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'80 SN 351w RR performance upgrades

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EagleEyedOne View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 2:49am
Hola,
Got this project back together, ran it most of last summer with no issues as I was still breaking it in. Ran it full throttle in the early Fall for the longest time yet, maybe a minute or so and while nothing happened directly after that run, A few weeks later, the engine liquid locked with water in the cylinders.

Pumped the cylinders dry, dried the plugs, fired it up, ran it lightly, then two weeks later, found water in the oil. Been trying to figure out what the $%&@ is goin on since.

Any thoughts about where failure is?

Put new intake gaskets on suspecting it might have been there, but still suckin water in from somewhere while running in driveway with hose feeding RWP.

Ugh.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 8122pbrainard Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 8:06am
Originally posted by EagleEyedOne EagleEyedOne wrote:

Any thoughts about where failure is?
.

Michael,
The exhaust manifolds?


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KENO View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 9:16am
Did you have water in all 8 cylinders, maybe just one bank of cylinders or just some cylinders?

Did you have water in the oil the first time? You only mention it the second time.

Is it a lot of water or could it be residual from the first time?

Have you changed the oil enough times to be sure any residual water was out after the manifold gasket change?

Questions, questions
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EagleEyedOne View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 11:10am
Morning and thanks for the questions..

PRIOR to the full throttle run I was on my 3rd break-in oil change. Did not notice any water in oil before or after the liquid lock. All eight cyls had varying amounts of water that got cranked out. Did not run it very much over the next 2 weeks after the liquid lock, but when I started and was warming up, I could hear the faintest knock and shut it down to find the water in the oil. Pulled the boat, changed the oil twice, each with one quart of kerosene and 4 qts oil to help flush the water before sitting over winter. Each of the two times had RWP fed by hose. On 3rd change had to stop water flow so could get a 'clean' change....

Fast forward last week, was tough trying to fix this over winter... replace intake gaskets, got boat running, ran for about 5 min after/during getting timing adjusted, shut down changed oil only once but it was way too milky in color to be just residual water. Then starts diagnosing...

During compression check, each plug was dry and each cylinder ranged between 125 and 137 psi. Haven't checked exhaust manifolds yet, maybe today.. air pressure tested the water cooling system by adapting an air fitting to the hose that feeds the tstat housing from RWP, blocked the exhaust manifold hoses from the tstat housing, and applied 80ish psi to see where things could be leaking.

Sprayed soapy water on front of engine and found a small bubbling leak on one of the timing cover bolts. That's about as far as I have gotten before tearing more stuff apart..

Thx.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MrMcD Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 2:09pm
Good effort so far but a little tune up is needed on your effort.
Gaskets that seal the cooling system are never exposed to more than 20 PSI in normal use.
Blowing 80 PSI can blow out your good gaskets.   Even running full water pressure from your garden hose can blow these coolant gaskets. Garden hose can be 60 PSI.
I like the air test and have used it a few times but I limit air pressure to 30 PSI and use a shut off valve at the engine with a pressure gauge attached before the valve so I can monitor air pressure to see if it is holding at the 30 PSI I installed.   A sealed engine should be like a tire, put 30 PSI in and it should stay.   Test the connections with soapy water and wait 30 minutes. Air leaks that are slow will take this long to form a bubble spot you can see.
If you have a cracked head or cracked block your leak might not open up till the engine is hot.
PS: When you release the air pressure so it slowly. My set up was on a quick disconnect. When I released it 30 PSI of water came blowing out of my engine all over my garage and me. I had forgotten there was water in the water jackets, I expected just air to blow out.
It was probably only a quart but under pressure that quart got a lot wet quickly.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 8:26pm
If you ask 10 people, half will say manifolds, risers and the other half will say head gaskets, intake gaskets, cracked intake, cracked head etc.

Then somebody will mention the timing cover as a sneaky possible path directly to the oil sump, but not into the cylinders. (either a crack or bad gaskets) That would show up on the pressure test. Since you had external leakage fronm a timing cover bolt, maybe there' was internal leakage too

It confusing that you had water in the cylinders the first time but not the second time.

If you do MrMcD's test at 30 psi and isolate the system the rate of pressure drop will tell you the relative size of the leak if it's going down.

If it's steady then the exhaust manifolds would be suspect.

You don't know the results of the exhaust manifold pressure test yet ?

They're a little harder to test, don't know what your method is.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote TRBenj Quote  Post ReplyReply Direct Link To This Post Posted: June-23-2019 at 11:13pm
Start with a compression test. If that passes, then inspect as you start disassembly.

Water in cylinders + passed compression test likely points to exhaust manifold(s)/riser(s).
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-24-2019 at 7:06pm
Gents,

Thanks for the fine tuning comments and feedback. Well, the 80 psi didn't blow anything up, that I can see yet..

Compression results were 125 to 137 on a cold engine with throttle open, and butterflies held open.

Exhaust manifold testing on the engine - adapted air fitting with gauge on hose that fit to front of manifold and blocked rear of riser exit with old exhaust hose and a small pint paint can (fit pretty damn well in the hose with a lil electrical tape as a gasket...), added some air and all I got was air leaking at the head mating surface.

Testing with manifolds removed from engine - used same air adapter to front of manifold and riser exit blocked as mentioned, then back filled the manifold with water until all 4 ports were full. Added air and water came a gushing out of the ports.

Both manifolds exhibit the same result. Is this a proper exhaust manifold test?

Thanks!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-24-2019 at 8:59pm
At least the way I read your description of the exhaust manifold testing, neither test was a good test of the manifolds since you put air in the water side and blocked off the combined outlet which then put air back thru the exhaust gas side
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-24-2019 at 9:25pm
Ken, thanks for confirming I'm a dumbass...

It took explaining what I did to realize it wasn't a good test, hence my skeptical question whether it was a proper test... Is there a method or documented way to do this manifold testing?

Would appreciate any advice how to isolate the dry and wet sides in a test..
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 8122pbrainard Quote  Post ReplyReply Direct Link To This Post Posted: June-24-2019 at 9:40pm
Remove the risers from the manifolds and then making a block off plate for the manifold is best for the pressure test. Before you go to the work of making a plate, just fill the water jacket with water. Sometimes a leak into the exhaust cavity will show up.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-24-2019 at 10:59pm
Originally posted by EagleEyedOne EagleEyedOne wrote:

Ken, thanks for confirming I'm a dumbass...

It took explaining what I did to realize it wasn't a good test, hence my skeptical question whether it was a proper test... Is there a method or documented way to do this manifold testing?

Would appreciate any advice how to isolate the dry and wet sides in a test..


You got that dumb ass comment all wrong.

A dumb ass wouldn't have asked the question

I'd do like Pete said , with a couple of things to watch out for. If these are the original Manifolds and risers and they've maybe never been apart, you can try every concoction under the sun that claims to be the best penetrating oil out there to get the 4 bolts per manifold out without breaking some or.........you can go with Oxygen and Acetylene and have a better chance of getting them all out without any breaking.

Some penetrating oil and heating the area with the torches together will be the best chance.

The plate would be about 3X5 inches with 4 bolt holes and a rubber gasket sandwiched between the plate and the manifold.

Other than doing a water flow test with the riser still on the manifold and off the engine, it's kinda hard to test a riser due to the mixing that takes place between the water and exhaust sections unless you can get a good seal with an expandable rubber plug in the exhaust outlet section to separate the water and exhaust sections. Easy to say, hard to do.

For the flow test you would flow water thru with the manifold and riser in a normal position on a workbench (preferably outdoors) and look for water leaking from the exhaust ports onto the bench.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-26-2019 at 2:42am
Hola,
Ok, exhaust manifold testing... first water test by filling each manifold with riser off. No water flowing out the exhaust ports on both. Next, made plate and pressurized the water side with 50 psi which held for about 10+ minutes each.

Gettin a bad feelin here.. possible that a compression test is good on all cyls, but could have a head gasket cooling jacket blowout on both sides? Just don't know how both sides of the engine got liquid locked last Fall..?

As mentioned earlier, I put new intake gaskets on and torqued to spec of 24 ft lbs. Upon doing that, I decided to re-torque the head bolts (not mentioned earlier) as well and found that all bolts exterior to the valve covers were at low end of torque spec range at 105 ft lbs. Nearly all bolts under both valve covers required at least 1/4 to 1/2 turn to meet 105 spec.

Is there a test for the risers?

Thanks for the love boys, vacation count down has started and ends Jul6... :/
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-26-2019 at 8:29am
Earlier on, you tested the cooling side of the engine with air at 80 psi but I don't see where you isolated the air and checked for a pressure drop

I'd be nice to the engine and do that test over again with 20 to 30 psi and isolate the air like MrMcD described and see what the pressure gauge does before you decide to start tearing into things. It shouldn't take long to do this test
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-26-2019 at 11:37pm
Ok,
Tested engine through hose feeding tstat housing from RWP with 30psi as instructed by Dr. McD.. and lost 5psi over 60 minutes. Getting lost for what to do next, but if I had to take a stab, remove heads... pls tell me I'm wrong...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TRBenj Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 12:30am
Did you only get water in the cylinders every time it makes a milkshake or just the once?

Presumably you gave a good look for evidence of water intrusion when you removed the intake?

Timing cover would be my next investigation if you’re not getting water in the cylinders consistently.

I would expect a cracked head (water jacket to cyl) or head gasket failure (cyl to water passage) to show up in a compression test.

If you are indeed getting water into the cylinders consistently, that may implicate the risers since the manifolds tested ok? The slight pressure drop over time during your test may be worth investigating. I always figured that submerging the manifold in water to see where the air leak was coming from would be effective.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 1:32am
Hola,
I only realized water in all cyls once last Fall, but didn't remove plugs everytime I did an oil change. This last milkshake change after new intake gaskets did not have water wet plugs, but they're looking black and sooty, not the light brownish electrode.

Upon removing intake, we did check for intrusion, saw a little rust at the inside corners but no obvious blown gasketing. The graphite gaskets were replaced with black and blue raised rubber Felpro type with some high tack gasket sealant on the corner water jacket areas.

I think with how exh manifolds held 50 psi for 10+ minutes tells me they're ok, UNLESS heating them up opens a crack..? My gut says unlikely but won't rule it out. Submerging them would be interesting if expecting an external crack but if an internal, would be difficult to see where it comes from.

As mentioned earlier, one of the timing cover bolts was bubbling with soapy spray, for this test I gave the bolt a turn and the bubbling seemingly stopped but guess it could have been micro leaking over an hour..

Appreciate the late response TRB! Thanks.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 8:46am
Originally posted by EagleEyedOne EagleEyedOne wrote:

Hola,

Submerging them would be interesting if expecting an external crack but if an internal, would be difficult to see where it comes from.

As mentioned earlier, one of the timing cover bolts was bubbling with soapy spray, for this test I gave the bolt a turn and the bubbling seemingly stopped but guess it could have been micro leaking over an hour..

Appreciate the late response TRB! Thanks.


What Tim's saying is that you'll see air bubbles in the water, coming from one of the exhaust runner openings

You may not know where the crack is but you'll know there's a crack

Your's held air real good though so submerging them probably would show nothing.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TRBenj Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 8:59am
What ken said. Internal leak = air out the exh manifold runners.

On the intake I meant searching for evidence of a leak into the valley from the water passage at the front. Rusty lines or pure water droplets (not mixed with oil yet) may indicate the source.

On the timing cover, the concern is an internal leak (water—> oil) as well. The bubbly bolt is curious but likely unrelated. A crack here (like the intake and exh) would not show up on a compression test.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 9:10am
I mentioned the timing cover earlier, you mentioned a slight external leak from one of it's bolts and TRB mentioned it again.

Like he said, I'd go there next Bad gasket seal or cracked cover like he said.

5 psi out of 30 says something's leaking . Some of the 5 psi pressure drop could be from hot compressed air cooling off during that hour but not all of it.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 9:34am
Did you happen to have the valve covers off when you did the 30 psi air test?

An external crack in the water jacket or one of the big allen headed plugs leaking will let water mix with the oil up there.

With the covers off you might hear or see some leakage.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EagleEyedOne Quote  Post ReplyReply Direct Link To This Post Posted: June-27-2019 at 3:30pm
Hi Ken,
Valve covers were not off during the last 30 psi test, easy enough to do again with rubber gaskets and give it a more thorough check while in there.

Sounds like digging into timing cover is next project to begin this eve.

Thanks Gents!
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