I acquired this barn find slant six engine of unknown origin.
Upon disassembly; I discovered it was in pretty good condition including bearings and cylinder walls so; I just performed a basic restoration by thorough cleaning and replacing the piston rings, valve springs, seals and gaskets including replacing the cracked and broken umbrella valve seals which is probably the reason the engine was taken out of service. Cracked and broken valve seals = Smoking engine.

When replacing seals and gaskets; I determined this engine might be a limited production version from around 1985 with less common "T" side seals at rear main seal.

When trying to identify the engine by looking at lists and charts; I never did find this particular engine ID: 6 225 2 9 5 X (see attached)

Can somebody please inform me what year this engine is and any other details that might be relevant to this particular engine?

There is also a "Mystery Port" at the rear of the head on the left side behind #6 exhaust port. (see attached)

It looks like a 1/2" diameter, "dead end" port which is about 4 inches deep and has bolt hole above it and my gasket kit does include a gasket for it but; I have no idea what this port is used for.

Maybe a big temperature sensor?

Any ideas?

Please respond.
Kindest regards; Scorch.

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Scorch G.D.

The mystery port is for the air injector system. Either tap it and put a pipe plug it it, or use the gasket for it as a pattern and make a cover plate.

Is it a hydraulic lifter valvetrain? That would put it at 81 or newer.

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Official Cookie and Mater Tormentor.

I thought it might be part of an air injection system BUT the port is a "dead end". Is about 4.5 inches deep and no air flow through it. No reason to cap it off.

It has solid lifters and adjustable rockers.

The first gasket kit I bought was missing these little "Side Seals" for the rear main seal cap assembly and the gasket kit manufacturer informed me they only had these side seals in the slant 6 from 1982 to 1983. (see attached) And there was a "B" version of the gasket kit for 1982-1983 engines.

Any luck with that ID number?

Please respond.
Kindest regards; Scorch.

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Scorch G.D.

I have no idea who you talked to about that rear main seal, but they have no idea what they are talking about. Every slant six from day one till the last one built (except maybe the aluminum engine) used those "L" shaped seals. The picture you show has the rear main seal for the slant six and the big block, the slant six "L" side seals, and the big block side seals. Most seal sets sold in today's market are sold as a single part number for both the slant six and the big block. I have even seen big block seal sets that do not have those side seals. You fill the side cavity with silicone sealer, and then insert two things that look like pipe cleaners.

EDIT: did you replace any bearings? What bearings did you use? The bearings changed between 1960-1976 and 1977-end.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

What year do you think this engine might be based on the ID stamp?

The gasket kit manufacturer is "EngineTech" which offers two versions. CR225-A and CR225-B
It was their tech support agent who said that when I discovered the A version did not have those seals.

But when I look at their drawings today, both kits show the L seals. "A" kit is earlier version with fewer gaskets and deflector valve seals. "B" Kit is later version with more gaskets and positive valve seals.

No, I did not replace the main or rod bearings because they are still in nearly perfect condition.
Was just a very basic restoration on a budget.

Merely disassembled the engine, cleaned it out, polished surfaces, replaced the rings and springs and reassembled it.

Now in the process of converting a cheapo engine service stand into a slant six test stand.

Kindest regards; Scorch.

Kindest regards.

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Scorch G.D.

The hole at the rear of the head is not a blind hole. There is a small passage that run the length of the head and has small ports above each exhaust valve to inject clean air into the exhaust stream. Pull the exhuast manifold and check for the air injection holes in the roof of the exhaust ports.

I really never got into ID stamps on the engines. I can tell what parts I need just by looking at them.
As for the gasket set I think the main difference is in the valve cover gasket The solid lifter engines use a different valve cover than the hydraulic lifter engines.

As for the port at the rear of the head, Reed is correct. You do need to plug it.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

About the year. I'll take a guess, but I could be totally wrong.
6= cyl
225 = displacement
R= regular fuel
2 9 = feb 9th
5 = `1965, 1975 0r 1985
Not 1965, has 5 freeze plugs, later engine brackets, air conditioning pulleys, two bbl intake, and air injection head. PS mounting boss has only two bolt holes instead of three
Probably not 1985: 1985 would be truck or industrial application. Has car oil pan, and you stated mechanical valve train. Crank damper is for forged crank.
I'm thinking around 1975/76: Forged crank (by damper) and no "E" in the engine ID, solid lifters, style of valve cover, 2 bbl manifold, egr and air injection. The dipstick and tube are longer that the early ones, and shorter that the truck ones. However I question the engine brackets I'm not sure of the years and I can't see the pass side, but I think that style was used from 67 until sometime in the early '70's when they went to the spool type mount.
Like I said this is just a lot of guess work and who knows What was changed over the years.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Scorch
Welcome to the forum!
You do nice work, well constructed run stand.
Some of the members can be short or abrupt, but they are well meaning folks with a slant six love.
You won't find a better place to find answers in this world!

Welcome aboard!

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Hyper_pak

That 2bbl intake is a '78-'80 EB-welded 2-piece item.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yes. And it's not the original intake that was on this engine which was just a regular cast iron, single barrel intake.

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Scorch G.D.

I do not recall seeing any air injection ports when I had the valves out and cleaned the head.

That port is about 4.5 inches deep. It goes almost all the way across to the right side of the head and AWAY from exhaust ports.

I stuck a hose in the port and tried to blow through it with mouth but; no air flow to any exhaust ports.

I stuck a bore scope in the port and found no passages on sides, top, bottom or back of port.
All I see is some corrosion in port and bolt hole giving the appearance it has never been used. (see attached)

Kindest regards; Scorch.

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Scorch G.D.

Well, don't plug it and see if you have an exhaust leak out of it when the motor is running. If not you're golden. If you do you can make the plug and cover it up. No harm, no foul.

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Official Cookie and Mater Tormentor.

Don't think it's 1965 because it has the later head without the spark plug wells and cups.
Don't think it's 1985 because it has solid lifters and adjustable rockers.

Intake manifold is two barrel aluminum intake I installed. Is not the original cast iron single barrel intake.
The harmonic balancer is new aftermarket part which appears to be identical to original.
And yes, did have AC compressor mounted on this barn find engine.
Original engine brackets were the spool mounts for car which I replaced with truck brackets.

Here are a couple more photos to examine.

Kindest regards; Scorch.

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Scorch G.D.

Thank you and no worries. I am quite familiar with the nature of forums and chat rooms.

The test stand is a work in progress and still needs a lot of work.
Battery tray, control panel with gauges, switches and throttle lever, fuel tank, radiator, wiring etc.

Kindest regards; Scorch.

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Scorch G.D.