Forum Home Forum Home > The Garage > AMC 6 Cylinder Engine Repair and Modifications
  New Posts New Posts RSS Feed - My Own Engine Head (84-86 VAM 282) and Headers
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

My Own Engine Head (84-86 VAM 282) and Headers

 Post Reply Post Reply
Rambler Mexicano View Drop Down
AMC Addicted
AMC Addicted

Joined: Mar/05/2011
Location: Guadalajara
Status: Offline
Points: 639
Post Options Post Options   Thanks (0) Thanks(0)   Quote Rambler Mexicano Quote  Post ReplyReply Direct Link To This Post Topic: My Own Engine Head (84-86 VAM 282) and Headers
    Posted: May/15/2018 at 8:59pm
After several months I finally had the chance to make the move I had planned since last year on my 1981 VAM Rally GT (AMC Spirit GT).

Removing my cars's engine head to have it ported and lowered in height for a higher compression ratio.

To keep my car from bing rendered useless until the present head comes back, I'll put back the original 1981 VAM head that now is being used as my spare.

The current head on my car is 1984-1986 VAM Jeep head used in 282 cubic inch six cylinders. It's main characteristic is that is has 5/8 sized spark plugs, which allows more space for the internal portion of the intake ports, which have been redesigned to be as round as possible, creating higher free flow of mixture. These are considered the most powerful VAM heads ever made.

As far as we have documented, the only difference between this head design and the early 1982-1983 head still used in VAM's car line was the valve cover.  The early 82-83 head still had the regular metal valve cover and undulated spark plugs' side while the 1984-1986 unit changed to the flat spark plugs' side and plastic valve cover (same unit used in AMC 258s since 1981).

The original head of my car was VAM's 1977-early 1982 design with metal valve cover and 13/16 spark plugs, which is going back to car for the time being.

Other than that, both heads are virtually the same.

I promised you guys pictures since last year and finally here they are:

Outside the repair shop.

First time it moves since January.

The Eagle-design grille is the actual original grille for the 1981 VAM Rally models. The only difference lies in materials, since the Mexican-made grille is made from aluminum while the American-made unit is plastic.

Spark plugs' side, cables disconected.

Originally a plastic valve cover was used in this head, now it has the original 1964-1980 (United States) metal valve cover modified to coincide with the flat side of the head. This keeps the original 1981 appearance (for Mexico) of my car/model.

AC Delco / Chevrolet High Energy Ignition (HEI) electronic ignition - 45,000 volt spark - Vacuum Advance-modified for higher acceleration.

Top view of the head and the headers without the intake manifold and carburetor getting in the way, flat side of the head (spark plugs) is clearly visible thanks to the removed valve cover. Rockers and pushrods also removed, allowing view of the top of the valves and springs.

Closer top view of the head and headers.

This one is more positioned towards the headers.

These headers were designed by VAM and produced by DACIA, a local specialized exhaust company based in Mexico City.

A more central top view of the headers.

Only the accelerator cable and steering pump hose get in the way of the view.

Closer-up view of the exhausts for cylinders 1, 2, 3, and 4.

These headers are divided in set of pipes for the first three and another set of pipes for the second three cylinders, forming two separate final outlets.

Side view of the headers.

This one clearly shows the flat sheet of metal (base) in which these come in contact with the engine head, clearly shows the size and shape of the hollows for the intake manifold going through.

Notice the flat rectangular metal extrusions working as guides to put the intake manifold in place, I hadn't noticed them before.

The two final outlets of the headers connecting to the exhausts.

At this point originally a Y-shaped portion would unite both exhausts outlets as one.

I intentionally had that portion removed for better performance in my car. This will help engine temperature to get lower and require less engine effort to push out the gases. Both exhausts are interconnected by an X-shaped portion near the transmission crossmember.

Closer-up of the last picture.

The clutch-pedal control rod getting in the way.

What is this part called in English? The correct term.

Close-up of the valves on cylinder 1.

Close-up of the valves on cylinder 1 and 2.

Valves on cylinder 6.

This one shows to the right the temperature sensor (and its respective cable) next to the head bolt.

Close up of the central exhaust ports on the headers, cylinders 3 and 4.

Haeder exhaust port on cylinder 1.

Connecting guide for the top radiator hose and one of the heater core hoses.

Seems I'm gonna have to replace this one soon. It's starting to look pretty rusted out.

Edited by Rambler Mexicano - May/15/2018 at 9:03pm
Mauricio Jordán

Cuando no se es una empresa famosa se deben hacer mejores automóviles.
- Vehículos Automotores Mexicanos S. A. de C. V.
Back to Top
Gisulf View Drop Down
AMC Apprentice
AMC Apprentice

Joined: Jul/02/2015
Location: Klingerstown PA
Status: Offline
Points: 153
Post Options Post Options   Thanks (0) Thanks(0)   Quote Gisulf Quote  Post ReplyReply Direct Link To This Post Posted: May/16/2018 at 5:30pm
Thank you for these posts, Mauricio. I've enjoyed learning about VAM.
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

This page was generated in 0.063 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
If you have problems logging in or registering, then please contact a Moderator or