ANDYZ28

I have installed my hand built 383 roller ('96 truck block) in my old '82 Z28. In the process I want to use the '84-'86 style dual snorkel air cleaner system which includes EFE (Early Fuel Evaporation) function of "heat stoves" from both exhaust manifolds. This allows warm air to enter the air cleaner and is very helpful in daily driver status. This is also VERY good way to reduce or eliminate carb icing which is something I know all too well.

The problem is; I have so-far been unable to locate the passenger side exhaust manifold. I have posted this in the parts wanted forum, without success.

Attached is a photo of the manifold I am seeking. I hope someone can identify it, even though it is on an '87 engine.

Thanks, Andy

RamIt

You better make sure that manifold will bolt up to your vortec heads.
My vortec heads dont have the rearward most bolt hole in the head and needed headers to work.

ANDYZ28

Thanks, I never even thought of that. I will check it out today.

naf

iTrader: (7)

Without the rear bolt, no problems with exhaust seal here.

naf

iTrader: (7)

And TPI manifolds can be used. They used a spacer that can be replaced with the EFE. Just make sure the pass side has the longer down pipe.

gt4373

The L69 Right(Passenger Side)Manifold Does Not Have A Heat Stove.

JamesC

iTrader: (5)

Nope x2.

JamesC

RamIt

The Monte Carlo SS L69 had that heat shield on the passenger side.

ANDYZ28

WHAT!

ANDYZ28

I looked at the heads earlier today and indeed "no 7th bolt hole". Now what;

Run with 5 bolts, which apparently works just fine. One of my 1990 IROC-Z 5.7 cars the rearmost bolt was broken anyway, and had been for a long time without issue.

Headers......don't have the money. I have a set of Edelbrock headers, but I do not have the Y pipe (DAMNIT).

I may need to run with the 5 bolt setup due to $$$$ issues.

SERIOUSLY..........the Monte Carlo SS is the one that uses the EFE on the passenger side manifold? I had no idea! It would appear that the engine in the picture might be from a Monte Carlo. I am told that it is an '87 engine with center bolt heads. Carb engines were available for the Monte Carlo in '87?

I am now looking for the right side manifold for an '87 Monte Carlo?

Thanks for all the help guys, Andy

RamIt

Lol. Yep but don't think they had the dual snorkel air cleaner though. Just one on the passenger side with the L69.
My big block ran with a missing exhaust end bolt for many years. I didn't use gaskets and no leaks.

ANDYZ28

My search and research for one f these manifolds continues.

Thanks, Andy

naf

iTrader: (7)

Someone is confusing heat stove with EFE. Totally different systems.

EFE is the valve installed between the manifold and the y on the pass side. Forces exhaust gas through the crossover passages in the intake to help warm things up. L69 had the EFE .

JamesC

iTrader: (5)

And a heat stove on the driver's side.

naf

iTrader: (7)

and vacuum operated flaps in both snorkles

Ozz1967

iTrader: (4)

But only Camaro's had the dual snorkel. Firebird's got the cowl induction and one snorkel.

JamesC

iTrader: (5)

Yep x2.

ANDYZ28

Their must be some sort of spacer which takes the place of the heat riser on TPI engines. Is it still available?

Thanks, Andy

Ozz1967

iTrader: (4)

there is no "heat riser" on TPI engines that I'm aware of. The "heat riser" was to let warm exhaust air up into the intake of the carbed cars to help with warming up.

JamesC

iTrader: (5)

The spacer takes the place of the EFE valve on a TPI motor.

JamesC

ANDYZ28

Will I need to use the spacer in place of the heat riser?

naf

iTrader: (7)

Either the spacer or the EFE valve needs to be installed between the pass manifold and y pipe. The spacer is a little harder to come by but an EFE valve will fit. Spacer is preferred, of course. Try John in RI for the pieces.

Heat stove is something completely different. It connects to the factory air cleaner snorkel with a short 'foil' tube. Replacement tube for it can be picked up most anywhere.

JamesC

iTrader: (5)

Or the classifieds. Anyone with a TPI who has swapped to headers should have one sitting around.

JamesC

John in RI

iTrader: (167)

+1


I know the exhaust spacer changed a few times over the years. The LG4 version has a flap inside it. The valve is spring loaded & defaults to "open" and gets vacuum 'closed' by a valve & a controlling sensor placed in the cooling passages of the intake. Here is a picture of the LG4 version with EFE valve still installed:



The TBI style is the same dimensions as the Carb version but has no internal flap,.... Here is a picture:



The TPI version has a larger hole to accommodate the larger exit ports on the TPI manifolds. This is the TPI version:




When comparing a TBI spacer to a TPI spacer you can plainly see that the TPI version has a wider opening at the "top" (or flared) end.


Interestingly; if the opposite ends are compared the "bottom" (or flat) ends are the same size:


This leads me to believe that a TBI spacer could be machined to the larger opening for TPI applications ?!?!

In any case; I don't have a stock L69 spacer to comment on. I'm sure that I've always used the TPI spacer when re-installing the L69 manifolds I've used. I would assume that if the HO cars had the Thermo Vacuum Switch on the Intake - then there is probably an EFE spacer too. I'd also have to believe the opening is as large as the TPI version,... I say that because I know the HO manifold and the TPI manifold exit ports are the same size.

Hope this helps ?!?

ANDYZ28

Is it possible to locate one of the TPI style spacers? I imagine new ones are no longer available?

I have a set of GM parts books from 1991 but I cannot seem to make sense of the listings for this spacer to locate the part number and begin yet another long search.


Thanks, Andy

DynoDave43

iTrader: (11)

Great pictures and comparison. Thanks John in RI.

John in RI

iTrader: (167)

Thanx Dave !! I was just lucky enough to have a couple of them handy !

( Oh Ya,.... Congrats on COTM !!!!! )

Andy, I had another member ask me for 1 of these things about a week ago and never herd back from him. As a result; the TPI spacer I've got is still available under these terms.....


If you can't find one local and still need it - just send me a PM.

ANDYZ28

John, the only answer I have is; I am in the midst of installing a 383 in my old '82 Z28. I will be using stock manifolds, and the missing/needed spacer is just one of the many "snags" I have encountered. If you send it to me, I will try and have one reproduced on a CNC machine to have a clean copy. Which one I will need>you probably know better than I do.

I could return it to you when done?

I would appreciate your advice on this.

Thanks, Andy

John in RI

iTrader: (167)

I'm sure we can work something out,... Send me a PM when you can.

DynoDave43

iTrader: (11)

Thank you sir!

Once patterned, could more copies be made on that there CNC machine?

ANDYZ28

"Once patterned" is the issue. I do have plans to reproduce it though.

DynoDave43

iTrader: (11)

Good to know.

anthony64ss

iTrader: (1)

I am not sure what heads you're using but I saw vortecs mentioned.

The vortec head has no provision for the efe system as there is no exhaust crossover. You can bolt everything up but it will not be a functioning system. I swapped out my l69 for l31 and replaced efe with the solid spacer shown above. No problems with exhaust leaks missing that last bolt on the passenger side manifold either.

One thing I did have to do was remove heat shielding on the drivers manifold. The exhaust ports are raised on the vortec heads and it interfered with the valve cover rail.

ANDYZ28

I received the part in the mail yesterday. It appears to me the easiest way to go about this is to make it on a lathe eliminating the bulky and unused portions of it. Including the two bolt holes. After all, it is the inside we are concerned with anyway.

What do you guys think??????????????

DynoDave43

iTrader: (11)

Large inner diameter is certainly key where the TPI manifolds are concerned.

I would guess that those half-moon shaped bolt holes are more of an assembly aid than anything. Very handy at "line speed" at the factory, but perhaps not as vital in the service world.

Still, access to this area in-car is not great. So anything that might help hold this 3-piece monster together while you get the bolts started might prove handy.

How's that for taking both sides of an issue? I guess they probably are not a deal breaker either way.

John in RI

iTrader: (167)

+1


I find that those 'alignment tabs' are a big help in keeping that spacer lined-up when setting the Y-Pipe in place. I'd replicate them if possible.

John in RI

iTrader: (167)

Bump ?

sofakingdom

iTrader: (1)

You can take a LG4 one and turn it into a L69 one by opening up the inner diameter. I use a die grinder with about a 1" sanding drum for such things. The Y-pipe will still fit to the flange.

You can take one of the common easily obtained carb ones and turn it into the much more difficult-to-source valveless EFI one, by removing the shaft and vacuum motor, and tapping the shaft holes for 1/8" pipe plugs.

John in RI

iTrader: (167)

I'd really like to get my spacer back.


I'm sure it was made very clear that when you sent $6 to me that it would be used to cover the cost of SHIPPING this spacer to you for use as a mock-up and that the spacer was to be returned as soon as you were finished making one for yourself. I was trying to do you a favor - please return my Spacer AS SOON AS POSSIBLE.

ANDYZ28

No problem

John in RI

iTrader: (167)

Bump

ANDYZ28

On the way back to you, along with a new replacement, and another $6.00.

John in RI

iTrader: (167)

Got the package yesterday Andy,......... Glad to have it back and glad I was able to help out a little too.

P.S. Nice work ----> the newly milled replacement seems like it will fit good and it sure looks great !