a fast turn around time. Best part was the custom risers had the water dump much farther out than the premade risers. It dumped about 2-3" from the back end of the risers. More protection from reversion that way.

They were great to work with. They called me and had me talk to the man/welder who was doing the custom work so he would get it right. Nice....

HowardRC · Dec 12, 2016

shunter2005 said:
If you are looking to the future, I would suggest IMCO. I went with IMCO Powerflows on my old 454 mag. My boat had a Corsa Quick and Quiet setup with Corsa muffled tips and were power robbers for sure. The new IMCO's were a great change from the original Corsa system. May have added 1-2 mph max, but it sure could breathe better and sounded great.

Reason I went with IMCO, I was looking to the future rebuild. The Powerflows are rated to around 600-650 hp and that was going to be my hp goal. Unfortunately, sold the boat before I modded it.

If you do go with IMCO, and are looking to use their "A" risers, make sure you get a template kit from them to measure and design the risers. I installed the manifolds and then used the template to design the risers. They only charged me $100 extra to custom make the risers and had a fast turn around time. Best part was the custom risers had the water dump much farther out than the premade risers. It dumped about 2-3" from the back end of the risers. More protection from reversion that way.

They were great to work with. They called me and had me talk to the man/welder who was doing the custom work so he would get it right. Nice....

Thanks for the info. When I pull the trigger, I will most likely go with the "S" risers since my exhaust exits under the swim steps.

BDMar · Dec 12, 2016

HowardRC said:
Thumpers or Powerflows? My engine is stock with over 1000 hours, but I do plan on repowering at some point within the next few years.

Powerflow

BUSTI · Dec 13, 2016

HowardRC said:
Thanks for the info. When I pull the trigger, I will most likely go with the "S" risers since my exhaust exits under the swim steps.

I am really impressed with my IMCO powerflows. They are older ones and the hard anodizing looks brand new on the jackets. I put all new gaskets last year and the boat is a 2004. 11 years on them and they're awesome.

Enen · Dec 18, 2016

I have a set of Powerflows from my last engine I'd sell if you are interested. They are sitting on a pallet at Schiada in Van Nuys.

Uncle Dave · Dec 20, 2016

Enen said:
I have a set of Powerflows from my last engine I'd sell if you are interested. They are sitting on a pallet at Schiada in Van Nuys.

And thats one nice thing about powerflows- I got some money for my small block ones after 10 years and they were in nice shape.

Went back to Imco for my big block build. Just getting it back together.... I get 725HP and 800ft lb through them.

Fred and the team at Imco have always treated me right.

I just had imco build me a custom pet grooming tub and it came out awesome.

UD

HowardRC · Dec 20, 2016

Enen said:
I have a set of Powerflows from my last engine I'd sell if you are interested. They are sitting on a pallet at Schiada in Van Nuys.

Do they have the "S" risers?

Enen · Dec 20, 2016

HowardRC said:
Do they have the "S" risers?

I think so. Here is a vid Alexi shot that shows them in detail

[video=youtube_https;-q9UM7QpdxY]https://youtu.be/-q9UM7QpdxY[/video]

Ibeplumbing · Dec 20, 2016

Enen said:
I think so. Here is a vid Alexi shot that shows them in detail

[video=youtube_https;-q9UM7QpdxY]https://youtu.be/-q9UM7QpdxY[/video]

Is this your old setup?

Enen · Dec 20, 2016

Ibeplumbing said:
Is this your old setup?

Yes sir.

Uncle Dave · Jan 12, 2017

Still got em Enen?

UD

Enen · Jan 15, 2017

Uncle Dave said:
Still got em Enen?

UD

I do. Sorry didn't see this post.

Uncle Dave · Jan 16, 2017

No prob one of my posts was a dupe- Call into Alexi...

Maxed out has a nice one but wrong tailpiece.

D

satellitemike · May 13, 2017

Enen said:
I have a set of Powerflows from my last engine I'd sell if you are interested. They are sitting on a pallet at Schiada in Van Nuys.

I am looking for a set, will they fit the 502 block and if so how much?
Please feel free to PM me on it, thanks.

shunter2005 · May 13, 2017

satellitemike said:
I am looking for a set, will they fit the 502 block and if so how much?
Please feel free to PM me on it, thanks.

If you are looking for manifolds with the standard "A" risers? I have a set of polished Powerflows available.

satellitemike · May 13, 2017

shunter2005 said:
If you are looking for manifolds with the standard "A" risers? I have a set of polished Powerflows available.

Not really sure what I am looking for, I was told my OEM manifolds are rusted and starting to seep. I wouldnt mind upgrading but they would be going on my 99 240 Hallett w 502 and wouldn't make much of a difference performance wise, would be surprised to 2MPH! How much you looking to get and I would imagine shipping would be pretty steep?

shunter2005 · May 13, 2017

satellitemike said:
Not really sure what I am looking for, I was told my OEM manifolds are rusted and starting to seep. I wouldnt mind upgrading but they would be going on my 99 240 Hallett w 502 and wouldn't make much of a difference performance wise, would be surprised to 2MPH! How much you looking to get and I would imagine shipping would be pretty steep?

PM sent

EMI or IMCO exhaust?

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