Airflow to engines - Flame
06-04-2013, 02:57 PM
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Airflow to engines - Flame
I recently had a marine survey done for a refinance and change in insurance. The surveyor pointed out that the only air getting into the engine compartment is from the two vents on the rear of the hatch. There are no vents in front of the engines forcing air into the engine compartment. Based on some formula that surveyors use, this would not give the engines sufficient air thus causing them to starve for air. Anyone have any insight on this?
Also, he pointed out that my intake vents to the engine compartment are only 6" away from the blower ducting discharge vents. The requirement is 24". So, the fumes the blowers are pushing out could in fact be sucked back into the engine compartment because they are so close.
Anyone have any thoughts on this as well? Thanks!
Also, he pointed out that my intake vents to the engine compartment are only 6" away from the blower ducting discharge vents. The requirement is 24". So, the fumes the blowers are pushing out could in fact be sucked back into the engine compartment because they are so close.
Anyone have any thoughts on this as well? Thanks!
06-11-2013, 10:28 PM
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There was some discussion on this yrs back and some of the guys w heats added vent to the front of the hatch. If you search back I'm sure you will find them To the second part of your post. I always lift my hatch when I start my boat to let any fumes out that might have accumulated
06-16-2013, 08:20 PM
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Your surveyor is correct that the Flame (and Heat) engine compartments are not properly vented for intake or exhausting hot air.
Interesting for a company who builds boats in the desert with 115o temps. Add another 20/30 degrees to the engine compartment for engine generated heat. My concern was/is what this does to hurt peak power. We know hot air is the enemy of horsepower, because it doesn't have as many oxygen molecules as cool air. I added Eddie Marine billet vents to the front of my hatch, and rebuilt it to clearance the larger supercharger I added.
My motor orginally had a Merc/Wieand 256, and I now have a Blower Shop billet 871. It's approximately 2" taller than 256.
When I rebuilt the hatch, I also added a middle 13" intake (same size as the corner vents) to flow air to the flame arrestor. It's similar to the reverse intake on a Z28 hood. I could probably make more power with a Harwood type scoop, but I prefer to keep the sunlounge stock looking and useable.
I'll see if I can find the old threads and pull them up for you.
Regards,
Steve
Interesting for a company who builds boats in the desert with 115o temps. Add another 20/30 degrees to the engine compartment for engine generated heat. My concern was/is what this does to hurt peak power. We know hot air is the enemy of horsepower, because it doesn't have as many oxygen molecules as cool air. I added Eddie Marine billet vents to the front of my hatch, and rebuilt it to clearance the larger supercharger I added.
My motor orginally had a Merc/Wieand 256, and I now have a Blower Shop billet 871. It's approximately 2" taller than 256.
When I rebuilt the hatch, I also added a middle 13" intake (same size as the corner vents) to flow air to the flame arrestor. It's similar to the reverse intake on a Z28 hood. I could probably make more power with a Harwood type scoop, but I prefer to keep the sunlounge stock looking and useable.
I'll see if I can find the old threads and pull them up for you.
Regards,
Steve
Last edited by Steve Zuckerman; 06-17-2013 at 09:47 PM.
06-20-2013, 09:14 AM
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Your surveyor is correct that the Flame (and Heat) engine compartments are not properly vented for intake or exhausting hot air.
Interesting for a company who builds boats in the desert with 115o temps. Add another 20/30 degrees to the engine compartment for engine generated heat. My concern was/is what this does to hurt peak power. We know hot air is the enemy of horsepower, because it doesn't have as many oxygen molecules as cool air. I added Eddie Marine billet vents to the front of my hatch, and rebuilt it to clearance the larger supercharger I added.
My motor orginally had a Merc/Wieand 256, and I now have a Blower Shop billet 871. It's approximately 2" taller than 256.
When I rebuilt the hatch, I also added a middle 13" intake (same size as the corner vents) to flow air to the flame arrestor. It's similar to the reverse intake on a Z28 hood. I could probably make more power with a Harwood type scoop, but I prefer to keep the sunlounge stock looking and useable.
I'll see if I can find the old threads and pull them up for you.
Regards,
Steve
Interesting for a company who builds boats in the desert with 115o temps. Add another 20/30 degrees to the engine compartment for engine generated heat. My concern was/is what this does to hurt peak power. We know hot air is the enemy of horsepower, because it doesn't have as many oxygen molecules as cool air. I added Eddie Marine billet vents to the front of my hatch, and rebuilt it to clearance the larger supercharger I added.
My motor orginally had a Merc/Wieand 256, and I now have a Blower Shop billet 871. It's approximately 2" taller than 256.
When I rebuilt the hatch, I also added a middle 13" intake (same size as the corner vents) to flow air to the flame arrestor. It's similar to the reverse intake on a Z28 hood. I could probably make more power with a Harwood type scoop, but I prefer to keep the sunlounge stock looking and useable.
I'll see if I can find the old threads and pull them up for you.
Regards,
Steve
How much extra noise did it add to the cockpit when you added those vents?
Marc
06-20-2013, 01:44 PM
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Hi Mark,
Not much really. I had to spin the old blower really fast to keep up with the engine improvements we made (2 to 1, or 12,000 rpm wot) so it was loud back then. The 871 is basically running 9% over, so it's quieter, even though it's bigger, and runs a Gilmer belt. It does have some blower whine, but nobody seems to mind. The serpentine belts (vs V belts) to me have always been relatively quiet too.
I don't think you'll find it objectionable.
Regards,
Steve
Not much really. I had to spin the old blower really fast to keep up with the engine improvements we made (2 to 1, or 12,000 rpm wot) so it was loud back then. The 871 is basically running 9% over, so it's quieter, even though it's bigger, and runs a Gilmer belt. It does have some blower whine, but nobody seems to mind. The serpentine belts (vs V belts) to me have always been relatively quiet too.
I don't think you'll find it objectionable.
Regards,
Steve
