1 ... 85 86 87 88 89 ... 93
NOHOME
NOHOME MegaDork
1/26/22 12:21 p.m.

On the bottom of the gasket the compression mark make it pretty that on the sides it the flame ring not gasket material trying to make the fluid seal...which clearly doesn't work.  Sealant it is.

Kinda lost me on this sentence so had a hard time relating to what was being demonstrated in the image.

 

Pete

mke
mke Dork
1/26/22 12:29 p.m.

In reply to NOHOME :

There are the metal flame rings that outside of that gasket.  The gasket seals, flame ring protects the gasket form contact with fire.  You can see a clear imprint from the cylinder flanges and then between and on the ends the imprint is gone meaning the only contact is with the flame ring, leaking nothing to actually seal.  

Newer style MLS gasket are coated with rubber or some other sealing material right to the bore so with a gasket like that at least there is hope it will work, but my older style composite gaskets....well....I need to add sealant to at least the flame ring area

APEowner
APEowner GRM+ Memberand SuperDork
1/26/22 12:44 p.m.

In the picture of you using the depth mic it looks like you've got the base resting on both the block and the cylinder.  I assume that's either not really the case or it's just for the photo and that you know that it should be solidly on the cylinder with a gap between the base and the block.

Is there any correlation between the cylinder protrusion and the ones that leak?

What's the difference in protrusion between the two middle ones?  It wouldn't take much of a difference to prevent the lower one from sealing.

mke
mke Dork
1/26/22 7:21 p.m.

In reply to APEowner :

For sure the base is on the liner and the rod is off, I'm pretty careful about that.  No real pattern I can see, but this mic is probably not the ideal way to look for 1 thou or less variation, I probably should have set up a 1/10th  indicator.

But for now, sealer on

and head on

While it was off I took the opportunity to grind the snot out the bosses that hold the inner cam cover studs hoping it helps with intake install.

before pic on the other head

 

sobe_death
sobe_death Dork
1/26/22 10:08 p.m.

Are you pulling both heads so you don't have to pull the engine again?

mke
mke Dork
1/26/22 10:53 p.m.

In reply to sobe_death :

Yes, they were both leaking....then see if  I can figureout how to pressure test it before going any further.

Rigante
Rigante Reader
1/27/22 5:47 a.m.

Hope that works. This is such an exercise in perseverance and mental fortitude 

NOHOME
NOHOME MegaDork
1/27/22 9:45 a.m.

The obvious way is assemble and pressure test the system at the water hose points. Why will this not work?

 

Any way you could inject pressurized smoke into the cylinder and look for it in the water jacket? 

 

mke
mke Dork
1/27/22 10:30 a.m.
NOHOME said:

The obvious way is assemble and pressure test the system at the water hose points. Why will this not work?

Any way you could inject pressurized smoke into the cylinder and look for it in the water jacket? 

Its mostly just a logistics question....water goes through the timing cover but I want to test the heads so I need to make a block-off plate.  Same on the coolant outlets on the heads. 

Then what method to follow and what is passing or failing?  The factory says this:

I'm just flat not doing that, my intake port walls after  the port relocation and porting are quite thin and 8-10 bar?...hell NO.  I also don't want to risk water getting into cylinder and piston rings where it will rust and damage things is very sort order....damage to the liners caused by a coolant leak is part of what this rebuild repaired and a big part of why there is Evans coolant in the engine this go around.

I'm leaning toward 3bar with air.  I did the heads that way when I was repairing them so I know they hold but but pressure testing with air is not the safest though (lots of stored energy to power projectiles should anything fail) which is way the factory uses water.   Not sure what I have for pressure gauges and I know I don't have threaded valve stem to put air in should I go that way or an appropriate pump should I decide to use coolant or anything like that.

...leaning toward air to see if it's leaking....but if it is, finding it becomes the next trick so fingers crossed that is a problem I don't need to solve.

golfduke
golfduke Dork
1/27/22 10:33 a.m.

I would assume Air would be more sensitive to water anyway.  that's what I would do.  It's easier to track leaks down as well. 

sobe_death
sobe_death Dork
1/27/22 11:11 a.m.

Maybe fill it with dyed water, then pressurize with air...  That way your air volume is much lower at 3 bar than having the entire empty cooling system, and the leaks become easier to track.  Would squirting a little oil in each cylinder to coat the rings alleviate rusting issues from any leakage?

Mezzanine
Mezzanine Dork
1/27/22 11:46 a.m.
mke said: 

Then what method to follow and what is passing or failing?  The factory says this:

 

The manual says 8 / 10 (divided), not 8-10 (minus). So eight divided by ten is .8 Bar (11.6 PSI), which is probably still a little low.   .8 to 1 Bar is a reasonable range though; perhaps there was a decimal point overlooked? There's clearly some translation losses here.

 .8-1 Bar (11.6 - 14.5 PSI) is a reasonable pressure test range. There's no way they meant 8 bar. That's 116 PSI... I'm probably being a little glib here with my interpretation of what is written, but a standard radiator pressure test seems like a reasonable place to start, followed by pressurizing the cylinders with air to see if it pressurizes the cooling system at all. 

bigeyedfish
bigeyedfish Reader
1/27/22 1:05 p.m.

I read it as 0.8 Bar as well, though it is a silly way to write a decimal.  11 - 12 psi seems like a decent test at least for a first pass.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
1/27/22 1:19 p.m.

Depending on the water pump and thermostat geometry, it is possible to get 8-10 bar of water pressure inside the engine.  I have measured 50psi in a bone stock econobox Ford and 200+psi in a modified big block Ford.  It was a lot of effort to get it below 75psi to prolong heater core and core plug life.

wvumtnbkr
wvumtnbkr GRM+ Memberand PowerDork
1/27/22 1:26 p.m.
Pete. (l33t FS) said:

Depending on the water pump and thermostat geometry, it is possible to get 8-10 bar of water pressure inside the engine.  I have measured 50psi in a bone stock econobox Ford and 200+psi in a modified big block Ford.  It was a lot of effort to get it below 75psi to prolong heater core and core plug life.

Isn't that exactly what the cap is for?

 

I would pressure test at 15 psi for 2 hours.  If it goes below about 13.5, I'd be spraying everywhere with soapy water to find the leak.

 

Edit...  leaving what I wrote, but I believe you are referring to pressure with the thermostat closed.  That does paint a different picture.

mke
mke Dork
1/27/22 2:40 p.m.

The easiest way to think about it is the cap limits the pressure at the inlet to the water.  Then the pump pumps and the pressure goes up, pressure drops entering and flowing through the block, more through the heads, more through the radiator and at the point you are back to cap pressure.

 

So 15psi for the cap, another 30-45 maybe if the tstat is closed gets you 45-60psi

For Evans coolant the cap  is 2psi, so 32-45? and that is where I got 3bar should do it.

mke
mke Dork
1/27/22 8:20 p.m.
Mezzanine said:
mke said: 

Then what method to follow and what is passing or failing?  The factory says this:

 

The manual says 8 / 10 (divided), not 8-10 (minus). So eight divided by ten is .8 Bar (11.6 PSI), which is probably still a little low.   .8 to 1 Bar is a reasonable range though; perhaps there was a decimal point overlooked? There's clearly some translation losses here.

Reading an Italian manual takes some getting used to.  They use the European decimal point,  aka a comma,  and for whatever reason the US division symbol means a range.  God forbid you should look for the same spec in 2 different manuals because odds are they don't match and some specs aren't in any manual, you just need to know it.

I['m not sure why the spec is up to 10 bar....but it might just be how high they can run the pressure on the assembly line so they don't need to wait more than 1 cigarette to move to the next operation?  Or High pressure can look more constant because everything is springing a little at that number?  Either way I'm not doing it surprise

Syscrush
Syscrush Reader
1/28/22 8:48 a.m.

Wow, today I learned. The whole idea of 0.8 bar made so much sense to me that I thought you must be mistaken about the division sign used for a range, but Wikipedia backs you up...

In Italy and Russia, the ÷ sign is sometimes used in engineering to denote a range of values.

mke
mke Dork
1/28/22 2:13 p.m.

Ferrari manuals are a challenge to read and understand.  I need 4 for my car, an older one that covers a lot/most of things, but then a smaller 308QV/328 that is changes...so the old manual unless there is an update in the newer one  and then the the 400i and TR...I don't have the TR as it seems close enough to the QV.  The 400i manual is an update to the 60s so the hardest to follow.

 

Good to know the Russian manuals might be similar, now I feel good about buying a Lada or Mosckvich....wait...no I don't :) 

Mezzanine
Mezzanine Dork
1/28/22 5:26 p.m.

That's AWFUL! Neither my Fiat or Moto Guzzi manuals use a divide symbol... Anyway, I'm just glad you're not going to 10 Bar. That's nutty. 

mke
mke Dork
1/30/22 7:10 p.m.

In reply to Mezzanine :

The day a ÷ symbol where I expect a "-" is my biggest problem will be a pretty good day cheeky

East coast storm delayed my air fitting and gauge but I did get the second head off and back on.  Still need to make the block-off plates but that will be quick.

bentwrench
bentwrench UltraDork
1/30/22 7:39 p.m.

In reply to wvumtnbkr :

Water pressure likely doesn't change with the closing of the thermostat as a bypass passage maintains water circulation in the motor.

bentwrench
bentwrench UltraDork
1/30/22 9:32 p.m.

I'd double the cap pressure for testing the motor itself, not a cooler or anything.

Check any water/oil coolers also!

You can always O-ring the liners, a thin stainless wire to bite into the fire ring.

mke
mke Dork
2/1/22 12:34 p.m.

Like everything on this project the leak test is confusing.  For sure there is a leak, the pressure bleeds down 1 psi per minute at 30psi, and maybe 1/2 that at 15 psi so 30 to 0 is about an hour.

 

Also for sure the leak is not into the cylinders.  I have gapless rings that should seal so I used a compression tester hose to make a bubble tester and nothing, not even a hint of of air flowing in any of the cylinders.  When I was actually running the test and not trying to photo it, I held the tip of the hose about 1/8" in the water, so there is no even 0.125" water pressure (0.005psi) in there.   

With everything off in the shop, I can't hear anything.....no idea where it's leaking.

When I went to install the second head I realized I screwed up a little on the 1st.  I put sealer on the coolant flow passages on the block but the head has more  holes....so where the circles are there are no holes in the block for coolant flow but the head gasket does seal of holes in the heads.....that could be a leak.  I'm pretty sure if I pull the head with sealer on it the gasket will be destroyed....and that may or may not be the leak.

 

I googled how to leak test a cooling system and found 15 psi for 2 minutes with the coolant full....if its only losing 1/2 psi/ minute of air at 15psi, so that would be 1/50th of that with water or about 0.02psi in 2 minutes and would easily pass.  another source said 15 minutes....I'd lose about 0.15 psi in that test test and again pass so  I'm leaking toward saying its good enough......

 

Syscrush
Syscrush Reader
2/1/22 1:48 p.m.

There was no sign of coolant in your oil, right?

1 ... 85 86 87 88 89 ... 93
Our Preferred Partners
MpywqJSk5nM4D5g8UJdNa2HINTHc8Z9GawEZ7ZOwYdA0WNHbmmFM5BtD4VUkhRPN