E85 fuel for marine use

[carburetorguy]

Hello!
I am interested in hearing your point of views, know how and or experience on this subject in you are willing to share.
Stock Chevrolet based Volvo Penta 5,7l/230 hp marine engine with carburetor. Mechanical fuel pump.

In all honesty it is a Quadrajet carb on this engine. I choose this index cause it seems to attract more interest.

Please let me hear what you think. I have zero experience with E85 but I have working on US carbs as a biz since the mid 80’s

I break it into three categories first)
1) Jetting suggestions as a base?
2) Overall fuel system upgrade?
3) Ignition mods?

Thanks from
Peter
www.carbguy.com

[jmarkaudio]

A Holley will be easier to set up for E85. It probably can be done with a QJet... If you want to keep mechanical pump look for a circle track methanol pump. Pull the gas tank or replace it, you will need to get any varnish out of an old tank as E85 will, and plug everything up... On small tanks that have set too long with gas I have actually used E85 to clean them, let it soak full and flush well. Ignition a good CD ignition will be a boost. One difference, boats tend to keep the engine cooler, E85 likes a bit of heat, so that may be something to have to look at.

[carburetorguy]

Hi!
Thanks for reaching out, I appreciate it!

When you are talking about heat, is that in the term of of the induction system overall temp?
To minimize the risk of too cold, condensation or plain ”freezin” ?

Thanks from
Peter

[jmarkaudio]

Ethanol vaporizes just above 170 degrees, usually needs a fair amount of engine heat to vaporize enough fuel in the induction. Boats use freshwater to cool, and never allows the engine to get too warm A Quadrajet primary would do a great job of atomizing the fuel, mods will be a bit more difficult as they were never meant to handle a lot of HP worth of gasoline to begin with, much less E85. An Annular 4150 would be best, keep the carb on the small end to keep induction vacuum higher, vaporize fuel better.

[carburetorguy]

Thanks, I appreciate it!
Peter
www.carbguy.com