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Mexican Engine Heads |
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abdywgn
AMC Fan Joined: Aug/30/2007 Location: Illinois Status: Offline Points: 20 |
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This is all very interesting, and in the time frame of reading this, I came across this ad:https://chicago.craigslist.org/nwc/pts/6194912299.html
I went to look at it but it seemed like a standard 258 unless I was missing something. The owner measured the bore and if memory serves me correctly, it was 3.753 and the intake valve size was 1.7?. The ports looked large in the picture but again seem regular size. What is this? Bob |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19611 |
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Mine only lasted 70K miles, but it was bored too loose... too much piston to cylinder wall clearance. That allows the piston to rock a bit. I went the budget route with 258 crank and rods, 4.0L pistons. Cheaper because no custom parts, but the piston goes down further in the bore at the bottom. The bottom of the wrist pin was at the bottom of the bore. Causes a little piston rock when coupled with a too loose bore. IIRC the AMC spec is like 0.003" piston to bore clearance. I built a stroker in early 2000, before we knew as much as now. The guy who bored my block cleaned it up so that only one sleeve was needed (might have been two... 4.0L blocks were harder to come by in junkyards and still rather costly in 2000). The only catch was it had like 0.006" clearance. May have been okay with standard stroke, at least a bit longer, but the extra side load and piston rock wore it faster.
Use 4.0L rods and custom stroker pistons and you're a bit further up the bore, reducing rock. Keep the piston to cylinder wall clearance near stock on top of the longer rods and you will have a 100K+ engine. Might not last 200K like 4.0Ls are commonly found still running good, but will still last a long time. Mine was still running very well at 70K, but had started consuming oil at about a quart every 600 miles or so and had started smoking on hard acceleration/pulling hills. Enough I could just see it in the rear view mirror, but not smoking people out. Would have soldiered on a while longer had I not liked the smoking. |
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Frank Swygert
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19611 |
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abdywgn -- looks like a VAM 258. I wouldn't go by the valve cover date, but looks to be close. I don't recall the size of stock AMC valves, but I think 1.7 is standard intake size. The end exhaust ports are definitely bigger...
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Frank Swygert
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abdywgn
AMC Fan Joined: Aug/30/2007 Location: Illinois Status: Offline Points: 20 |
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there is one block that is a 258, that one has the VAM casting letters. another block is a 232 and I think that was also had the letters. the pictures are deceiving, the ports look huge but it's been awhile since I've had a manifold off to see the port size. I looked at the parts and even though it was properly represented, I was hoping the head had bigger ports or valves. Sadly, I did not get casting numbers. Bob
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mitchito
AMC Apprentice Joined: Oct/02/2016 Location: Brooklyn, NY Status: Offline Points: 210 |
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Mauricio, do you know if the 282 uses the same head gasket and manifold gaskets as the 258? I checked with DC gaskets in Mexico and they have only one listing for 258. In their online catalogue is shows the Rally as being a 258 and only lists the Gremlin, American and Rally so I don't know what to do. I blew the head gasket on my Lerma and the head is in the machine shop.
http://www.dcp.com.mx:8080/DC13/varios/CatalogoElectronico.jsp |
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1982 Rambler Lerma
1981 Rambler Lerma coupe 1978 American (Concord base) 1977 Gremlin 1976 Pacer X |
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Rambler Mexicano
AMC Addicted Joined: Mar/05/2011 Location: Guadalajara Status: Offline Points: 970 |
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DEC. 2017 UPDATE.
Pictures Are Now Visible [12th OCTOBER 2016] Hello again everyone, Although I have been obtaining some new material on VAM's engine heads I haven't posted it here for a reason. Unfortunately, as we all know, these ojetes at Photobucket decided to remove the posibility of linking pictures to remote sites like this one. So far, I haven't located any other site where we can upload pictures that we can remotely link to the board. I am going to have to keep on using my Photobucket account to share the pictures with the board although I am going to have to leave them here only as link that will have to be clicked individually along with their respective description. Updates: I have made some research on the second head design I posted in this topic, the VAM Jeep head design. I was wrong in some things that I will correct here. The plastic valve cover was not used in the VAM Jeep/VAM 282 in 1982, it was until 1984 that it was implemented. However, the plastic valve cover was implemented in the VAM 258 since 1983. The 1982-1983 VAM 282s and VAM Jeep 282s with the updated head design with small 5/8 of an inch spark plugs and rounded out intake ports in their internal portions still had the regular metal valve cover. The remaining novelties on this head are these: I tried my best to take pictures of the early 1982-1986 intake port design, which was VAM's last and best. At least so far, what we know is that the 1982-1986 intake port design was the same, there was no difference between the early 1982-1983 heads with metal valve cover and the 1984-1986 heads with the plastic valve cover. Unfortunately, I have not been able to locate an available early 1982-1983 head (off the engine and with the valves removed) to confirm this as a hard fact. If such a case happens I'll document it and share it here. Here are the pictures: Intakes' Side, two intake ports, dark: Intakes' Side, one intake port, dark: Intakes' Side, one intake port, lighted with camera flash: Intakes' Side, one intake port, lighted from the valve's side: Full Combustion Chamber, lighted externally from the intakes' side: Closeup Combustion Chamber, lighted externally from the intakes' side: Closeup Intake Valve Port, lighted externally from the intakes' side: Closeup Combustion Chamber, lighted with camera flash: Closeup Intake Valve Port, lighted with camera flash: Closeup Intake Valve Port, dark: Closeup Intake Valve Port, dark: Edited by Rambler Mexicano - Dec/23/2017 at 9:04pm |
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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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Rambler Mexicano
AMC Addicted Joined: Mar/05/2011 Location: Guadalajara Status: Offline Points: 970 |
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DEC: 2017 UPDATE
Pictures Are Now Visible. Second Update: I managed to find a 1971-1972 VAM 282 head. A person I met not long ago owns a 1971 VAM Javelin that is undergoing revival as it sat in its spot for several years. This is the first model ever to incorporate the 282 six and 1971 is the ONLY year in which the engine incorporated the starter on the intakes' side of the block. For 1972 the starter would be relocated to the distributor's side of the block and the engine would also be installed from the factory in the Classic (Matador) model as well as the large-size Jeeps (Wagoneer and Pick Up). The engine was taken down and rebuilt, unfortunately I got to know about it AFTER the head was already installed back in the engine. Thus, I was unable to take pictures of the combustion chambers as well as the valves. Fortunately, the intakes were still not put back in place and I was able to take pictures of all 12 ports. Also, while the valve cover was in place it still wasn't screwed. This allowed me to take pictures of the head from the top, showcasing the valve tops and springs. Fortunately, the valve rockers were also still not in place and the head still not being tested, there was no oil covering the internals. The 1971-1972 VAM 282 head was the only VAM 282 head with small valve diameter (1.7 inch intake and 1.4 inches exhaust if I'm not wrong). It was also the only 282 head to have the flute-type shaft to hold all the rockers. For 1973, it would be replaced with the Go Pack head with independent rockers and large valve diameter. However, the intake porting of this head would be the standard design instead of the performance-oriented one of the sports package. The 1971-1972 282 engine head is the same unit used in the 1969-1972 VAM 252 six cylinder engines (standard in the Javelin in 1969 and the Rambler Classic in 1970). Both engines have the same compression ratio and the same bore. Pictures Here: Full Head View, Water Pump's Side: Full Head View, Intakes' Side: Valves for Cylinders 1, 2 and 3: Valve Close Up for Cylinders 1 and 2: Cylinder 1 Valves: Full Intake/Exhaust Ports View: Cylinder 1 Intake and Exhaust Ports plus Cylinder 2 Intake Port: Cylinders 3 and 4 Intake and Exhaust Ports: Central Exhaust Ports, Cylinders 3 and 4: Cylinders 1 and 2 Intake Ports: Edited by Rambler Mexicano - Dec/23/2017 at 9:21pm |
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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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1982AMCConcord
AMC Addicted Joined: Jul/13/2012 Location: Kenosha, WI Status: Offline Points: 1286 |
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Thank you for researching this. The VAM engines are of great interest to me.
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19611 |
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You can upload pics directly to the AMC Forum. Use the full editor and it will allow you to upload. You have to have at least 20 posts before you can upload directly, but that's not an issue for you. Of course you can't link to other sites, if you need/want to do that.
Here are some alternatives: https://www.ghacks.net/2017/07/02/photobucket-alternatives-for-third-party/ Edited by farna - Oct/13/2017 at 10:46am |
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Frank Swygert
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mitchito
AMC Apprentice Joined: Oct/02/2016 Location: Brooklyn, NY Status: Offline Points: 210 |
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Someone asked if the 282 uses a 258 head gasket. I can tell you it absolutely does not. You must use a 4.0 head gasket to match the bigger bore. The 282 Engine uses the older valve cover design at least to '82. so you would buy a gasket or valve cover from a '70s 258. Here is my 282 after head gasket job. Thanks frank and everyone who helped
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1982 Rambler Lerma
1981 Rambler Lerma coupe 1978 American (Concord base) 1977 Gremlin 1976 Pacer X |
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