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View Full Version : Goal reached but not with Donzi



flying tomato
08-17-2011, 10:46 PM
I have owed a 1984 Donzi Hornet III for 2 1/2 yrs now and it has been the source of the "speed bug" that has gotten into me.
I came to the realization that i needed a faster hull in order to get to 80 mph (my goal).

I came across a 1995 24' Python in Jan 2011. The boat was running with a 454 Mag and would run about 62 mph. Not fast enough. I built a 540 for the boat with a goal of 80 mph. On monday I reached the goal doing 83 mph. I built the engine 4 times in the last 8 months. 2 times not my fault, 2 times I take the blame. Here is what I learned and want to convey:
1. If you are going to upgrade the oil cooler, use number 12 fittings and hose and use the biggest cooler you can.
2. Have the rotating assbly balanced.
3. Keith Eickert exhaust is much better for big displacement motors than Stainless Marine. (I gained 7 mph by going to KE exhaust--everything else was the same) I believe i had the first gen SM exhaust.

Greg Guimond
08-17-2011, 10:58 PM
Talk About Other Boats

blackhawk
08-18-2011, 03:02 PM
I have owed a 1984 Donzi Hornet III for 2 1/2 yrs now and it has been the source of the "speed bug" that has gotten into me.
I came to the realization that i needed a faster hull in order to get to 80 mph (my goal).

I came across a 1995 24' Python in Jan 2011. The boat was running with a 454 Mag and would run about 62 mph. Not fast enough. I built a 540 for the boat with a goal of 80 mph. On monday I reached the goal doing 83 mph. I built the engine 4 times in the last 8 months. 2 times not my fault, 2 times I take the blame. Here is what I learned and want to convey:
1. If you are going to upgrade the oil cooler, use number 12 fittings and hose and use the biggest cooler you can.
2. Have the rotating assbly balanced.
3. Keith Eickert exhaust is much better for big displacement motors than Stainless Marine. (I gained 7 mph by going to KE exhaust--everything else was the same) I believe i had the first gen SM exhaust.

Nice work. Any idea on hp? I would guess about 575-600?

mrfixxall
08-18-2011, 03:05 PM
I have owed a 1984 Donzi Hornet III for 2 1/2 yrs now and it has been the source of the "speed bug" that has gotten into me.
I came to the realization that i needed a faster hull in order to get to 80 mph (my goal).

I came across a 1995 24' Python in Jan 2011. The boat was running with a 454 Mag and would run about 62 mph. Not fast enough. I built a 540 for the boat with a goal of 80 mph. On monday I reached the goal doing 83 mph. I built the engine 4 times in the last 8 months. 2 times not my fault, 2 times I take the blame. Here is what I learned and want to convey:
1. If you are going to upgrade the oil cooler, use number 12 fittings and hose and use the biggest cooler you can.
2. Have the rotating assbly balanced.
3. Keith Eickert exhaust is much better for big displacement motors than Stainless Marine. (I gained 7 mph by going to KE exhaust--everything else was the same) I believe i had the first gen SM exhaust.


4) Always listen to Fixx's and Buizillas advise! ;)

Ghost
08-18-2011, 03:23 PM
Regarding Greg's note, I've heard tell you can move a thread, but I've never done it.

More important, congrats on the boat!! Sounds like you made some monster improvements. Gotta be pretty cool to see it run like that with a motor you built.

I stumbled into those KE manifolds recently and tought they looked interesting--sounds like they really work.

Mike

tnc110
08-18-2011, 06:32 PM
7mph with exhaust!!!!
thats crazy...are you saying the KE picked up 7 over the SM or over stock?

how does it sound now compared to before?



I have owed a 1984 Donzi Hornet III for 2 1/2 yrs now and it has been the source of the "speed bug" that has gotten into me.
I came to the realization that i needed a faster hull in order to get to 80 mph (my goal).

I came across a 1995 24' Python in Jan 2011. The boat was running with a 454 Mag and would run about 62 mph. Not fast enough. I built a 540 for the boat with a goal of 80 mph. On monday I reached the goal doing 83 mph. I built the engine 4 times in the last 8 months. 2 times not my fault, 2 times I take the blame. Here is what I learned and want to convey:
1. If you are going to upgrade the oil cooler, use number 12 fittings and hose and use the biggest cooler you can.
2. Have the rotating assbly balanced.
3. Keith Eickert exhaust is much better for big displacement motors than Stainless Marine. (I gained 7 mph by going to KE exhaust--everything else was the same) I believe i had the first gen SM exhaust.

flying tomato
08-18-2011, 11:01 PM
Yes, all else was the same and I gained 7 mph when I switched to KE exhaust. The motor is a 540 cid, with all the good stuff, aluminum heads, bob madera camshaft, dominator 1050 carb.

Before switch motor would only turn about 5k.
After the switch 5700 rpms.

Same prop. Went from 76 to 83.