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4G63T Head oil port mod

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BogusSVO

10+ Year Contributor
5,891
318
Jul 1, 2009
Pensacola, Florida
4G63T Head Oil Port Modification


This is a simple and effective mod done to the oil port from block to head.

I have found out a restriction can occur when excessive milling of the head has been done.
Resulting in low/poor oil flow through the cylinder head that can cause lifter tic, cam tower gaulding, and in some cases on turbo engines that feed the turbo oil from a port on the head, to cause the turbo to fail.

Appox mod time with head of engine is 2 mins.


Stock oil port….

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Take a die grinder with an aluminum burr and grind and chamfer the oil port, while staying inside the gasket-sealing ring. (I find a ¾ base tree burr works best)

So the end result looks like this.

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I prefer this to be done before the head is resurfaced.

I hope you find this useful.
 
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I am new here, and I do not even own a DSM, But I do machine work for some guys that do have them, we have found this mod very useful, I hope you will too.

since I am a Noob.. and likely will be for some time, i will post here.

Mods if you feel the need to move any of my post to a more apporpate fourm, Please do.
All I wish to do is share what I have learned about your heads and engines
 
This is the guy that has done all of my heads. This mod kills the lifter tick! Tell your machinist to do this. Milling the head reduces the oil flow to the upper end. This restores proper oil flow to your head (and your turbo 1g guys)!
 
I never understood why that valley was there...I mean that is a HEAD BOLT hole...but obviously oil flows around the bolt and into the head or something!?!

Awesome Idea Man!!
 
Welcome to the site BogusSVO!
It's great to have another experienced machinist on board, they're few and far between. I hope you'll post frequently and in detail.

Have you seen or done the oil pump front "bypass" mod? Opinion on it? Any other headwork tips other than the usual oil drainback and flash cleanup?
 
TurboTalon ..... ask rbwTrans... he's my bud, every one of his heads has this done, along with another guy here local that runs dirt track "stinger class"

the reason this mod came about was Rick was having a problem with lifter tic, and after he swapped out lifters, 3 times, including to the updated 3g ones, it just would not go away, the head came off and we noticed that the passage from the block to the head had gotten smaller from the head bein surfaced several times, I ground the passage, and Rick bolted the head back on, and the lifter tic was gone, Ever since I have done this mod on EVERY 4G63 head that has passed through my shop. (aprox 30 or so)
I have not had one ill report back on it. But several calls telling me lifter tic was now gone.

Yes I do plan to do some more "how to" post for you guys. I have several more I need to write up and post.

Glad I can help you guys out!!
 
LOL i love tuners! THATS A HEAD STUD HOLE!!!!

That small notch is there to give the machinist and or a SMART DSM owner a idea of how much the head HAS or CAN be decked. Im not sure what the machinist technical term is for it but its a inspection spot....not a oil pressure/relief port. It even shows you that in the FACTORY SERVICE MANUAL!

Your a "machinist" and couldnt see that a head stud goes through that hole? Next your going to tell me you hollow drill the head stud to allow for better oil flow:tease:

Did you even look on the block and see that their is NO matching spot for your "special out oil port"???
 
LOL i love tuners! THATS A HEAD STUD HOLE!!!!

That small notch is there to give the machinist and or a SMART DSM owner a idea of how much the head HAS or CAN be decked. Im not sure what the machinist technical term is for it but its a inspection spot....not a oil pressure/relief port. It even shows you that in the FACTORY SERVICE MANUAL!

Your a "machinist" and couldnt see that a head stud goes through that hole? Next your going to tell me you hollow drill the head stud to allow for better oil flow:tease:

Did you even look on the block and see that their is NO matching spot for your "special out oil port"???

It's obvious that you misunderstood the mod that bogusSVO has done.
It's a legit mod, it's a viable solution. He's opened up the spot where the head gets it's fresh, pressurized oil supply from the block.
 
Wow what a lack of complete brain power. Even when youre told the truth you still cant accept it. That hole is a head bolt/stud hole, and there is a 'pin' in the block that locates the head to the block. No oil can EVER pass through that hole. The head does NOT get its supply from the block in any of those locations.

No 'real' insult meant, but hes a Phord owner....and you havent learned anything about my head, or you would know that i am right.
 
Wow what a lack of complete brain power. Even when youre told the truth you still cant accept it. That hole is a head bolt/stud hole, and there is a 'pin' in the block that locates the head to the block. No oil can EVER pass through that hole. The head does NOT get its supply from the block in any of those locations.

No 'real' insult meant, but hes a Phord owner....and you havent learned anything about my head, or you would know that i am right.

OK so the way the internet works, I'm supposed to keep posting the right answer until no one disagrees, right?
How long will the doubters keep posting the wrong 'truth'?
 
LOL i love tuners! THATS A HEAD STUD HOLE!!!!

That small notch is there to give the machinist and or a SMART DSM owner a idea of how much the head HAS or CAN be decked. Im not sure what the machinist technical term is for it but its a inspection spot....not a oil pressure/relief port. It even shows you that in the FACTORY SERVICE MANUAL!

Your a "machinist" and couldnt see that a head stud goes through that hole? Next your going to tell me you hollow drill the head stud to allow for better oil flow:tease:

Did you even look on the block and see that their is NO matching spot for your "special out oil port"???

You're correct, it is a head stud/bolt hole. That wasn't disputed (it's pretty obvious). If you have a spare head laying around, go grab a light and point it down into that hole. You can see another hole about 1/2" down (if you're looking from the bottom of the head).

The parts used to gauge how much material has been removed from the head are also visible in this picture. In fact, the part of the head that BogusSVO has ported in the picture is "pointing" to it. It's the little circle with the freeze plug looking piece in it.

Here is the block and I have outlined the part that would be affected. Sorry the picture is blurry.
 

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OK so the way the internet works, I'm supposed to keep posting the right answer until no one disagrees, right?
How long will the doubters keep posting the wrong 'truth'?

Doubter... hmm. How long have you had YOUR car? How many motors have YOU built?

Just because my post count is low, doesnt mean anything except im new to this board.

:::going to dig up the DSMCD manual to prove im right:::

Best i could do, i circled the pin im talking about, it fits in the recess completely blocking anything, as if the bolt/stud didnt already:

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You're correct, it is a head stud/bolt hole. That wasn't disputed (it's pretty obvious). If you have a spare head laying around, go grab a light and point it down into that hole. You can see another hole about 1/2" down (if you're looking from the bottom of the head).

The parts used to gauge how much material has been removed from the head are also visible in this picture. In fact, the part of the head that BogusSVO has ported in the picture is "pointing" to it. It's the little circle with the freeze plug looking piece in it.

Here is the block and I have outlined the part that would be affected. Sorry the picture is blurry.

Wrong side dude, the pins are in the top left and bottom right, the head is 'opposite' when upside down. Where you are pointing is still not the right spot.

It may be the right spot, since the pic shows the intake side, but still no oil can flow from there.
 
No, it's the correct spot. Note the position of the engine stand. The transmission would bolt on that side (the right in the pic), so you're looking at my block backwards.

Here's a pic inside that hole. I hope the resize worked correctly. LOL
 

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The mod is done to the exhaust side. There's no alignment dowel there.
BTW I've had my DSM since 1994. I took the time to understand how the oil flowed through the entire engine during my first rebuild many years ago.
 
Oh ok, for poops and giggles, lets say that youre correct. We will also ASSUME that you know your motor NEEDS oil pressure. Right? Well, IF oil came out of that hole (it looks like someone bored through into the oil galley, big no no), then it would go STRAIGHT to the 'open air' of the head, and NOT through the galleys, lifters etc....

Ever pre oil your motor with a drill spinning the oil pump and forget to put the valve cover back on? Ever wonder how the lifters could shoot oil 5ft in the air? Thats only a LITTLE bit of pressure, but if that was wasted getting sprayed into the area of the head that allows the oil to drain back in to the block, what would be the point?
 
Oh ok, for poops and giggles, lets say that youre correct. We will also ASSUME that you know your motor NEEDS oil pressure. Right? Well, IF oil came out of that hole (it looks like someone bored through into the oil galley, big no no), then it would go STRAIGHT to the 'open air' of the head, and NOT through the galleys, lifters etc....

Ever pre oil your motor with a drill spinning the oil pump and forget to put the valve cover back on? Ever wonder how the lifters could shoot oil 5ft in the air? Thats only a LITTLE bit of pressure, but if that was wasted getting sprayed into the area of the head that allows the oil to drain back in to the block, what would be the point?

There's a bolt head and washer to cap off the top of the head bolt hole, so oil won't shoot out.
 
I going to have to bow out and give my apologies here. I just went and checked several heads and blocks and the THE oil pressure port in the block. In all the 1g heads thats a rough port like he shows above but on 2gs is a very precisely drilled hole. Directly to the right of that hole is a allen head plug for oil port access. Im still stumped as to how the oil pressure flows around the head stud and into that port with precision. Anyone with l19 or a1 head studs knows how tight those studs are in the head. But that is infact the ONLY oil pressure port going into the head and porting it out will infact help.
 
Oh ok, for poops and giggles, lets say that youre correct. We will also ASSUME that you know your motor NEEDS oil pressure. Right? Well, IF oil came out of that hole (it looks like someone bored through into the oil galley, big no no), then it would go STRAIGHT to the 'open air' of the head, and NOT through the galleys, lifters etc....

Ever pre oil your motor with a drill spinning the oil pump and forget to put the valve cover back on? Ever wonder how the lifters could shoot oil 5ft in the air? Thats only a LITTLE bit of pressure, but if that was wasted getting sprayed into the area of the head that allows the oil to drain back in to the block, what would be the point?

Oil travels around the bottom of the flywheel end stud on the exhaust side of the head, exactly where that picture shows. The bottom is sealed by the deck surface and the head gasket, the top by the bolt head, or washer if using studs.

Here is a diagram from the 90-91 FSM that shows that oil clearly shares that hole with the stud. This is the 1.8 diagram, the 2.0 isn't as detailed but I assure you, it works the same.

1.8L
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2.0L
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If you still feel the need to resist that this is, in fact, how oil is plumbed to the cylinder head, please, go take (or find) a picture of the sealing surface of the cylinder head, and point out where you think the galley is.

I'm going to take a wild guess and say the picture of the galley in the stud hole may look jagged because it appears that that head started life as a 7 bolt head and was machined for the larger 6 bolt head studs.

*Edit* This isn't directed at you Ken.
 
Here is a clear view of the top of the block. That is infact the ONLY oil pressure port coming up the head. I AM WRONG AND ILL ADMIT IT:coy:
 

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I'm going to take a wild guess and say the picture of the galley in the stud hole may look jagged because it appears that that head started life as a 7 bolt head and was machined for the larger 6 bolt head studs.

*Edit* This isn't directed at you Ken.

Heh, believe it or not, with the exception of 8 bent intake valves, that's a completely unmolested 6 bolt head. For some reason, the holes with dowels don't have the rough surface like that and you can see that it becomes much smoother about another 1/2" past the oil hole.

Edit: I wonder why they didn't machine that lip just a little farther down the hole. That could significantly increase the amount of oil that reaches the head. Maybe it was an attempt to keep more of the oil on the rotating assembly sort of like a metering device. I'd be interested in what differences that could make.
 
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