Oil port Mod #1

[BogusSVO]

4G63T Head Oil Port Modification #1


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 off engine is 2 mins.


Stock oil port….

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.

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

I hope you find this useful.

 

[cheekychimp]

Moving this here for discussion by the more tech savvy. Let's have some input on this guy's posts. He is making a lot of effort and trying to share useful knowledge. I am aware (from my own rather limited technical knowledge) that he doesn't always do things the same way you guys do. So let's get some information exchange going and try to turn these posts into accurate useful posts worthy of inclusion in the how-to archive where they can be preserved for reference by future members and most importantly provide accurate and correct information that we ALL feel comfortable passing on to newbies and long standing members alike as the RIGHT way to do things.

 

[prove_it]

As far as this head mod is concerned, I highly recommend it if done right. Do not go past the sealing area and this will help oil flow to the head. I've noticed less valve noise with this done. Some day I'd like to take oil pressure readings and see how much it improves. I do also like to clean up the oil drain holes. I've seen some pretty big casting "shelves" that will slow oil return to the pan. Not sure if it really helps much, but it takes minutes and I don't see any harm.

I'm not sure if Cheeky is wanting to discuss this mod, or all of BogusSvo's post in this thread, so I'll keep it to this mod for now.

 

[EMX5636]

I do this to almost all the heads I'm having re-done. I also found a bunch of old ARP studs that used to have an undercut bolt for that hole to also allow oil to flow better up into the head. I'm using one in my car, and still holds 105ft/lbs.

 

[EHmotorsports]

I did the same for my Engine. take the Gasket and scribe the area you want to grind and don't go past it.

 

[BogusSVO]

Yes I would agree if you are new to this mod that you use the old HG to help protect the HG surface.

I have lost count on how many heads I have done this mod on.

In the past few years I have also gone to grinding the cast flashing out of the oil return ports, it has to help with getting the oil back into the oil pan, instead of stalling on the ledges it has to flow over.

The under cut studs are nice to have on that corner for oil flow, but (IMHO) not needed. You can simply take a small burr and slot from the oil hole in the head casting through the machine ledge.

The above will not hold true when installing a 2g 7 bolt head on a 6 bolt block, due to the size differences be tween the head bolt size between the 1g and 2g, and the head bolt holes need to be reamed out to a min of .500

 

[vr4play]

I definitely recommend using something to protect the head. I was doing my head late one night after work and someone walked in and I flinched a little and the burr jumped out of the pocket and went out onto the gasket area. I dropped it off to the machine shop and he had someone weld it up and they welded the whole thing up so we had to start over again by tracing the head gasket and he put it in a mill and milled me a new spot. I am also using the undercut studs as I am using a 2g head and feed my turbo from the head as well. We opened up that hole to .500".

 

[tyeler18]

I've had this done on my 1g when I rebuilt the motor. It had decent lifter tick when cold. Upon reassembly, I forgot to bleed/clean my lifters, but they have been quieter than ever. They had 170k on them at the time of my rebuild, and they're still nice and quiet today.

 

[cheekychimp]

Quoting prove_it:
I'm not sure if Cheeky is wanting to discuss this mod, or all of BogusSvo's post in this thread, so I'll keep it to this mod for now.



Yeah, confine comments in this thread to this particular topic but please post up in his other threads so that we can get good accurate info everywhere to produce some decent how-to threads and/or avoid sticking anything in that section that is bad practice (since those tend to get taken as gospel).

 

[JackstandTSi]

click

Here is a video from Jafromobile on doing the oil port mod, Im not sure if he is registered on here but his videos have been a ginormous help for DSM's

 

[CutlassJim]

What is oil port mod #2?????????????????? /ubbthreads/images/graemlins/confused.gif

 

[prove_it]

Opening up the filter housing pressure bypass holes /ubbthreads/images/graemlins/dunno.gif

 

[BogusSVO]

I posted Oil port Mod 2 The title is a bit misleading, it is more of a head bolt mod that needs to be done so a 2g 7 bolt head will mount on the 6 bolt block.

The 7 bolt uses a 11 head bolt/stud, with 12mm head bolt holes, and the 6 bolt uses a 12mm head bolt/stud with a 13mm head bolt hole.

With the way the 4g63 passes oil into the head, forcing the 2g head on the 6 bolt block can cause an oil restriction.

Jafro and I have PM'ed a few times, the vids I have watched of his I do tend to agree with what and way he is doing and explaining.

Porting the OFH is the primary way to lower oil pressure once a BSE has been done.