Matt,

This is not an issue with the exhaust system. Corrosion requires several things to work in conjunction before it can happen. You must have an anode, a cathode and an electrolyte which is the fluid that makes the connection. In the case of the exhaust the fluid is not passed through the surface that mates the dissimilar AL and cast iron together since all the fluid is passed externally through hoses. A real world example is the intake manifold that passes the cooling water from the heads and into the intake before reaching the thermostat housing. If an AL intake is used without an inert bronze crossover the intake will corrode at the point where the coolant passes through from the cast iron head to the AL intake. If that passage were sealed closed and the water was passed through an external hose this would not be a problem. 

Link to Corrosion Tech Article
/blog/articles/newsletter-07-13-06r1_web

Regards

Andy
Performance Product Technologies/IShopBoating
8002 West 6th Street
Stillwater, OK 74074
(405) 533-3812
Fax (775) 257-1769
[email protected]
www.perfprotech.com

Matthew,

Thanks for your inquiry and the opportunity at earning your business. I would go with the coated AL exhaust as there would likely be other fit up issue to deal with if you try and go with the Dry Joint on your older engine. Does your engine have spacers between the manifold and risers? Using the link below you can add your selected product(s) to your shopping cart and the shipping estimator located at the bottom of the shopping cart page will give you a shipping cost based on your specific postal code. Let me know if you need any further technical information or help placing your order. In either case I will be glad to assist!

Link to Tech Information
http://tinyurl.com/yb8rzl7

Link to Coating Tech Info
http://tinyurl.com/nkouoc

Link to Exhaust Kits
http://tinyurl.com/3yoz4kf

Regards

Andy
 
Performance Product Technologies/IShopBoating
8002 West 6th Street
Stillwater, OK 74074
(405) 533-3812
Fax (775) 257-1769
[email protected]
www.perfprotech.com

From: [email protected] [mailto:[email protected]]
Sent: Sunday, June 19, 2011 12:33 AM
To: PPT – Marine Engines & Parts
Subject: Contact Us Submission

Matthew writes:
Hi there I have a 1996 Mercruiser 5.7 carb v8 (ser: 0F784766) and I need to replace the manifold and risers. I am unsure whether I should go with the new dry joint option or look at getting your coated or infused aluminium types. Could you please give me your opinion of how I should go and what kits I can get with my model engine. Your advice would be appreciated regards Matt

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