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off shore cooling verses drive cooling

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niterider64

New member
I am having a 502 mpi built w/ an upgraded cam and Cmi high top headers but basically stock. I have recently had the water line and fitting replaced in the transom assy, corrosion was clogging it off, new sea water pump and new circ pump. The builder says he will not warranty it unless I get an off shore cooling setup. I understand the 502's do not have cooling between the cylinders but is this overkill. He is also going to drill a 1/2 hole in the stat housing to provide cool water directly to the circ pump. If I go w/ off shore will I # 1: loose speed due to the pickup. 2: need to buy a strainer. 3: Increase chance of picking up a bag or other garbage and clog my intake. 4: will I do damage to the drive if I block off the cooling water, do I need to drill a hole in the jacket to keep water flowing. 27' Powerquest, should run upper 60's hoping for 70 at 5100 rpm 25" mirage. Looking for any knowledgeable comments.
 
There is a little more to the story. He rebuilt the eng for me and installed it in the boat previously. It never ran right from day 1, made a lot of metallic noise, would not make full power. I brought it to the dealer. He said it was in limp mode due to the drive reservoir low and found the timing 8 deg to far advanced. Dealer added a little oil removed limp mode and set timing properly. I thought my problems were over, it ran better but only ran 4700 rpm w 23 prop. Long story short, damage had already been done, I boroscoped cyl and found pieces of crown missing, saw parts of the rings. Builder is eating all the labor while I am buying new pistons, rings and circulator pump. So to warranty it a second time he wants me to install the off shore cooling. He tried to blame me for some of the damage because he said not to run full throttle for the first 5 hrs. I took the boat out 5 times, 1 hr each time, at the end of easy cruising I brought the throttle to full for 15 seconds just to see what it would do. Each time I went out I made some small changes- removed a 2nd fuel strainer, added an electric delivery pump, set proper timing, installed new thru hull exhaust, had bad flapper-source of some of the metallic noise. Builder said I helped cause the damage by going to full throttle during break in. I know that 15 sec at the end of each hr of run did not cause scoring/ heat damage and pieces of piston crown missing. Friends say I should pay nothing and sue him but this is the real world, small claims, if I won would give me a judgement not cash and the summer would be over. I don't mind buying the new parts, I did not pay for new pistons originally, he said they were in good shape, he honed and re ringed. I like the idea of a pressure gauge, I'll see if he accepts that. HAPPY MEMORIAL DAY EVERYONE!
 
Find a new engine builder.............

The key to breaking in a newly ringed engine is to cycle it, raise rpms under load to ~ 3500 or so and then let off under load to 2000 rpms.

I assume you have a roller cam? if not then a new cam and lifters need to be run on initial start up at 1500 - 2000 rpms with no load for the first 20 - 30 minutes. if that is done then the cam/lifters should be good to go. I don't think a roller cam is a sensitive to break in as a flat tappet cam but I could be wrong on that.

This keeps the rings under pressure (expanded to cylinder walls) to break them in. In other words start to plane off the let off the throttle then repeat.

This should be done for about the first 24 hours of running time.

In reality if he is building this motor for the second time it should be run on a DYNO and all parameters checked and set and verified. And this will be almost an acceptable break in by itself.

It is the ONLY way to have it done correctly. If not he is only assuming everything is right. If it fails twice it is on him not you as he did not dyno it and verify his work.

There is no way what you are doing is causing any issues. As long as the engine does NOT over heat there is not much you can do to prevent any mechanical issues.


Machining tolerances (as in bore diameter and ring gap and most important is the cross hatch pattern he is using when honing the cylinders) and also assembly technique is key!! to a good engine. not so much how it is "broken in". Breaking an engine in has more to do with its life span.

Don't get me wrong, improper break in can cause damage but that is wide open throttle for extended periods of time from the beginning or idling under 1200-1500 rpms for long periods of time (refer to second and third sentences)

Ask the question of someone who purchases a brand new boat, Do they really baby it when they leave the dealer? I think not!! besides it is under warranty and there is no way to determine if the user broke it in properly..........99% of NEW/REBIULT engine failures is due to over heating, loss of oil pressure, or poor machining and assembly or the occasional failed internal mechanical component. Not the person driving it unless they run it at wide open throttle from the get go.........

As long as you drive it easily for the first 24 hours of use and do not run it at wide open throttle for more than a few minutes at a time (very few) then there is no issue on you.

That's my opinion...............When we rigged new boats for customers we took the boat out for a water test before delivery. DO you not think we did not run them at full speed/wide open throttle? How can you deliver a boat to a customer that you don't even know if it reaches its top speed? It may need a different prop or maybe (very rare) but a mechanical issue and it is best you as the dealer/seller find it before the customer while his whole family is out for a fun time on the water and the boat fails mechanically............
 
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and found pieces of crown missing, saw parts of the rings. Builder is eating all the labor while I am buying new pistons, rings and circulator pump. So to warranty it a second time he wants me to install the off shore cooling.
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Ayuh,.... That sounds like Detonation more than bad coolin',.....

Has anybody checked to make Sure it's gettin' the proper fuel flows,..??
 
He showed me the piston damage and both face and skirt were damaged. He said detonation would not damage the skirt, that was from improper break in from the rings not broke in properly and making metal to metal contact w the cylinder. I know he is full of sh*! Detonation causes the whole piston to heat and maybe got to big for the hole. During the first rebuild I questioned him about sending out the injectors he said not to bother. He is not a fuel inj guy, he is old school buy his own admission. When things started going wrong from the day I got it back he was blaming the fuel inj. On this second time around I have sent the inj out to be cleaned a flow tested. During the first 5 hrs of run I put a fuel press gauge on the rail and got a steady, at all rpm, reading of 38psi. Another small piece of info: this is a gen 5 block 1995 but has been updated w/ cool fuel, roller cam, single acc belt. When he says something I feel is b/s I let him know I disagree but there is a fine line here, I do not want to piss him off and sever what working relationship we have. He is doing all the labor I don't mind buying the new parts, neither of us were sure of the time on the old ones (pistons and circulator pump). It should be going back together in a couple of weeks, I will continue the story.....
 
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niterider64 said:
There is a little more to the story. He rebuilt the eng for me and installed it in the boat previously. It never ran right from day 1, made a lot of metallic noise, would not make full power.....Long story short, damage had already been done, I boroscoped cyl and found pieces of crown missing, saw parts of the rings. Builder is eating all the labor while I am buying new pistons, rings and circulator pump. So to warranty it a second time he wants me to install the off shore cooling......
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KGhost has it right on the break-in and running the engine. If it's machined and assembled properly you shouldn't have these issues. I recall an episode of Gas Monkey Garage (aka Fast 'n Loud) where they roached a brand new Ford 302. There was a miscommunication with the engine builder and they should have used break-in oil when starting the engine. They thought he had used the correct assembly lube and filled with regular oil causing lifters to stick and flat spotted the cam. Since you have a roller cam and lifters it might not be the same situation, but worth considering.

Here's a little reading on assembly lube and break-in oil: http://www.enginebuildermag.com/2014/10/break-in-oils-and-assembly-lube-needs/

Do you know if he primed the oil system prior to starting the engine? I have a friend that frequently builds engines and he made up a tank and pump device that he connects to the oil pressure sending unit port just prior to starting the engine. He'll put about 3 quarts of oil in the engine then send the remaining 2 quarts through the system using the pump. Immediately after he reinstalls the sending unit and starts the engine. If the builder didn't prime the oil system that could also explain a few things.

I don't think I'd go modifying my boat to meet the engine builders 'warranty'. Did it run and cool fine before this? If yes, then it should be fine with the rebuilt engine. If you think this guy can rebuild the engine properly, and he's willing to eat the labor cost, I'd just go with it and not worry about warranty after he's done. Just drive away with your newly rebuilt engine, break it in with the proper oils, then run your boat however you want. If the engine fails again you'll know the problem was the builder. You said he's 'old school' and doesn't know injection. I think that's a pretty good hint that a different mechanic/builder will be a better option in the future.

Kj
 
Personally, and I admit to being a bit of a curmudgeon with NO tolerance for BS, once a vendor of any kind starts to BS me...THAT IS THE END. There is no relationship. I'd lick my wounds and find another builder. There is a value to peace of mind.
 
Kevinj, I agree completely. It cooled fine before 2 yrs ago replaced cooling line at transom assy. now new sea water and circ pump. even if I did the off shore, if it came apart again he would say hit the road. I will ask him about the pre oil, good idea.
 
niterider64 said:
I will ask him about the pre oil, good idea.
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Cooling isn't your problem and I would not modify my boat to meet his 'warranty' for however little it's worth.

Also, don't give him a chance to blame you for failures. If the builder insists on a specific break in procedure, then ask him to give you a copy in writing. Keep an accurate log of your break-in steps and then if anything else happens you have that for your defense. However, if it were me I'd never go back to that guy for repairs. But, at bare minimum, you'll have everything documented and if there are future problems you have the information to work from.

Oh, one more thing, ask him to give you a document with all of the measurements and tolerances of cylinder bore, journals, pistons, valves, etc. With that info in hand you'll know for sure if everything was done right.

KJ
 
I dont care what he says...

Most new boaters take delivery and beat the sh!t out of them right out of the gate.
It may reduce the motors overall life span but rarely does it cause catistrophic failire .

So if you did not beat the snot out of it This is not you problem!!!!!!
 
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