Cylinder Head 102 - Hydro Test Valves

[@Mario3sgt]

Just wanted to say thank you for the video. At the shop I work at we had sent some heads out for a toyota 4run... once the tech re installed everything we where having lots of problems with power and overheating. I decide to remove the heads one more time and performed this test (hydro). And guess what all the valves where leaking a lot. Thats also when I notes thx to your other videos that they never even pulled the valves out all they did was clean the head form the out side and resurface it

[@nezerac]

Hey that's life. I loved it because I'm learning so much about cars (fixing my ford due to previous owner not replacing ANYTHING for 20yrs :D). The Ironic part about it is that the leaky head I swapped out for a less leaky head seemed to be a bit torquier. It was a flat and I upgraded to the later model roller style camshaft. Same port size, same camspecs (lift/duration) but for some reason my old wore out flat just seemed to pull a bit harder.

[@6string71]

I just want to say thank you for taking the time to these videos. I'm working on some BB Chevy heads and tried this test using mineral spirits. I have a couple that begin to weep after about 3 or 4 minutes. I tried lapping the worst one after watching your other video unfortunately it didn't seem to improve any. I'm worried about messing up the angles on the seats by getting too crazy trying to lap it out. As long as no drops are forming immediately should I leave sleeping dogs lye or valve job?

[@iaind8902]

I use WD40 because its a penetrating oil and it shows results fast as well as does some cleaning.

[@BulliKid]

Cams have to be taken out to perform this correctly right? Because my cyl 1 TDC has overlap and all are open.

[@williambartholomew5680]

I don't bother leak-testing valves on a used head, only do it after lapping them all. And don't need to use water, set the head down flat and spray a little carb/brake clean into each port watching for leaks in the combustion chambers. Any signs of moisture mean re-lapping, also don't need to do it with the springs installed. If they leak while you hold them up by the stem they'll still leak when the springs are installed.

[@apperty]

I use petrol and the valves are not locked with the springs ;),I had a minor leakage,lapped them again and then locked them ,no problems

[@Tomyp89]

I use naphta or gas. Low viscosity, fast leak + bonus nice smell :)

[@Terasl6vi]

Hi, Little trick: you can pour a drop of gasoline (solvent) to the other side of the valve, because petrol is thinner as water is the result to see immediately. Greetings from Estonia Janek

[@1wheeldrive751]

Yeah, the only “water test” worth doing is to fill the ports with water and shoot compressed air at the valve seats. That tests if the valve will seal air, which is a whole lot lower viscosity than any liquid, and it’s what you need to seal to make compression. It also gives a very precise location of the leaking spots so you can pay attention to those when lapping or deciding to grind or replace seats. I’d have just plugged the EGR port in that one cylinder with putty and do the test.

[@MadWeiner]

Did I sense a little cylinder head sarcasm towards the end?

[@haneifk]

i'm doing my first rebuild on a 4AGE 16V motor. I think the valves have 148k miles on them. but if they pass this hydro test it would be okay to use them again? i would think with 140k miles it would be time to just replace at this point?

[@BoostedCajun]

I have a question for you 4G63 Yoda Master Jafro, why would you weld up the water ports on a 4G63 head? I presume for race only applications? What's the reasoning/justifiable benefit for doing so?

[@Jafromobile]

+BoostedCajun If you have a concrete-poured 1/4 mile car, it doesn't need coolant. It also doesn't need to see street use. It needs to be shut down after a pass and dragged back to the pits with a 4-wheeler. None of my cars will be built this way, but notice the way I said that, I didn't say "never". I just don't have any track-only drag cars right now.

[@IsmaelAdame]

thats right, i tried with water and barely saw the leak. with gasoline showed me the problem

[@top111quebec9]

Remove valve spring ,clean valve , check valve guide wear ,hand valve lap with paste .

[@MiguelHernandez-hc8ui]

Hey Jafro, thanks for the video, I just used this method to find a leak on my G4JS head. Two questions; did you still get good compression even with the valves that bubbled with the air gun? And I found two intake valves that are not visibly bent but leak out fully within ~15 mins. Should I just try pulling them and grinding them? Thanks!

[@TriniRogue]

Ummmm probably not related to the test that you did however it got me thinking, does the head affect the displacement of an engine?, for e.g if you have say a 1640cc engine which I'd assume they would approximate and just call it a 1.6L engine and you put a "bigger" head onto the 1.6 (something that would hold more water) bumping the displacement from 1640 to like 1670cc basically approximating the engine to 1.7L is that possible? hopefully you get where I'm coming from, just curious if that would be a way to squeeze some more displacement out of an engine.

[@Jafromobile]

+TriniRogue Yes and no, it's possible, in fact... this is a 1.6L head on a 2.0L block. What that means is the combustion chamber domes are cast smaller than the ones on a 2.0L head, and therefore it reduced the overall volume of the combustion chamber and having the opposite affect on the condition you describe. However, changing the overall volume makes no difference on the swept volume. That's all based on the diameter of the piston, and the length of the stroke. That's usually what people refer to when they describe an engine's displacement. Swept volume. What you need to think about is how it affects compression. In regards to compression ratios, call X the volume of the entire combustion chamber with the piston at the bottom of the stroke, and call Y the volume of the entire combustion chamber with the piston at the top of the stroke. Not only is the difference in those volumes the swept volume, but it's your compression ratio. X : Y If you used a "bigger head", you would reduce compression. That might not be a good thing depending on your goals, but it can be in forced-induction configurations. Generally a lower compression engine makes less power, but if you exceed the compression limits of your fuel, it can cause pre-ignition. Summary: I'm cheating. I used a dirty trick with a head that looks the same to pick up an extra point on the compression ratio. I used a different piston to pick up yet another 1.4 points. Most 4g63s of this year build are 7.6:1cr. Mine is 9.8:1 I made a video on this called "calculate your compression ratio". ;)

[@TriniRogue]

+Jafromobile Thank you for taking the time to clear that up for me :), im also going to watch the calculate your compression ratio video now XD, the info one receives from your channel is priceless man love it and thank you again.

[@mdanny445]

Hey friend, nice video thnx for posting. Well i have a issue with my toyota 2.7L cyl head it seems thateven though i followed your example, i still kept getting seepage past the intake valves. Even after i did it with the head upright, does hand lapping even help now with hlc?

[@taksuyama]

I made a mistake of installing the cam and rocker arm assembly with the valves sticking out of the cylinder head. I did this same test with mineral spirit and it is leaking badly. do you think replacing the valves and lapping will be enough? I stupidly did this after paying a machine shop to do the valve job :(

[@Jafromobile]

+Tak Suyama Wait... so the valves leak after you removed the cams? If so, you have bent valves. If they're bent, no matter of lapping will fix that. You'd need to replace the bent valves that are leaking if it fails the leak test with the cams removed. I find valves for around $11 a piece. All is not lost.

[@taksuyama]

Got new valves and now following your valve lapping video. Thank you ***** !

[@taksuyama]

Do you think I need to worry about the valve guides?

[@Jafromobile]

+Tak Suyama if the head was hot and it was running when they were bent, I'd say "probably". But cold on a bench... Probably not. It's impossible to be 100% sure without measuring them, but it's unlikely enough that I wouldn't worry about it.

[@NoSleepRacing]

Someone might have already said this but another good thing to use is alcohol. It is less dense and will seep into any gaps that water might be to thick to go though

[@buddybestor]

Dude, you are the MASTA! Wonder why that one port had its own separate exhaust port?

[@SIBUK]

Use a solvent instead of water.

[@TheTremayne1]

I just so happened to come on your videos an i must say that im already very impressed by your knowledge from the 101 video witht the ice cube trays.. wow ingenious man. Keep it up. Thumbs up an a like.

[@efilimone]

hi does the engine need to be in TDC to get all the valve close in order to perform the test?

[@Mebob2001]

i always found using brake clean or throttle body cleaner works best, due to braking down the cabon at the same time, but we all have our own way's:)

[@douro20]

I hate leaving water in something made of virgin aluminum or alloys which contain a lot of magnesium or tin...

[@iansimpson2812]

I was looking for a comment like this. I have not had a lot of working experience with engines, but is it reasonable to be concerned about corrosion doing a test like this with water?

[@zismael7054]

hello Jafro, I would like to know if the intake valves is 100% no leaking or is their a certain leaking that is normal. People have told me that the leaking is normal. If its true can you explain it o me. Because when i took the head from machine shop the intake valves is still leaking a bit. The machine shop told me this is normal. is it true? waiting answer if anybody knows about this.

[@Jafromobile]

No. It is not normal. If the valve is closed with the valve springs installed and water is leaking out, the seat is leaking. Water is a LOT thicker than air. But in context over the internet I have no idea how much is leaking and how fast or whether you used water, carb cleaner, gas, etc... If it's 1 drop an hour, it's different than 1 drop a second... but if it's leaking at all, then it would fail a vacuum test. Vacuum tests are the standard by which a valve job is most accurately tested. I didn't have that equipment prior to making this video.

[@zismael7054]

***** I used the carb cleaner. Its start leaking after a minute but slow a bit.

[@Jafromobile]

A drop a minute with carb cleaner is not so bad. It's much thinner than water. Water might not leak at all based on that info, but keep in mind that on a fresh valve job, once it goes back into use the valves will bed more strongly into the seats. A trickle, frequent drip, or if it just pours out of the valve, all of those things mean its bad. A drop a minute with any liquid I'd let slide. If you're worried about them, lap the valves lightly and see where and what the seats look like. Watch Cylinder Head 105 for details about that.

[@alycestapleton]

your machine shop is rubbish then wtf if you have any leaks then your seats are fucked mate lol

[@smithraymond09029]

For a minute there I thought it was former president Jimmy Carter filming this :-) that voice.

[@markphilpot4981]

Water may not show up leaks like maybe a solvent would, but it is far safer! I figured you catch hell over that. Volatile liquids are not particularly smart and definitely not smart in one’s home garage. Duh!🙄

[@renejacques8288]

If the water test is not efficient why even do it?

[@Jafromobile]

Because sometimes you think it's unwise to tell people on KZbin to use flammable solvents. The implication is fully made and accredited in order to let people make up their own minds, and exercise their own free will. Inefficient doesn't mean it doesn't work. You saw it work. Vacuum testing works best and I cover that extensively in "Not Another Valve Job".

[@renejacques8288]

@@Jafromobile Do you know what testing is?

[@MainyMitsu]

So what if there is maybe 1-2 droplets of water after a long period of time (hours)? Is this considered bad enough to cause a serious drop in compression?

[@llewvirtue861]

Any size leak is not good for performance, if you only driving to the supermarket, you can let it go a bit longer, but it will only get worse with time

[@constantiniacobescu7262]

you should try with gasoline instead of water

[@Bevoin1970]

5:09 why am I laughing with you..? :-))) Excellent as always...

[@douglascunningham1840]

Blow air into each valve chamber and look for or leaks. Use a vacume cleaner to suck up the water

[@MainyMitsu]

Is a valve job the only way you can fix the leaking???

[@llewvirtue861]

Yes

[@FordMan2007]

Intake valves will 99% of the time always be bigger than exhaust valves

[@evilcowboy]

yep. Also you can just follow the intake port and wind up at the intake valve lol. Very hard to get confused after the head is removed. But to a novice I could see it happening. So yeah bigger valves being intake is a decent rule of thumb on most engines.

[@Usermaxism]

Are those spark plugs still good after the wáter test?

[@c0mputer]

Yes

[@StealthShadow5]

Next time use the dye in the water and a uv light is more easy to see and quickly

[@sara78130]

hi mate if i put water on top if is not leak is man good yes

[@Jafromobile]

+KURDISTAN uk No leaks? You're good!

[@sara78130]

ok thanks mate

[@no_bull]

Just do a vacuum test on the ports, its more accurate...then you will know 100% if you have to reface the valves and cut the valve seats if needed, or you can escape cutting the seats by doing valve synchro grinding!

[@chinthalasuman8854]

Nice video

[@HonestEvolution795]

Hot water works better. or just anything that is thinner than staight water.

[@hp11208]

Good info thanks.

[@douglascunningham1840]

I took mine to an auto machine shop and had the aluminum head

[@douglascunningham1840]

Chical cleaned and refaced.

[@douglascunningham1840]

Chemical

[@bigE35094]

I put an ear plug in the E.G.r port hole..

[@NorthCarolinaMechanics]

What does it mean when the valves leaks?

[@cheesememe4986]

You have bad valve seats/valve guides are bent/valve is bent. If any of these are true you could end up cooking your valve because that contact to the valve seat and the guides are what dissipate the heat on it.

[@frappebaileys4407]

K. O'Pharrow when a valve leaks it means that it's not seated properly on the valve seat.so there exaust gasses by-passing the valves when the piston is moving up.So when valves are leaking your cylinder looses compression and it could also, in some cases, leads to burned valves

[@Flumphinator]

6:38 stache reveal.

[@sargeek1975]

lap them.......?

[@markwallace5274]

Yeah I prefer isopropyl alcohol works great and cleans up easier well evaporates lol

[@sharikfarooqui3392]

checked with petrol buddy

[@Adam19832]

I prefer the test with gasoline

[@macgyverdroid]

water is thick! you should use gasoline

[@kawasakipilotu]

incorrect use of water should be used gasoline

[@SD-pi9co]

I use mineral spirits

[@miskopetrovic3690]

Koja glupost,postoji vakum uredjaj koji ispituje zaptivanje ventila.

[@Adam19832]

I prefer the test with gasoline