5.7l fwc Motor issues, any ideas on what would cause this?

[Cocktail Time]

Alright, I'm looking for an easy answer that my mechanic and I are overlooking. I have a problem with my port motor but it seems strange they happened at the same time and rather than just repair and forget about it, I'm trying to figure out the cause; Symptoms are:

1.Low compression in #6 and #7 (68, 78)
2.#6 spark plug is bent.
3. No sign of overheating and plugs do not look exposed to coolant...

We are assuming the head gasket failed, that explains the low compression. But how the plug got bent is bugging me. Any recommendations on the things to look at? I'm hoping the #6 cylinder is ok, no wrist pin issues. We are going to remove head, check to make sure it is not warped, do valve job, then re-assemble. If you can think of something we're missing, let me know...Thanks! Dan

 

[jitts3]

Did the failure happen suddenly or over time. It the # 6 plug is bent hen you (for some time ran with a miss with a shorted plug. It is possible that a piece of head gasget got loose and rattled around the cylender and hit the plug.
Ok, now heres the question. What are "you" callinjg #6 and #7. Seems to be you have a bad head gasget between two cylenders.
This is a chevy v8 firing order

This is Ford

I'm not sure you are identifying the proper cylenders.

The red is ford cylender order. See the difference. The red arrow points to a typical common wall head gasget failure.



Hope this helps. PM me if you need more help. I'll be gald to help.

 

[tobnpr]

Rod or crank bearing let go, allowing the piston to hit the plug.
Wrong plug(s) installed, allowing piston to hit plug.
You accidentally bumped the plug and it was bent when you installed it.
Can't think of any other cause...

 

[jitts3]

Rod or crank bearing let go, allowing the piston to hit the plug.
Wrong plug(s) installed, allowing piston to hit plug.
You accidentally bumped the plug and it was bent when you installed it.
Can't think of any other cause...

Nah, If a rod bearing went out there would be a knocking noise that would not be able to be ignored. Plus there would be no oil pressure. If it was wrong plugs, they would all be shot. It is possible it was damaged upon instalation, but that would have caused a dead cylender and should have been noticed if that was the case. I think he has the cylender numbers mixed up and has a common wall head geaget failure.

 

[Cocktail Time]

#4 and #6 cylinders. Sorry for the bad info in post. Sounds like gasket went between #4 and #6. Not sure how the plug was bent but a piece of gasket or (hopefully not) a piece of a valve must have gotten into the cylinder. Thanks for the responses, I'll post back with what happens next...
Dan

 

[jitts3]

Sounds right. Keep us posted. Should be ok, A piece of valve would leave you short on compression in only 1 cylender.

 

[Cocktail Time]

Ok, as it pains me to post this, here are photos of the damage. I have a destroyed cylinder and a nice groove etched between the #4 and #6 cylinders.

Recommended fix, a new long block. Here are a few photos of the block and head. I am no mechanic, so suggestions are welcome. Motor was running well but with only 7 cylinders. This was my first clue something was up. No smoke, no overheating, actually the motor was running well, just less than usual power for that side.

<a href="http://s209.photobucket.com/albums/bb56/dsch555/?action=view&current=DansBullshit002.jpg" target="_blank"><img src="http://i209.photobucket.com/albums/bb56/dsch555/DansBullshit002.jpg" border="0" alt="Photobucket"></a>

Here are two photos of the damage...

<a href="http://s209.photobucket.com/albums/bb56/dsch555/?action=view&current=DansBullshit003.jpg" target="_blank"><img src="http://i209.photobucket.com/albums/bb56/dsch555/DansBullshit003.jpg" border="0" alt="Photobucket"></a>

Messed up huh?

 

[Cocktail Time]

As an aside, for those of you that believe in Karma. When I got to the boat today, we were ready to bring it to a ramp and put it on a trailer well overrated for my boat. Get to the boat and my mechanic has taken the plugs out of the stbd motor to check compression and never replaced them. So much for limping in on one motor. Both motors out of action...
I had the marina tow me over to the boat ramp and help best they could to get us lined up on the trailer. For what it's worth, 75 degree ambient air does not make the lake water much more than coooold. My feet are still numb and not from the tequila...
Trailering a boat with underwater exhaust is a pain in the arse. It can be done but will back up the ramp and fuel delivery guys and piss them off. No wind was a plus. Still a pain to get right.
For all you (us) do it yourselfers out there, god bless you.
By the time I got the boat and trailer to my friend's shop, the trailer brakes were locked and I could not move the boat in reverse. That being said, as I am cursing Sea Ray, Ford and anyone else in earshot, I notice a big pool of red transmission fluid under the truck...great.

Bottom line, I hope to have my gasser demons exercised and once repaired either love this boat for a long time or buy a big ass diesel and pray for the best.

Please look at the pics, donations are readily accepted...

Dan

 

[sprink56]

Wow..I am so sorry this happened. My brother is going through the same scenario on a 5.7/260 in his Formula.

FYI...not a Ford engine...5.7 is the 350 cu. in Chevy that's been around since Adam loved Eve. The firing order is 1-8-4-3-6-5-7-2 on a standard rotation engine. All of the even cylinders are on the left side(facing the water pump)odd to the right, numbered front to rear.

My brother in Birmingham is ordering a 5.7 long block from these folks in Hollywood, Fl http://www.rapidomarine.com/default.aspx?p=/engines/default.aspx

$1450 plus freight $150 is tough to beat.

Now, why did this happen? In my brothers case it was water injestion due to a rotton manifold on the port bank.

Since you are FWC you may have had a riser go bad and leak into the manifold at 4 or 6, or the gasket between the riser and the manifold did not seat properly the last time it was changed.:huh:

Hope this info helps and gives you some options.

 

[PlayDate]

Dan,

That sucks...the boat, the truck and the trailer? You didn't mention how many hours were on the engine....I'm just curious. I'm guessing that engine has been low on power for a little while. The groove it cut between the cylinders takes a little while to form (I can't see how deep it is) and the material from the groove finds its way to the compression rings of the pistons which scores the cylinder walls.

Karma......fooey. Go pistol or trap shooting and write the names of the parts on the targets and fire away!!!

-John

 

[chollyjohn]

I have one simple question. If yoru current mechanic can't figure the problem or have an idea what is wrong. Have you got a second or third opinion? SOme mechanics dont like to speculate....some do.

 

[Nehalennia]

Fixing your pics

Here are two photos of the damage...

 

[fc3]

That does not look too bad. Machine shop couldn't plane the deck?

 

[Cocktail Time]

Doug, thanks for fixing the pictures.

Frank, I agree that it doesn't look too bad. Once we have it out of the boat and cleaned up, the plan is to resurface the block, heads and give it a valve job while at the machine shop. When I see long blocks for $1450, I wonder if I wouldn't be better off just buying a reman'd motor? Any idea what a fair cost to tear down and reassemble a 5.7ltr should be?

Thanks again for the responses,

Dan

 

[fc3]

Depends on how much machining you do and how much you have to replace. If you're just going to plane that surface, magnaflux the block and heads, triple angle grind the valve seats, and hone the bores. Then buy new bearings, rings, and a gasket set, you are only talking about $1,500 I think. That's not including the actual tear-down and reassembly, which I'm assuming you are doing yourself. If you're sending the entire job our and want all new everything, 3-4 grand. I'm probably off. It's been forever since I've had to do this stuff. The only machine shop work that I'm sure of current prices is that a head rebuild (magnaflux, new guides, triple angle, etc) for a big block is about $170 per head.

Of course a shop in GA is going probably have entirely different rates than one there in NJ.

Best regards,
Frank

 

[sprink56]

Doug, thanks for fixing the pictures.

Frank, I agree that it doesn't look too bad. Once we have it out of the boat and cleaned up, the plan is to resurface the block, heads and give it a valve job while at the machine shop. When I see long blocks for $1450, I wonder if I wouldn't be better off just buying a reman'd motor? Any idea what a fair cost to tear down and reassemble a 5.7ltr should be?

Thanks again for the responses,

Dan

My brother recently faced this same problem...we came to this conclusion...why go to the trouble & expense of R & R engine A~Z without replacing it with a fresh long block that has been run in and has a 12 month warranty? :huh:Spend a few hundred more and extend the warranty.

He's putting in the fresh long block and then take his time gong through the take out and keep it as a spare.

Makes mucho sense to me. I think this is the best all around way to go. I'm guessing you will want to do risers and manifolds while you have it out. I figure you are looking at about $225~$2500 tops, A~Z.

BTW...keep in mind your reverse rotation factor..if you have one

 

[Cocktail Time]

My fingers are crossed here. Decided to go with a long block from Rapido as suggested. Thank you for the link. Turns out I have a friend in FL that bought two 7.4's from them, one crapped out after a few hours and they did right by their warranty.

$1450 plus $150 for reverse rotation. Nice attention to detail, crated properly plastic wrapped, with a Felpro gasket set and correct parts for a reverse rotation block.

Hopefully it will be installed and running by Saturday. Busy next few days...

Thank you all for the advice, lets see how she runs!

Dan

 

[sprink56]

My fingers are crossed here. Decided to go with a long block from Rapido as suggested. Thank you for the link. Turns out I have a friend in FL that bought two 7.4's from them, one crapped out after a few hours and they did right by their warranty.

$1450 plus $150 for reverse rotation. Nice attention to detail, crated properly plastic wrapped, with a Felpro gasket set and correct parts for a reverse rotation block.

Hopefully it will be installed and running by Saturday. Busy next few days...

Thank you all for the advice, lets see how she runs!

Dan

I'm glad it's moving in the right direction. My brother in Alabama is getting his Thursday. He opted for an extra $200 to get 325 HP. His is going in place of a 260 in a '83 232 LS Formula. I told him to start preparing to replace the drive...that old No. 1 MerCruiser (pre-alpha) will not handle that 325 HP for long...oh well he's single and knows what he's doing.:thumbsup:

 

[berth control]

Bummer of a deal with that motor Dan. Even worse with the trailer, truck, and loading problems!

It was asked, but I am curious how many hours you have on the engines and what the compression is on the other. I assume it is fine since you mentioned it still had plenty of power, but I am curious. About getting the long block - smart move. I had to replace the 5.7 in my last boat (actually, the new owner did it as part of the purchase agreement), but we decided to do the same thing for the reasons already mentioned - warranty being the biggest.

Boating by Saturday- now that's ambition!!:smt038:smt038:smt038:smt038

 

[northern]

We had one cylinder go to low pressure. 25PSI lower than the other cylinders and a bent spark plug tip. I only took the pressure after I lost power so do not know if it was that way before. Mechanic said it could have been a loose nut in the carb (that is why they use brass) bent the plug contact or the rings got so carboned up they poped off a piece of the piston. We ran the engine 3.8 V6 for 250 hours after that. Oil consumption was the same, power was the same and no vibration. We normally ran it at 3,800 RPM.