6.2 MPI upgrades...
#1
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Anyone outhere doing any winter upgrades to their 6.2 MPI's. Looking for any information on equipment and results. I run twin late model 6.2's.
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Yep, I modified one last winter with after market EFI, ported heads and a little bigger cam and stainless marine exhaust. The boat picked up 7 MPH on GPS and a lot of low end. However, the customer still wanted more so I've got it back putting a Whipple on it. I'll post results in another month or so.
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You don't need any mods with the whipples. Problem is ECU. If you have the newer smartcraft PCM555 ECU it won't work. The MEFI 3 will. We replaced the ECU with a programmable FAST system. The only extra clearance needed is in front for the pulleys. It is no taller or wider than stock.
Bob
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My engines are 04's so I assume they have the latest ECU - PCM555. I know they are silver in color. Pulleys could be an issue, I will have to uncover the boat to check it our...it's a Fountain 29 Fever.
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I'm very interested in what others have done to the 6.2 as well. I just picked up a '01 312 fastech with twin 6.2. I've read on this forum that most folks think its not enough power. I personally like the set up. I'm not looking to be in the lead pack on any poker runs so the power seems good to me. However, the exhaust manifolds are showing signs of rust around the flanges and I'm estimating I'll need to replace them in the near future. I was looking at going to the Stainless Marine exhaust package. Best warranty in the market, dry flange, and rustless aluminum and stainless steel. From other posts on this forum I understand a new exhaust system will gain some power. I'm not looking for major increases in HP but some would be nice.
Since I'll have to do the exhaust anyway I was looking at other easy mods for some increased speed. I want to avoid pulling the engines so I want to limit mods to only those that can be done with engines in the boat. Again, max power is not my concern. If it was I would not have bought this particular boat.
I was considering machining the heads (3 angle valve job and porting) and Stainless Marine manifolds and risers. Then bolt her back up and see where that puts me for RPMs on the current props. After testing her out I was planning on sending the Props to Houston Prop for them to work some additional magic.
Boat runs about 66 right now and I was hoping this work would put her above 70.
Since I'll have to do the exhaust anyway I was looking at other easy mods for some increased speed. I want to avoid pulling the engines so I want to limit mods to only those that can be done with engines in the boat. Again, max power is not my concern. If it was I would not have bought this particular boat.
I was considering machining the heads (3 angle valve job and porting) and Stainless Marine manifolds and risers. Then bolt her back up and see where that puts me for RPMs on the current props. After testing her out I was planning on sending the Props to Houston Prop for them to work some additional magic.
Boat runs about 66 right now and I was hoping this work would put her above 70.
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The stock 6.2 EFI is not very conducive to increased HP levels. I wouldn't do any mods unless you plan on doing something with the fuel system. If you are pulling the heads, do a good bowl blend on them. They also respond well to larger valves. The 6.2 I did last year consisted of a slightly larger cam, bowl blend and 2.02/1.6 valves, stainless marine exhaust and an aftermarket EFI system with FAST ECU. I didn't touch the short block. The head work and fuel system are the biggest things to do. That boat picked up 600-700 RPM and a lot more low end. I don't think it's imperative to change the cam since they use a decent Crane cam (#104224) stock, but if you have the engine out anyway it's some cheap HP. This project ended up costing him about $9k including all labor. However, the EFI system was about 1/2 of that cost. A carb setup would knock a good $3k off of that.