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I have begun the rebuilding of the 4.2 engine from my 77 CJ-7 barn find project. My local NAPA store in Buckeye, AZ has a reputable engine shop attached and run by an family friend of my wife. Its good to have friends with years of experience to help. I opted for NAPA's deluxe master  rebuild kit which is a good value when you get it all at once.

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I was pleased with how clean the hot tank process got my dirty block and sheet metal. I had given up on scrubbing and even the pressure washer didn't work well. After taking measurements it was decided to go with the .030 re-bore.  My sharp eyed engine man noticed that the oil bypass valve retainer had damage to the shoulder that fits into the block for alignment. I think I understand how this valve works and felt this damage would compromise the integrity of the valve. I am  not sure how the damage occurred other than  forces applied during removal or installation. Luckily there is a good bit of info about the valve in my Jeep CJ re-builders manual by Moses Ludel.

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A trip to my local AMC junk yard did not yield one. I'm not sure if this part is still stocked anywhere. I decided to see what I could do with my MIG welder and I think I succeed but I would still use a new or salvage one if I can find it.

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Next I installed the nice brass plugs that come with the kit and the oil passage plugs. The new cam is standard OEM grind and fit nicely into the new bearings installed by my shop. I'm not sure exactly what holds the cam in place on this 77 vintage engine. Chain? Lifters? Distributor? All three? My engine does not have the spring and Pin thing on the timing cover that Ive heard about on later engines. My jeep project had signs of good regular care by one owner. My crankshaft was still within specs for a polish only and standard bearings. 

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The crankshaft is now installed after verifying still in specs on oil clearance with plasti-gauge.

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Nice work, Stuart...Did you polish the crankshaft?  Looks good...No regrind and balance?  Inline sixes are very tolerant of balance, OEM cranks and flywheels generally do not create an issue.  I usually grind 0.010"/0.010" undersize and balance the reciprocating parts.  Match weighting helps, too.  Not sure if any of this is in your plan...

I'll look through my OEM Mopar parts for the 4.2L projects.  I may have a valve retainer.  The original part number is J3173225.  The number may have been updated later by Mopar.

Moses

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Moses,

No regrind. Just a polish. I cant afford to get too carried away, hopefully I'll be ok. My 77 jeep factory shop manual showed up today, lots of good info in there. I got the timing chain on today. I fumbled around with that quite a bit but got it clocked correctly. I have wondered if Mopar has a stock of the older jeep parts like the valve retainer. Ill have to check.

Stuart

 

 

 

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Stuart...I'll look for a retainer in my boxes of NOS Mopar parts and get back...I am doubtful that Mopar has any interest in this part (J3173225) or AMC era engines.  Unlike us, they focus on new models and late technology...This part is officially discontinued, though I found a package of four (NOS) at eBay by running the part number.  That particular ad is in Spanish.

I will let you know if my boxes of parts include a retainer...

Moses

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Stuart...I messaged a note your way...Found a J3173225 Retainer, brand new in the original Mopar bag...I have two (2)...See my message.  Pleased that you're working with a '77 factory service manual, that's first generation information..Moses

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I'm sending the Retainer your way, Stuart...The 4.2L/258 engine looks good, always easier to install the main seal with the block upside down.  Nice attention to detail!

Moses

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The long hot summer is over and I'm finally able to get some things done and update progress. The new by-bass valve retainer has been installed. Thank You Moses!  Pistons tapped int place with no trouble. I had some trouble with the front timing cover spacing clearing the cam gear retainer bolt. My solution was to glue two timing cover gaskets together which gave me the clearance need to to keep the cam gear retainer bolt from grinding against to timing cover. The replacement harmonic balancer did not want go on without ridiculous amounts of force so I backed it off several times and finally had to remove and lightly polish the mating surfaces. It went on normally after that. I used the 4 piece oil pan gasket and spent a lot of time making sure I had potential leak area well sealed. The oil pan is now on so we will see how that works. At some point I realized that my water pump pulley was missing from this project. I thought this was no problem until I learned how hard they are to find for a two groove early 4.2 engine. Mine is a 77.  I brought one home from our local AMC jeep salvage yard which turned out to be from an 87 YJ. This is a problem since apparently the later 4.2 engines used a pulley and water pump combination with a shallower offset which causes the belt to not align properly on my 77 engine. I briefly considered using a later model water pump that doesn't stick out so far but didn't know what other problems that would introduce. I finally found a salvage one on E-bay from Southwest off road in New Mexico. This part seem to be the right fit from a 76-86 4.2 engine so I am back in business.

Piston install.JPG

oil pan gasket.JPG

water pump pulleys.JPG

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Nice work, Stuart, appreciating the cooler weather here, too.  The electric bill with my Haier portable air conditioner running in my shop leaped up $75 per month during our similarly hot summer.  Worth it, at least I was able to continue using the shop.  Glad you're getting relief and able to pursue the 4.2L engine build.  See my comments below:

22 hours ago, Stuart_Snow said:

The long hot summer is over and I'm finally able to get some things done and update progress. The new by-bass valve retainer has been installed. Thank You Moses!  Pistons tapped int place with no trouble. I had some trouble with the front timing cover spacing clearing the cam gear retainer bolt. My solution was to glue two timing cover gaskets together which gave me the clearance need to to keep the cam gear retainer bolt from grinding against to timing cover.

I'm sure you confirmed that the sprockets and chain align vertically.  Was the timing gear hub thicker?  The cam sprocket washer looks like normal thickness...The cam sprocket appears to ride flush.  Correct?  If everything else is okay, a thicker gasket stack shouldn't create any issues.  1981-up Mopar catalogs show the "pin kit" that consists of the camshaft bolt with a hollow recess for a tensioner spring and a pin that rides against the timing cover.  This arrangement only works for engines that use a timing cover designed for the pin and spring tension...Your earlier '77 4.2L/258 setup should not require the spring-and-pin nor a bolt with the recess for the spring and pin. 

For later 4.2L sixes, this 1981-86 parts illustration shows cluster #13 off to the left.  Zoom-in for detail:

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The replacement harmonic balancer did not want go on without ridiculous amounts of force so I backed it off several times and finally had to remove and lightly polish the mating surfaces. It went on normally after that. I used the 4 piece oil pan gasket and spent a lot of time making sure I had potential leak area well sealed. The oil pan is now on so we will see how that works.

Smart move on polishing the damper hub and crank snout.  4-piece pan gaskets are a real chore to install with the engine in the chassis, it's much easier on an engine stand with the block upside down!  Results are always better on the stand.

At some point I realized that my water pump pulley was missing from this project. I thought this was no problem until I learned how hard they are to find for a two groove early 4.2 engine. Mine is a 77.  I brought one home from our local AMC jeep salvage yard which turned out to be from an 87 YJ. This is a problem since apparently the later 4.2 engines used a pulley and water pump combination with a shallower offset which causes the belt to not align properly on my 77 engine. I briefly considered using a later model water pump that doesn't stick out so far but didn't know what other problems that would introduce. I finally found a salvage one on E-bay from Southwest off road in New Mexico. This part seem to be the right fit from a 76-86 4.2 engine so I am back in business.

Your cylinder block bores and new pistons look great!

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Damper/pulley clears the timing cover, right?  The cover seal benefits from a fresh location on the damper hub...

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Helpful to point out the difference in water pump stickout height, dramatized in your photo/comparison below, Stuart.  Thanks for sharing and helping others avoid this problem.  One of the issues is the later/optional use of serpentine belts that altered the water pump stickout length.  Serpentine belt use began in the late 4.2L CJ era, alternating with V-belt use.  All YJ Wrangler 4.2L engines and 4.0L sixes use a serpentine belt.

water pump pulleys.JPG

 

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On 10/14/2018 at 12:03 PM, Moses Ludel said:

I'm sure you confirmed that the sprockets and chain align vertically.  Was the timing gear hub thicker? 

This is all I can figure. My vertical alignment is good. I'm glad I test fit the cover or I wouldn't have noticed this problem.

On 10/14/2018 at 12:03 PM, Moses Ludel said:

Damper/pulley clears the timing cover, right?

Yes and I remembered to use sealer on the back  where it mates against the oil slinger. My CJ re-builders guide helped me head off trouble here. I used a longer bolt to pull the ballancer on and the extra threads saved me when the forces got too hard. Lucky thing I decided to back off  and figure out what was wrong.

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You're wise to respect force limits, Stuart.  Interference always has a cause.  It's possible to split a damper hub at its keyway from too much force.  Also, it is always wise to isolate the applied force to the damper as you did with the long bolt...I prefer using Grade 5 or 8 rod stock and Grade 5 or 8 nuts and washers to pull the damper onto the hub.  The threaded rod stock, threaded into the crankshaft snout first, will not rotate and apply twisting force to the snout threads.  The washer and nut pull the damper onto the crankshaft snout.  Load is on the rod stock threads. 

Footnote:  Never pound a damper onto the crankshaft snout.  The main bear inserts have a set with side thrusts to control crankshaft end float.  Avoid pounding or forcing against this internal bearing surface.

Moses

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I have made a little more progress in that I have the head  and water pump on the engine. One of the things missing from this project was the head bolts. I was able to find a set of ARP bolts at JEGs that were reasonably priced. The Felpro gasket  was put on dry per its instructions. The old Jeep shop manual says to use "perfect seal" sealer which I believe predates modern gaskets. When in doubt follow the instructions from the manufacturer. 

I followed ARP's instructions for use or their Ultra Torque assembly lube. My shop manual specifies 105 ft lbs. ARP specifies moving up in three equal steps to 100 ft lbs following the shop manual circular tightening sequence. I marked each bolt with a witness mark for the last two steps and didn't see any anomalies in turn radius between bolts. About midway through each pull up to 100 ft lbs I felt a decrease in the amount of force needed to turn the bolts. This caught me off guard and I'm guessing it is the Ultra-torque lube doing its thing to the pre-load. Let me know if this sounds strange.

The old Prestolite distributor is getting  replaced with a DUI HEI unit from Performance Distributors provided by Summit along with a set of their wires. Im looking forward to what this will do for me.

The old BID unit has an electronic module that dates itself with the "Made in Hong Kong" label. I remember seeing that a lot on things as a kid growing up in the 70's but not since the British gave up control I think. 

This beast of an engine is getting pretty heavy on the stand and reminds me of the tractor engines I grew up around in the Midwest. I'm anxious to get it back in the jeep but need to go through the T-18 and spicer 20 first. I recently verified that the T-18 on this 77 jeep has the 6.32:1 first gear which will suit my needs.

The CJ-3B in these pictures gets used as a work table too often due to its fenders and hood. I know its a terrible way to treat a jeep. Its engine is the one from the re-build guide at https://www.cj3b.info/Engine/Rebuild.html but that is another story. I'll have to start a thread for this jeep in the vintage section.

 

 

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ARP head bolts.JPG

DUI Distributor.JPG

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