Destroyed Valves???

[NHerron]

If (tiny or small) droplets form in the matter of minutes and they say "that's the best it'll get" after cutting seats and matching the valves, sorry they are mistaken. I would find another machine shop to be honest

 

[dsm-junkie]

If (tiny or small) droplets form in the matter of minutes and they say "that's the best it'll get" after cutting seats and matching the valves, sorry they are mistaken. I wold find another machine shop to be honest

Kind of was thinking the same thing!

 

[YZFR1]

Maybe BogusSVO could chim in and let us know what is an acceptable air leak seal on the valves? It would be highly appreciated!

 

[bryanwheat]

When i do valves i vacuum test them and am able to get them to hold vacuum pressure for at least 20 seconds and it will slowly bleed off. Getting this to seal like this water will never leak thru any of them.

 

[YZFR1]

Yeah, i think that's what they did. I actually saw them doing it, they hooked up this soft plate up to the runners to seal them in and started to pull air through it. Not sure about how many seconds they held it but they had a gauge on it that read something like 20-25% vacuum on all runners.

I made a post about it in the "How To Fluid Test a 4G63 Cylinder Head" thread but noone ever got back to me. I'm getting decent leak down test numbers though, on an engine that is not fully brocken in, yet. This does concern me a bit though, as maybe my compression and leak down numbers should be higher.

 

[JonathanNL]

The Intake are some replacement valves, as far as oe spec or not I can not say, but for turbo use, I would not trust them, even at stock boost levels.

Listen to the man, get rid of those inferior quality valves (so stamped as "made in 'Japan' ") or you will regret it.

Result of stock boost level on a t25:

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Can you read what it says on the valve?

 

[dsm-junkie]

Listen to the man, get rid of those inferior quality valves (so stamped as "made in 'Japan' ") or you will regret it.

Result of stock boost level on a t25:

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Can you read what it says on the valve?

Holy #$%& I definitely will get rid of them now!!!


Well guys just finished installing my OEM valves and getting ready to do a test on them! I will let you guys know the results!!!

 

[bryanwheat]

Did you lap the valves when you put them in? They won't seal well if you don't.

 

[dsm-junkie]

Did you lap the valves when you put them in? They won't seal well if you don't.

Yes I did!!

 

[bryanwheat]

Yes I did!!

Sounds like you should be set then.

 

[dsm-junkie]

I do have a question that I'm a bit confused on! So when the pistons are at TDC and you turn the crank with the timing belt on...... the intake valves are supposed to open before the pistons reach TDC and the exhaust valves open after the pistons start to go down from TDC right??? The only way valves and pistons make contact is if the valves open when the pistons are at TDC correct??

 

[bryanwheat]

I do have a question that I'm a bit confused on! So when the pistons are at TDC and you turn the crank with the timing belt on...... the intake valves are supposed to open before the pistons reach TDC and the exhaust valves open after the pistons start to go down from TDC right??? The only way valves and pistons make contact is if the valves open when the pistons are at TDC correct??

They will be bent from them being open while the piston is at top dead center. The intake valves open after the piston reaches tdc and is on it's way down. When the piston gets to the bottom of the cylinder the intake valves close and the piston goes back up in the compression stroke. From there the piston is driven down to the bottom of the cylinder. When it gets to the bottom the exhaust valves open and the piston starts to travel up. When the piston gets close to the top of the cylinder the exhaust valves close so that the piston doesn't hit them.

 

[dsm-junkie]

They will be bent from them being open while the piston is at top dead center. The intake valves open after the piston reaches tdc and is on it's way down. When the piston gets to the bottom of the cylinder the intake valves close and the piston goes back up in the compression stroke. From there the piston is driven down to the bottom of the cylinder. When it gets to the bottom the exhaust valves open and the piston starts to travel up. When the piston gets close to the top of the cylinder the exhaust valves close so that the piston doesn't hit them.

Great!! I was asking because I want to make sure I'm using the correct timing marks while the head is off so basically I can see which valves are moving first! So the intake valves should be the first to open following the the exhaust valves!! Thanks for all the help!!

 

[NHerron]

Follow this guide and you'll be golden
http://www.dsmtuners.com/forums/art...5-timing-belt-tensioning-tips-4g63-turbo.html

 

[dsm-junkie]

Alright guys! I'm starting to put the head back together! I'm playing it real safe this time! I have a couple questions on cam gears! When installing cams both of the dowel pins should facing up right?? Now when my cam gears are on the cams these are the correct timing marks that I should use right?? Is there anything that i'm missing?? Thanks guys!!!

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[bmoha7321]

As long as you time it to the crankshaft...

 

[NHerron]

Yes, exactly, both dowel pins straight up. The exhaust cam, consequently the dowel pin, will naturally sit a little bit off-center pointing to oh, 11 o'clock so keep that in mind.

So what I did was this.

Rotate the exhaust cam gear clockwise about one tooth more than the intake gear and PUT the belt on both gears at that point. Zip tie them. NOW align the crank timing mark and the oil pump timing marks perfectly. With belt zip tied to cam gears, string the belt around idler pulley, oil pump gear, crank gear, and tensioner pulley.

Rotate the engine six times and the marks should now line up perfectly

This was pretty much what luv2rallye's article outlined in the beginning, some reason I forget it everytime and end up playing around with it for an hour. But eventaully I remember...

 

[dsm-junkie]

Yes, exactly, both dowel pins straight up. The exhaust cam, consequently the dowel pin, will naturally sit a little bit off-center pointing to oh, 11 o'clock so keep that in mind.

So what I did was this.

Rotate the intake cam gear COUNTERclockwise about one tooth (or basically the same movement the exhaust gear did) and PUT the belt on both gears at that point. Zip tie them. NOW align the crank timing mark and the oil pump timing marks perfectly. With belt zip tied to cam gears, string the belt around idler pulley, oil pump gear, crank gear, and tensioner pulley.

Rotate the engine six times and the marks should now line up perfectly

Great Thanks for the clarification!!!

I started to install the rest of the parts and when I torqued down the caps to 14 ft lbs the valves started to push back out So i'm guessing that the lifters weren't collapsed correctly! I stuck a small paper clip through the top of every lifter ! I can still fill like they can be pushed in more! Theirs resistance when I push them down and they come back up to their original place! Whats the proper way to collapse them!

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[NHerron]

As long as you got ALL the fluid out by releasing the check valve with the paper clip and pressing down as far as possible, you will be okay. Make sure all the fluid is out! The valves that are open slightly is due to the cam lobe pointing down. Even with the lifter being at the lowest of its travel, it is still titering the rocker enough to open the valve in combination with the height of cam lobe

Hope that makes sense, I've never tried to explain that before

 

[dsm-junkie]

Yes, exactly, both dowel pins straight up. The exhaust cam, consequently the dowel pin, will naturally sit a little bit off-center pointing to oh, 11 o'clock so keep that in mind.

So what I did was this.

Rotate the intake cam gear COUNTERclockwise about one tooth (or basically the same movement the exhaust gear did) and PUT the belt on both gears at that point. Zip tie them. NOW align the crank timing mark and the oil pump timing marks perfectly. With belt zip tied to cam gears, string the belt around idler pulley, oil pump gear, crank gear, and tensioner pulley.

Rotate the engine six times and the marks should now line up perfectly

As long as you got ALL the fluid out by releasing the check valve with the paper clip and pressing down as far as possible, you will be okay. Make sure all the fluid is out! The valves that are open slightly is due to the cam lobe pointing down. Even with the lifter being at the lowest of its travel, it is still titering the rocker enough to open the valve in combination with the height of cam lobe

Hope that makes sense, I've never tried to explain that before

Well I kind of got that! So what are the lifters supposed to feel like when they are fully collapsed?? If I just move the cam when installing wouldn't the valves still open when the cam spins???

This video really helped understand the concept!


Bleeding 4g63 lifters - YouTube

 

[bmoha7321]

What head gasket are you planning on using? Hopefully not Cometic. What has been done to that head? Has it been checked and no warp? You have the head off in your hands. This would be a good opportunity to send it to a machine shop.

 

[dsm-junkie]

What head gasket are you planning on using? Hopefully not Cometic. What has been done to that head? Has it been checked and no warp? You have the head off in your hands. This would be a good opportunity to send it to a machine shop.

OEM head gasket will be used! Head has already returned from the machine shop! Just a stupid mistake on my end thats making me go through all this!

 

[NHerron]

That dude has a wicked thumb nail for a guy

 

[dsm-junkie]

Alright guys! I'm still having trouble after I collapsed all of the lifters! So I collapsed all of the intake lifters! A lot of oil did come out! I installed everything but when I tighten down the caps that hold the camshaft the valves slowly open everyone I tighten the caps! Did I not collapse the lifters enough? Should I align the camshaft another way? Right now I was tightening the camshaft down with the dowel pin facing up! I'm really stuck on this one part! Here is a video of me pressing down the lifters to show how much they are collapsed! Do I need to do more collapsing?

Rocker collapse - YouTube

 

[donniekak]

Um, no. Valves should be air tight until the lobes hit them. Otherwise you would have no compression.

In a dohc 4g63 head, with cams, rockers, and lifters installed, all 16 valves are never closed at the same time.