who Knows about Reversion?

guys, its over 30 dollars each time i break down the manifolds. the gaskets are about 15 each, thats $60 for both sides. the water is coming in , being sucked in, i can see the wetness on the tip of the manifld where the gases meet the water. the wetness goes clear inside the elbow. i think ricardo is right and i need to call the builder and ask what cam was installed.

Did you re-adjust the lifters?

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stang32 said:

guys, its over 30 dollars each time i break down the manifolds. the gaskets are about 15 each, thats $60 for both sides.
Stang, if you do not find the problem, that $60 is going to seem like peanuts compared to the cost of yet another tear-down and rebuild.

the water is coming in , being sucked in, i can see the wetness on the tip of the manifld where the gases meet the water. the wetness goes clear inside the elbow.
i think ricardo is right and i need to call the builder and ask what cam was installed.
Yes.... once you have the specs, you can check the profile and indexing!
That will then become one more item either found or eliminated from your P of E list.

Click to expand...

Docksidemarineservices said:

Did you re-adjust the lifters?
I too would like to know the answer to this!

Since you still have the water issue, the 8 stop static procedure is going to be your best bet!
It is super simple to do!

Click to expand...

Stang, this was mentioned earlier in this thread:

I have seen around the center head bolts, the head casting has cracked and water comes up out under the bolt. Usually due to over tightening or weak/thin castings.

Click to expand...

Let's explore this.
If the builder used the light castings, they may have missed cracks, or they developed cracks once installed and tightened.
And by the way, the light castings should NEVER be used for the SBC Marine build.

Look at your cylinder heads. Which of these images do they look like?

May I call your attention to the attached, which are screen shots of pages #7 and #8 from the paper cited in post #16.

Installing some types of cams can trigger this problem especially with "aftermarket" elbows without a

vacuum break feature.

View attachment Exhaust Elbows.pdf

HOWEVER.... this does not explain water seen in the test with the engine not running and the manifolds off.

sandkicker said:

May I call your attention to the attached, which are screen shots of pages #7 and #8 from the paper cited in post #16.

Installing some types of cams can trigger this problem especially with "aftermarket" elbows without a

vacuum break feature.

View attachment 18868

HOWEVER.... this does not explain water seen in the test with the engine not running and the manifolds off.

Click to expand...

bob, yes i read that as well, that document was very informative.
the test done with the engine not running was prior to my resurfacing the matting areas and installing nee gaskets. i plan on re doing that test but havent yet.

RicardoMarine said:

Stang, this was mentioned earlier in this thread:



Let's explore this.
If the builder used the light castings, they may have missed cracks, or they developed cracks once installed and tightened.
And by the way, the light castings should NEVER be used for the SBC Marine build.

Look at your cylinder heads. Which of these images do they look like?

View attachment 18866

Click to expand...

i answered that already, there is no water in the head valley. i removed the v.c's to clean up the foamy milky substance from the underside if the covers and there is nothing but clean fresh oil on the tops of the heads

RicardoMarine said:

Stang, this was mentioned earlier in this thread:

I have seen around the center head bolts, the head casting has cracked and water comes up out under the bolt. Usually due to over tightening or weak/thin castings.

Click to expand...

Then I said:

If the builder used the light castings, they may have missed cracks, or they have developed cracks once installed and tightened.
And by the way, the light castings should NEVER be used for the SBC Marine build.

Look at your cylinder heads. Which of these images do they look like?

Click to expand...

View attachment 18866

Click to expand...

then you said:

i answered that already, there is no water in the head valley. i removed the v.c's to clean up the foamy milky substance from the underside if the covers and there is nothing but clean fresh oil on the tops of the heads.

Click to expand...

If the inside of the valve covers were milky/foamy, then there has been oil/h2o in that area.
By design, the upper area of the heads (underneath the valve covers) will drain the oil back to the oil pan quickly.
In other words, seeing that they are clean is not necessarily an indicator that there are no cracks.

My question is.... which castings do you have? Light castings or heavy castings?
Do they have the scalloped areas, or do they not have the scalloped areas? If they used the light castings (which should never be used for the Marine SBC), they might be cracked (key words "might be").


Stang, I have been an automotive SBC enthusiast since the mid 60s.
I began working as a professional mechanic in 1968. I have built many SBC engines for both Auto and Marine use.
I also owned/operated a small AQ series Volvo Penta repair biz for 24 years.
I am certainly no stranger to the SBC engines.

People like yourself join forums like this one for help. We as the members offer our help!
We will see clarifications being asked for, corrections being made, images being posted, an occasional Google search finding, etc. Sometimes it can get quite involved and very long, such as with your thread.

It best serves the OP (original poster) and the members when we do not post rude, nasty, ill informed comments.... no matter what the reason. If a member is having a bad day, week or year, they need to keep it to themselves!


One last comment:
It looks like you have two issues here..... excessive ignition advance (in order to idle well) and water in your oil.
I think that you will be chasing your tail on this until you develop a good, solid, systematical and methodical plan of attack.
Your job is to make a Process of Elimination list and follow it.
Leave no stone un-turned.

You have been given you some ideas here.
Since you may not be experienced in this area, I suggest that follow what is being suggested.
If water is entering due to a casting crack, then that is what you need to investigate.
If water is entering due to reversion (incorrect cam indexing), then that is what you need to investigate.
You will likely not find any short-cuts.



.

lets forget about the timing issue for now as i believe that issue has been resolved. i have the timing set @ 8*, the vacuum gauge was moved to the carb port whcich feeds the choke pull off and is now relatively steady within range of 20in hg.
since i have not touched the timing since the oil flushes i have not seen water in the engine, only in the bottoms of the manifolds.

back to the reversion issue.

the insides of the v/c's were milky foam due to the water intrusion prior to the 3 oil flush/changes.
i have not adjusted the rockers yet. this morning i pulled the water hoses from the manifolds and ran the engine , the manifolds were dry after running for 15 minutes.

i then reconnected the hoses and ran the engine for 10 minutes and again there were small puddles in the bottom of the manifolds and a wet water trace runnung down from the horizontal portion of the elbow. you can clearly see the water running down the side of the elbow into the manifold

i spoke to the builder(A$$hole) and he tells me the cam has a 112 lobe seperation but , get this, he told me he may or may not have reused a cam from another marine core since the roller cams are billet and do not wear down, i was like WTF, so how are you certain this is the right cam, he told me that all the cams are miced and checked prior to assy.
ughh, makes me want to punch a wall

the head castings are heavy, no scallops

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stang32 said:

lets forget about the timing issue for now as i believe that issue has been resolved. i have the timing set @ 8*, the vacuum gauge was moved to the carb port whcich feeds the choke pull off and is now relatively steady within range of 20in hg.
since i have not touched the timing since the oil flushes i have not seen water in the engine, only in the bottoms of the manifolds.
OK.... that's one thing off the list!


back to the reversion issue.
the insides of the v/c's were milky foam due to the water intrusion prior to the 3 oil flush/changes.

i have not adjusted the rockers yet.
This is important. Perhaps do that next, and for God's sake, use the 8 stop static procedure.

this morning i pulled the water hoses from the manifolds and ran the engine , the manifolds were dry after running for 15 minutes.
15 minutes is excessive!

i then reconnected the hoses and ran the engine for 10 minutes and again there were small puddles in the bottom of the manifolds and a wet water trace runnung down from the horizontal portion of the elbow. you can clearly see the water running down the side of the elbow into the manifold
Not good!


i spoke to the builder(A$$hole) and he tells me the cam has a 112 lobe seperation
108* to 110* is acceptable! I doubt that 112* would be an issue.
The lobe separation angle determines where peak torque will occur within the power range. It will also have an effect on idle quality and manifold pressure.... i.e., vacuum!

but , get this, he told me he may or may not have reused a cam from another marine core since the roller cams are billet and do not wear down,
I would not worry about that. A SBC roller camshaft in a car/truck will go for 200K to 300K miles. There is no real conversion for car/truck miles -vs- marine engine hours.
If you are curious, look at your invoice and see if you were charged for a new or used camshaft!


i was like WTF, so how are you certain this is the right cam, he told me that all the cams are miced and checked prior to assy.
ughh, makes me want to punch a wall
Mic'ing a cam is not the same as checking the profile.
In order to have checked the profile, he would have used a degree wheel and dial indicator on #1 intake and #1 exhaust roller followers.

the head castings are heavy, no scallops
Good!

Click to expand...

We need to get past the cam shaft issues.

the cam used is very mild.

The cam is designed for a moderate HP and torque. It is designed for the least amount of issues based on its intended use.
See tight LSA and Wide LSA comparison in pic attached.

Lets drop the cam issue. I said in the beginning its a NON issue.

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kghost said:

the cam used is very mild.
The cam is designed for a moderate HP and torque. It is designed for the least amount of issues based on its intended use.
See tight LSA and Wide LSA comparison in pic attached.

Click to expand...

Your humor sucks as bad as your posts....

There is no way that what ever cam was used it would cause what he is experincing...

It would have to be a high lift, very close LSA, very low vacuum at idle and lope like a MOFO...

With 20" vacuum at idle....its a mild cam as I have said!!

Move on and adjust rocker arms .