4G63T Head oil port mod

[BogusSVO]

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.

 

[95TalonOwner]

Thanks for the tips guys, my problem doesn't lie here I'm getting plenty oil to the head its rod knock unfortunetly. Whats the best way to figure out which cylinder? Drop the pan and wiggle?

Doesn't really matter which cylinder. Rod knock usually means engine rebuild time.

 

[rtincher22085]

200 miles on fresh motor and you mean to tell me I have to rebuild my whole motor again because of a faint rod knock which could be just a defect since there ain't no metal shavings in my oil?

 

[pneumo]

200 miles on fresh motor and you mean to tell me I have to rebuild my whole motor again because of a faint rod knock which could be just a defect since there ain't no metal shavings in my oil?

If you're telling us you have rod knock, then yes you should fix it.

 

[rocketfish]

had my machine shop do this mod! had no problems what so ever

 

[joe sobo]

well, alot of guys on here think, "oh, since the head fits down without drilling the 7 bolt head, that they do not need to. another member on here found out the hard way. he put all new internals, including wiesco/eagle...... well they could not figure out why the engine kept spitting t-belts. what was happening is they used a 2g head on a 1g with arp studs. and when i bought the car and pulled the v.c, there was hardly any oil in the head. so i took the risk, and started the car with the v.c off. low and behold, there was nothing comming out. i pulled that one stud out, and put a stocker back in to test my theory, and wam!!. the oil shot 10 ft. in the air. ALWAYS DRILL OUT THE 2G HEADS STUD HOLES TO FIT ONTO THE 6 BOLT ENGINE

 

[brian92tsiawd]

Thanks for the great info. I will defi itely have to keep this in mind when I start building the spare 6 bolt sitting in the garage.

 

[voxer475]

so do you HAVE to get the head resurfaced after doing this?

 

[miguelmcv]

Is it a bad Idea to drill Just the 2g Head Hole that carries the Oil and leave the others intact which there is no oil running through them?.

 

[BogusSVO]

Voxer475... No the head does not have to be milled after this mod, UNLESS the die grinder skips across the HG surface. Most the time there is another cause for the head to be pulled. Blowen HG bent valves ect.

miguelmcv... the head alignment dowels are there, so the bolt hole size being 13mm will not cause issues.

 

[miguelmcv]

Thanks BogusSVO for the reply.

 

[Rideit636]

I just did this to the head I'm building. Super stoked to get this build done. As money comes I guess...

 

[MidShipCivic]

IN THEROY, this mod may also help reduce the excessive oil pressre that is caused by the BSE, by allowing more oil to flow to the head, and alowing some of the oil pressure to bleed off.

Kinda weird kiggly restricts, this opens up.. people add head studs along with a the restrictor w/o ever doing this mod they should make ticking their profession huh?


If you block off BSE w/o doing anything else it will send more oil pressure to everywhere else that includes the lifters. Now, if you send block out balance shaft holes and provide better flow to the lifters by doing this mod I'm sure of it that doesn't do anything appreciable as to relieving elevated pressure.

To tell you the truth you actually don't want that to happen the way the oil goes up through the head through the transmission side of the engine (farthest away from the pump) and would cause you problems in the crank end play subject. (this not what happens though it beveling that area provides better flow to the head)

well, alot of guys on here think, "oh, since the head fits down without drilling the 7 bolt head, that they do not need to. another member on here found out the hard way. he put all new internals, including wiesco/eagle...... well they could not figure out why the engine kept spitting t-belts. what was happening is they used a 2g head on a 1g with arp studs. and when i bought the car and pulled the v.c, there was hardly any oil in the head. so i took the risk, and started the car with the v.c off. low and behold, there was nothing comming out. i pulled that one stud out, and put a stocker back in to test my theory, and wam!!. the oil shot 10 ft. in the air. ALWAYS DRILL OUT THE 2G HEADS STUD HOLES TO FIT ONTO THE 6 BOLT ENGINE

How do 12 mm head studs fit through an 11mm hole?

 

[BogusSVO]

Kinda weird kiggly restricts, this opens up.. people add head studs along with a the restrictor w/o ever doing this mod they should make ticking their profession huh?


If you block off BSE w/o doing anything else it will send more oil pressure to everywhere else that includes the lifters. Now, if you send block out balance shaft holes and provide better flow to the lifters by doing this mod I'm sure of it that doesn't do anything appreciable as to relieving elevated pressure.

To tell you the truth you actually don't want that to happen the way the oil goes up through the head use the transmission side and would cause you problems in the crank end play subject. (this not what happens though it beveling that area provides better flow to the head)

I would agree, there will be not much in the way of a pressure drop at this point, maybe 1 or 2 psi if I had to guess.

The BSE will and dose cause a rise in the oil pressure, that is well known.

This whole mod came about beacuse of a friends 4g head that suffred from lifter tic, swapped the HLAs several time, thinner oil, tried a few diffrent fixes.

Come to find out the head was surfaced several times, and the oil trough was now shallow, I ground it out, he bolted it back on and no more lifter tic.

We figured the head was getting good pressuer, but not enough flow.

How do 12 mm head studs fit through an 11mm hole?

The stud is 11mm for the 7 bolt, not the hole, the 7bolt head bolt hole are close to the 12mm size and the head can be forced down in some cases over the 12mm 6 bolt studs

 

[MidShipCivic]

The stud is 11mm for the 7 bolt, not the hole, the 7bolt head bolt hole are close to the 12mm size and the head can be forced down in some cases over the 12mm 6 bolt studs

I would think the 7 bolt head would provide slightly bigger clearance around it's bolt (but still be in the 11.XXmm range) but, not too much clearance since Mitsubishi wanted more surface area and a stronger head (somehow) I didn't know ppl forced heads on the larger 1g studs.

 

[kchaazz]

To all who are concerned about an undesireable increase in oil pressure after the balance shaft delete, the proper solution is to port the pressure relief hole on the oil filter housing. This is nothing new, and there have been articles on this for years. Porting this hole is very easily and quickly done, especially if done when youre doing a BSE because the OFH will already be off the motor.

 

[honda_burner]

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.

I just wanted to say thank you to this guy. I always see threads that turn into a pissing contest and no one ever backs down. You knew when u were wrong and admitted it. Thank you

 

[92gsxbafaro]

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

thanks alot im deffinately getting this done when i do my head gasket!

 

[jakelandry]

Just to include my .02, I had lifter tick to the extreme. While i was replacing my hg i went ahead and did this mod with a dremal. Diddnt have the head resurfaced, diddnt replace my ticking lifters.. It completely eliminated my lifter tick. This mod is amazing and i recomend it to anone who doesnt have the money to replace their lifters.

 

[bradikus7]

This has been a very informative thread. Thank you to the OP for experimenting and coming up with this solution.

I soon will be having a head decked and this oil port mod done. I am also going to be adding L19 headstuds however this will be a 7bolt head on a 7bolt block. Is it necessary to do the Oil port mod #2? I am unaware if the actual headstud is larger on L19s but I was thinking oil port #2 was mainly for 7bolt heads on 6bolt blocks?

 

[BogusSVO]

Bradikus.. no, you will not need to do #2, you are right about that being a 7 bolt head on a 6 bolt block

 

[bradikus7]

Bradikus.. no, you will not need to do #2, you are right about that being a 7 bolt head on a 6 bolt block

That's what I thought but you know what they say about when you "assume"! Thank you for chiming in on it.

 

[nitrouskris]

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….

You must be logged in to view this image or video.

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.

You must be logged in to view this image or video.

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

I hope you find this useful.

i just noticed the post. i have been doing for years and NEVER had a probelm. great post

 

[jimbob_843]

Is it just me or does that ofh mod pictured above look a little over-done?

 

[pneumo]

Is it just me or does that ofh mod pictured above look a little over-done?

HAHA! whoa I didn't see that before! Yes, the pic marked 'after' is waaaayyyy overdone. The pic with the D shape port is nice, not too big and it's ported in the right direction.

 

[TSimage]

To all who are concerned about an undesireable increase in oil pressure after the balance shaft delete, the proper solution is to port the pressure relief hole on the oil filter housing. This is nothing new, and there have been articles on this for years. Porting this hole is very easily and quickly done, especially if done when youre doing a BSE because the OFH will already be off the motor.

That before an after pic shows the INCORRECT way to port an OFH.. Holy crap people do not expose the sides of the piston like that