More power out of 6.2's
 

Whats the best way to up my 6.2's 320hp to about 400hp?? What is the lagging factor on these?? Heads, intake, exhaust??

6.2's don't have the internals for bigger HP.....leave them alone. Remember the 320 HP 6.2's weigh less than BBCs and a 454 Mag was only 330 HP ten years ago but obviously had more "build up" potential.

Being a Bahamas boater I think good fuel consumption and reliable motors are worth more to you than 160 extra HP.

+1
The only solution would be to put the 400hp 383s from mercury.I think they are about 12k each but you may be able to get them cheaper.

http://cgi.ebay.com/ebaymotors/ws/eB...d=280554490356

They are "remanufactured" motors only, no new 383's available. The 400 HP only is there if you replace the exhaust with CMIs. So add in the cost of the CMIs and you are into it for 25K+ real quick.

Did not know that.

My guess is they simply bore all the 6.2 blocks they take back under warranty.....6.2 motors are used in everything out there from cruisers to small Fountains!

I had read that they take manufactured defects from either the 350 or 6.2 and turn them into 383.

Yep, I have one in my little Donzi X-18. I run the hell out of it. Great engine.

They have been boosted with success. I would prboably want to go into the internals if I wanted to do much with it.

Looks like I may be keeping my pantera, so just trying to speed her up a tad. I was hoping to throw some better heads on or something like that to get a few more MPH. I have Stainless Marine exhaust but that's it for mods so far. I'm even thinking -2 shorties, my prop shafts are 5.5" below the hull, so thinking shorties would give me a few more MPH and better fuel econ. Right now she pops up on plane with no cavitation.

Austin, call Laz Mesa.

Thats a name I have heard latley, I wonder what he's been up to,I miss his build/dyno threads:drink:

I've done quite a bit of researched for upgrades to the 6.2 and I'm sorry to have to report that there is no inexpensive way to get the power you want.

I have a pair of 6.2's in my Formula 312. After my stock exhaust manifolds rusted out I also replaced them with Stainless Marine manifolds and I lost horsepower!

The 6.2 is a great engine, for the power range. But all the components are designed to that one specific power setting of about 320 HP. The Stainless Marine manifolds flow more exhaust, but in this engine, if its not coupled to improvements in the intake manifold and the heads, then the exhaust is sub-optimized and actually hurts performance.

If you are trying to upgrade the 6.2, the best option I found was to bolt on a Whipple super charge. That was what I was thinking when I replaced the stock exhaust manifolds with the SM ones.

But if you do the math, with all the stuff you have to do to the 6.2 you are probably better off just selling the engine and buying a 496 HO or 502HO. Also, you can boost the power of the 6.2 but you will be stressing an engine that wasn't designed for really high power.

This is good advice. OSO member UncleToys had nightmare experiences a few years ago with Whippling the 6.2s, it was well documented on the board but his posts have since disappeared. Not sure if he deleted all his posts as he became a "un-member" here or if the mods destroyed them but it left an impression on me as I followed his story.

In any event, I think the OP should just be happy with his boat and enjoy the reliability of the stock 6.2s, there's something to be said for going down to the dock and getting in a boat that starts everytime. My boating philosophy has always been to lay off the mods to engines that weren't built for it, if you want faster/bigger/better just save and get a new boat or engines that will do exactly what they're designed to do.

Agree with not building them,Do they even have forged pistons? Or will they be like the 496s.I did put IMCO exhaust on mine but just there version of the stock manifolds and while I did not gain any top end did not loss any either.But what I did gain is with 270lbs off the back of the boat in planes quicker and rides better.

Austin, What speeds are you reaching now ? Do you remember reading on the Pantera site about a O/B powered 28... that my be the way to go. "HIGH LIFE"

Probably shouldn't let the cat out of the bag but here's a little upgrade that will net you a couple of MPH. For some reason The original spider caps & rotors seem to hold these motors back a bit. I have replaced dist caps & rotors on many 6.2's (which are out of warranty) with replacements from Advance Auto parts. They are BWD manufacture # DS161 on the cap and DS 157 on the rotors. On a 330 Formula with 6.2's that has been running 52 MPH (This is the speed out of the box for this particular boat) since delivery back in 2002 now runs 58 MPH and bangs the rev limiter. The owner was amazed and couldn't believe it. To prove to him that this was the reason I swapped back to brand new merc kits and ran the boat. 52 MPH as original. Swapped back to the BWD's and back to 58MPH. I believe the phasing on the rotor/cap is a bit different on the aftermarket causing an increase in timing and the increase in RPM. The other plus is that they are half the cost of the merc units. I have been doing this for years with no engine failures.

I'm sure there will be a bunch of neah sayers but this has been the case with over a dozen boats I service regularely. $30.00 per side cap and rotor. Give it a try and report back.

Great tip, thanks!

Thanks

If you guys can pick up even 1 mph for $60 you owe this man a beer. If you try it out report back, sounds like a cool deal.

This would be great... and worth several cases if it works. I have tryed to look up those part numbers online and can't find anything in the Advanced Auto Parts site. Back in the Bahamas now so I can't just drive up to the store- downside of living on an island. If anyone finds these online please post url.

Try this catalog BWD part#'s Rotor D236 / Cap C282
http://bwdbrand.com/SMPTools/upload/...log/BWM-09.pdf

The above #'s are correct. I just checked the stock in my truck and have boxes with the old #'s, boxes with both the old and new #'s and the #'s above.

Links to parts at Advance Auto.

http://shop.advanceautoparts.com/web...GRPTUNEAMS____

http://shop.advanceautoparts.com/web...S_667730955___

One more tip to save you some coin. The IAC's on the 6.2's fail constantly. Here's the BWD replacement #50522. Compare to Mercs $98.00 each.

http://shop.advanceautoparts.com/web...S_536977104___

Anybody try this yet?

I did slight improvement but I think its just because they are new.The IAC is the same but the plug is on the other side the wire is just long enough.

I just got the parts in and will be installing them soon. Will post what I find.

Expensive Date, when you say slight, do you mean a few mph... or no change?

Like 1 MPH but I feel thats because they are just new parts.Letme know if you see anything different.

I opted to not do this, I went with OEM parts but I will say I did gain RPM that is no lie. Expensive Date is right the IAC valve is on the other side but will work but yet again I was worried and went OEM.

I know this is an older thread, but has anyone tried this? With any success ?
Thanks