Manifolds to CMI
 

Had the opportunity to pick up a CMI set up for a pretty sweet deal. Currently have manifolds wondering what difference if any that I'll notice switching to the CMI's.

built in water injection!

Thta would depend on what manifolds you have, what CMI's you got and how much power you are running. On a 500hp engine, I doubt you'll see a difference.

No doubt. With all the problems CMI has had with grenading engines due to their leaky tin cans, there's no way I would go out and buy a set to put on my boat! If I were buying a replacement set, I'd go with SM.

CMI... too many problems being reported.
What do you have now, Imco powerflow?
If you were to upgrade to anything w/ your 650+hp, it'd be to a Stainless Marine Gen III.

I believe they're Etops and I was able to get rid of an item worth about half the price of the CMI's I traded for. If they're not worth putting on, I'll sell them.

546ci 650hp(ish).

From the vid in your signature, it looks like you have Gils. You should gain a little bit with the E Tops and your HP. If I had to guess, I'd say maybe 20hp.

If I see CMI's on a boat, I look at them as a liability.

They look great and make some power, but they're pretty expensive and ticking time-bombs!

I've had Gil manifolds crack, but my CMI's have never had problems.

20hp seems a little much. I thought I'd pick up a better throttle response, maybe a little torque, and a better sound...... but 20hp...... damn:eek::drink:

C'mon now lets not over exagerate here , have had CMIs on the last 6 boats and never had a prob ..... the whole fvcking universe is a ticking time bomb :evilb:

Bolt them puppies on you'll be glad ya did :coolcowboy: if your still skered let me know what ya want for them ..:drink:

The longer runners will help on an NA engine. 20 HP is only going to be about 1mph.

I switched from Gils to CMI's on my 525SC in my pantera and didn't really notice a difference, but exhaust is not nearly as important on an SC'd engine.
I will say that the CMI's look a lot better and its a lot easier to get to spark plugs.

Just make sure you drain them after every run Jay.

?? Even in fresh water?

5 years on my CMI's no issues

Good advice Phil-- thank you. Gordo, 100% of my boating is saltwater so flush every time regardless. If I were you, I'd do it as well. Better safe than sorry.

Even in fresh water, if you have a small crack anywhere, leaving that water sitting in the headers gives it time to dribble down into the head. Go to crank it up and BOOM. Easier to just drain it.

RHR,
There are plenty of guys running CMI's for years w/o problems, does that mean there's no problem with them or that many others haven't grenaded their engine because their CMI's leaked???



OP,
They are a real potential liability. If the gamble is worth it to you, bolt them and roll the dice. Chances are pretty good you wont have a problem... but if you do it's going to be real costly!

At a minimum I'd suggest having them tested every so often.