ZZ502 DUD questions
 

Long story, so I will give you the coles notes version. I am looking for suggestions.
Last year I bought a Sea Ray Pachanga 22 for day to day driver at the cottage, me not being able to leave well enough along decided the old 330/Bravo that is came with was not suitable for this boat. It wasn't fast enough.
The boat with the Bravo ran 66mph on GPS, which I thought to be pretty damn good for old 330. So I went searching for a replacement powerplant. So I came across in the back of Powerboat Mag ( yes sadly I still have a subscription ), and add for motors, and bought a ZZ502 for 5500 bucks and had is shipped up to Canada. I wasn't looking to spend a ton on the motor, after all the boat is a 89 and I didn't want to get too upside down financially with it. On the ZZ502 I added Imco powerflow exhaust, the merc ignition and a 800cfm holly carb. plus all nice billet hardware like pullies and lifting rings and a crossover water system. For that matter everything on the motor is new.
So I get a guy that is known to be slow but does good work to install the motor, he takes 4 mths ( that is another issue ).
The motor also has a remote oil filer and cooler system.
So the first time we run the boat we notice it has a reversion problem, for those of you that know the P-22 it has the canister mufflers, we had to remove them and get Imco to make us some risers that would fit the boat, that dumped the water a lot farther down the line. Problem solved, another 2k. So we finally get the boat on the water, without a muffler system ( I wanted a sleeper ) and it seems to run great. I mean it pulls like an animal to 4000 rpm then falls flat on it's face. It takes a lot of coaxing to get it to turn 4800-4900 rpm at 71.9 mph..... or a 5.9 mph gain. This is bad enough in it's self, but the oil pressure drops to zero.... so naturally I freak and shut it down, leave it a min, and re-start it and it is at 20 and slowly climbs to 30, then 40 at idle, and it all seems fine. I question the gauge, but it checks out. I then run it one more time, again runs great can cruise all day anywhere from 2200-3500 rpm all day, but lean on it and all hell breaks loose. So the last time I lean on it, it does the same thing, pulls hard to 4000, takes a lot of coaxing to get to 4800-4900 and the same 71.9 mph and then the pressure drops. So I take it to the trailer. Once on the trailer, I notice the dip stick has been spit out and so have a quart or two of oil. I should add that the water temp is highish, and moves around a lot while driveing even at a steady speed. Like if I were crusing at 3200 the water temp is moveing from 140 to 170 with in a few min, back and forth.
Needless to say, I am at witts end and and have loss of the boat for this season. I am not getting much from the guy that I bought the motor from, and he has not called my engine guy back... after many msg's left.

What do you think, I am considerin taking the whole boat and motor to Active Engines in Toronto haveing them pull the motor, put it on the dyno and then problem solve.... and go through it if neccesary till it is right.

Thanks for any help/ideas.
RT

Re: ZZ502 DUD questions
 

If you're close to Toronto I suggest taking the boat to a high performance marine shop first. Some of your problems may be due to the rigging as opposed to the engine itself. I know Speedmaster Marine sends engines to Active, so you could try them. The engine may indeed end up at Active, but it sounds to me like you have some oil and water plumbing issues.

The lack of top end power, dipstick and oil blowing are engine related. Blow-by is caused by leaky rings and/or valves. I don't know whether the short episode of reversion contributed to this or not. There is a possibility that the engine had blow by when you bought it. Did you do any compression testing at the start?

Welcome to high performance boating and Good Luck!

Re: ZZ502 DUD questions
 

I agree with tomcat. we had a 540 blower motor do the same thing with oil pressure and found the oil pan was to small. new pan fixed problem, as for blowing oil and no top rpm , leak down the motor and see what shape it might be in.

Re: ZZ502 DUD questions
 

Small oil pan is interesting, it is only 6 quarts.

Tom Cat, I have seen your mock up motor at Teds many times. I just am not a fan of paying big labour bills when I can do 90% of the work myself. I build a lot of 2.5 Merc race motors ( Just won 2 major Drag races ). But I am not a 4 stroke guy, I understand them.... but it is not my forte. Add that my shop doesn't have the height to pull big motors.

Active did another boat of mine with Blower motors, and I was happy with them.

The plumbing is definalty ok. I think there is a motor issue, like a head gasket. I would think this motor would make about 500 hp or at least 200 more than the old 330, I expected 10-15 mph more. Not 6
The motor was brand new in the crate. I have not leaked it down, but the reversion issues were only on the hose and never under load.
I don't recall if I mentioned, but the damn motor is so smooth, and idles like a dream, it just has no go. and the heat and more importatly the oil issues.

RT

RT

Re: ZZ502 DUD questions
 

Did you do any spark plug checks to check the carb jetting before you leaned on it? Lean jetting in a high perf engine can cause a lot of nasty problems including damaged rings and pistons and blown cylinder head gaskets. The loss of oil pressure is most likely from high oil temp. What kind of oil cooler are you running? Your engine puts out as much heat and hp as a HP 500 so it needs an oiling system to match. That old 330 system is way to small and will kill your engine in no time.

Re: ZZ502 DUD questions
 

There is a lot of good info on this board. Do some searches and you can find good info. Like this http://www.offshoreonly.com/forums/s...ight=oil+lines

Re: ZZ502 DUD questions
 

The oiling system is from Herb Stotler, it hs a 2X10" cooler.
I don't know that all the plugs have been checked, but the motor was a little on the fat side.
One thing I heard was that if you were over full of oil this would happen, my motor guy says no way.
Also, the one time I did hear from the guy I got it from, he said that foaming oil would cause the lifter to not work right, and that would cause the flat power up top.
What could cause foamy oil, or enough crank case pressure to spit the dipstick and or oil.

RT

Re: ZZ502 DUD questions
 

2 x 10 is too small. 2 x 18 is minimum and I would prefer 3 x 18. Eddie Marine has the 3 x 18 for about 200.00. Best price anywhere. If you have a small pan, foaming can be a problem. Worse when the oil is hot. Do you have a windage tray?

Re: ZZ502 DUD questions
 

Replace your thermostat with a 140 degree. They're cheap. Replace your impeller with the kit from Merc if there's any question it needs to be. Good insurance. Make sure all hoses are routed correctly and there are no obstructions. What kind of breather set up do you have? Lack of breather will cause excess crankcase pressure which causes oil to pump out the dipstick. Unfortuately, overheating and detonation can cause excess crankcase pressure from damaged rings, pistons or blown head gaskets also. I'd get a leakdown test to make sure everything is ok.

Re: ZZ502 DUD questions
 

The valve covers are vented to the breather. It has an Imco bypass system on it.... the plumbing is easy and clear.
One thing my mechanic doesn't like in the imco system is how there is cold water dumped directly on top of the thermostat.
Pump is new. I asked about detonation and he said it isn't, but I am not so sure. 32 degrees timing, 9.8 compression and 91 octane.
I have a leakdown tester, just not the time to do it, it isn't at my shop it is at the riggers...... and to get him to do something is BRUTAL.

Re: ZZ502 DUD questions
 

If you take it to Mike at Active be prepared for the "OOOHHHHHHHHHH you thought youd save some money and buy a crate engine.....and now you want me to fix it up" tongue lashing "you know a crate engine IS NOT a marine engine........"

Im not saying dont bring it there because hes one of the best around here.......but just so you know :(

Re: ZZ502 DUD questions
 

hope everything works out ok........

Re: ZZ502 DUD questions
 

Ya, I already got that. I have know Mike and Wayne for years with the STV boats. And he build me some blower motors.

RT

Re: ZZ502 DUD questions
 

Cold water on the thermostat??? That sounds weird. Got any pics of the plumbing? Std. cooling goes in the front of the block, up to the back of the heads then forward to the thermostat. Then it's dumped overboard through the tailpipes. With your ignition timing and decent gas, I wouldn't think detonation was the problem either.

Re: ZZ502 DUD questions
 

Cooling sounds correct. Water comes from outdrive to sea water pump to oil/ps cooler to top of thermostat housing which has one inlet, three outlet and sits on top of the thermostat. At that point the engine water pump is one of the outlet and pumps water through the block into the heads up to the intake manifold at the thermo housing under the thermostat. This allows the water to come up to thermostat opening temp (usually 143 deg) then pass back into the housing. The other two outlets from the housing route to the exhaust manifold then to the riser and out the exhaust.

I have to agree, 500hp is way too much for that stock 330hp cooler. Your oil temp is probably way too high. I had same problem when I upgraded from a 502 to a 600hp 540 cu in. I have a 3 X 18 cooler in my hands ready to install. I also run straight 50wt now. Multi 20w50 did not act as a 50wt once warmed. Gained 10lbs oil pressure just from oil swap. Need another 5 from cooler to be comfortable. Also note, crank windage will foam your oil...

As fro falling on its face, sounds like lean on the top end (like other suggested). Need to check with a NEW set of plugs, run max throttle, SHUT DOWN QUICK AS POSSIBLE( no idling), do a plug read. Everyone else here has some great info as well.

As for crankcase press, sounds like the breather assembly is too restrictive or there is a blow-by issue with the rings.

Re: ZZ502 DUD questions
 

some interesting ideas here

Do any of you think an 800 Holley is too small a carb for this motor?

RT

Re: ZZ502 DUD questions
 

How many rpm are you wanting to turn? Rule of thumb is

cu in X rpm X vol eff. / 3456 = carb cfm

Your case
502 X 5200 X .90 /3456 = 680 cfm should be ok and have a good carb if heads are done or flow better than expected.

I actually have a 950hp. I turn 5400 with ported heads, manifolds. Went to a 1100 race modified carb on the dyno and lost some horsepower and torque.

Re: ZZ502 DUD questions
 

you guys rock

Re: ZZ502 DUD questions
 

here is the motor showing the plumbing, the oil system and pullies are not on it yet. But you get the idea.

Re: ZZ502 DUD questions
 

The 6 quart pan that comes on a ZZ502 is too small. You need the 8 quart pan. GM performance parts makes one; same as the marine pan.
I would do a compression test and leak down test to see if the engine is OK before making a lot of changes.
Good Luck... :(

Re: ZZ502 DUD questions
 

The plumbing looks correct. The line to the top of the therm. housing allows water to go to the exhaust when the therm. is closed. It doesn't interfere with the thermostat. If you drill 3 3/16 holes around the perimeter of the thermostat, the temperature fluctuations will be much smaller.

Re: ZZ502 DUD questions
 

You said you used a remote oil system. Did you change the block's internal bypass valve to the higher pressure marine spring and eliminate the other bypass valve that routes oil to GM's oil cooler holes? If you didn't the light bypass spring is opening and oil is neither filtered or cooled; gets really hot. this could be part of your oil pressure problems.

Ted's not expensive if he saves you from experiencing a problem. Shop rates get you knowledge too, not just labour. But hey, I learned just about everything the hard way so who am I to talk. :rolleyes:

Re: ZZ502 DUD questions
 

Firewalker - dont mean to hijack your thread but your PM box is full...... did you actually save any money having a heavy item like a motor sent up here from the states with shipping /brokerage fees/dollar etc etc...... as opposed to buying it from you local chevy dealer up here????......doug

Re: ZZ502 DUD questions
 

Firewalker,

Bear with me here....I am no engine guru but I'll offer what I can from my experiences with my ZZ502/502.

My ZZ is on its 3rd season. Mine's in a Wellcraft 23 Nova. It runs like a bear. But I've gone through oil temp problems with mine as well. And the consequential lack of, or very low oil pressure after a hard romp.

I'd suggest that you get an oil temp gauage ASAP. After installing mine I would not be with out one, even on a stock set up.

I'd also suggest a bigger oil cooler. The stock 7.4 oil cooler is absolutely useless on the ZZ. And the 454 mag cooler isn't much better. I currently run a 3 x 22 Hardin Marine and includes cooling for the power steering and is "ok". But actually I could use one size bigger, considering that I am still using the restrictive stock Merc oil lines and fittings. The stock 1/2 inch fittings are not 1/2 inch....they are more like 3/8 inches. I'm sure thay do restrict oil flow.

Through trial and error I've discovered that water/engine temperature directly affects oil temperature. I was told that by a fellow site member but being hard headed, I had to find out for myself. And, I found out that he was right. That being said, I'd suggest a 140* thermostat. I bought a Merc stat after trying out a couple of cheapies from auto parts stores. The Merc {or Quicksilver...don't remember exactly} provides a much steadier temp...less flucuation.

Another suggestion, and this helped me, I would remove the bipass valve from the block that is in the center of the remote pad adapter location, where the oil filter would normally be located. Take it out and leave the hole empty. Also, yank the 11 lb. side bipass valve, and replace it with a 30 lb valve.

The combination of the bigger oil cooler, lower temp tstat, and bipass valve changes, lowered my oil temps from +300* to a now maximum of 255*. Yes, 255 is still too high. But a helluva lot better than being over 300. I've run almost WFO for 25 miles in poker runs and oil temp stays right around 250, and never gets higher than 255. After stoping afterwards, oil pressure is 35-40 lbs. I consider that a victory.

Oil....I run full synthetic as it handles heat better than the majority of dino oils. I use Mobile 1 V-Twin 20/50. Previous to that I ran Valvoline 20/50 synthetic.

BTW, I did not realize why my oil pressure dropped to 10-15 lbs at idle after spanking it, until I put the oil temp gauge in and started posting questions. I was real lucky that I did'nt cook the engine.

My ZZ was delivered carb to pan. We took the pan off my old 7.4 and put it on the ZZ. Also went with better/marine head gaskets. I sent the Holley 850 Vac carb that was bolted to the ZZ to Nickersons for marinization and tweaking. It came back jetted a tad on the fat side. I left it fat to protect from lean out at WOT. Also took the water circulator pump off the 7.4 and bolted that to the front of the ZZ.

All I've ever fed the ZZ is 93 octane. I think you can use 91 with the 9.6:1 compression, but what's another few bucks at fill up time.....cheap insurance IMO.

What prop are you running? How much does you boat weigh? I'm running a labbed 25 Mirage Plus and turning 5000 to 5100 rpms. Boat weighs a little over4000 lbs. I put a couple of nicks in the prop this summer so it gets shipped back to Throttle Up for repairs soon. Plus I plan on having them bend it a little to get the rpms in the 5300 to 5400 range. Red line is 5800, but no need to take it that high as far as I'm concerned.

I had a bud tell me the ZZ502 was a POS and would'nt last in a marine application. Few weeks after the ZZ was dropped in the boat, the Humble Little Nova did a whoopazz on his 502 efi mag powered 28 Velocity. Last summer after putting around 75 hrs. on the motor Mr. Velocity and I got into it again. My buds 502 mag overheated while we were running. Cost my bud around 4,600.00, and he still had not proven his point.

I've read a few things people have written about the short comings of the ZZ502 in marine application. Obviously they can't be compared to Merc's Blue motors. But I think if they are set up properly they are quite capable.

Hope this info helps. And I hope there's no serious damage to your mill.

Good Luck!!

Re: ZZ502 DUD questions
 

Rob, call me at the shop.

Sean

Re: ZZ502 DUD questions
 

I cleaned out my inbox.

Sean, send me your number.

Thanks for all your help. This is awsome!.

RT

Re: ZZ502 DUD questions
 

Hey I never got into it with you :D

Re: ZZ502 DUD questions
 

Good thing too.....ya would'a crushed me :eek: :drink:

Re: ZZ502 DUD questions
 

If anyone happens to have the part numbers for the 8 quart oil pan and the 30 psi bypass valve that would be a BIG help. The motor is a GEN 6


Thanks

RT

Re: ZZ502 DUD questions
 

If your going to pull the motor and install a bigger pan buy one of the aftermarket ones. They have 10,12,14 qt pans that will work on your motor. Your oil cooler can never be too big nor your oil capacity.see the thread in post 6,it will clear up some of your oiling questions,Smitty

Re: ZZ502 DUD questions
 

Wish that thread was around a few years ago when I was going through the oil temp. Great info!!

Firewalker, if you decide to get a bigger pan, good idea to check and make sure there are no cross members or other obstructions in the bilge that will interfere with a bigger pan.

Re: ZZ502 DUD questions
 

Pay close attention to Tom Cats post #22, It is imparitive that you reserch the inblock oil bypass valving for it is different if you go with a remote oil cooler, changes from that if you have a remote filter, and chages again if you are using the two at the same time!!!!
Also the cam that comes in the crate motor is on a 110 separation with minimal lift and low duration, no torque above 4500 RPM!! Carb is most likely to large at higher RPMs with that cam. just my 2cents hope it helps!!

Re: ZZ502 DUD questions
 

I was talking to my engine guy/installer. I told him about all the info here and he doesn't see how it can be the bypass. To quote him "GM is't stupid".......... I am getting frustrated. He is going to talk to his engine builder about it.
Anyhow, I lost the boat for the year, and about 20k into it. I WILL NOT have this issue next year. I think the boat is going to Active.... or at least the motor.

Thanks for the help.

RT

Re: ZZ502 DUD questions
 

if the oil is foaming you have aeration in the pan due to windage. I don't believe the zz comes with a windage tray. Also if the engine has done this a few times you have possible damaged the bearings. I would pull the pan and pop off the front main and check the bearing. If the bearing has a "blotchy" look to it then you need to replace the bearing. The air bubbles have compromised the integrity of the babbit and this will lead to bearing failure.

Chris

Re: ZZ502 DUD questions
 

Look here...
http://www.offshoreonly.com/forums/s...ght=gen+bypass

GM part number 25161284

Dave

Re: ZZ502 DUD questions
 

Hopefully your engine builder has heard of the bypass problem. If not, he's not very well informed. GM does dumb things all the time. Look at the Aztek. ( I work there, I know. ) Do a search on oil bypass and see how many times this has been talked about.

Re: ZZ502 DUD questions
 

Firewalker,
I can tell you right now that if the oil filter by-pass valve issue was not addressed that you need to ASAP! The other thing is that you can't use the oil filter/cooler adapter that was on the Gen IV motor. You need to run one that is for a Gen VI. I would suggest a billet one from Eddie Marine or Rex marine.
The ZZ502 cam isn't so bad but, I hope you used the right distributor gear, it should be a "melonized" gear specific by GM High Performance. Was the cam degreed before you put the motor in the boat? If you install that cam @ 110degree Intake lobe centerline you should see better top end. As far as running a cam with more lift I would check the specs on your valve springs if you are going to change cams.
You definetly should be running the 8quart Marine pan and I do agree that the bearings should be checked!
If you really want to wake up that motor, e-mail me & I will relay the gobs of experiences and ultimate success of over 550 reliable HP that I have with my 502!! It's the same basic motor but quite frankly you have a better set of heads to start with!!

Re: ZZ502 DUD questions
 

The bypass valve is not the ENTIRE/ONLY issue. Just one chain in the link. Read the post by Arcticfriend. It will give you most all of the answers you are looking for. It is very informative and relates directly to your oil and oil temp issues.

Might also want to discuss this with more than one "engine guy/installer". He put a car engine in a boat. Lots of ZZ502's have been put to marine use successfully. Your guy failed to realize that a few simple changes are necessary. The changes are not that expensive. But they are necessary.

Also like cstraub said....windage tray!!

Good luck.

Re: ZZ502 DUD questions
 

Firewalker, Lots of good infor here on this thread. Read them ALL. The oil bypass valve change is necessary. Think of the added restriction by adding the extra lines and remote oil filter unit. The oil pan MUST go. Aftermarket, Stef's, Teague, Hardin, etc. Please don't go the car aftermarket way. Some stuff crosses over, and some does NOT.

Really recommend you put on a recirculating pump. The only way to properly regulate the water temp (keeping it within a close tolerance of temps) and your motor will definitely like it. Of course after you have selected the right thermostat.
See pic of my ZZ502 project motors.
Three last words: Big Oil Cooler

Re: ZZ502 DUD questions
 

All ZZ 502s come with factory windage trays. This is the same tray that is in all 500 HPs. Like Kidnova said the bypass valve is not the only issue, and I just want to say from having as many ZZ's pass through my shop I would say it is the least issue. This is a pressure diff valve and as the oil gets hotter the less the restriction through the filter.
The most important issue is oil amount and oil cooling which come from a bigger oil pan, cooler and having ample size lines with the correct adapters. If you look at his first post he said the oil dipstick had been spit out, and I'm sure the oil was too. This is more than likely why he lost oil pressure.
I would copy some of these posts and give them to your engine guy so you can have a trouble free NEXT summer and I would definitely take a look at the bottom end if you lost oil pressure under load at that kind of RPM.