rvtransport

I own a pair of 6.2s in a 292 formula. I have already added 1.6 roller rockers and revalution marine exhaust. I am thinking of pulling motors freshen them with new pistons 9.5.1 and add edelebrock e-tec 200cc heads and comp extreme marine roller cam 230ex @.050 224in @.050 112 centerlines. Will it run with stock injection with maybe bumping fuel pressure a little? I have installed raylar kits on 496 engines with no other ecm changes and worked great! I even own a 06 chev pick up with raylar kit with stock gm ecm with fuel pressure bumped runs excellent! Has any one played with motorrolla ecm on 2006 and newer merc 6.2s

rhsj2006

I have the same boat, no engine mods yet. What type of performaince increase did you see by adding the Revolution exhaust and 1.6 rockers?

rvtransport

I did not gain much from exaust, a little better out of the hole and mid range also a good wieght savings but when I installed 1.6 rockers I gained 2 mph in all conditions!

rhsj2006

2 MPH is impressive for a rocker change. Did you change valve springs as well? How many hours on your engines when you swapped those in?

4mulafastech

Hello fellow 292 owner! Attached is a thread you will probably be interested in. Not sure about your questions on fuel pressure or the ecm. It is my understanding the stock intake is restrictive and there is not much headroom with the EFI system either.

Ditto on rhsj2006 questions. Also, what brand roller rocker did you go with? Thanks.

http://www.offshoreonly.com/forums/g...fications.html

http://www.offshoreonly.com/forums/g...fications.html

rvtransport

Thanks 4mulafasttech! That changes my mind on stock injection. I will post results if I do change any thing.I did not change valve springs and used jegs 1.6 alum roller rockers. The boat has 125 hours total about 50 hours on mods. So far so good but since new the starbourd engine uses oil port nothing. Fastest speed to date is 73 gps. I also changed to 30 bravo one labs. I wish I would have kept 28s and bounced rev limiter and have better planning and mid range because boat is usually loaded down with people and gear.

bobl

I guess this saves me posting anything. Thanks for digging those threads up. FYI, we later added a Whipple to this engine and ETEC heads. It made almost 600 HP on the dyno.

4mulafastech

You're welcome! I remembered that thread from a while ago.

600 HP! Nice. Did that go back in the Cobalt?

bobl

Yes, a 20' Cobalt. It accelerates as fast as any pleasure boat I've been in. You can't drive it past about 75, but the owner wasn't looking for top speed, just acceleration.

4mulafastech

Cool. I bet he's ruined more than a couple people's day with that sleeper.