Thinking about putting a blower / procharger on 383
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I want to get more out of the 383 (385) in my river boat and am seriously considering a procharger. Any thoughts or experience that might be of use?
Before you groan and say, bottom end, etc...
The current bottom end was built by a pro marine builder and has forged H-beam rods, forged 4340 crank and -16cc dished forged pistons. Everything was balanced and blueprinted. I turn it 5500 - 6000 rpms now, sometimes for miles at a time, without issue running a thermostatted oil cooler and high quality synthetic oil.
I'm assuming that I might need a different set of heads with larger combustion chambers to drop compression ratio, but am under the impression that I won't need to go top of the line with the heads if I'm running boost. I'm not positive what the static compression ratio is now without measuring after I get it apart or double checking with the builder (my memory sucks some days!). If memory serves me, it's approaching 10:1 with the block zero decked and a tight quench. I do know I consistently get 190 - 195 psi static compression test on all cylinders.
Runs great on 93 octane currently, but I want to get more power out of it and short of a new build with more cubes, forced induction seems a good option. We didn't run it on the dyno because it wouldn't have changed what I did and it wasn't convenient once I finished putting everything together. I'm assuming somewhere between honest 400 and 450 hp now with marine exhaust and as it sits in the boat.
Thanks in advance for assistance.
Before you groan and say, bottom end, etc...
The current bottom end was built by a pro marine builder and has forged H-beam rods, forged 4340 crank and -16cc dished forged pistons. Everything was balanced and blueprinted. I turn it 5500 - 6000 rpms now, sometimes for miles at a time, without issue running a thermostatted oil cooler and high quality synthetic oil.
I'm assuming that I might need a different set of heads with larger combustion chambers to drop compression ratio, but am under the impression that I won't need to go top of the line with the heads if I'm running boost. I'm not positive what the static compression ratio is now without measuring after I get it apart or double checking with the builder (my memory sucks some days!). If memory serves me, it's approaching 10:1 with the block zero decked and a tight quench. I do know I consistently get 190 - 195 psi static compression test on all cylinders.
Runs great on 93 octane currently, but I want to get more power out of it and short of a new build with more cubes, forced induction seems a good option. We didn't run it on the dyno because it wouldn't have changed what I did and it wasn't convenient once I finished putting everything together. I'm assuming somewhere between honest 400 and 450 hp now with marine exhaust and as it sits in the boat.
Thanks in advance for assistance.
Last edited by wtfo; 12-06-2009 at 09:07 AM.
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I don't see any problem with adding a Procharger. I have done tons of them and as long as you do the neccessary items, then you should have a very reliable piece. You did not mention if it is efi or carb. I personally am not crazy about using a blow through carb with a Procharger. I just find them difficult to tune. I would go to efi if it isn't already.
You need to drop the compression to about 9:1. Cranking compression doesn't really have anything to do with static compression. The is going to be determined more by the camshaft. The smaller the cam, the higher the cranking comp.
You need to be sure that the fuel system is up to the task. You need to pull out the pickup in the tank to be sure it will flow enough fuel. Most production setups will not. You need at least 1/2" (or -10) fuel lines and a large enough fuel/water seperator. Obviously the pump needs to be large enough and you should use a return style regulator whether it is carb or efi.
Most imporantly of all, the engine needs to be built with good parts and assembled with care. None of the other stuff matters if the engine scatters. Good luck with it. I would not hesitate to do it. Just do it once and do it right. Give me a shout if I can help in any way.
Eddie
You need to drop the compression to about 9:1. Cranking compression doesn't really have anything to do with static compression. The is going to be determined more by the camshaft. The smaller the cam, the higher the cranking comp.
You need to be sure that the fuel system is up to the task. You need to pull out the pickup in the tank to be sure it will flow enough fuel. Most production setups will not. You need at least 1/2" (or -10) fuel lines and a large enough fuel/water seperator. Obviously the pump needs to be large enough and you should use a return style regulator whether it is carb or efi.
Most imporantly of all, the engine needs to be built with good parts and assembled with care. None of the other stuff matters if the engine scatters. Good luck with it. I would not hesitate to do it. Just do it once and do it right. Give me a shout if I can help in any way.
Eddie
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I don't see any problem with adding a Procharger. I have done tons of them and as long as you do the neccessary items, then you should have a very reliable piece. You did not mention if it is efi or carb. I personally am not crazy about using a blow through carb with a Procharger. I just find them difficult to tune. I would go to efi if it isn't already.
You need to drop the compression to about 9:1. Cranking compression doesn't really have anything to do with static compression. The is going to be determined more by the camshaft. The smaller the cam, the higher the cranking comp.
You need to be sure that the fuel system is up to the task. You need to pull out the pickup in the tank to be sure it will flow enough fuel. Most production setups will not. You need at least 1/2" (or -10) fuel lines and a large enough fuel/water seperator. Obviously the pump needs to be large enough and you should use a return style regulator whether it is carb or efi.
Most imporantly of all, the engine needs to be built with good parts and assembled with care. None of the other stuff matters if the engine scatters. Good luck with it. I would not hesitate to do it. Just do it once and do it right. Give me a shout if I can help in any way.
Eddie
You need to drop the compression to about 9:1. Cranking compression doesn't really have anything to do with static compression. The is going to be determined more by the camshaft. The smaller the cam, the higher the cranking comp.
You need to be sure that the fuel system is up to the task. You need to pull out the pickup in the tank to be sure it will flow enough fuel. Most production setups will not. You need at least 1/2" (or -10) fuel lines and a large enough fuel/water seperator. Obviously the pump needs to be large enough and you should use a return style regulator whether it is carb or efi.
Most imporantly of all, the engine needs to be built with good parts and assembled with care. None of the other stuff matters if the engine scatters. Good luck with it. I would not hesitate to do it. Just do it once and do it right. Give me a shout if I can help in any way.
Eddie
Fuel system was done already (lines, tank pick-up and separator, still running mechanical pump) - ran into that problem on original upgrade.
heads are currently World sportsmans with some porting work, 64 cc combustion chamber. was thinking of going with analogous head in 72cc to drop the compression ratio to the right range.
cam is currently a comp xm270H installed straight up.
it's a carbed engine now... not so sure I wanted to deal with adding efi. bears serious consideration.
the current build was done with good parts and done well.
Last edited by wtfo; 12-06-2009 at 10:49 AM.
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Thanks very much for your advice and information.
Fuel system was done already (lines, tank pick-up and separator, still running mechanical pump) - ran into that problem on original upgrade.
heads are currently World sportsmans with some porting work, 64 cc combustion chamber. was thinking of going with analogous head in 72cc to drop the compression ratio to the right range.
cam is currently a comp xm270H installed straight up.
it's a carbed engine now... not so sure I wanted to deal with adding efi. bears serious consideration.
the current build was done with good parts and done well.
Fuel system was done already (lines, tank pick-up and separator, still running mechanical pump) - ran into that problem on original upgrade.
heads are currently World sportsmans with some porting work, 64 cc combustion chamber. was thinking of going with analogous head in 72cc to drop the compression ratio to the right range.
cam is currently a comp xm270H installed straight up.
it's a carbed engine now... not so sure I wanted to deal with adding efi. bears serious consideration.
the current build was done with good parts and done well.
I have a 2.3 liter whipple setup for a carb that might be a good choice.
Steve
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That would be an excellent choice.....especially for a carb setup. The Whipple works great with a carb. Like I said earlier, I don't really care for a blow thru carb setup. The Whipple is a much better choice and will be so much easier to tune. You should seriously consider that.
Eddie
Eddie
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The whipple in my opinion is a better way to go. It is more precise. I too had done a lot of prochargers in the past with great success, but between them not keeping up to date on the newer stuff & some other things it just doesnt seem to be the best way to go on a lot of stuff these days.
Jamie / Lakeside
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We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]