jeffswav

Here is the one I use, the auto oil coolers will not work http://www.eddiemarine.com/store/car...l&p=13577&c=47
Distributor http://www.performancedistributors.com/marinedui.htm

ROTAX454

The #6 MSD box does not alter the timing. You can lock out the timing and use this timing control from MSD. Carry with you a few retard "pills". Set your total for 36 and place a 0 in the box. When needed, replace the 0 pill with a 4 and presto, you have 32 degrees of total timing. The start setback is sweet too.

http://www.msdignition.com/Products/...ed_Retard.aspx

Kidnova

We dropped a new GM ZZ502/502 in my 23 Wellcraft Nova several years ago, 2002... I think. My ZZ came with brass freeze plugs so no problem there. We took the Thunderbolt IV ignition system from my 7.4 and used it on the ZZ. We also changed over the circulating pump, oil pan, alternator, and starter. I switched to a 23x3 combo oil and power steering cooler. And, my engine guy changed the head gaskets. After running the engine/boat for about 1/2 the season I was having oil tem issues so I yanked the 11 lb. pressure relief valves from the oild filter pad, and replaced the side valve with a 30 lb. Been quite a while since we made the swap so I'm sure I'm forgetting something.

Anyways, for the 1st season I ran the ZZ with the vac Holly 850 that came with the engine, and ran the stock Merc exhaust, with Imco Sound Advantage. There was no cam change. The ZZ cam is very similar to the older hp500 cams, which I understand did have reversion issues. Due to that I kept the idle at +750. Realizing the potential for reversion, after going thru no wake zones and after docking, I'd make it a point to crack the throttle a few times to clear any water from the exhaust manifolds. The 2nd season I changed to the Revolution Marine exhaust. That exhaust was affordable, and had/has more rise than the Merc exhaust. I also had the carb "marinized" by Nickersons to conform with coast guard regs. btw... the engine ran just fine prior to sending the carb to Nickersons.

The only problem I had with the ZZ was oil temps, even with the bigger cooler. My oil temp sensor was (and still is) connected to a port on the remote oil filter housing. I have it there because I figure that's where I'm going to get temp readings at their highest. Allot of guys like the sensor in the oil pan, which will give an ambient oil temp, and likely lower than what I see. Regardless, and not to start an oil war... I always used (and still do) Mobile 1 V-Twin 20/50, due to its ability to withstand higher temperatures.

Prior to yanking the ZZ and having it turned into a 557, I ran it as described above, for four seasons in my 23 Nova. Speeds were anywhere between 69 and 73 on GPS with a labbed 25 Mirage Plus, depending on the water I was running in. Again, as described above, the engine ran flawlessly. And I ran it HARD... ALLOT )

Now, this was a brand new ZZ crate engine that no one had phuk'd with. When my engine guy tore the ZZ down for the 557 project it had about 140-150 hours on it, and the internals looked to be in great condition. As we looked things over, he commented that the engine/internals would easily go another few hundred hours.

IMHO if the ZZ502 you have is "stock" and has not been messed with, you should be able to run it with the carb and cam it came with.

Good luck and lett'r rip......

morrowcarl72

thanks kidnova your amazing i think im going to run down and pick it up next weekend im super excited to see how she does....


and thoughts on the locking of the timing and or retard boxes

Kidnova

From what I hear about MSD's you won't need to worry about locking out the timing... it'll rust up and lock up on its own / However, reading the post by ROTAX454, he seems to like the MSD and he knows far more than I do about the subject. So I'd pick his brain. I ran the ol' faithfull T-bolt IV on my ZZ502 and it ran just fine. I did however use a T-bolt V ignition module to get around the rev limiter. In fact, I'm still running the T-bolt on the 557 ... bored, stroked ZZ502. I run the T-bolt with a Crane box on the 557.

The 557 also runs like a dream, with a mild solid roller. I thank rmbuilder aka Bob Madara for the cam. Bob was also key in picking out and furnishing the AFR 315 heads w/complete valve train, and 454R intake. And he was great with advice about the rotating assembly, which is Callies.

If no one has gotten their grubby paws into the ZZ you're looking at, and it's been maintained (oil changes/good oil), and if it hasn't been abused, you should be fine. I'm no guru so if I were to spend any real $$ on a used engine, I'd have a trusted pro look it over before buying it.

morrowcarl72

so i have been looking at exhaust for the last 3 hours online... prices between 1000-6500 and dont understand how one exhaust has a better ability to stop reversion more than any other.... i need some help making some choices here.... only thing i found online proving it had the ability to stop resonance reversion was this super long article about how there has only been a few manifolds ever built that have lips in them to help stop the water from coming back into the motor... any thoughts?

any suggestions?
anyone know what i might be missing minus the fact that some are shinny some are aluminum some are stainless etc

PatriYacht

Performance exhaust introduces the water further back from the exhaust port so the water has to climb further uphill to get into the cylinder head. The ones most resistant to reversion are dry all the way through the transom. Don't worry about them getting hot, they are water jacketed. The MSD will work fine. Use the black bushing in the distributer and set it for 34 degrees at 3000 rpm.

morrowcarl72

ok well i feel like a complete retard here but can anyone explain more in depth to me which bypass valve i remove and which one i replace?

i get the idea and have no issues with that what i dont get is which one is which and or where it is at? center vs side of pad...

morrowcarl72

nvm i figured it out.... do i need to install a 30psi or could i go with tapping it and plugging the hole all together like in a race application?

Kidnova

Some plug the hole and some put a 30 lb valve in. I went with the 30 lb valve. From what I've read/heard, the side valve only opens if the filter gets plugged, but I can't swear to that. I change oil/filter every +,- 20 hrs. so makes no difference to me.

As far as exhaust is concerned, see PatriYahts post.... decent exhaust exposes water further back. I came across a used set of KE headers. KE's are the best bang for the buck, if you can find some used, and in good condition. If the ZZ cam is a reversion concern contact rmbuilder/Bob Madara and he can set you up with a good cam. Plus with an rmbuilder cam you'll likely see more tq/hp than with the ZZ cam. But as I mentioned before, I never ingested water into the combustion chamber. At least none that I'm aware of.