Wes, as I had the same engines in my 292 and I went back and forth on what to do. In the long run it was cheaper to get a different boat. I got into my 35 Fountain for less than it would have cost me to make my 292 as fast as the 35.

I have the blue motors so I think I would be safe tossing a set of whipples on. I would do a lot more research befor I did something like that. But from my understanding I have all forged internals. I have no idea what speed I could excspect from that.... I don't ask cuz I don't want to sit at night a think about how cool it would be.

Now back to our regular scheduled fight

Burg came out swinging in the first round... Landed a few good shots
But I'm giving the the last 3/4 of the round to ICDE .... Seems to be doing well with his combo quotes.

:banned:

Did I miss something???:confused:

I'm surprised nobody's suggested the AFR 265's in this thread yet

Blue motors still have cast pistons. I've done a few small block Whipples. Doing 4 N/A 6.2 builds right now. I'll post some results when done. I also dyno'd and tuned a couple of 6.2's last spring for a fellow OSO member. He had a small cam upgrade and intake swap, and made 400 hp. If your target is in the low to mid 400 range don't give up on the 6.2.

bobl - I would be interested in your dyno results. Also curious about what cam and intake were used. I know the 6.2s are rated 320 prop h.p. I wonder what the loss is from crankshaft h.p. to the prop on Bravo 1.

A lot.... But I think a mod came and cleaned it up.

Damn... I was sure I had forged pistons.... Seems dumb that merc put all that work into this motor and put cast pistons on it

Bobl and I are working on a pretty aggressive 383 build for my Sunsation. We will let you guys know how it turns out!

I know better now! I think we would all be in a better mood if mptrimshop would just post up that other page on his browser! :D

AFR 265 vs Dart 270. Which one will make more torque from 1100rpm to 1500rpm

Bobl..what kind of sound are your 400hp sbc's making. What does it take to make a mean sounding SBC, always loved the lope of the HP500's, 500EFI, and 525's. Is it possible to get a small block to have this exhaust note, at times I feel my stock 350 MPI mags sound weak at idle.

I rebuilt a totally stock 6.2 a few years ago. It made around 350 hp at the crank on my dyno. I 've measured a consistent 10% loss through the drive on many engines tested at the crank, then installed in the boat and retested at the prop. So 350 is right in line with Merc's 320 PSHP claim.

Looseconnection, It's really all about the exhaust. You put some cmi headers on a sbc you can get aggressive on a cam and it will sound great and make nice power.

If you guys cant keep the thread on track I'm going to close it. I already cleaned this up once, next time I will issue timeouts.

BobL - thanks for the loss info on crank to Bravo 1 propshaft horsepower. I went to the CMI site and they claim a fair increase in h.p. with their headers over stock on the 6.2s. Other members have said they got zero m.p.h. increase after the install. Have you done any dyno work to support this exhaust manifold change?

SpeedGirl - sorry you have had to work overtime moderating this thread. It is disappointing to see the number of replies going way up, and then reading responses that have nothing to do with the original post. I appreciate the expertise of those on this site.

Looking here: http://www.mercruiserparts.com/selec...doc_nbr=878366 most of the parts are still available. Most are expensive though, especially the crankshaft.

Examples:

938-8412812 HEAD, Cylinder $1,130.48 $973.68
429-842405 CRANKSHAFT $4,770.53 $4,108.84
431-849195 CAMSHAFT, Roller $1,377.57 $1,186.52
807352A2 MANIFOLD ASSEMBLY, Intake $1,362.16 $1,220.02
861484A1 BODY ASSEMBLY, Throttle $553.30 $487.68
861334A5 PLENUM ASSEMBLY, Intake $808.30 $712.44

Sorry boys no porn site URL's or opinions about homosexuals but I did have some info that the
OP may appreciate. :evilb: :evilb:

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They hosed me on the stainless steel braided lines !!!!!!

http://www.offshoreonly.com/forums/g...roubles-2.html
I'am working on a project the starts with the 6.2 MPI. I would bet the same pistons are being used in the Scorpion, sounds like the forged pistons are not holding up. It has a 4340 crank, but most likely the 5.700 forged rods as found in the 5.7. They are called forged; that not being a 2618. I will let you know how it goes on this project.
Figure in boring to 4.030, CP pistons, AFR 190s, cam, lifters, rocker arms, push rods, rebalance and the Holley Stealth HP EFI. Throw some tubular headers on top of that. $$$$$. This isn't a budget build. Figure the cost; of EFI, then figure in a intake, carburetor, flames arrestor, fuel pump, distributor, wiring harness, ignition box, you will be over 1k in those parts alone. You can throw some iron eagle heads on there, they will make power. I saw a video; taking a set of 882 and working well over in the tune of $1000+, run them on a 383 carb, take them of and bolt on a set of Iron Eagles, the Darts blew the 882s away. If I can find it I will post it up.

http://www.offshoreonly.com/forums/g...roubles-2.html

Click on this and go to beginning of thread.

Very interested in these builds Bob. Looking forward to the results. Will these N/A builds be okay on 89 octane?

Wes, I've not tested the small block CMIs. I have done several sets on 496's with before and after dyno tests. I saw 28 HP increase with the sport tubes at the prop on a 496 HO. I certainly would not expect more than that on a small block, probably less.

CaptainYARR's engines will run on 87, the other 2 are higher compression and will require 91.

Are there still problems with pistons on 6.2 MPI's or did Mercury Mercruiser introduce an improved piston design at some point to fix the issue ?

I blew one piston on one and a head gasket on the other with about 200 hours. Year 2004 motors in a 2005 boat. Bobl suspects ethanol clogging injectors. No matter what the cause, it looks like I'm in good company.

I have no idea, if there was a correction to that. I doubt; they would change the piston, if it was caused from injectors. I spoke to Bob,( Marine Kinetics ) about the issues with the 6.2 and the 383 Scorpion. He mentioned "inverse radius",on the lobe ramp, was the issue with the valve train. I know he will be happy to give the technical break down. This isn't the first time we have discussed "inverse radius".
My client has pulled the trigger on building the 383 off the 6.2 . We had a discussion about just selling the stock 6.2 complete, minus the front accessory pulley brackets, sea water pump, alternator, and power steering. I'am putting it out there starting at $5k and would accept a realistic offer, if we can cover, building a new short block. The boat is well taken care of, the engine has 300 hrs. He also has a Y pipe, silent choice, and tips, if someone is interested.

Forgot to tell you. The injectors were so clogged up they didn't even try to run a "before" flow test, according to the injector service. They all cleaned to flow within spec though.

Ouch! Well there we have it in my case!

So are you guys thinking it might be a good idea to yank the injectors and have them looked at every 150-200 hours?

I have 6.2's in my 292 with 320 hours. They run as strong and smooth as day one. At least every other tank full of fuel I treat the fuel with MerCruiser Quickleen or SeaFoam. If the fuel will be sitting a while I alway use a fuel stabilizer. So IMO if you keep up with the fuel treatment there should be no need to pull injectors.

Injector cleaners containing PEA, will keep injectors very clean. GM and BMW did a study some time ago. A point to note is most available cleaners contain zero PEA. Redline Fuel system cleaner, Amsoil and REGANE(the expensive one) all contain a healthy dose of this very effective detergent.

If you ask me, yeah it's a hell of a lot cheaper than my engine builds. I wish I would have done it when I got the boat with 130 hours. Looking back on it, I think it probably needed it that early. We are planning on having it be an every other year item. It's cheap insurance.

I ran SeaFoam and it still happened to me. I won't be using it anymore and I'll just be pulling the injectors every couple years to be extra safe.

What company's are recommended?..... From what I found on the net.... After the first time you will know if it was needed. Most provide befor and after data

Sea foam is not good at cleaning fuel injectors. Contains ZERO PEA. I'm not surprised you noticed nothing. I've studied these chemicals and have seen the results. Head over to bobistheoilguy to read up on the fuel injector cleaners that deliver what they promise. Need to get past the hype and check out the science. Companies don't like PEA because it's expensive. There is no other more effective cleaner for said use. Everything else is just solvent.

Companies that use PEA are : Redline oil, Amsoil, Regane(their top tier product). Chevron techron(expensive concentrated formula).

PEA also cleans valves and combustion chambers very well as it is a high temperature detergent.

I'll keep that in mind for sure, but I won't be putting all my faith in anything from a bottle after this. Can't hurt to run it on occasion though! How often are you running it?

Scott Sjogren (at Pier 57 where purchased my Fountain) suggested running ValvTech fuel additive full-time. It really adds very little to the overall cost of running the boat. I have also used Chevron Techron in my Corvettes, truck, and (yes it is a bit embarrassing to admit) the Prius. When the tank gets close to 1/2 I add 5-6 bottles of Chevron Techron to the boat once per year. So far, so good. BTW - Scott's opinion is the 6.2s should get at least 850 hours before needing a refresh.

I run it in all of my cars and trucks, as well as my two boats. Use it about every 3rd tank. The companies that produce it usually will recommend adding a bottle once your tank is near empty and then filling up after the bottle is dispensed. Remember, we are talking PEA for removal of deposits, PEA isn't a miracle worker that will remove debris from screens inside the injector or repair worn passages. Ethanol or not, injectors get dirty. Plenty of studies out there show that certain cleaners will keep injectors clean for their given usable life. I do not own a scorpion motor, but that's besides the point as we are discussing gasoline fuel injectors. An $8 bottle of injector cleaner is pretty cheap insurance in my book.