tuner adapter: 1 piece vs. 2

[bfly]

I have a 96' 245 carb block mounted on a 200(not hi-perf)2 piece tuner adapter with a g-force tuner. I'd tell you how it happened but it's a long story. Anyway,does anyone know what's to be gained by going to a 1 piece adapter? Will my g-force tuner bolt to it or will I have to get a new one? Any help would be appreciated. I was on mercury parts express looking at parts under the hi-perf serial # and the part numbers were different for the exhaust plate but the parts diagram looks pretty much the same as a stock 200.

[Raceman]

The advantage of the one piece plate is strength, not performance. If the one piece has the same port shape the tuners are interchangeable, although generally speaking the aftermarket tuner has no performance advantage either.

[sosmerc]

Don't forget that your cooling system will behave differently when switching between the two-piece and the one-piece. You may want to research "cooling system" problems and modifications...there have been numerous informative threads on the subject.

[bfly]

I was told by a reputable source that this block wouldn't be able to breathe through this 2 piece design. Is this info incorrect?

[sosmerc]

There may be some very, very minor difference, but if the exhaust openings are the same size and length and you are running the same tuner, the only real difference might be the way some water exits around the tuner. I doubt you detect the difference other than noise.

[bfly]

maybe I should ask this question a different way...does a 1 piece tuner adapter have bigger exhaust ports than a 2 piece or are there multiple exhaust port sizes for 1 and 2 piece designs:confused:

[MTCM]

Not to be overlooked is the one piece plates have no upper flexible "mounts" like the two-piece does which eliminates the decision to go to solid upper mounts vs. stock flexible upper mounts in the two piece plate. Solid mounts mean better handling/steering with the trade-off being more vibration is felt in the hull and your butt.......................:D

From a maintenance/reliability standpoint the two-piece plate (being two pieces that it is) is just another place to develop a leak between the adapter plate and the exhaust plate.

Like Raceman said, the gain will be strength, the only performance advantage I would think would be the improvement in the handling and steering of your boat.

[bfly]

my upper and lower mounts are solid already. Maybe I have a 1piece already? How do I tell the difference?

[MTCM]

Technically the one piece plate has no "mounts". The top of the Swivel is bolted/threaded straight into the plate. There are no "mounts" solid or otherwise that get "sandwiched" like between the two-piece plate.

[Raceman]

"does a 1 piece tuner adapter have bigger exhaust ports than a 2 piece or are there multiple exhaust port sizes for 1 and 2 piece designs"

Merc has used several different exhaust port configurations over the years. The first 2 liter V6's of the 70's had very large openings in the bottom of the powerhead which carried down into the plates. When the 2.4 liter engine was introduced in '78, the holes in the bottom of the block were considerably smaller and the plates matched. I'm unsure how many different changes have been made since, but basically if the holes in your 2 piece plates match the holes in your block, you're not gonna find a significant performance advantage in changing to a 1 piece. As MTCM said, the fact that the one piece plates don't use motormounts make them desireable in high perf applications. That was primarily what I meant by "strength". We ran the old 2 piece plates for a long time with solid mounts installed before Merc came with the one piece.

I guess the bottom line is, if I had an engine with 2 piece plates, and it was down anyway, and I had a one piece laying on the shelf, then I'd stick it in it. If I had to scatter the engine and buy the plate, I'd spend the time and money on something that would make a measureable difference. That's all assuming that your components aren't mismatched now.

[bfly]

Thanks alot for all the info.scream and fly rules!!!!!!!!!!!!!!!:D