Engine rebuild time

Engine rebuild time

elwood blues

Always Off-Roading Jeeper
Export, PA
1978 CJ7 4.2L Comp Cam & valve train, MC2100 carb, MSD ignition, Dana 30 front, T18 trans, Dana 20 txfr, AMC 20 rear.
So, I've been gone the last couple of weeks and the CJ has been just sitting for probably 3 weeks or so. I get in today to go for a spin and the valve noise that I have had for a while is today very much more definative and pronounced. It is now a very distinct pinging that I believe is a bad valve (I'm hoping it's not in the bottom half of the engine).

I'm looking for some estimates on prices that you all have paid. Right now my plan is to disassemble to see what I find, but to take everything to somewhere local to have the bulk of the work done, i.e valve replacement and cleaning etc. I'll do the disassembly/reassembly.

One more question, I'm not looking to go overboard here, but I also don't want to skimp, what/where should I start looking at for parts?

Thanks all :chug:
I would not worry about buying parts for now, The thing to do if inclined is to dissasemble as much as you want or can and take it to a good machine shop to be rebuilt. The machine shop should buy the parts because they are gona know what it needs and what sizes, this is assuming it needs rebuilding.
Right now my 4-134 is at the machine shop and cost of all machine work is $875 less parts, a complete engine rebuild parts package is around $950. That price gets it a short block assembled with me to finish the rest.
I know yours is a 258 but it gives you some idea
I would pull the head and look at the cylinders. The 258 has a very strong bottom end, if your not using oil and the compression isn't bad a valve job may be all that you need.:cool:
Depending on what you want to do you might be able to fix it without rebuilding it but figure on 1000-1500 for a rebuild for good machine work and quality parts, I used to spend around 600 on my V8 heads to get new valves phosphere bronze valve guides and a 3 angle on a Serdi machine and always had the throats opened up it was like 100 to do the block 60 for the crank 60 for the rods it will add up :chug: Just Empty Every Pocket
elwood this is what i used for parts 71-90 Jeep 4.2 258 Engine Master Rebuild Kit: eBay Motors (item 370449972948 end time Nov-02-10 06:01:21 PDT)
the parts are bought in bulk and packaged in engine tech packaging. that being said mine came with clevite 77 bearings, melling oil pump, federal mogul pistons, and federal mogul rings, it came with cam and lifters not sure of the brand but stock profile, i'm not sure of the gasket set either but they were good quality, it also came with the good copper freeze plugs, and clevite77 cam bearings. for machine work i had the block hot tanked, magnafluxed, bored .30 over, cam bearings installed, cylinders honed, and decked. the head i had it hot tanked, magnafluxed, resurfaced, and a fresh valve grind. i had the rods cleaned and the new pistons pressed on. i also had the crank polished it didn't need turning. all of that cost me $375 or $400 i can't remember exactly i would have to look at my receipt. that being said i have no leaks, great compression, good power, and all for a little less than $1,000, granted its not exactly a high performance build but it is all new, and reliable.
Timing chain=$30.00 American dollars
The way things are going at work, it doesn't look like I'm going to have a chance to get much done over the next month or so. But, with that being said, I'm going to start tearing into the engine as soon as possible to see what I can find. gert you make a very good point about the bottom half not normally being the problem with the 258, so for right now I'm just looking at a valve job, new cam, lifters, pushrods and timing chain and gears. I've also got to make a couple of phone calls to places around here to do the work. Thanks for all the info guys, I'll let you know as progress happens...
if you got it that far apart, i'd put new bearings and rings in it.

It may come down to time and money too, with the holidays fast approaching dumping a lot of time and money in the CJ probably won't fly with the boss (wife) too well. If I can do a top half rebuild and be good that may be the route I run.

The one thing I have going for me Cheepjeep is that odometer only reads 55000(ish) miles and I don't have any leaks, so I'm banking on the bottom half being fine.
if needed theres a place 2 miles from the house that has heads for 200 or 250 without core.....you need it i got ya...i called last week.....they got a 258 in stock....i heard good things bout them

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a donation.

Help support Jeep-CJ.com by making a donation.
This donation drive ends in
Top Bottom
AdBlock Detected

I get it, I'm a Jeep owner and ad-block detectors kinda stink but ads are needed on this site. This is a CJ site, all the ads are set for autos (some times others get through.) I cannot make them just for Jeeps but I try.

Please allow ads as they help keep this site running by offsetting the costs of software and server fees.
Clicking on No Thanks will temporarily disable this message.
I've Disabled AdBlock    No Thanks