351W Trouble

[RobotMan 264]

Not a good day today. My son Told me he thought the car was running a little sluggish. I cranked it and seemed to be idling fine. Newly built engine has 2200 miles and we changed break in oil to regular zinc based oil at 500 miles. I told him we should give it another oil change. After change I checked oil and noticed a milky color which obviously indicates water. I looked in old oil jug and sure enough there was green water in bottom. So I ran some more and cannot smell or detect radiator fluid in exhaust pipes even though there is quite a bit of condensation coming out. I collected that and I am sure it is just plain water. So, my strength is not internals of the engine but I’m thinking intake gasket or maybe timing cover issue?  Could head gasket have issue and not show up in combustion in exhaust. I need an attack plan and opinions from the wealth of knowledgeable guys on this site. Thanks in advance. 
 

Rick

[dcm0123 15]

In past I have checked for leaks of water into the combustion chamber by removing rockers, bringing cylinder to top dead center and screw an adapter into the spark plug hole to pressurize with 100 PSI air. This is how we used to change valve stem oil seals without removing the heads.  With your radiator filled and cap off, look for air bubbles.

Who built the engine? Were the surfaces inspected closely for signs of gasket material remaining on them? Are the block, heads and intake the original ones?

If you end up stripping it down and do not find a problem you may want to have the head checked for cracks before you reassemble it.

Make sure the intake gasket matches up with both the head and intake ports. Maybe a good idea to put a thin coating of RTV made for coolant system around the water ports going through the gasket front and rear.

Same with the timing cover gasket water ports. Check the timing cover surfaces closely. They corrode around the coolant passages. I had to replace mine. You may want to start there before you pull the intake.

Not sure how to detect water going directly into the oil such as from head gasket or intake unless you take it apart and look for a damaged gasket. Only way I can think which might work is mix a fluorescent dye used for leak detection with the coolant before you take it apart and run it. Drain the engine good before you disassemble. When you open it up look for traces of the dye coming past the gaskets. In the dark a UV light will cause the fluorescent dye to glow. Not sure where you can buy the dye. We use this at work to look for water leakage on products we build. A similar dye is used in AC systems to look for leakage.

[RobotMan 264]

1 hour ago, dcm0123 said:

In past I have checked for leaks of water into the combustion chamber by removing rockers, bringing cylinder to top dead center and screw an adapter into the spark plug hole to pressurize with 100 PSI air. This is how we used to change valve stem oil seals without removing the heads.  With your radiator filled and cap off, look for air bubbles.

Who built the engine? Were the surfaces inspected closely for signs of gasket material remaining on them? Are the block, heads and intake the original ones?

If you end up stripping it down and do not find a problem you may want to have the head checked for cracks before you reassemble it.

Make sure the intake gasket matches up with both the head and intake ports. Maybe a good idea to put a thin coating of RTV made for coolant system around the water ports going through the gasket front and rear.

Same with the timing cover gasket water ports. Check the timing cover surfaces closely. They corrode around the coolant passages. I had to replace mine. You may want to start there before you pull the intake.

Not sure how to detect water going directly into the oil such as from head gasket or intake unless you take it apart and look for a damaged gasket. Only way I can think which might work is mix a fluorescent dye used for leak detection with the coolant before you take it apart and run it. Drain the engine good before you disassemble. When you open it up look for traces of the dye coming past the gaskets. In the dark a UV light will cause the fluorescent dye to glow. Not sure where you can buy the dye. We use this at work to look for water leakage on products we build. A similar dye is used in AC systems to look for leakage.

Thanks for your time and input. Greatly appreciated.  

[RobotMan 264]

I determined the intake bolts were extremely loose and torqued them in sequence to recommended torque. Most of the bolts were turned at least one full turn. I was amazed this could happen. Anyway, drained oil and currently have no water in oil. Will drive some and check again later.

However, I still have a performance issue I need some advice on. The engine hesitates severely and hiccups when you dump the accelerator to speed up quickly but will run smooth if you ease up to the same point gradually.  It runs smooth if I maintain the speed even at high RPMs. This just started recently. Thoughts or suggestions? 
Specs are:

351 W

4 bbl

4160c 600 CFM Holley carb

Rebuilt engine

.030 over

Stock build with mild cam ( what engine builder told me)

Currently use 93 octane gas

Stock distributor with dual vac advance

Replaced points with Petronix electronic kit

Factory P/S, P/B, and A/C

Thanks again for help,

Rick

[bigmal 225]

Hi mate, for me I would do a compression test, re-torque the head bolts and do another compression test. this will help identify a possible head gasket leak.

Also change the intake gaskets. 

[DocWok 30]

10 hours ago, RobotMan said:

However, I still have a performance issue I need some advice on. The engine hesitates severely and hiccups when you dump the accelerator to speed up quickly but will run smooth if you ease up to the same point gradually.  It runs smooth if I maintain the speed even at high RPMs. This just started recently. Thoughts or suggestions? 

Sounds like you may have an accelerator pump issue with your carb.

When you look down into the carb you should see 2 solid streams of fuel being injected as soon as you start any movement of the throttle linkage, if not you will need to chase down why it's not operating correctly.

[RobotMan 264]

I will take a look. Thanks

[RobotMan 264]

Just an update. Checked all the wires and replaced plugs. Must have had one breaking down. Instantly started running better but still a bit sluggish When punching it or climbing a hill. Checked the base timing at idle and was about 9-1/2 BTDC. Looked at my old setup notes And noticed I had base timing at 12. Changed the timing and bang, the torque and pull at the top end returned. Maybe the distributor was not tight and vibrated around a bit not sure? Thanks for everyone’s input. 
Rick

[jjstang 51]

On 5/18/2020 at 4:31 AM, DocWok said:

Sounds like you may have an accelerator pump issue with your carb.

When you look down into the carb you should see 2 solid streams of fuel being injected as soon as you start any movement of the throttle linkage, if not you will need to chase down why it's not operating correctly.

That was my first thought 

[Vicfreg 771]

If the Holley is sluggish, you may want to baseline the idle mixture by using a vacuum gauge.   Then set the curb idle.  A lot of people use the throttle plate adjustment screw to adjust the idle before adjusting the mixture screws. This causes your main (primary) throttle plates to be slightly "cracked", so when you come off idle, the car bogs.   There is a "transfer slot" cut into the primary throttle plates and underside of the carb which allow the car to run and come off of idle with the main throttle plates closed.

Try this and see if it works:

https://forums.holley.com/entry.php?429-How-To-Adjust-The-Idle-Mixture-On-Holley-Carbs

 

 

[RobotMan 264]

10 hours ago, Vicfreg said:

If the Holley is sluggish, you may want to baseline the idle mixture by using a vacuum gauge.   Then set the curb idle.  A lot of people use the throttle plate adjustment screw to adjust the idle before adjusting the mixture screws. This causes your main (primary) throttle plates to be slightly "cracked", so when you come off idle, the car bogs.   There is a "transfer slot" cut into the primary throttle plates and underside of the carb which allow the car to run and come off of idle with the main throttle plates closed.

Try this and see if it works:

https://forums.holley.com/entry.php?429-How-To-Adjust-The-Idle-Mixture-On-Holley-Carbs

 

 

Thanks for the tip!