I have an AMC 4.2 I6 out of my old 1983 CJ7, the plan 10 years ago was to rebuild the engine with a larger cam and some other goodies and then reinstall it into the CJ7 but I was young and dumb at the time and it’s hard to build an engine on a $9.25 an hour budget so I covered the engine and then life took its course and until yesterday I hadn’t messed with it at all. I wanted to see if it would even turn over or if it was locked up and likely junk so I went to turn it over and I was surprised to have it turn over, it had a little resistance at first but it turned freely. So I guess now I plan to breath life into this project again, I’m going to start by tearing it down to the short block and seeing what it looks like internally, story 10 years ago was it was the jeep just pulled behind an RV by an old couple, I pulled the head 10 years ago and the cylinder walls looked like it was factory, cross hatching looked very good so my thought was it was either rebuilt or original. So yes this will be my thread as I post pictures on this little adventure.
Rebuilding an AMC 4.2 I6
- Thread starter BigShug681
- Start date
Cool... Pics or it ain't real!
Oh they will come I first have to get it back out of the old frame
If the engine is still standard bore and cylinders look good, it sounds like you got a nice low mileage engine. It may only need some basic work like a camshaft upgrade, valve job, etc.
OT: I pulled out the vacuum cleaner to vacuum up all the memories accumulating around me with the mention of a CJ7;
Uncle taught me to drive stick when i was 14 with his '77 CJ (I6) and looked past the fact that several "incidents" on wooded dirt roads did irreparable body damage. He never fliched.
I inherited it in 1990, but having been a ME vehicle it suffered an early demise even tho the engine ran strong.
Uncle taught me to drive stick when i was 14 with his '77 CJ (I6) and looked past the fact that several "incidents" on wooded dirt roads did irreparable body damage. He never fliched.
I inherited it in 1990, but having been a ME vehicle it suffered an early demise even tho the engine ran strong.
Iirc most of those AMC blocks were higher nickel content, and pretty tough.
I believe it is original bore to be completely honest it had a very large bumper up front that also held the attachment arms for the tow behind setup for an RV internally there was almost zero sludge or deposits that would make me think it actually was ever ran very much
Take to machine shop get the block and head cleaned. New freeze plugs and cam bearings.
This one I plan to keep the brush bumper/rv hook up it has and possibly keep the transmission tho I recall it had a grinding issue going from 1st to second, I want to say it’s a 5 speed so might just look for an old 4 speed. The plan is to keep much of the original but ultimately swap it into a nicer CJ7 being that the tub of mine is pretty well rusted to oblivion
Those engines were blue, weren't they?
Plan to have them clean up the block, inspect the crank and do any work if any that would be necessary, cam bearings and I plan to then install a comp cams 4x4 cam or possibly the torque monster cam kit from Clifford performance and there 6=8 intake to run two Weber 38/38 carbs
Mine oddly enough was yellow but I plan to have it hot bathed and then rattle can it back to that beautiful AMC baby blue
My uncles was a 3 speed. I had to drive it down to Western VA in 15F with the cloth top. Wore an aviators bomber hat and pulled over every 150 miles for gas. 55 was about the limit from an RPM perspective HI range really mean "HIgher than LOW"
Run a dingle berry hone in the bores, new rings, valve job with new seals and springs, decent gasket set and your good to go. Camshaft with more of a stock grind (new quality lifters) will help with a more pleasant vehicle to drive. Then carb rebuild and drain the old fuel out of the tank. Proper break in and your driving.
The CJ7 it came from is more scrap metal then anything I plan to build this one for another CJ7 and put together a make shift engine run stand from a wiring diagram I found online and a cheap engine stand so I can break it in incase anything goes wrong
I like the torqueyness? Of them
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- Jun 13, 2013
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Collins Brothers Jeep is about the only source of AMC blue engine paint…
collinsbrosjeep.com
'73-'81 Motor Coatings Engine Enamel (AMC Engine Blue)
'73-'81 AMC Engine Blue Engine Enamel – CBJeep
collinsbrosjeep.com
This particular engine has oodles of torque , 210 ft lbs at 2000RPM however no HP, 112HP 3000RPM. Parents AMC Eagle and CJ7 were slow and thirsty.
When it was running the jeep could pull a mountain if I hooked it up to it just wasn’t going to be fast
