Oil port mod #2 for the 4G63t

BogusSVO · 07-11-2009, 07:48 AM

Oil port mod #2 for 4G63T
The head is a 2g head going on a 1g 6 Bolt short block.

This head has had oil port mod 1 done.

4G63T Head oil port mod

The head bolt holes have been reamed for the 1g head studs. To prevent any issues with oiling issues in the head, I have reamed the bolt hole that is in the path of oil flow to .500 the bolt hole was .470 the ARP head stud being used is .465 Leaving only appox. .005 total or .0025 clearance on either side around the head stud. I feel the addition .030 will alleviates any problem with oil into the head.

RipperXX · 07-11-2009, 11:52 AM

I think I understand this mod, but would the extra room around the head stud ever be a bad thing from a sealing standpoint? Like would that extra room allow for play in anything?

I am interested in these mods because although I have stock hydraulic lash adjusters, aka "lifters" they never ticked until I warped the head and had it shaved slightly, I am sort of surprised though as there wasn't much removed, it was just barely out of spec. Yet now it has a little tick every now and then at idle. I was just going to go with the revised lifters as it seems the simplest way of resolving the issue though and I likely still will but this is interesting.

BogusSVO · 07-11-2009, 12:21 PM

I do not go all the way thu the bolt holr, just a bout .250 above where the oil galley starts.

with it being kept down to that point, I do not think there will be any issues with alignment since the other 9 head bolts are kept stock.

I would think you will end up wil oil issues, with out this mod, especially with the 1g 6 bolt block and the 2g head with head studs.

300dollarGSX · 07-11-2009, 01:42 PM

This is exactly what I was thinking about in the first oil port mod thread.

I'm sure this would also help significantly for anyone oiling the turbo from the head.

So, you cut to about 1/4" past the hole in this pic?

That leaves plenty of the hole stock size for alignment purposes.

BogusSVO · 07-13-2009, 08:41 AM

yes, that is what I do.
But even if you go all the way through it would not matter, the alignment dowels is what will align the block/gasket /head.

and for sealing that hole for oil flow will be the head bolt washer, and the headbolt as well.

woooop · 07-13-2009, 04:43 PM

can i do this with a drill and bit and will it get ride of oil pressure. Mine is way to high and i ported the ofh and it did nothing.

BogusSVO · 07-13-2009, 05:01 PM

I honestly can not say if it would lower your oil pressure or not. But it would stand to reason if you had this restriction to and in your head, that releiving it would cause tour pressure to drop some. How much I do not know.
You may want to put an oil pressure gauge on the corner of your head, left front or side, with cam gears to your right. and check. there is a 1/8npy oil gally pughs there that you can remove and tap your gauge into.

I would be intrested to find out what the pressures are before the mods and after.

300dollarGSX · 07-13-2009, 05:21 PM

Quote:

Originally Posted by BogusSVO

I would be intrested to find out what the pressures are before the mods and after.

Me too. I am pulling the transmission out of the car now and will try and get some before readings. I am unable to idle the car at the moment because of a broken shift fork (stuck in 2nd). I'll try to get some readings from the oil filter housing and from the head.

BogusSVO · 07-13-2009, 05:33 PM

Quote:

Originally Posted by 300dollarGSX

Me too. I am pulling the transmission out of the car now and will try and get some before readings. I am unable to idle the car at the moment because of a broken shift fork (stuck in 2nd). I'll try to get some readings from the oil filter housing and from the head.

COOL!! that would be some good info to have!!

deflator · 07-13-2009, 09:38 PM

I am going to have this done when I drop my 2g head off to get the headbolt holes bored out for the 6 bolt block. Probably this week. I'll give the 1st mod a try as well

BogusSVO · 07-13-2009, 09:44 PM

post to what size you had the head bolt reamed to.
and if you can take the time, an oil pressure reading on the corner of the head.

JamiesTSI · 07-14-2009, 06:16 AM

The last time I put a seven bolt head on a six bolt bottom end I just machined a little off the head stud for the oiling port. The other ones where put in one at a time.

BogusSVO · 07-15-2009, 06:47 PM

Quote:

Originally Posted by JamiesTSI

The last time I put a seven bolt head on a six bolt bottom end I just machined a little off the head stud for the oiling port. The other ones where put in one at a time.

I would think machining the stud would weaken the stud some.

Black94DSM · 07-27-2009, 01:50 PM

So when you enlarge the bolt holes for the 1g studs, do you buy a 12mm bit? I'm in the middle of doing this now and I can't find any info on what size bit to buy.

BogusSVO · 07-27-2009, 02:48 PM

Quote:

Originally Posted by Black94DSM

So when you enlarge the bolt holes for the 1g studs, do you buy a 12mm bit? I'm in the middle of doing this now and I can't find any info on what size bit to buy.

on the 1g heads I have measured the head bolt holes fall between .503-.510

I would recomend doing the holes in a drill press, or head shop, if you hand drill them, you may end up with the head bolt hole off center, dur to the bit walking.

Black94DSM · 07-27-2009, 04:46 PM

Thanks for your reply! I drilled them out to just a hair under .500 due to a post Kiggly had written a while back.

The head went on smooth as silk.

I did however take in consideration to your theory about the oil to the head, so that was drilled out a bit larger.

BogusSVO · 07-28-2009, 08:56 AM

cool, did you also do the other oil mod?

Black94DSM · 07-28-2009, 09:27 PM

Quote:

Originally Posted by BogusSVO

cool, did you also do the other oil mod?

Yep I did. I didn't go hog wild on it though, I just smoothed out the casting and put a nicer radius on the edge leading into the stud hole.

BogusSVO · 07-29-2009, 07:07 AM

thats all it really needs.

a91talonAWD · 09-10-2009, 06:53 AM

(Oil Mod #2) <------------ do you think I should do this mod if I am using 6 bolt motor with the 6 bolt head? Or just do the oil MOD #1 since the head bolt size issue others have when using the 7 bolt head is not my issue... I just have lifter tick and the machine shop has the head. Also if you do suggest mod #2 how much bigger should the bolt hole be drilled, a 1/4 past the oil port.

empie1 · 09-10-2009, 08:40 AM

Quote:

Originally Posted by a91talonAWD

(Oil Mod #2) <------------ do you think I should do this mod if I am using 6 bolt motor with the 6 bolt head? Or just do the oil MOD #1 since the head bolt size issue others have when using the 7 bolt head is not my issue... I just have lifter tick and the machine shop has the head. Also if you do suggest mod #2 how much bigger should the bolt hole be drilled, a 1/4 past the oil port.

I would just do #1 and buy new lifters.

300dollarGSX · 09-10-2009, 12:44 PM

He's using a ream and opening the size to .500 (1/2"). I would suggest doing both mods if it's already at a machine shop.

a91talonAWD · 09-11-2009, 06:04 AM

Quote:

Originally Posted by 300dollarGSX

He's using a ream and opening the size to .500 (1/2"). I would suggest doing both mods if it's already at a machine shop.

even If I am using the 6 bolt head with the 6 bolt block?

dsm-onster · 09-11-2009, 06:35 AM

What about the actual hole in there that feads the head from the head bolt hole cavity:

Is there a way to get in there and just open that up a little? or would htat be a waste because the rest of the "piping" after that hole is about the same diameter?

TSIfreek · 09-11-2009, 12:17 PM

Quote:

Originally Posted by dsm-onster

What about the actual hole in there that feads the head from the head bolt hole cavity:

Is there a way to get in there and just open that up a little? or would htat be a waste because the rest of the "piping" after that hole is about the same diameter?

Matt that hole goes from one end of the head to the other. Its getting oil to that hole that dale is talking about here.

dsm-onster · 09-11-2009, 01:32 PM

AHA! Makes more sense. So the restriction is the terrible angle the oil has to take to get there and the design that in effect turns the link there in to a poor flow banjo bolt like design. . . I'm picturing this better as time goes by. Hold on I'll eventually catch up here

300dollarGSX · 09-14-2009, 07:00 PM

Quote:

Originally Posted by dsm-onster

AHA! Makes more sense. So the restriction is the terrible angle the oil has to take to get there and the design that in effect turns the link there in to a poor flow banjo bolt like design. . . I'm picturing this better as time goes by. Hold on I'll eventually catch up here

That's pretty much it, along with the restriction created by the small clearances. Mainly, the ARP studs are somewhat larger in diameter than the stock head bolts. They reduce the clearance to .005 (.0025 from the stud to head) or less and further restricts the oil flow to the head. So this mod, along with the other oil port mod linked in the first post, should increase oil flow significantly. Doing both mods should be particularly beneficial to someone who is running ARP head studs and has had the head surfaced.

Quote:

Originally Posted by a91talonAWD

even If I am using the 6 bolt head with the 6 bolt block?

Yes. I think that is a 6 bolt head that he is machining in the first post. Are you using ARP studs as well?

a91talonAWD · 09-16-2009, 09:24 AM

Quote:

Originally Posted by 300dollarGSX

Yes. I think that is a 6 bolt head that he is machining in the first post. Are you using ARP studs as well?

no studs, just new bolts. the reason I asked was I thought he was saying to do this mod #2 if you are using the 7 bolt block with a 6 bolt head cause the 7 bolt bolck has bigger diameter head bolts.

300dollarGSX · 09-16-2009, 11:44 AM

I see. You probably wouldn't need to ream the bolt hole, then. The 6 bolt holes are already larger and the stock bolts have a smaller outside diameter. You probably have the clearances this mod was meant to create with head studs. You could measure your bolt hole size and bolt diamter, then subtract to determine clearance. Please post your findings if you do so.

Edit: Check to see if your bolt hole has the small ridge or step just before the feeding hole (like the pic I posted). Removing that ridge should improve oil flow even with using stock head bolts. Honestly, it's all up to what you want to do or try.

a91talonAWD · 09-29-2009, 07:40 PM

Quote:

Originally Posted by 300dollarGSX

I see. You probably wouldn't need to ream the bolt hole, then. The 6 bolt holes are already larger and the stock bolts have a smaller outside diameter. You probably have the clearances this mod was meant to create with head studs. You could measure your bolt hole size and bolt diamter, then subtract to determine clearance. Please post your findings if you do so.

Edit: Check to see if your bolt hole has the small ridge or step just before the feeding hole (like the pic I posted). Removing that ridge should improve oil flow even with using stock head bolts. Honestly, it's all up to what you want to do or try.

just got the head back from the machine shop... they did not do either mod as I suggested to them(they said it was all "in spec"...) so I will be doing MOD #1... I will post if this eliminates lifter knock while still using stock lifters (not 3g lifters)

before mod#1