last ditch effort

[mh11]

Re: last ditch effort

Ok, so I basically need to get to the port side cylinder head then.

So I need to do the following then? Any help will be appreciated.

1) Pull the dizzy
2) Disco the throttle linkage
3) Pull the exhaust manifold
4) Extract the cylinder head to inspect the #3 cylinder with 0 compression

Is this as easy as it sounds, or am I missing something?

Do I need to pull any belts off, or water pump or anything?

Please advise. Thanks!!!

 

[bruceb58]

Re: last ditch effort

Intake manifold

 

[JustJason]

Re: last ditch effort

before you go pulling the head check your valves and make sure they are not to tight. Do a simple adjustment then recheck your numbers. Also check to see if any of the rocker studs have pulled.

 

[mh11]

Re: last ditch effort

Ok, I am not sure how to check the valves, you mean with a feeler gauge?

Any help will be appreciated for sure.

I love this boat, I would like to try to do most of the labor myself.

IF the valves are too tight, then they hang open? They don't close all the way meaning no compression?

Thanks again!

 

[captmello]

Re: last ditch effort

You can go on you tube and see the valve adjustment done while the engine is running. You say its a new crate motor? All your compression numbers are low for any healthy 350.

 

[JustJason]

Re: last ditch effort

Setting the valve lash is done by feel. Head up to the adults only section and download the appropriate manual for your engine, read the procedure for adjusting the valves then report back if you have any question on the procedure.
If the valves are to tight then yes you will have low/no compression. I'm not saying its going to fix your problem. But I would start there before pulling the engine. Plus look at the studs that the rocker arms bolt to. Look real carefully that they are the same height, especially on that cylinder with no compression. Its fairly common for them to pull.

 

[tracyb]

Re: last ditch effort

I agree check your valves. allthow if the valves are not closing you would be back fireing through the carb every time that cylender fires. you probley have a big hole in that piston. what youve got is a time bomb. do you want it to go off on the water?

P.S look for gas in the oil.

 

[Fishermark]

Re: last ditch effort

if the valves are not closing you would be back fireing through the carb every time that cylender fires

Not necessarily. It could be an exhaust valve that is stuck. If any. I will be interested in hearing the result. Be sure to post what you discover!

 

[mh11]

Re: last ditch effort

Well, I am hoping it's just a stuck valve. A friend of mine just loaned me his leakdown tester yesterday to try and see if it's coming out the exhaust which means exhaust valve, or if it comes out the carb, it's the intake valve.

This is correct right?

Also, he had mentioned that if the piston has hole in it, it will pressurize the oil, is this correct? If I was to pull the dipstick, and there is a hole in the piston, oil would come out the dipstick.

Would that be correct?

Also, I called a machine shop that I was referred to, and the guy said if it's just one burnt valve, he would fix is for around 75 bucks. That's if I bring him the cylinder head.

Does that sound fair? It does to me.

Also, can someone give me a list of stuff that I need to do to get that head off, maybe in order, I think I got it, but you guys are the experts.

Thanks again for all the help!

 

[dontask]

Re: last ditch effort

By the questions you ask, wouldn't you be better off turning this repair over to someone who understands engines better? Once the cause is found its still needs to be repaired correctly, which will be the cheapest route for you in the long run.
If you continue and you have to pull the heads--- do you have a recently calibrated torque wrench to use when putting the heads back on?

 

[mylesm260]

Re: last ditch effort

pulling and installing a head on a CSB is child's play.

If you've never done it before, than grab yourself the manual and READ IT.

Some stuff may look really straight forward, but the manual will give you a very important step that if you skip, you will mess up your entire build.

Remember to label all your valve train components as you pull them, and remember to use new MARINE head, exhaust and intake gaskets.

Make sure you torque the head down properly, both the order and the torque values.

Depending on how many hours are on the motor, I myself would pull both heads and have a valve grind done on both of them. May not be necessary, but if you're going to pull the intake manifold out, you might as well...


Be thankful you're doing all this in a boat, and not under the hood of an IROC or something where there is much much less room to work.

 

[fast50]

Re: last ditch effort

you came make a compression gauge read high or low from one cylinder to the next depending on the length you crank the engine over normally you bump the gauge 3-4 times and that is all you need to tell you if there is a problem i would let those numbers ride if that is how you did the test

 

[mylesm260]

Re: last ditch effort

He could at least pull that head and see.

Pulling a head is free, it costs you nothing but a bit of time.

If he sees a hole in his piston, or finds that the bottom end has failed on that cylinder and his piston isn't moving, than fair enough, the engine's done.

But he won't know until he pulls that head. There are several things that could cause no compression on a cylinder, it could be in the bottom, or the top end. Could be a badly cracked head for all we know.

 

[dontask]

Re: last ditch effort

you came make a compression gauge read high or low from one cylinder to the next depending on the length you crank the engine over normally you bump the gauge 3-4 times and that is all you need to tell you if there is a problem i would let those numbers ride if that is how you did the test

He stated that he was going to use a "leak down tester", no cranking needed.
Saves allot of guessing.

 

[dontask]

Re: last ditch effort

IMHO a complete waste of time. Unless you think ALL the valves went bad and/or the head gaskets are leaking in every lung on both banks. The chances of that are slim and none and slim left the building...

Read the other posts on which direction the loss of compression is going. All the guessing and debate would have been over with in less than an hour. Its a tool and it gives more definitive information. Just like having a flexible cylinder borescope in your shop, saves time and guessing. They are great tools and with the right experience and training it gets you to the end result faster. If you only have and use a hammer in your tool box you will only know how to bang bang bang.

 

[mh11]

Re: last ditch effort

Ok, to the first person I think, yes I have a torque wrench to tighten the head down.

Well I put the leakdown tester on, brought the cylinder to what appears to be TDC on the number #3 cylinder which is the dead jug, released the pressure, and whoosh the air is coming out the outdrive, as my wife witnessed.

So this would leave me to believe it is an exhaust valve problem. Anyone have any opinions?

Nothing appeared to be coming out of the carb which would indicate an intake valve problem, correct?

If there was a hole in the piston, oil would be pressurized out the dipstick, correct???

Let me know what you all think, but it seems a little silly that one cylinder would be dead with regards to rings, correct?

Also, I did the comp check with all the plugs in the motor, just took one at a time out, could that be the problem with the low readings? Please advise.

Thanks again for all of your input, I just want to tow the kids around the lake in a week or so.

Thanks!!!

 

[MikDee]

Re: last ditch effort

It sounds to me like your exhaust valve is not closing? (leaking out the exhaust) Nobody mentioned it, but check for a loose, or broken valve spring on that cylinder, if you can turn the spring by hand, with the rocker arm loose (take the pressure off that rocker arm, either loosen it, or bring that cylinder to top dead center to test) then that's your problem. Otherwise, the head has to come off.

 

[dontask]

Re: last ditch effort

If you are sure that cylinder is on TDC. Then have you eliminated a valve stem to guide issue? If the stem is rusted or carboned up not allowing it to return to the full seated position would cause a compression issue. Are you sure that the hydraulic lifter lash adjustment has not been done incorrectly? Try backing off the lash adjustment counting the number of turns until the rocker is loose. Recheck the leaking and if no change then you know where the adjustment needs to be returned to (if it was adjusted properly to began with).
Sounds like you are just trying to deal with compression in this one cylinder to get the kids tubing so I won't debate the other compression numbers.
If you do not get anywhere after this I suggest you turn the job over to someone with more experience. As you said "one last ditch effort" is finally up. No offense but with the questions you have asked so far tells me that engine rework is not for you (alone).

 

[MikDee]

Re: last ditch effort

before you go pulling the head check your valves and make sure they are not to tight. Do a simple adjustment then recheck your numbers. Also check to see if any of the rocker studs have pulled.

You can go on you tube and see the valve adjustment done while the engine is running. You say its a new crate motor? All your compression numbers are low for any healthy 350.

After rereading this thread, being it'a new 350 crate engine, having such low compression numbers, another possiblity is your valves could be set too tight?

 

[mh11]

Re: last ditch effort

Please help! I got the motor apart and thundershowers are coming it looks like...................

Ok, I pulled the intake manifold off......

1) Seems like there is maybe some gas in the oil. It may be my imagination since I had gas all over my hands and had dripped some in the intake.

What does that mean? Is this possibly a bad thing?

2) The oil seals on the pushrods in the block, they are all at somewhat different heights stickin out of the block, is that correct?

3) The stud on one valve is noticeably higher than the other one on the cylinder that was 0 compression. The number 3 cylinder. Is the exhaust valve not opening????

Do I need to take the head off anyway??? The valve spring does not appear to be broken, the rocker arm has some play in it, it's not frozen.

Again, the number 3 cylinder was showing zero compression just to be clear when I did the test.

Help!!!! Thanks again for all of the advice!!!!