I might have bitten off more than i can chew...304 rebuild

[CLE_76CJ7]

I need help... My cousin was going to send his 76 cj7 to the great trail in the sky, until I offered to take it sight-unseen. Now I have a Jeep in bad shape and little money or know how on how to put it back together. It has a stock 304 that is in pieces- the block and heads have been machined and the heads assembled. There is a complete rebuild kit with it. I have a chiltons that can tell me how to assemble the engine components but not the order in which to assemble them. I am mechanically inclined, I just haven't ever attempted an engine rebuild. Can anyone help me with the order of assembly? Anything I need to watch out for? Secret hints or tips that will help me get my poor Jeep back on the trail? anything will help, Thanks

[jeepsr4ever]

Do you have an extra $4-500 dollars to have a shop assemble the engine. Sometimes that a good road due to the amount of things that can go wrong and the warrantee you can get.

[Mudrat]

The first one is always the hardest until you get your confidence built - and your motor.:wink:

Tearing down and putting together an engine may seem daunting, but it's just mechanical. Part A fits with Part B with the correct tolerances - they are all in the book. The tricky part comes when you need to get the mechanical and electrical to play nicely together.

What kind of parts or pieces is your motor in now? What has been done and what do you want to do? That last question depends on how you plan to use it - mud, rocks, racing, putt'n around. And THAT selection will guide HOW to build your motor and the price tag behind it (or in it). I've got about 3 bills in mine and it's a fairly strong 360, Jeff (Blown7) has gobs more $$ invested in his 401, but he's also about 1000 HP :shock: with a blower on it!!!

So, grasshopper, question #1 If your just looking on reassembly of current parts, just 'freshen' up the top and bottom end with new bearings, seals and valve job.

'Rat

[CLE_76CJ7]

well, my cousin blew the motor about 5 yrs ago and then proceded to tear into it. He had the block bored .030 over, the heads were worked over, he bought a rebuild kit including lifters, cam, and the whole 9 yards. then it sat in his buddy's garage until last Thursday when I pulled it out and took it home. the only thing mounted on the block is the crank. I am just aiming to get the Jeep running for a play toy for now since I am working on a shoestring budget. I also have the TH400 and quadra-trac that I will need to deal with as I move along with my project. Not to mention the severe rust that Jeeps are known for.

[jeepsr4ever]

Well if you have a good digital camera and patience we can walk you through just about anything if your up for it!

[CLE_76CJ7]

I'm waiting to borrow an engine stand from a friend so I can get started and then I will be ready to start on the build up. I am at a severe disadvantage since I am not the one who tore it apart. Do i need to clean the surface rust off of the outside of the block before starting? if so, what is the best method?

[Goose]

Let me offer you a couple of general words of advice..

Go buy some of the little rubber caps that go over the rod bolts so you dont nick the crank.. and.. finally dont sweat it.. guys have been known to replace spun bearings alongside the trail in the dirt, "just to get it home" and still been driving them years later..

an afterthought .actually grab a chiltons or haynes manual for the jeepthat will certainly help..

[Mudrat]

I have the Haynes, Chiltons and TSM for mine - but your Chiltons will get you through, with help from the board here (or in Dusty's case bored 8) wazzup Bro? :? )

For the surface rust on the outside - no big deal, a wire brush and AMC Blue paint :t: will handle that. If you have some rust on the INSIDE we'll need to address that if it's on a machined surface (cylinder walls, bearing journal, or one of the machined mating surfaces (head-to-block, front cover-to-block or ... oil-pan-to block which is not that critical.)

[1980_Cj7]

Where are you located? There might be somebody close to you that wouldn't mind offering some help.

[ironman_gq]

as far as surface rust goes as long as its not on any internal surface of the engine or crank and cant become airborn by touching it then it should be fine. I Would recommend getting a book that is a little more specific when it comes to reassembly steps than the hayes manuals. They can be a little too general sometimes. I think this is something that anyone can do as long as they can read instructions and a torque wrench.
Good Luck! :t:

[CLE_76CJ7]

There is some light rust on the cylinderwalls the i was going to hit with a cylinder hone... is that a good idea? as far as the other surfaces go, I will have to check it out in the morning. I am in Udall, KS, about 30 miles southeast of wichita. If there is anyone in my area who wouldn't mind helping a newbie I would be thrilled. I am relieved that I found this board so I have some experience behind me before I dive into this. Thanks

[Mudrat]

A fine hone and lots of lube - not sure who recommends what, but you want a light oil and use lots of it to wash the debris out. Think of what you use when you sharpen a knife.

[CLE_76CJ7]

I hit the cylinder walls and the machined areas withan "ultra-fine" scrubby pad and some wd-40. the machined surfaces i followed up with some 180 grit emery cloth on a block with lots of wd-40. everything cleaned up pretty good :idea: . I am still going to hit the cylinders with a hone. is wd-40 ok to use? if not I'm open to suggestions. I have some pics of what i am working with if any one can help me so I don't screw up too badly #-o

[CLE_76CJ7]

I hit the cylinder walls and the machined areas withan "ultra-fine" scrubby pad and some wd-40. the machined surfaces i followed up with some 180 grit emery cloth on a block with lots of wd-40. everything cleaned up pretty good :idea: . I am still going to hit the cylinders with a hone. is wd-40 ok to use? if not I'm open to suggestions. I have some pics of what i am working with if any one can help me so I don't screw up too badly #-o

[jeepsr4ever]

At this point when you hit the cylinder walls with a hone you cant use moly rings due to the chang ein cross hatch

[CLE_76CJ7]

should i avoid the hone and just use the scrubbie and some more elbow grease?

[Mudrat]

At this point when you hit the cylinder walls with a hone you cant use moly rings due to the chang ein cross hatch
Why not use an ultra fine hone and re-establish the cross hatch?? About 45* each way up and down??

As long as the WD40 flows esily it'll work. Just try not to scrub one spot too long. The reason to use a hone is equal pressure throught the stroke and circumfrence.

http://www.aa1car.com/library/2002/cylinder_honing.jpg

http://www.etoolcart.com/ProductImages/brushresearch/thumb_BRMGBD6.jpg

[CLE_76CJ7]

do i need to find a flex hone or will one with fine stones work ok? what grit do i need to look for?

[Mudrat]

do i need to find a flex hone or will one with fine stones work ok? what grit do i need to look for?
If it's just surface rust the finest grit you can find - normally a 180 and speed with a lot of lube will be fine.

http://www.etoolcart.com/ProductImages/brushresearch/thumb_BRMGBD6.jpg
Read the directions - don't just shove it in the bore and then start spinning, you need to rotate slowly going in and then faster with a hi speed drill in and out to create the 45* cross hatch pattern - pulling out just before (wait - wrong thread :shock: ) make sure it's spinning when you pull it out of the bore. (but then again, that's what she said :mrgreen: )
There is an art to it. Try a few strokes to see if you have it right before going all the way. WAIT, am I realy writting this?? :shock:

[AMX69PHATTY]

Don't forget and be sure to wear rubber .............. gloves :?:

[Mudrat]

OH! I feel so validated :wink: :?:

76CJ7 - seriously, make sure the hone is rotating when you put it in and take it out - no straight up and down action - your 'motor' won't like it :t:

And do use lots of lube :idea:

[CLE_76CJ7]

Who knew this could be so much fun! :lo1l: . i'll get it on the stand friday and then let the good times roll!!!

[jeepsr4ever]

Its hard to get the hard moly top ring to seat on a fine or wrong crosshatch. Hard to say where exactly the crosshatch is at but take it from me it can be a bear to break ring set in. You should use a set of iron rings at this point and with iron you can get away with almost any type of circular surfacing so most any hone will do!

[CLE_76CJ7]

My pistons already had a new set of rings on the when i took on this little project, how do I differentiate moly rings from iron ones. Is there a performance difference between the two?

[82Waggy]

Yes, Iron rings hate unleaded fuel.

[Mudrat]

Yes, Iron rings hate unleaded fuel.
OK, this is one I can't answer - and obviously 76CJ7 doesn't want to run he engine for 4-5K to find out he oopsed. :roll:

So MY question - do Moly rings react magnetically like the iron ones? Or how does one tell what rings 76 has now (knowing he should change them anyway... :idea: )

[CLE_76CJ7]

My cousin replaced the rings when he started on the motor, but it has been so long, he doesn't remember the details ](*,)

[Dusty]

[quote="Mudrat"]I have the Haynes, Chiltons and TSM for mine - but your Chiltons will get you through, with help from the board here (or in Dusty's case bored 8) wazzup Bro? :? )

................[\quote]


Pat you need more projects.... :(:

[CLE_76CJ7]

OK, I began installing the pistons and connecting rods into the block. It all went smooth until I got to the number 6 cylinder. The rod is too wide to fit on the crank journal with the number 5 rod :banghead: . The rod on the number 5 cylinder is what gave out and blew the motor in the first place, so it is new (or new to this motor) Do the rods come in different widths? It is between 1/32 and 1/16 too wide. I am assuming it is the number 5 rod causing the problem, I got frustrated and gave up for today. I'm going out again tomorrow to pull the number 5 back out to measure the width and that of the number 6 rod. Am I going to need to shell out the funds for a new set of rods? :dontknow:

I got out to measure the rods and I was correct...the number 5 measures 1 1/64" and the number 6 measures 31/32". What do I need to do?

[jeepsr4ever]

Sounds like you got a 258 replacement rod instead of a 304/360 rod...same dimensions only the bottom end is wide!

[ironman_gq]

get a 304 replacement rod from your local parts store. Napa and autozone should work.