Oil in injector housing? [Archive] - ZR-1 Net Registry Forums

Paul Workman

12-05-2010, 04:24 PM

The LT5 does use a bit of oil that way. Several have fashioned an oil catch can to collect the oil before routing the vapor back to the plenum. You can see such an arrangement in this photo of =Jeff='s LT5.

http://i185.photobucket.com/albums/x220/6PPC_bucket/Vettes/7-25-09001.jpg

A local speed shop (Winner's Circle) has an assortment of cans in various shapes. I'll be checking that out as part of a winter project.

I'll keep y'all posted.

P.

A26B

12-05-2010, 06:54 PM

The entire crankcase ventilation goes through the injector housings. Over time, two things happen, (1) oil accumulates in the inj housings and (2) the inj housing bolts frequently work loose, allowing oil to seep along the gasket interface.

Install new inj hang gaskets on clean (with brake cleaner) dry surfaces. Clean the bolts and the tapped holes in the heads with brake cleaner to remove oil. Reinstall with Loctite 242 (blue) or comparable med strength product.

Aurora40

12-05-2010, 10:12 PM

Are you saying it was in the intake ports? Or just in the housing? As Jerry mentioned, the pcv system flows through the housing so there will definitely be oil in it.

A26B

12-05-2010, 11:20 PM

QB93Z

12-06-2010, 08:51 AM

Good analysis Jerry. Thanks for posting the pictures. We will need to come up with a compatibility chart because I have heard several conversations about what the interchange of heads, IH's and plenums.

Jim

zr1don

12-06-2010, 02:50 PM

My engine is a 91 and both i/h and heads look like B and D in Jerry's photos. There was no signs the oil entered the intake passageways, it appeared to come out of the i/h pvc areas. I am having problems passing CA's smog test, high NOx and lean burn indicated from the tests. One of the possible causes is malfunctioning pvc system. I'm thinking the pvc system may not be able to cope with the amount of oil coming through the system. Possible solution, catch cans?

A26B

12-06-2010, 03:13 PM

Good on the B & D match. Just making sure.

Is this the engine that is in the 90 you put RC injectors in last year?

I don't think the catch can is the solution to your emissions problem, but others may be able to address the emissions/catch can situation from experience.

Have you checked the PCV valve hoses, lower & upper to be sure they are not leaking vacuum?

zr1don

12-06-2010, 03:23 PM

Thanks for the info, Jerry!!!

This is the engine I put new RC injectors in several years ago, 2007 I think. I have checked both the upper and lower pvc hoses (they are new silicone hoses w/stainless clamps sealing the ends and the pvc valves).

Anyone want to share opinions on passing CA smog?

-=Jeff=-

12-08-2010, 03:31 PM

I've been thinking a bit.......

Does the head side of the injector housing look like this? A
http://i190.photobucket.com/albums/z224/A26B/INJHSNGS199010159505-6.jpg

or this? B

http://i190.photobucket.com/albums/z224/A26B/INJHSNGS199112507650.jpg

and, does the cylinder head look like this?C

http://i190.photobucket.com/albums/z224/A26B/CylinderHead1990.jpg

or this? D

http://i190.photobucket.com/albums/z224/A26B/CylinderHead9195.jpg

A Injector housings can be used with C or D heads,
but
B injector housings can only be used with D heads.

With parts being swapped around, it wouldn't be out of the question for later style injector housings with open crankcase ports (no "washer" type baffles) to end up on 1990 cylinder heads with the large crankcase vent holes. its OK to have small baffle holes in the heads AND in the injector housings, but for both to be unrestricted would put a lot of oil into the injector housings and subsequently the PCV system.

So B and C means you get a large amount of oil in the PCV system? In theory or was it tested on a Motor while it was being developed?

how much oil would you say that would be over engine running time (or miles).

What was the reason for the small holes to switch from the IH to the Head?

Would I also have to assume that the excessive oil would be seen out the exhaust as well?

Just curious and trying to understand it..

-=Jeff=-

01-01-2011, 02:37 PM

So B and C means you get a large amount of oil in the PCV system? In theory or was it tested on a Motor while it was being developed?

how much oil would you say that would be over engine running time (or miles).

What was the reason for the small holes to switch from the IH to the Head?

Would I also have to assume that the excessive oil would be seen out the exhaust as well?

Just curious and trying to understand it..

No input on this?

LGAFF

01-01-2011, 04:05 PM

Jeff, oddly enough on my 90 I did not put the baffle plugs in and it was smoking a lot....was not doing that prior to the change...although my compression readings were low.

-=Jeff=-

01-01-2011, 05:05 PM

Jeff, oddly enough on my 90 I did not put the baffle plugs in and it was smoking a lot....was not doing that prior to the change...although my compression readings were low.

okay, mine has no plugs either and as far as I know it does not smoke that bad.. been this way since 2008..

if it is an issues I need to get the older IH back on it

LGAFF

01-01-2011, 05:15 PM

What if you stuffed the Oil vapor galleys with Brillo pads(copper) would that reduce the flow enough...older European cars had that in their breathers...Jerry?

A26B

01-01-2011, 05:37 PM

So B and C means you get a large amount of oil in the PCV system? In theory or was it tested on a Motor while it was being developed?
Yes. B&C is a no-no.

I'm sure it wasn't theoretical. There were significant problems with crancase pressure in the LT5 during development. As such, you see some unusual crankcase ventilation parts on the LT5, compared to a typical engine. The big holes in the 90MY heads were enough to precipitate a design change to install restrictor baffles (washers in the 90 model injector housings. Nothing theoretical about it, just too much oil in the intake via the PCV system.

how much oil would you say that would be over engine running time (or miles).
If it causes the engine to smoke, knock, foul plugs or not pass emissions, it's too much. Exactly how much would be subject to gross speculation, depending on how the engine was driven. The higher the rpm, the greater the crankcase pressure & the more oil to the PCV system and ultimately back through the intake & combustion process.

What was the reason for the small holes to switch from the IH to the Head?
1. The cylinder heads were originally cast with no ventilation opening

2. Originally (for 1990 MY), the heads were machined out to 3/4".

3. Testing resulted in too much oil in the PCV system,so restrictor/baffles were added to the 90MY injector housings as a fix.

4. Greg VanDeventer said " hey, why are we opening up a big hole in the cyl head and then making a small hole restrictor/baffle to install in the injector housing? Why not save a few unnecessary steps and some bucks by just opening the heads up with a small hole for ventilation & leave the injector housings alone, with no baffle? So, for 1991 & later, heads have small hole & it was not necessary to make & install baffle washers in the injector housings.

Would I also have to assume that the excessive oil would be seen out the exhaust as well?

Sure, everything that goes into the PCV system ends up going through combustion.

Just curious and trying to understand it.

:wave:

A26B

01-01-2011, 06:05 PM

What if you stuffed the Oil vapor galleys with Brillo pads(copper) would that reduce the flow enough...older European cars had that in their breathers...Jerry?

My profession was oil & gas exploration & production. Fluid flow (includes gas) is a significant part of engineering design of well completion & production facilities. What is involved here is extraction of the liquid from a gas/liquid mixture at variable flow rates & differential pressures. The mist extraction itself can be relatively straight forward, much like what occurs in separating oil, gas & water during well production. The difference here, is that well production separation facilities are engineered with relatively steady-state conditions, whereas the LT5 during it operation will experience variable rate/differential pressure conditions.

The coalescing filter media (brillo pad) is going to hold quite a bit of oil under steady state condition of low rpm cruise, due to the large amount of surface area. At higher rpm, the velocity through the filter media is going to pick up a lot of that oil & carry it through to the PCV system.

The restrictor/baffle design (essentially an orfice), restricts flow rate with increasing back pressure as crankcase vapor volume builds during higher rpm conditions. Adding coalescing filter media (brillo pad) adds surface area & tortuosity for good extraction but would do little to impede flow volume as vapor volume increases.

Caveat: WAG requiring empirical test data to confirm or deny, highly theoretical opinion. :icon_scra

-=Jeff=-

01-01-2011, 06:48 PM

Thanks Jerry.. now I understand I could plug the holes of my late IH too right? are all 3 open currently? your one pic blocks the 3rd. if I have to do that now is the time for me since it is winter and I need to pull the plenum to swap the AC compressor.. what is a few more bolts and a set of gaskets.

A26B

01-01-2011, 07:20 PM

Thanks Jerry.. your one pic blocks the 3rd. if I have to do that now is the time for me since it is winter and I need to pull the plenum to swap the AC compressor.. what is a few more bolts and a set of gaskets.

Unless you know why you have late style inj hsngs on your engine, it would be prudent to check the heads too. If your heads happened to be 91 or later with the small hole, the would be no need.

now I understand I could plug the holes of my late IH too right? are all 3 open currently?

Yes. By "plug" I'm assuming you mean with the restrictor/baffle washer that has the hole in the middle.

-=Jeff=-

01-01-2011, 08:05 PM

Unless you know why you have late style inj hsngs on your engine, it would be prudent to check the heads too. If your heads happened to be 91 or later with the small hole, the would be no need. Yeah I put them on not knowing about having to have the baffles

Yes. By "plug" I'm assuming you mean with the restrictor/baffle washer that has the hole in the middle. Yes by plug I mean restrictor/ Baffle although 2 are baffles 1 is a Plug correct?

tomtom72

01-02-2011, 08:04 AM

Okay, I knew if I waited I would not have to start a thread about using late I/H's on 90 heads.:)

I've tried to find the correct diameter freeze plug that I could insert into the late I/H so I could duplicate the restrictor hole size on the 90 I/H's.....so far no joy in finding a plug that fits the opening.

My question would be would it be something that a machinist, :wave: Carter, could make from brass so we could drive it into the I/H opening? What size would it have to be?

:o I bought a plenum & I/H set from a 91 motor part out that were ported. I figured I could plug & play with that stuff on my 90 so I jumped.....I should have looked deeper as I didn't know about the PCV restrictor.....:redface:

:cheers:
Tom

Jeff, the hole that is completely "pluged" is the coolant passage in the I/H that exits coolant from the block thru the I/H and then into the tubes.

LGAFF

01-02-2011, 08:37 AM

I am going to look at the hardware store today for stainless washers....you know Kurt White has these for $9.99 each, not cheap but not too bad.

tomtom72

01-02-2011, 09:01 AM

I am going to look at the hardware store today for stainless washers....you know Kurt White has these for $9.99 each, not cheap but not too bad.

They are listed, but the inventory shows "0 units in stock" as usual it's my luck. I would have bought them just because I know they would be the right parts instead of trying to cobble up something.

-=Jeff=-

01-02-2011, 09:16 AM

What is the DIA of the late IH holes? is it the same as the 'non-baffled' area of the 90 IH?

tomtom72

01-02-2011, 09:50 AM

Okay, near as I can determine with my simple non-digital caliper/slide ruler....the holes are all the same size on the 90 and 91 I/H's....I only have those parts so I would figure the rest are the same also? I doubt that the holes are different sizes, it don't make sense.:icon_scra

The diameter is somewhere between 1 1/16 " and 1 1/32"....I tried 1 & 1/16" and it is too big.....I can't seem to find a 1 & 1/32" plug from Dorman's selection. They list it, but rockauto don't list it. It's a real pia to search thru the dorman pfd by size.

I almost gave up at one point. I tried to convince myself that using a ported plenum and I/H on an unported head is useless. However I figured if the difference between my stock head port size and the ported I/H wasn't that far off it would not be too much of a stupid move to use the ported stuff? Besides I figured if the ports' size difference was too big, I could always close up the bottom of the I/H port to the head port size. However unless I can fix the PCV restrictor issue first I'm not even bothering to pull my stuff to see how badly the port size & alignment is off. I was thinking of e-mailing Mr. Carter but it seems like I'd be wasting his time on such trivial stuff.

-=Jeff=-

01-02-2011, 10:00 AM

If you contact carter double the amount and I would buy a set

tomtom72

01-02-2011, 10:16 AM

If you contact carter double the amount and I would buy a set

I may work up to it yet....you're in Jeff! I'll double the order & keep you in the loop.:handshak:

-=Jeff=-

01-02-2011, 11:20 AM

do you have a PN for the dorman 1 1/32 freeze plug?

tomtom72

01-02-2011, 11:24 AM

do you have a PN for the dorman 1 1/32 freeze plug?

I'll pull up the pfd and look for it. Give me a minute.

-=Jeff=-

01-02-2011, 11:34 AM

I just did , 550-013 is 1-1/32"

tomtom72

01-02-2011, 11:38 AM

I just did , 55-013 is 1-1/32"

I found two others 555-165 and 555-173 both are steel.

I'm going to look in my shop at what I bought so far I know 1 1/8" is too big, I just can't be 100% that I didn't order any 1 1/32" ones.

Yea, I remembered correctly. I never bought any 1 1/32" plugs to try.

-=Jeff=-

01-02-2011, 11:43 AM

tomtom72

01-02-2011, 11:52 AM

Okay, I'll buy them from rock auto and let you know the results, okay? Unless you don't want to wait one me?

I just ordered them & the rest of my spring parts.

-=Jeff=-

01-02-2011, 01:56 PM

let me know, my car is together, if they don't work I might just port my OEM stuff and get it PC'ed to match what I have.. let me know how it works

tomtom72

01-02-2011, 10:56 PM

Okay, I placed the order this afternoon. I will let you know the results as soon as I get the parts. I hope this works. The only other thing I can think to do is ask Carter if he would be interested in making something. I'd send him my 91 I/H's so there would be no blowing the measurements on my part.

:cheers:
Tom

A26B

01-03-2011, 03:11 PM

:cheers:
Tom

Jeff, the hole that is completely "pluged" is the coolant passage in the I/H that exits coolant from the block thru the I/H and then into the tubes.

Tom,

If I'm understanding you correctly, you are referring to the 3rd crankcase vent hole in the injector housings, the other two being completely open or with "washer baffles for the 90 MY.

If so, although it is directly below the coolant outlet passage on the side, it is NOT a coolant passage and DOES NOT "exits coolant from the block thru the I/H and then into the tubes." It is a crankcase vent, just like the other 2, except that it is plugged off in the 90MY. The coolant from the block goes through a passage located between the front 2 cylinders intake ports on each bank.

In that regard, I'm at a loss to offer a reason for the 90 MY front, 3rd vent port being plugged with a solid washer. Adding to the mystery, when the washers were eliminated for subsequent models, the same vent port is open in the inj hsng and the hole is drilled in the corresponding cyl head area.

I think if it were me, with late model inj housings on a 90, I would put "drilled" washers in all crank case vent ports. If they opened it up completely in all years after the 90, then it seems a logical thing to do.

tomtom72

01-04-2011, 06:39 AM

Jerry, Thank you. My ignorance was showing....again. :thumbsup:

I saved the e-mail to my pc so I will not loose this info. My 90 I/H's are still on the car. I have the 91 I/H's in my shop, but have not looked at them in a while.

I guess my next Q is did they leave the 3rd hole in the head open on a 90 block? Or do I have to do some drilling? I am going to go look in the FSM, again.....I did when I unpacked the 91 stuff two yrs ago, and my heart sank when I discovered that all I/H's are not the same. I just don't seem to remember the FSM being of much help in this department.

Again, I thank you for sharing the light! :handshak:

:cheers:
Tom

Jeff, I got shipping confirmation late yesterday from Rock Auto. Should be by the end of this week or early next week on delivery.;)

A26B

01-04-2011, 11:29 AM

I guess my next Q is did they leave the 3rd hole in the head open on a 90 block? Or do I have to do some drilling?:cheers:
Tom

Yes, all the vent pasages in the cyl head are open in all year model engines, big hole in the 90 models, small hole in the 91~95. No mods to the head required.

tomtom72

01-04-2011, 04:56 PM

:handshak: Thanks Jerry!

And now Jeff....guess what came today? :-D That's the good news!

Now for the bad news, they are too small.:( However, if you apply some judicious compressive force to the product you can make it fit. I suggest the use of a flat bit of steel stock and a ball hammer. You need to flatten out the cup to a flatter shape to expand the diameter. :)

It requires a bit of hammering and if you flatten it too much you use the ball to make the cup come back. Thru trial & error ( mostly error ) I was able to get one to fit reasonably well in about 10 minutes. It will take some more work but I do believe these freeze plugs have a future in my I/H's. :mrgreen:

:cheers:
Tom

-=Jeff=-

01-05-2011, 10:46 AM

how much space is there?

maybe a slight bigger one will work

tomtom72

01-05-2011, 05:52 PM

how much space is there?

maybe a slight bigger one will work

:mrgreen: piece of cake! All mine are in & all have a 1/4" holes in them! Just get the plug and flatten them a bit. I suppose that if we started looking at the ones rated in mm's we could have found a better match?

All I know is mine are in, took me 1/2 an hour after work today.

Hey, Mr. Downey, umm Sir...umm is a 1/4" hole enough or should I go to 5/16"? :icon_scra

TIA!!! :mrgreen:

A26B

01-06-2011, 10:11 AM

Easy on the Mr.!

I wasn't able to get to a set of 90, 1st design injector housings to measure the washer/baffle hole diameter. However, I did measure the hole diameter in the cylinder heads for 91-95 models, at 7/32" drill. If your's are already drilled @ 1/4", i wouldn't re-do them, but i sure would not go any bigger.

If 7/32" is good for the 91~95, it should be good for the baffle washer too.

How about a photo or two of your fix in progress & the end result for "Mr" Dynomite & me?

tomtom72

01-06-2011, 03:24 PM

I was being the little kid who was in trouble asking the adult for another favor!

Any who here goes nothing....yea, I'm going to try to do this with pictures. Just in case I screw it all up here is the link to my photobucket album!!!
http://s215.photobucket.com/albums/cc123/tomZR1/

tools
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config012.jpg

http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config001.jpg

Reshaping the freeze plug.
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config003.jpg

Initial install.
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config006.jpg

I think I'll post this to see if I screwed it up! oh, the drilled holes are 1/4", but I may go a bit bigger?

tomtom72

01-06-2011, 03:28 PM

Darn....I'm amazed that I got it to work!

This is how I started to install the reshaped plug with the flat bar.
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config006.jpg

Then I used my other precision tools to recess the plug a la the OEM install. You can see the one on the right is dunn, middle in progress and the left is what the flat bar does.
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config023.jpg

Then it is supposed to come out looking like this, with a slight recess just like the factory did the real ones!
http://i215.photobucket.com/albums/cc123/tomZR1/91injectorHouCCVconvertto90config026.jpg

QB93Z

01-06-2011, 03:55 PM

Thanks for the pictures Tom

Jim

A26B

01-06-2011, 04:42 PM

One of those baffle plugs in the 90' Injector Housing has no hole.

That is correct

It also appears one of those vents in the 91'-95' Heads is not vented.

It's there, you just can't see it in your photo. All 3 holes are open in the cylinder head.

tomtom72

01-06-2011, 05:22 PM

That Ball peen hammer has sentimental attachment for me.... :mrgreen:

Anyway not that it isn't fairly obvious, the object is to get the freeze plugs flat enough so you get them to be a tight fit in the large CCV holes in the late model I/H's. These are 91 I/H's.

I used the flat bar & my mini-anvil to take some of the dish out of the plug. You play it by ear, if you go too far I used the ball hammer to reform the cup.

Then I positioned the newly shaped plug over the CCV holes and tapped the bar till the plug is flush all around. Next the socket to get that factory recess look. Don't worry if you knock it thru as you can get them back out and try again. The smaller drifts I used to massage the install! :neutral: to achieve that OEM look....well at least one of them came out that way! :sign10:

The reason that I did all three per side with a 1/4" hole drilled thru them was Jerry posted up that the CCV holes in the head had all three drilled holes. I figure it can't hurt. I have a catch can so I'll mind the amount of oil it catches, which is not much now with stock 90 I/H's on stock 90 heads. Maybe we need more discussion on that fine point? I don't have much to contribute to a discussion on that level.

Anyway, that's the long & the short of it.
:cheers:
Tom

LGAFF

01-06-2011, 05:41 PM

Schlitz beer bottles caps work too....just pop a hole in it with the corkscrew on the bottle opener.

PhillipsLT5

01-06-2011, 07:39 PM

Midwest beer, for all non FBI's

-=Jeff=-

01-06-2011, 09:42 PM

Midwest beer, for all non FBI's

Not sure it can be called beer. LOL

LGAFF

01-06-2011, 09:52 PM

Not sure it can be called beer. LOL

My employees got me a 6 pack as a joke.....honestly its pretty damn good..I was surprised....1960s formula...I think I would buy it again.

Wheres the Fallstaff?

tomtom72

01-08-2011, 08:14 AM

Just as a fwiw....I just got a digital slide ruler/caliper thingy...I know why didn't I have one in the first place! :o :p

26.5mm is the size of the holes for the CCV system in the 91 I/H'ings.

I was going to try a Sam Adams cap, but I didn't have any.

-=Jeff=-

01-08-2011, 09:25 AM

and the freeze plug you got (1-1-32) was 26.19mm and the 1-1/16 is basically 27mm (26.987mm)

-=Jeff=-

01-11-2011, 08:34 AM

ordered my freeze plugs, I figured since I had to remove the Plenum anyway for something else, what is a few more bolts

zr1don

01-19-2011, 02:04 PM

Update on my "oil in injector housing" question. When ready to install the intake plenum I noticed small amounts of oil coming out of the intake runners when I had the manifold tilted at other then a level attitude. I did not remove the throttle body from the plenum and I had not looked into the plenum yet. I opened the butterflies, used a flashlight and found the source of the oil. It was pooled in the bottom of the plenum and would not run out unless the plenum was tilted off level. The oil must be coming through the pcv system. I have cleaned the plenum and pcv hoses (the valves are new). I am installing a catch can and will post the results when I get it running again. This could be causing failing the N0X standard on my emissions test.

tomtom72

01-19-2011, 06:37 PM

Is that actually possible? The oil from our own PCV system causes our NOx emissions to be high? I'm not trying to be a wise guy...I admit that I don't know what effects all of our PCV blow by does to our emissions test results.

Which catch can did you get?

:cheers:
Tom

zr1don

01-19-2011, 11:31 PM

-=Jeff=-

03-18-2011, 10:52 PM

Well I finally pulled my IH off tonight for add the baffles, guess what the 550-013 ( 1-1/32") are too big

I measure the holes and they are close to .953" which is 61/64"

31/32 will be too big and 15/16 is too small, but dorman 550-011 will work like the ones you used Tom. guess I need to go find them tomorrow or something close..

I also had an email conversation with Greg Van Deventer, he said, duplicate the 90 exactly, 2 holes per side, both should be 6.6mm DIA ( just over 1/4")

so that is what I will do as soon as I find plugs

tomtom72

03-19-2011, 06:50 AM

I guess I will go rework mine then and pull out the plugs with the extra holes.

Thanks for the info from Mr. Van Deventer!

:cheers:

-=Jeff=-

03-19-2011, 10:18 AM

I guess I will go rework mine then and pull out the plugs with the extra holes.

Thanks for the info from Mr. Van Deventer!

:cheers:

I never asked why only 2 holes.. you might get a small amount of oil, he did say he was not directly involved with the 1990 PCV but was when they redesigned in 1991

tomtom72

03-19-2011, 06:19 PM

I never asked why only 2 holes.. you might get a small amount of oil, he did say he was not directly involved with the 1990 PCV but was when they redesigned in 1991

You know Jeff, maybe we can do an experiment since we both have 90 heads. I'll install mine they way I did them with the three holes and you do yours the right way and we can compare the volume of oil that ends up in our catch cans. Maybe that will tell us something?

:cheers:
Tom

mike100

03-19-2011, 07:12 PM

The pcv system is one the possible causes of high N0x. If it is not working properly or if the system is allowing oil to enter the intake manifold, according to recommended troubleshooting, it can cause high N0x. The catch can I am installing I bought on ebay, if it works and the N0x comes down, I will post results.

did you ever do up a catch-can? I'm about "this close" to buying something and making a double-T hose connection for the PCV's and running though a can (eliminating the hard-pipe). There's a million and one catch-cans on ebay and I was wondering if you did your yet.

-=Jeff=-

03-19-2011, 08:05 PM

You know Jeff, maybe we can do an experiment since we both have 90 heads. I'll install mine they way I did them with the three holes and you do yours the right way and we can compare the volume of oil that ends up in our catch cans. Maybe that will tell us something?

:cheers:
Tom

it might, but the can was not catching everything I don't think.. plenum and IH had more oil then I thought when I pulled it apart..

Searched a bunch of parts stores today, nobody had the 550-011 I needed, so I used the 550-013 and ground them smaller on the grinder.. added the holes and they worked good.. hoping to start the reinstall later tonight.

zr1don

04-29-2011, 03:09 PM

My ebay catch can was not removing all the oil coming through the pcv system as evidenced by oil traces in the hose at the connection to the plenum. I bought a water seperator for air compressors from Loews, modified it slightly and it seems to keep all oil out of the plenum. I passed CA emissions testing w/the oil catch system and using thermo wrap on my headers and CATS.

LGAFF

12-21-2011, 03:06 PM

zr1don

12-26-2011, 10:02 PM

For anyone doing a catch can - if the can does not turn the airflow a couple times, plus use a filtering material, it probably won't get all the oil out. On my can the air comes in the side of the can near the top and exits out the other side across from the inlet. Inside, there is a verticle seperator plate from the top of the can to about 1/3 the way to the bottom. This forces the incoming air to turn 90 deg moving down the can and then another 180 deg to exit at the top. I stuff the same filtering material in our cam covers in the exit side of the can to stop any remaining oil from the airflow. So far the the pcv connection entering the intake has been dry, and I find oil the catch can. Especially after a high rpm blast or two ----or three---- or----.

-=Jeff=-

12-26-2011, 10:07 PM

I don't expect it to get all the oil out, but some helps

Paul Workman

12-27-2011, 07:24 AM

If you have the smaller diameter(alittle over an inch) breather holes, O'Reilly and most other stores stock Dorman 555-018.....it is a hair small, however using a 17mm socket you can expand it to a perfect fit by driving the socket into the plug

Most of you young whipper-snappers were still squirmin around in chitty diapers when all GM SBC freeze plugs were just a flat disc - just slightly dished. The idea was/is the dished plug fits easily in the hole and would bottom against a little lip that was machined into the hole. The convex side of the plug faced out, and when driven in - thus flattening the disk - the edges expand to tightly seal the hole.

As far as this discussion goes, if there is such a lip in the 90 IH holes, then I'm wondering if the convex Dorman (sp?) plugs might not be thus installed w/o trying to flatten them to fit before installing them? :icon_scra I'm just axin'...;)

P.

tomtom72

12-27-2011, 09:07 AM

On the 91 I/H's that I have as spares there is no lip to stop the plug. You just have to eyeball it as you drive the plug to make sure you don't go too far in and have it fall into the cavity.

I am not sure what there is on a 90 I/H as far as a lip inside the hole. I never tried to pull out the plugs that were there from the factory.

:cheers:
Tom

-=Jeff=-

12-27-2011, 09:37 AM

Shrek

12-27-2011, 11:52 AM

I'm currently in the process of removing the secondary vacuum system from my wife's 91. I removed everything yesterday and had a good bit of oil in the IH, PCV lines, and Plenum. I have a catch can from Elite on the way and hope that takes care of the Plenum. I was surprised to see it had IH and Heads as pictured for the 90 MY. My guess is most of the early 91's got 90 parts installed.

http://i190.photobucket.com/albums/z224/A26B/INJHSNGS199010159505-6.jpg

http://i190.photobucket.com/albums/z224/A26B/CylinderHead1990.jpg

Scrrem

01-16-2012, 02:02 PM

Looks like I will be doing this operation....I bought some injector housings from what I was told was a 90 car..OPPS. They are 91 injector housings, now that they have been ported, I guess I need to get some plugs and try my hand at plugging these things up :mad:.
Rich

Paul in VA

01-17-2012, 08:56 AM

Scrrem

01-17-2012, 09:14 AM

Hi Rich:

I know this guy who has a 91 (that finally feels like a CAR instead of an antique statue) that would gladly take your IHs if you really want to stay all 90. In fact that pleneum looks like a 91 also... Just want to make sure you know you won't loose anything if you decide to keep your car all 90.

Hey Paul,
Not worried about keeping it all 90, just bugs me the ebay seller advertised them as 90 parts :mad: when in fact they were 91+. Oh well, live and learn, I know better now. I have some plugs coming, I will plug up the holes and move on.
Rich

Paul in VA

01-17-2012, 09:25 AM

If you change your mind... just say the word and I'll run over!!! What you have, even if it's the wrong year, is pretty AWESOME work!

Scrrem

01-17-2012, 10:41 AM

550-013 is a concave steel plug.. might buy those if I can get them local to see if they will fit, although I need to pull the IH off first..
min of
EDIT: Rock auto has the 550-013 for .20ea but sold in a pack of 10 for $2.00

Man, these little buggers are tough to find locally in my neck of the woods..3 Autozones, 1 Pep Boys and even a local machine shop...no luck. Will try ordering online.
Rich

pantera1683

01-17-2012, 06:33 PM

Man, these little buggers are tough to find locally in my neck of the woods..3 Autozones, 1 Pep Boys and even a local machine shop...no luck. Will try ordering online.
Rich

Rockauto:thumbsup:

Jagdpanzer

01-17-2012, 08:13 PM

Rich,
If you don't have any luck I can turn you out a set on the lathe out of aluminum.

LGAFF

01-17-2012, 08:17 PM

I also had luck using 555-091...Western auto has them as a 1" plug

I think there are 2 different hole sizes in the IHs, I had one set that needed over 1" and one that did not

Scrrem

01-17-2012, 09:30 PM

Rich,
If you don't have any luck I can turn you out a set on the lathe out of aluminum.

Thanks Phil, I was able to order some from Summit, they are back ordered. I will look at some shops when I am in AZ.
Rich

efnfast

09-11-2013, 03:25 PM

Dynomite

09-11-2013, 06:01 PM

Soooooo, I've got 91 IH coming for my 90. That means I need to do something. Are we still using freeze plugs, or have we come up with something better? Thanks Locobob for the heads up on this. This would have been a big stumbleing block trying to do this over a weekend.

Yep....this thread is a bit old but the technology stays the same :D

Adapting 91 IH to 90 Heads.

Three Dorman 550-013 plugs (two plugs drilled 7/32) were used to restrict IH PVC ports of the 91 IH (90 Heads do not have the required restriction).
http://i287.photobucket.com/albums/ll142/dynomite007/A%20Engine%20LT5/91IHPVCM_zpsc6d06f62.jpg

efnfast

09-12-2013, 08:01 AM

Thanks Cliff, I've got some 550-013 and 550-012 on the way. This would have brought my weekend project to a grinding halt. I ASSUME I cannot pop the old ones out of the original IH?

tomtom72

09-12-2013, 08:17 AM

I never gave that a thought....hummmm? I am thinking they do come out? I can't remember, but we did have a thread that discussed exactly how much trouble it was on the assembly line to do the 90 oil vapor holes. I just don't remember all the particulars.

Sorry I'm so forgetful Steve!

:cheers:
Tom

A26B

09-12-2013, 08:51 AM

Thanks Cliff, I've got some 550-013 and 550-012 on the way. This would have brought my weekend project to a grinding halt. I ASSUME I cannot pop the old ones out of the original IH?

You could remove the baffles from the 1990 housings, but they would not fit into the 91 housings without machining. The drive plugs fit the cast hole as-is.

efnfast

09-12-2013, 08:55 AM

Thanks guys.
Jerry, I still have to put an order together for you. I think I have a side line on injectors. -Steve

efnfast

11-14-2013, 03:14 PM

Ended up using the Dormann 555-012 plugs. flattened them in a vise to make them slightly larger in diameter. Drilled 7/32" holes in two of them and drove them in place with a 3/8" extension. Looks good, lets hope it works good.

XfireZ51

07-25-2014, 06:30 PM

Someone had asked about the plenum and IH I have for sale. They have a 90 and so the issue of oil port restriction came up. Searched the forum and came up w this thread. For grins, and since different people were using different sized Dorman plugs, I decided to measure the 2 sets of IHs I have.
One is a NOS w a manuf date of Sept.89, the other was on a motor and they were made 1 year later. Here's a picture comparing the two ports.

The dimensions are 1 5/32" 29.32mm
1 1/32" 26.25mm

The larger ports are the earlier NOS IH.

http://i187.photobucket.com/albums/x198/Z51Xfire/Mobile%20Uploads/8497FB69-A9B8-4828-BFA5-AA2F6BAE6623_zpsioyj4md7.jpg (http://s187.photobucket.com/user/Z51Xfire/media/Mobile%20Uploads/8497FB69-A9B8-4828-BFA5-AA2F6BAE6623_zpsioyj4md7.jpg.html)

A26B

07-25-2014, 10:22 PM

The top picture is of the same injector housing used for 90~92. The machine work to increase the port diameter to 1-5/32" is obvious and was done at Mercury in preparation for the baffle to be installed. The baffle was just never installed and it would work just fine on 91~92 models, just as it is, without the baffle installed. Some like this were probably installed on early 91 engines.

The bottom picture is of an "un-machined" port and would have been installed on 91~92, (can't see the injector bores so I am assuming it's the 90~92 style).