Oil in injector housing?
 

Just pulled my injector housings, when I lifted them off the head there was what seemed like a lot of oil that came from the area where the pvc breather tubes come from. When I lifted them off enough oil drained out that there was oil over most of the rear half of the head - i/h mating surface. Is this normal? If not, what do I need to do to correct it.

Re: Oil in injector housing?
 

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/x...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.

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Does the head side of the injector housing look like this? A
http://i190.photobucket.com/albums/z...10159505-6.jpg

or this? B

http://i190.photobucket.com/albums/z...9112507650.jpg

and, does the cylinder head look like this?C

http://i190.photobucket.com/albums/z...erHead1990.jpg

or this? D

http://i190.photobucket.com/albums/z...erHead9195.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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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?

Re: Oil in injector housing?
 

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?

Re: Oil in injector housing?
 

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?

Re: Oil in injector housing?
 

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..

Re: Oil in injector housing?
 

No input on this?

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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?

Re: Oil in injector housing?
 

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.

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.

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.

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

:wave:

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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.

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

Re: Oil in injector housing?
 

Yeah I put them on not knowing about having to have the baffles


Yes by plug I mean restrictor/ Baffle although 2 are baffles 1 is a Plug correct?

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

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.;)

Re: Oil in injector housing?
 

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.

Re: Oil in injector housing?
 

: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

Re: Oil in injector housing?
 

how much space is there?

maybe a slight bigger one will work

Re: Oil in injector housing?
 

: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: