Greg this in-depth content on your engine build is killer! I'm in the planning phase of a turbo build and knowing that miata-specific content on this kind of stuff exists is so invigorating and makes me want to go even further!
Rule of thumb is if it takes less than 10sec for the needle to drop from 20" to 10" then you either need a valve job, replace valve guides or both. I'm a engine machinist and do this for a living and I never rely on a vacuum test alone.
Dude...perfect time to release this. I was just wondering how i was going to check how well my valves were sealing, without taking it to a machine shop. Im in the middle of a forged engine build so this helps out majorly!
@TheCarPassionChannel, Apologize for responding so many years late, But I was wondering if this could also be used to test out cylinder leaks on all 4 pistons if we used a little bigger pad and expanding pvc? thx in advance!
making one of these and found a way so you dont have to kill a hose to do it. you get an ac shutoff valve then you also get a ac line to barb adapter this way you dont have to cut a line and if you already have an ac line in house you can use it. though i would say remove the valve depressor if you want with a tool tldr ac hose --- ac shutoff valve --- acline to 1/4 barb fitting ---- t in the pressure gauage --- to valve adapter
Really appreciate this video. I made my own with the old yellow ac line off a manifold kit I had, a vacuum gauge off an autozone hand pump, a steel cover plate for electrical outlet boxes cut and drilled, some semi-hard tubing, related fittings, and foam off a piece of pipe insulation. I think I spent $40.
@@TheCarPassionChannel I was thinking this way you can get a specific reading for each valve. BTW Thank you Greg, your videos have always been an inspiration what is possible to do without having a fancy shop put together by sponsors. All the best from Germany!
Have you heard anything about the Garrett GBC turbos? The GBC22-350 looks like the sweet spot for a ~300 hp Miata. It's not super expensive either. I haven't found any videos on them yet.
Yeah I'd be really interested to see how they are on a 1.6/1.8 Miata motor, might be great sizing. Maybe even the smaller ones if you're looking for 180-200hp
If you can’t get atleast .7 bar without the seals installed you likely have worn out guides. The guides are meant to be within a thou or 2. I don’t know the exact spec for these heads, that’s about average from what I’ve seen. (I’m a cylinder head machinist)
Hey wanted to mention if you've got a hand vacuum pump/tester you can make a similar tool to work with it to do this too. How I tested mine when I put it together. I used mightvac vacuum/pressure tester.
Just put everything together in Amazon cart it’s $150 for everything now 2 years later . Can’t believe how prices have increased. My local machine shop who just resurfaced my heads charges $150 for resurfacing $150 for pressure testing $75 for hot tank Total of $375 out the door , it pays for it’s self after the first use so I would like to build my own to test how good my valves are sealing after new valve stem seals & the hand lapping I did with 350/450/700/1,000 grit Diamond polishing compound
Good info video.....Even a 3 Cfm pump is Way to large & Will give Misleading good reading by Over-pumping the Actual valve leakage Rate....A 10 Liter/Minute (0.3 Cfm) vacuum pump Rate is much closer to Commercially used, built-in to Professional grade valve seat cutter machines....You want something that takes about 10 seconds to pull a Full scale reading into a Perfect seal.....Adding an Inline 0.010" Orfice Restriction to a 3 Cfm pump + a good Shut-off valve is about right.....A Good valve seat will take at least 60 seconds to leak back up to atmosphere.....
$1.00 tool. With valves and springs installed, pour diesel into intake ports, look for leaks. Repeat on the exhaust ports. Any leaks, lap that valve and recheck 😉
Good video. I rigged up something similar after seeing the outrageous plate kit prices. I sacrificed locking suction cups and I used ac manifold gauges for the valve, lines, gauge. I ended up teeing in a bigger vacuum gauge for accuracy. In lieu of oil, I used grease to identify the leak, easier to pinpoint the problem area. As caveat, if you have money in the head, take it the machinest. DIY is good to double check, but don't get burned if you got it built up.
Nice video & good idea however,....your 3 cfm pump is still Way too much as considering the typical head port is around 0.2 cu ft volume, you really Need to get your vac pump throttled down by placing a 0.040" diameter orfice tube connected between the pump & your shut-off ball valve.....A/C servicing Isolation ball valves work best & don't leak....Ideally, you want to pull > 20" Hg, close Isolation Ball valve & turn off pump...When Cyl Port vac drops to 18" Hg, Begin Stopwatch Timing until port vac drops to 8 " Hg vac...It needs to take > 10 secs to have a Good pass Valve--Seat rating....
You're on a roll! You'll be a pro engine builder and tuner in no time. "Car Passion Engine Building and Tuning". Ignore the fact that trying to Swype "passion" usually typos "pain". It's completely unrelated.
all you need to test your valves is this take a compression reading log it each cylinder now add 1 small spoon mtr oil each cylinder retake comp reading did oil help (higher reading ) if it helps it is your rings leaking if no help it is your valves leaking simple
Been keeping up with you on fb through the groups especially Rare and Vintage Miata parts and the Mazda Miata Club! Love to see you back with more content woo!
Greg can you please help me - I want to turbo my 2012 NC , Which is the best one - I’ve heard about Flyin Miata but I don’t think they make a kit . Thanks again for your time Aussie NC
I just drove an NC with the Fab 9 Tuning "GT Kit" on the stock 2.0L and it was really great. I haven't installed one myself yet but the performance was awesome!
Now I question which method is better.... leak check with a liquid such as alcohol/water vs a vacuum test? I like you can isolate the valves without removing the head using the vacuum and it's less of a mess. Great video! I already have a cheapo pump for AC work, will try it out next time i need to do a check. Thanks!
I tried the methods using water, alcohol, acetone, and seeing if it will drain through a valve, I just didn't like it. I really wanted something measurable. Next video I'll be putting it to work!
Fantastic video and tool! This is a huge pro even if you are just going to use it to confirm the results of a compression and leak down test. In my case I know that 2 cylinders had low compression and that the majority of the leak was coming from the exhaust valves but this will further confirm the results. I think I will also use your oil pour technique on the valve stem seals because if the seals are not installed properly or worn out that may be a good was of inspecting them.
![Save Money And Lap Your Own Valves! [Measured Results]](http://i.ytimg.com/vi/TPCrR-R7cTY/mqdefault.jpg)
![Save Money And Lap Your Own Valves! [Measured Results]](/img/tr.png)
Btw yes they all smoke like that. Could be steam if there’s moisture in the air being boiled away at vacuum.
Greg this in-depth content on your engine build is killer! I'm in the planning phase of a turbo build and knowing that miata-specific content on this kind of stuff exists is so invigorating and makes me want to go even further!
JAFRO!!!!! one of the best youtube channels on engine building there is
Rule of thumb is if it takes less than 10sec for the needle to drop from 20" to 10" then you either need a valve job, replace valve guides or both. I'm a engine machinist and do this for a living and I never rely on a vacuum test alone.
Cool video
Oh nice, you got a canchecked...
You're the best
What size tap is that?
I think I figured it out… 1/8 -27
@@nathanhood8578 You need to use whatever size tap matches the barb fitting you use
Dad!?
Dude...perfect time to release this. I was just wondering how i was going to check how well my valves were sealing, without taking it to a machine shop. Im in the middle of a forged engine build so this helps out majorly!
Does this work on rotaries? 😜
Amazing, maybe I'm gonna test that when I'm gonna put my new big cams in my vvt 👌
Bro you put thread sealant on so thick, it looked like sour cream on a taco.
Anyone who mentions that = verified channel OG
Can't you just use a vacum hand pump ?
Can you use this as a DIY leakdown tester? Assuming you get a fitting for the spark plug threads.
I wonder if the piston rings would let too much air through
So glad you give jafro the shoutout he deserves
@TheCarPassionChannel, Apologize for responding so many years late, But I was wondering if this could also be used to test out cylinder leaks on all 4 pistons if we used a little bigger pad and expanding pvc? thx in advance!
I know its an older video you made but i like how informative and simple you made the information understandable with video 😊 kudos i liked it 😊
Is this test have any effect if we use low CFM (2.0) pump
making one of these and found a way so you dont have to kill a hose to do it.
you get an ac shutoff valve
then you also get a ac line to barb adapter
this way you dont have to cut a line and if you already have an ac line in house you can use it.
though i would say remove the valve depressor if you want with a tool
tldr
ac hose --- ac shutoff valve --- acline to 1/4 barb fitting ---- t in the pressure gauage --- to valve adapter
Really appreciate this video. I made my own with the old yellow ac line off a manifold kit I had, a vacuum gauge off an autozone hand pump, a steel cover plate for electrical outlet boxes cut and drilled, some semi-hard tubing, related fittings, and foam off a piece of pipe insulation. I think I spent $40.
Why not replace a ports valve with some kind of rubber plug to test valves individually?
You could do that as well
@@TheCarPassionChannel I was thinking this way you can get a specific reading for each valve. BTW Thank you Greg, your videos have always been an inspiration what is possible to do without having a fancy shop put together by sponsors. All the best from Germany!
Lol i was writing a comment about the sparkplugs when you mentioned it haha
That tool sucks!
Im trying to repair my compression tester vain vacuum pump
Overkill, don't need a vacuum pump.
Way better than your stethoscope video!
Have you heard anything about the Garrett GBC turbos? The GBC22-350 looks like the sweet spot for a ~300 hp Miata. It's not super expensive either. I haven't found any videos on them yet.
Yeah I'd be really interested to see how they are on a 1.6/1.8 Miata motor, might be great sizing. Maybe even the smaller ones if you're looking for 180-200hp
If you can’t get atleast .7 bar without the seals installed you likely have worn out guides. The guides are meant to be within a thou or 2. I don’t know the exact spec for these heads, that’s about average from what I’ve seen. (I’m a cylinder head machinist)
Good info thank you
Shouldn’t rotary owners be able to test their apex seals this way?😂 super cool Tool, makes me want to build one, just to have it
Hey wanted to mention if you've got a hand vacuum pump/tester you can make a similar tool to work with it to do this too. How I tested mine when I put it together. I used mightvac vacuum/pressure tester.
How’d you do it?
Loving the regular content grep. Keep it up
Great idea, you could also create a pad that will cover each piston to see how good your rings are.
I’m here dad
Just put everything together in Amazon cart it’s $150 for everything now 2 years later . Can’t believe how prices have increased. My local machine shop who just resurfaced my heads charges
$150 for resurfacing
$150 for pressure testing
$75 for hot tank
Total of $375 out the door , it pays for it’s self after the first use so I would like to build my own to test how good my valves are sealing after new valve stem seals & the hand lapping I did with 350/450/700/1,000 grit Diamond polishing compound
Good info video.....Even a 3 Cfm pump is Way to large & Will give Misleading good reading by Over-pumping the Actual valve leakage Rate....A 10 Liter/Minute (0.3 Cfm) vacuum pump Rate is much closer to Commercially used, built-in to Professional grade valve seat cutter machines....You want something that takes about 10 seconds to pull a Full scale reading into a Perfect seal.....Adding an Inline 0.010" Orfice Restriction to a 3 Cfm pump + a good Shut-off valve is about right.....A Good valve seat will take at least 60 seconds to leak back up to atmosphere.....
Awesome video man, will forsure build one of these. Am planning to do a mix of Neway cutters / lapping my 4age. Like you I also don’t trust myself 😂
I Droolz over parts piles 🤤
$1.00 tool. With valves and springs installed, pour diesel into intake ports, look for leaks. Repeat on the exhaust ports. Any leaks, lap that valve and recheck 😉
Good video. I rigged up something similar after seeing the outrageous plate kit prices. I sacrificed locking suction cups and I used ac manifold gauges for the valve, lines, gauge. I ended up teeing in a bigger vacuum gauge for accuracy. In lieu of oil, I used grease to identify the leak, easier to pinpoint the problem area. As caveat, if you have money in the head, take it the machinest. DIY is good to double check, but don't get burned if you got it built up.
Also, you can run a vacuum on the head surface side to check for weak valves springs.
Nice video & good idea however,....your 3 cfm pump is still Way too much as considering the typical head port is around 0.2 cu ft volume, you really Need to get your vac pump throttled down by placing a 0.040" diameter orfice tube connected between the pump & your shut-off ball valve.....A/C servicing Isolation ball valves work best & don't leak....Ideally, you want to pull > 20" Hg, close Isolation Ball valve & turn off pump...When Cyl Port vac drops to 18" Hg, Begin Stopwatch Timing until port vac drops to 8 " Hg vac...It needs to take > 10 secs to have a Good pass Valve--Seat rating....
You're on a roll! You'll be a pro engine builder and tuner in no time. "Car Passion Engine Building and Tuning". Ignore the fact that trying to Swype "passion" usually typos "pain". It's completely unrelated.
Would this show if valve seals were leaking? If so, with the head still on is there a way to differentiate between valve seals and seats?
No, this is not an accurate test for valve stem seals
@@TheCarPassionChannel would a bad stem seal throw off a reading?
@@PerpetuallyYankin yes it is possible; you can also put grease around the stem seal to help prevent this
Great video! I was about to do this vacuum test for my car and realized the head has a lot of chips and cracks. I might just need to replace it😭
all you need to test your valves is this take a compression reading log it each cylinder now add 1 small spoon mtr oil each cylinder retake comp reading did oil help (higher reading ) if it helps it is your rings leaking if no help it is your valves leaking simple
Just as I was checking the insta page for info on the new vid, here it is. Btw I would still kill for one of them hats, no matter the quality :/
Been keeping up with you on fb through the groups especially Rare and Vintage Miata parts and the Mazda Miata Club! Love to see you back with more content woo!
I don't have a drill tap thing. which one should I get?
Why not do a leak down test while the head is installed?
I couldn't do a leak down when I had a hole in my piston
Another quality upload. Nice job.
Thank you this was absolutely insightful. This goes for other cars besides miatas too!
great minds think alike . you are spot on.
New vids...its like Christmas! Haha love the dyi tricks.
They all sound like that. Totally normal.
Good info, I may make one of these myself!
Awesome video, very helpful!
Ah yes another crank peters video!
The Miata legend love your vids
Jafro is quality 👌🏻
Nice use of a vaccum pump
Greg can you please help me - I want to turbo my 2012 NC ,
Which is the best one - I’ve heard about Flyin Miata but I don’t think they make a kit .
Thanks again for your time
Aussie NC
I just drove an NC with the Fab 9 Tuning "GT Kit" on the stock 2.0L and it was really great. I haven't installed one myself yet but the performance was awesome!
@@TheCarPassionChannel
Thanks Greg ,
Ive contacted Fab9 - excited !!!!!!!!
Thanks for your time - I really appreciate it,
Cheers Aussie NC
yay miata dad uploaded again
Now I question which method is better.... leak check with a liquid such as alcohol/water vs a vacuum test? I like you can isolate the valves without removing the head using the vacuum and it's less of a mess. Great video! I already have a cheapo pump for AC work, will try it out next time i need to do a check. Thanks!
I tried the methods using water, alcohol, acetone, and seeing if it will drain through a valve, I just didn't like it. I really wanted something measurable. Next video I'll be putting it to work!
@@TheCarPassionChannel looking forward to it!
Master !!! 🙌🏼
this is just what i needed... im block sanding my head and lapped my valves and ive been putting this off haha
Fantastic video and tool! This is a huge pro even if you are just going to use it to confirm the results of a compression and leak down test. In my case I know that 2 cylinders had low compression and that the majority of the leak was coming from the exhaust valves but this will further confirm the results. I think I will also use your oil pour technique on the valve stem seals because if the seals are not installed properly or worn out that may be a good was of inspecting them.