5.7L bravo 1 Water in cylinders 1 and 3 after overheat need advice

Oshkosh1

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That head gasket is "washed" between a couple of the cylinders. It's blown. Take it to a machine shop to have it mag'd and tested for straightness...
 

mr300z87

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dropping the heads off on Monday, and will order gasket set this weekend hopefully next weekend it will be back together. My good friend was able to score a Gallon of acetone from work today so I will test the manifold also before re assembly just to be sure hope to salvage a few weekends of boating in September. Wish me luck.
 

NHGuy

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You are doing the right thing. Please let us know what is found at the machine shop.
If the heads are not good, or if you just want an upgrade you can get better heads. GM or clone vortecs will get along well with your EFI and will give you better wide open and midrange.
 

Oshkosh1

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Make sure they are checking for cracks in the heads too.

If I drop a head off at a shop stating it blew a gasket from overheating and they DON'T...I'd find another shop. They should mag and vacuum test it prior to doing ANY work(other than cleaning up the chambers) on it. Vac testing takes 10 sec per cylinder and particle testing can also be done in just a couple of minutes.
 

mr300z87

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Thanks for the info guys, I know what needs doing as did the guy I spoke to yesterday. NHguy my engine has a Rochester 4 Barrel carb not FI and although the Vortec heads give extra power and that is always a good thing it comes down to dollars and cents. With the non Vortec heads I already have the intake and carb setup with Vortec heads I would need to purchase a new intake and who know what else not compatible. Also remember I am working on my project Sea Ray Sundancer 250 and this boat will most likely be sold next year, fully repaired of course. Another note as stated earlier in this thread, I have a friend who is going to give me a running Vortec 5.7L from his truck which will be back up if this repair does not go well. I am figuring that this repair if the heads and exhaust turn out to be alright will be only around $350 which includes the head repair and gaskets to put it all back together. Keeping my fingers crossed.

Mike
 

mr300z87

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Here are some pics of the head and gasket, I know everbody here likes pics
No1

No 3

Water Jacket

Wet spot between Head and Gasket

Intake water jacket
 

mr300z87

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This morning I pulled the starboard side head, although I found no evidence of water in the cylinders there was some milkshake in valve train. I did notice that the piston tops seem to have a lot of carbon on them. Here is a photo, I sprayed the cylinders with rust inhibitor, probably should have take a photo before.

The piston with the most carbon is #6 which had 95 PSI on my compression test. Do I even try and get the head done or is this engine just tired? I never notice any oil consumption or smoke and it has alway run flawlessly, up until now it has started on the first crank with only 1 pump of the throttle and left partially open. I found a couple of reman long block engines in the 2K range, but I am not sure I want to spend that much money on this boat. I could try and rebuild this one myself (I have never done one before) but I do have the ability to do so. I would love to find a running drop in like I found for my friend last year. Better yet can anybody say OUTBAORD!!!!! there I said it.
 

thumpar

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That spot where the head gasket is missing the piece is suspect to me. You can see rust all around it.
 

Oshkosh1

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Have the heads re-surfaced after they're confirmed good, have them grind and lap the valves and install new guide seals. Buy a set of good Viton coated head gaskets, slap it all back together with new ARP head bolts torqued to spec and drive it. Check the head bolts in 4-5 complete heat/cooling cycles and you're done. Clean up the block with a razor. Get it as close to perfect as you can. It's all about the prep work.
 

mr300z87

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Well its kinda a sad day for me, I do appreciate everybody's advice, but we have decide to through in the towel on this engine. I pumped out closet to 4.5 quarts of Chocolate milk from the engine then pulled the plug from the pan and some water and a little bit more chocolate milk came out. My wife and I have decided rather than spend a couple hundred on the heads, another $150 on gaskets to have the bottom end go out in a year it was best to put the money and time towards finishing the Sea Ray Sundancer. We have owned this boat for 5 seasons and has run flawlessly for us for about 110 hours, a value can not be put on the family time and enjoyment we have gotten out of her. She will run again it is too nice a boat to part out.

So this afternoon I put all the pieces back together so it at least looks complete, this was to prevent me from loosing any parts or forgetting how thing go. In the meantime I will keep my eyes open for an engine, complete used drop in would be preferred. I also still have my eyes on my friends Vortec 350 from his truck. It would just need a manifold some SS head gaskets, brass freeze plugs and it will be ready to go with a few extra HP to boot. Hope to see you all over in my Sea Ray thread, weather permitting the 7.4L engine should run in the boat next weekend. I could even possibly sea trial it in a few weeks using the drive from the Invader. That 4 letter word WORK always get in the way of my fun though. And if all else fails we might go look at a 27 Formula PC 27 with newer closed cooling 7.4L/Bravo 3 and sell everything else. Have a great rest of Sunday
 

bruceb58

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I also still have my eyes on my friends Vortec 350 from his truck
My gues is that his isn't a true Vortec unless he replaced his original engine. Just so you know GM did call some engines "Vortec" before 96 that did not have the "Vortec" heads.
 

mr300z87

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Bruce I am just going with what he told me. It is not the original engine from the truck. He said it was a gm create engine. He is also a pretyy knowlegable enging guy. II'll know more when iIget it. 8 bolt intake vortec 12 bolt non vortec right?
 

bruceb58

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Bruce I am just going with what he told me. It is not the original engine from the truck. He said it was a gm create engine. He is also a pretyy knowlegable enging guy. II'll know more when iIget it. 8 bolt intake vortec 12 bolt non vortec right?
Yep...If you said that before, I may have missed it.
 

thumpar

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Yea, just check the bolts. My 1994 GMC said Vortec on the air filter cover but of course it was not a real Vortec.
 

mr300z87

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All my research tells me that 96 was the transition year from non Vortec to Vortec heads in the mercruiser world and probably in the auto world too. Just like boats car parts are manufactured before assembly of the car and left over non Vortec engine could go in, say an early 96 would have Vortec badging but wear non Vortec heads. Most consumers will never know the difference. I personally like my v8 engines to be of the Mopar variety so this Chevy stuff is kinda new to me.

Question, I am lesierly looking for a replacement engine and have come across a couple truck/van engines. The one I am most interested in at the moment is out of a 1995 GM van. It supposedly runs good and only has 56k on it. My question is besides the head gaskets, freeze plugs, and all mercruiser marine stuff what else needs to get changed? IE: cam, balancer, timing cover. I would be using the Rochester carb and intake from the original engine.

On the flip side I mentioned this engine my boss and he said would you want one of the engines from our fleet of Ford vans after 10 years and 45k miles. When I thought about that I thought fleet trucks live a tough life and probably not be the best choice to use to re power a boat. I'll follow up anyway though.

Another thought is that I have always wanted to rebuild an engine. Have the block/heads checked out and cleaned up as needed, buy a basic rebuild kit, and then do assembly myself, would be a fun project and cost about half what a reman engine cost. I am not buildings a hot rod engine just a basic 350 Chevy 🤔🤔. Couple a friends say they will help. Wish they would help with the money part😎😎😎😎
 

bruceb58

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Hold out for a 96 or newer with real Vortec heads. You would need to find a new intake though.

There was no transition during the year for auto/truck engines. A 96 will definitely have Vortec heads.
 
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mr300z87

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So besides the intake what else does a post 96 Vortec install require besides intake? When did the mechanical fuel pump provisions go away? This project will be on a tight budget so I want to use as many of the parts I have. Would the Rochester 4 barrel carb need to have jets updated do to better air flow of Vortec heads?
 
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