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[MASSIVE UPDATE] Mexican Engine Heads

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Rambler Mexicano View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rambler Mexicano Quote  Post ReplyReply Direct Link To This Post Posted: May/15/2019 at 3:40pm
Head to Head, Side by Side.

VAM 282 Heads, 1982-1983 unit versus 1984-1986 unit.

Spark Plugs' Side - 9 Pictures in This One

1982-1983 282 Head on Top

1984-1986 282 Head on the Bottom



From Left to right, cylinders 6 to 1 on Top Head and from 1 to 6 on Bottom Head.

Both have the same height, the same spark plug size and the inclination of the spark plug is also the same. Portions for the AC/Alternator and ignition coil are the same. The main difference between both heads is evident, mainly reduced to the flat top for the plastic valve cover in the 1984-1986 unit.



From left to right, Cylinders 6-5-4-3 on top and 1-2-3-4 on the Bottom.



From left to right, Cylinders 4-3-2-1 on top and 3-4-5-6 on the Bottom.



Closer look, all spark plugs in place. From left to right, cylinders 6-5-4 on top and 1-2-3 on the bottom.



Closer look, no spark plugs, more visible outlets. From left to right cylinders 3-2-1 on top and 4-5-6 on the bottom.



Closer look, from left to right cylinders 6-5 on top and 1-2 on the bottom, sparks pugs on top.



Closer look, from left to right cylinders 4-3 on top and 3-4 on the bottom, sparks pugs on top.



Closer look, from left to right cylinders 2-1 on top and 5-6 on the bottom, sparks pugs on top.



Closest look, cylinders 6 on top and 1 on the bottom.

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Both Engine Heads now both shown straight instead of one upside down. Once again, the 1982-1983 unit on top and the 1984-1986 unit on the bottom.



Notice the hollows for the Alternator/AC and the distributor coil, the gap for the distributor seems to be slightly larger in the 1984-1986 head. There is some thicker metal portions near cylinders 2 and 5 on the bottom head not present on the top one. Also one of these portions in missing on the cylinder 6 corner of the bottom head.



Cylinders 6 to 4 from left to right, spark plugs in place.



Cylinders 4 to 1 from left to right, visible spark plug outlets.



Cylinders 6 and 5 from left to right. Closer look.



Cylinders 4 and 3 from left to right. Closer look.



Cylinders 2 and 1 from left to right. Closer look.



Cylinders 6, closest look.

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Vertical View of Both Heads

1984-1986 unit to the left and 1982-1983 to the right. Virtually exact spark plug inclination on both heads



From to to bottom, Cylinders 1 to 4 on the left head and 3 to 6 on the right head.



From to to bottom, Cylinders 1 to 3 on the left head and 4 to 6 on the right head, spark plugs in place.



From to to bottom, Cylinders 1 to 1 on the left head and 5 to 6 on the right head, spark plugs in place.

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Valve Train

1982-1983 head on top and 1984-1986 head on the bottom



Valves and Springs are the same in both heads. The only true difference here is the flat spark plugs' side for the plastic valve cover on the bottom head (metal on the top head).



From left to right, cylinders 6 to 3 on both heads.

It is visible that the hollows for the pushrods in the 1982-1983 head (top) are totally round while those on the 1984-1986 head (bottom) are larger.



From left to right, cylinders 3 to 1 on both heads.

The numbers and internal etchings of the heads are different from one model to the other.



Cylinders 6 and 5 from left to right.

Notice the upside down VAM engraving on the bottom head.



Cylinder 6 valves, springs and rocker arm mounts.



Rear view of both heads.

Notice that both heads have the temperature sensor in the same spot near the farthest bolt hollow.



This picture showcases a MAJOR difference between both heads.

The internal bolt hollows fixing the head to the engine block are placed LOWER in the 1984-1986 head  than in the 1982-1983 one. Thus, the seven bolts on this side are SHORTER than the other seven external ones. The 1982-1983 head has all 14 bolts of the same length.

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Combustion Chamber Sides

1982-1983 head on top and 1984-1986 head on the bottom.



In both heads, the combustion chamber size is the same. Both valve diameters are lso shared between them.

Thers is one major difference though. The 1984-1986 head (bottom) has ten round cooling ducts instead of just five like in the 1982-1983 head.

Also, the spark plug seats have an additional metal portion linking them to the distributor's edge. The hollows under the spark plug next to the combustion chamber are also smaller.



From left to right cylinders 1 to 4.



From left to right cylinders 3 to 6.



From left to right cylinders 1 to 2.



From left to right cylinders 3 to 4.



From left to right cylinders 5 to 6.

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Ports' Side

NOTICE:

Unlike al previous pictures, in this section the head on top is actually the 1984-1986 one. The on in the bottom is the 1982-1983 one.



The intake ports on both heads are exactly the same.

However, the exhaut ports are another story.

The exhaust ports on the 1984-1986 head have the same width as on the 1982-1983 one, BUT they are TALLER, and thus larger. The 1984-1986 does have a nigher exhaust capacity.



Exhaust port 1 and Intake ports 1 and 2.



Intake ports 2 and 3 plus exhaust port 2.



Intake ports 4 and 5 plus exhaust port 5.



Intake ports 5 and 6 plus exhuast port 6.



Exhaust ports 3 and 4.



1982-1983 Intake ports for cylinders 1 and 2.



1984-1986 Intake ports for cylinders 1 and 2.
Mauricio Jordán

Cuando no se es una empresa famosa se deben hacer mejores automóviles.
- Vehículos Automotores Mexicanos S. A. de C. V.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: May/15/2019 at 3:57pm
Thank you for all of the work in writing this up Mauricio!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/16/2019 at 6:05am
Those "cooling ports" you mention are likely ports to wash out casting sand. I don't think there are matching opening on the block so water can circulate through them. Basically just the lowest part of the head water jacket, sealed by the head gasket. If there are matching openings in the block they are indeed for cooling...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rambler Mexicano Quote  Post ReplyReply Direct Link To This Post Posted: May/16/2019 at 8:48pm
Originally posted by farna farna wrote:

Those "cooling ports" you mention are likely ports to wash out casting sand. I don't think there are matching opening on the block so water can circulate through them. Basically just the lowest part of the head water jacket, sealed by the head gasket. If there are matching openings in the block they are indeed for cooling...


You're right Frank, those ports are nonexistent in the engine block. Thanks for pointing this out.
Mauricio Jordán

Cuando no se es una empresa famosa se deben hacer mejores automóviles.
- Vehículos Automotores Mexicanos S. A. de C. V.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thikstik Quote  Post ReplyReply Direct Link To This Post Posted: May/23/2019 at 12:10pm
Originally posted by farna farna wrote:

Well, the 4.0L head is better than the VAM head. So there really is no reason to spend the money to ship one across the border, except for curiosity. The intake, however, may be worth it. While there are adapters for the 2300 to the AMC 2Vintake an intake made for the 2300 should be better.

The 4.0L block has about the same bore as the 282. You should be able to use the 282 head on it without notching. Again, with the excellent 4.0L head there really is no point in swapping. The only gain by using a 282 block is that you can drive a mechanical fuel pump, but you get a lot of weight in return.

I'm not putting down the VAM effort at all. At the time it was bigger and a bit better in some respects than the US sixes. The 4.0L just took those developments one step further.

Great info on the VAM sixes, do keep it coming!!

Agreed.  Flow technology has come along way and bigger ports, valves arent always the best.  At full out maybe so but not under the curve where they can hurt low end by limiting air charge velocity.
Great info.  Would love to just switch intake.

75 gremlin x, jeep 4L headed 258,Clifford cam, intake,header. 390 holley. I want a 282 VAM motor!

AC/PS/PDB.

72 AMX , 304 2bbl, 3speed, now disks...probably will sell, want an automatic /AC.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote mitchito Quote  Post ReplyReply Direct Link To This Post Posted: Jun/01/2019 at 7:48am
On my last trip to Mexico I brought back a few intakes and 2100 carbs which I had rebuilt. I will have one or 2 for sale as I decided to keep the single barrel on my Gremlin and I had one extra before that. I will bring them to the AMO meet in St. Louis. I did have one polished and it came out really great. 

As for the 4.0 being better, yes, but a pain to mount the power steering pump. No such issue with the 4.6 head
1982 Rambler Lerma
1981 Rambler Lerma coupe
1978 American (Concord base)
1977 Gremlin
1976 Pacer X
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