3AC Guts (VERY Pic intensive!)

Typrus · Post by **Typrus** » Tue Feb 21, 2006 10:16 pm

I put it here because I am pulling the old 3AC engine apart more for fun than anything at this point. I will add as I go, so long as I remember to shoot.

Remember, this Terc died from oil starvation. It never siezed, just stopped running.

A place to begin. By this point, the fueling system and vacuum system is off. Manifolds and all.

I next moved to removal of the valve cover.

Pretty fair shape for being starved I'd say.

I next examined the ports, manifolds, and gasket.

Don't let this happen to your water jacket folks...

Manifolds stacked, but unbolted and unmeshed.

The underside of the intake manifold.... A heat transfer plate for better fuel atomization perhaps?

It went straight through to the top of the exhaust mannie which had this interesting flap.

Open at rest

Closed through effort

Here's the 3 emissions ports that are randomly tossed on the exhaust mannie. The unplugged one up top is EGR, the middle one with tube still on went to the air cleaner housing, and the small hole with 2 bolts attached held the O2 sensor.

I thought it funny that the EGR feeds purely off the #4 cylinder, while the cleaner housing used I believe #1 exclusively... Very restrictive inside I might add. The intake mannie was no better.

Heres some gasket comparison to openings.

Cyl #'s 2/3

The overlay is lightly colored pink.

Here is just #4... pitiful lol.

Thats just a tad of restriction.

I dunno where I put the pics of the gasket on the intake mannie, but they were all about as bad as #4... Talk about your inconsistancy.

Heres the exhaust mannie... Not near as bad, but could be improved.

Heres the exhaust mannie as it sits by itself mounted to the block.

Here is an example of the half-bolt-hole's used where the intake and exhaust mannies mesh.

Now for the goods.

A all-cyl shot of the Cylinders, pistons, and block

An all-chamber shot of the combustion chambers in the head.

Cyl's 1&2 in the block.... Yummy, eh?

Cyl's 3&4... Just nasty.

Combustion chamber of piston #1

#2

#3

#4

The carbon build-up is evident. This was not a healthy running engine, and I only need look at the caked carbon located throughout the exhaust, including a solid cake over the O2 sensor to see that.

sandshadow · Post by **sandshadow** » Tue Feb 21, 2006 11:27 pm

Great pics.

What plans do you have for this engine? Will you be porting the head and manifold?

takza · Post by **takza** » Wed Feb 22, 2006 5:39 am

There's nothing like waking up to some nice dirty grimy engine pictures....better for you than egs & bacon for sure....

observations...

* good pics...clear and detailed

* I don't see much unexpected in the pics...except maybe there IS a little too much carbon...at least it's even or whatever

*your indexing job on 3 and 4 didn't go too well?

* I see real possiblities for porting and that squish area just cries out for a groove or two...that guy on the groove site would help I'm sure

* can you feel much ridge at the top of the bores? any crosshatching left in the bores?

* what makes you think the engine was oil starved?

* the rest of us are envious...you get to have some fun...but just remember...it's easier to take them apart than to put them back together?

Typrus · Post by **Typrus** » Wed Feb 22, 2006 9:29 am

When someone drives for weeks at a time with no oil on the dip.... That'll do er.... That and the obscene howling coming from the lower end.

Never indexed this one. Luck of the draw on #1.

Need to feel for that. The walls seemed smooth, but I didn't put much time into them.

I have no idea where this project is going. At this point I'm just exploring.

brianp · Post by **brianp** » Wed Feb 22, 2006 6:15 pm

thanks for the pictures! it's neat to see the guts of the engine.

takza · Post by **takza** » Wed Feb 22, 2006 7:06 pm

So this is the engine form your parts car?

Wondering if anyone has tried putting a limiter on that weighted valve to keep some exhaust hitting that plate in the intake all the time in order to help fuel vaporization and mpg?

Typrus · Post by **Typrus** » Wed Feb 22, 2006 10:26 pm

Its not a full seal, and if this one says anything, its likely gummed with carbon.

Errrmm.... Kind of. This is the ORIGINAL engine from the 84. Remember? I took the engine out of my 86 and put it in the 84?

To my sheer amazement, even after clocking close to 185,000 miles, the cross-hatched finish is plainly obvious and there is no ridge to be felt at the top of the cylinder wall.... This engine isn't natural

Right now I'm trying to remove the flywheel with it on the stand... Not as easy as it sounds... And it sounds hard! lol.

I am tempted to look into header designs........

T-Bone · Post by **T-Bone** » Wed Feb 22, 2006 10:27 pm

nice pics of the engine. thanks for posting them.

takza wrote:So this is the engine form your parts car?

Wondering if anyone has tried putting a limiter on that weighted valve to keep some exhaust hitting that plate in the intake all the time in order to help fuel vaporization and mpg?

that is a good question? if its done I wonder how will it would work?

zipty842 · Post by **zipty842** » Wed Feb 22, 2006 10:49 pm

Typrus wrote:To my sheer amazement, even after clocking close to 185,000 miles, the cross-hatched finish is plainly obvious and there is no ridge to be felt at the top of the cylinder wall.... This engine isn't natural

You're right, its an A motor.

Both of the 4AGE blocks i have for my mr2 were the same way. Including the one with the hole in the piston. Both motors were around 200,000 miles too.

coltarms · Post by **coltarms** » Thu Feb 23, 2006 12:57 am

I imagine that the intake manifold is cast? Are those restrictive areas where they protrude into the "gasket hole" just ridges that could be "dremeled" out or are they that far undersized all the way down?

Ever give this engine your magic seafoam treatment?

Maybe I'm just stupid. How the hell do I get the PCV valve out of the valve cover?

You could use this engine to test out all the theories that everyone here suggests; a 4ac head, cleaning valve seats with a drill and a piece of vacuum hose and some polishing compound, seafoam, 3asu cam, etc

Gasoline Fumes · Post by **Gasoline Fumes** » Thu Feb 23, 2006 1:58 am

Typrus wrote:Right now I'm trying to remove the flywheel with it on the stand... Not as easy as it sounds... And it sounds hard! lol.

Having trouble keeping the flywheel and crank from turning? You need an impact wrench. If you don't have one, try hitting a normal wrench with a hammer. Sometimes it works.

takza · Post by **takza** » Thu Feb 23, 2006 6:05 am

coltarms wrote: Maybe I'm just stupid. How the hell do I get the PCV valve out of the valve cover?

Took me a while to find out how...it's old hard rubber...you just pry and pull like hey. Don't trash it though.

T-Bone · Post by **T-Bone** » Thu Feb 23, 2006 11:42 am

i just replaced mine a few days ago. it was a pain in the ass to get it out. the rubber turned into hard plastic so i just broke the plastic up and got it out that way. i got a universal rubber seal to replace the one that i broke.

T-Bone · Post by **T-Bone** » Thu Feb 23, 2006 11:42 am

i just replaced mine a few days ago. it was a pain in the ass to get it out. the rubber turned into hard plastic so i just broke the plastic up and got it out that way. i got a universal rubber seal to replace the one that i broke.

Typrus · Post by **Typrus** » Fri Feb 24, 2006 11:01 pm

Did the same thing.. Just make sure to grab any parts that might fall in...

Never SeaFoamed this one. It croaked before we started using the treatment.

I'm more interested in Singh's grooves and so on.......

More my issue is getting it off from under the stand support bolts.