Engine Repair Question

[Mosesatm]

Took my car to a local mechanic shop today to see if they could diagnose the rolling noise in the engine. One of the techs said that the noise is probably coming from a piston with collapsed skirts and what sounds like a rolling noise is actually the skirts contacting the cylinders as the piston moves up and down. That seems to make sense. It’s not a tapping noise like a wrist pin would make, and the noise seems to lessen as the revs increase.

Of course that conversation then turned into an estimate of $9,000 to rebuild a 302 block with aluminum heads, roller rockers, stroker kit, 4V carb and intake, and headers. That’s not exactly in my budget so I asked what it would cost to fix the one bad piston. $2,500 - $3,000!!!!!!!!

Looks like I’ll be fixing it myself. First a few questions, though.

If the tech is correct and one of the pistons has one or both of its skirts collapsed could I drop the pan, and find the faulty piston by measuring all the skirt/cylinder wall clearances?

Since the engine is good and tight, and otherwise does not need a rebuild, if I find the bad piston is it safe to replace only that piston and its rings? I know that goes against everything we’ve ever heard about engine repair, but from a realistic point of view can it safely be done?

The biggest concern I see with such a repair is in the weight of the new piston vs the old pistons so I’d need to pull another one to make sure they are similar. That turns into, “well if I’m pulling 2 of them I might as well do all of them.” And that eventually turns into a complete rebuild.

I guess the overriding question is - where is it safe to stop the repairs and still have a fairly reliable engine? If I don't do the work I'll need to know what to get bids on from other engine rebuild shops.

What is a decent price from a shop for a removal, short-block rebuild, re-assembly, and reinstall?

Thanks for any insights you can offer.

 

[Perkchiro]

Arlie: I'm no expert, but I think I'd get a second opinion. If it's as you describe and your piston skirts have "collapsed", I would be afraid of loose metal scoring your cylinder walls. I would suggest you drain your oil and check for metal fragments by filtering. I would start by pulling your pan and inspecting the crank and rods. I would rotate the crank and let the pistons drop to their lowest positions and see if the piston skirts are cracked or gone. I've heard that you can replace a piston through the bottom of the engine, but I would be more inclined to pull the engine and break it down on an engine stand. I know that sounds like a lot of trouble but if you are thinking "overhaul", that's the best way to do it. You should consider rebuilding it yourself but if you're not into that, just removing and reinstalling would save $$$$. Just my intial thoughts on the subject. I really hope it's a simple problem to fix, but it doesn't sound good. I know others here may have some ideas for you too. Good luck and let us know how it goes.

 

[Mosesatm]

Steve,

I recently had the pan off to replace the oil pump (no problem with it, just a precaution) and I was pleasantly surprised at how clean the bottom of the pan was. I didn't filter the oil though.

 

[somethingspecial]

Arlie, I just picked up a J code 68 coupe. Tim and I pulled the motor ourselves and I took it into the local Napa Machine Shop. I am having the entire engine rebuilt (long block) for $2,500.00, and that's with Keith Black pistons, balanced, Hardened valve seats, everything. I would get a second opinion for sure. Mike

 

[PNewitt]

Arlie,

First, my sympathy to you and your problem. I'm sure at some time, each of us have had that problem (or, unfortunately, will, in the future). I remember when I had an engine not start, because the block cracked at 217K miles, and there was sludge on the dipstick. It was a sick feeling....

So--I had to stay at a friend's house, and for a week, I pulled the motor myself, had to switch the intake, water pump, pulleys, etc. It was a mess, but I HAD to do it to get home, 500 miles away.

Steve makes sense. I'd get a second opinion. $9K sounds kinda high. There are crate motors for less than that. Is this an original motor? Original block? How many miles on this motor--original or rebuild?

A rolling sound (grinding type of rolling?) might be a crank bearing, or a seal that's going out. If it lessens with the increase in RPM, it sounds to me like something that likes oil to smooth out whatever is "wrong". A bad piston skirt would cause more noise, and a LOT more friction problems. Like Steve pointed out, the scoring of the cylinder would make sure you had to pull it all apart, and you (worst case) might lose the block altogether, if it's deep scoring.

One time, the motor refused to turn over, and I thought I'd blown it. I slept on it, and remembered that I had a (cheap rebuild) starter that had self-grenaded about a month before, and left shrapnel in the bellhousing. The next morning, I pulled the starter (a new Ford one), and there was this zig-zag piece of metal wedged between the starter gear and the flywheel gear. Could your flywheel be scratching something? If you'd pulled the pan, could the front pan seal be out of alignment, "scratching" something? You might think of stuff like this, beacuse it happens. Then we think--dang, I wished I'd thought of that before...

Mechanics (some, not all) like to talk you into a new motor. Rebuilds are mostly labor, and lots of cash. I'd get another opinion., with a scope, a good ear, and someone that is really experienced with our vintage of engines.

Sorry--this is armchair advice, but maybe it will trigger a better answer.

Wishing for the best outcome,

Paul N.

 

[CALIF GIRL]

I have to agree on the "get a second opinion". We pulled my 302 out,took it to a shop and had it rebuilt for less than $2,000.00.

 

[rvrtrash]

I'd get a second opinion also. I had mine rebuilt, with extras, for about $2500.00 . At $9000, i'd spend an extra $1K and get the new 500hp Boss 302 and put it in.
http://media.ford.com/newsroom/release_display.cfm?release=24698

You can change just the piston, if the cyl. walls are ok, but you'll need to pull the head and take it out the top. It's at best a short term fix and you'll be rebuilding the whole thing in a year or so anyway. If you decide to pull the engine yourself, which isn't that bad really, email me offline and I'll walk you through it.

 

[Russ]

Arlie, I'm sorry about your engine....but, if you are at all mechanical, and like to work on engines, you can save a bunch of money by fixing your engine yourself! I agree with everyone else, that $9000 to repair a 302 cu in engine is out of line. I recently rebuilt my J code engine and here is what I spent:

1) Machine work on the block...including line boring the mains, boring the cylinders, installation of new camshaft bearings, grinding the crank = $325
2) Rebuilding the heads....new valves, new springs, hardened valve seats in the exhaust valve seats, = $400 (the heads did not need to be resurfaced)
3) Purchase new, name brand parts for the engine.....including new pistons, cam, lifters, timing set, rings, rod and main bearings, oil pump, gasket set and freeze plugs = $220 from Northern Auto Parts (northernautoparts.com)

I had the machine work and the head work done by a local machine shop in Flagstaff. I assembled all the parts to complete the engine.

That's a total of $945 for everything you need for a rebuilt long block. Now all you need is time and a factory shop manual. I would encourage you to give it a try. It is very rewarding, and you CAN do it! Hope this helps,

Russ

 

[Mosesatm]

Thanks for all the comments and advice.

The shop I took it to is considered one of the best in town. It's where people go who want engines David and Joe can appreciate. This shop is used to big invoices and big profits. I really wanted them to diagnose it more than actually fix it, anyway.

The more I thought about the piston skirt theory the more I found flaws with it, just as Paul did. It seems more likely to be a badly worn front main bearing; worn so badly by the accessories (Air, Water pump, PS, Alternator) that it is wobbling at low speeds but then smooths out at higher rpms. Plus the noise seems to be in the front of the engine.

Here's the new plan for today (no matter what's wrong with it)

331 stroker kit
Edelbrock Performance Package (Intake, Carb, Cam)
Rebuild and port the heads - I can port them if the mechanic wants too much
Remove the power steering and install the $150 converter thingy
AOD
Probably need some better exhaust manifolds or headers

Any thoughts on that plan?

 

[joedls]

Here's the new plan for today (no matter what's wrong with it)

331 stroker kit
Edelbrock Performance Package (Intake, Carb, Cam)
Rebuild and port the heads - I can port them if the mechanic wants too much
Remove the power steering and install the $150 converter thingy
AOD
Probably need some better exhaust manifolds or headers

Any thoughts on that plan?

I think that's a great idea. Although, I wasn't too pleased with my Edelbrock's performance. I went to a Demon. One word of caution with the AOD and headers. The crossmember I bought for the conversion didn't work. The headers wanted to dump right into the crossmember. There was no way I was going to hook up the exhaust to the headers using that crossmember. Had to fabricate one. The crossmember I bought was from Ron Morris Performance. Here's a couple of pics of the fabricated crossmember.

 

[joedls]

One other thing, Arlie. The engine I got was nowhere near $9K. I supplied the blower,carb, ignition, and accesories, but the rest of this engine cost me about $4500 with shipping. And that's with a couple of upgrades (forged pistons, roller cam, port-matched heads, high-flow water pump). And the builder has a very reputable shop. He started building NASCAR engines and got into the street engines a couple of years ago.

 

[Perkchiro]

Arlie: Sounds like a winner to me. Some of us here have rebuilt their own engines, and I can say that it was a rewarding, educational experience and the most fun out of the whole restoration. I think you're on the right track and making a good decision. If you have a lot of miles on the engine, or a lot of little problems with it or you just want to make more horses, rebuilding it is the way to go. You might give some thought to buying aftermarket heads instead of rebuilding them. It was actually cheaper when I checked into it. You might also consider the hypo cast iron exhaust manifolds instead of headers just as a comparison. I have an Edelbrock performer intake and a 600 cfm Edelbrock carb with electric choke. I'm really pleased with that set-up. Let us know if you need any help or advice as you progress forward.

 

[PFSlim]

Lets all meet at Arlie's house and rebuid his engine!!!!!! He can feed us, take us to shows, house us, etc., all for the low price of $9,150.00.

Just kidding of course. This thread reminds me of how many smarts folks we have on this site.

Paul

 

[miller511]

Arlie,

I like your plan.

FYI- I just ordered a complete long block 347 roller cam with Edelbrock heads from Coast High Performance out of Torrance, CA for about $5K.

I previously went to my local speed shop and started spec'ing out an engine with the guy and next thing I knew we we up to almost $9K. Of course they were going to build me a monster fire breathing 500HP 347 ;-)

-Jeff

 

[somethingspecial]

Arlie, I chose to have my engine rebuilt by the shop instead of doing it myself, only because I don't have the time. I've rebuilt engines before, and it IS rewarding. I had my wife help me and she loved it.
I was going to put headers on the 302 engine being built now, but then I had to get a drop bracket to lower the power steering piston 1 inch, as the headers hit. Then Tim reminded me about headers. All the headers I have used or seen in the past did one or two things. Cooked Starters, and/or burned Spark Plug boots off. Another problem you may have is the headers get so hot, after a while, they rust out. Headers in my experience, depending on the collector, always seem to have an exhaust leak. Mike

 

[joedls]

Arlie, I chose to have my engine rebuilt by the shop instead of doing it myself, only because I don't have the time. I've rebuilt engines before, and it IS rewarding. I had my wife help me and she loved it.
I was going to put headers on the 302 engine being built now, but then I had to get a drop bracket to lower the power steering piston 1 inch, as the headers hit. Then Tim reminded me about headers. All the headers I have used or seen in the past did one or two things. Cooked Starters, and/or burned Spark Plug boots off. Another problem you may have is the headers get so hot, after a while, they rust out. Headers in my experience, depending on the collector, always seem to have an exhaust leak. Mike

I've had good luck with my ceramic-coated Doug's headers. No leaks and no cooked starters on my convertible so far. I did buy a mini-starter and wrapped it in a blanket, though.

 

[PNewitt]

Arlie--

"IF" it's the front main bearing, as you may know....that would be a lot easier than pulling the whole motor. It involves removing the radiator, water pump, all brackets, the timing cover, and oil pan. Old, stock timing gears have plastic (nylon) on them, and they degrade over time. It might be time for a new, better, all metal timing chain. After 100K miles, they get sloppy, and the timing never gets right....

Besides, if you're going to do "something", you might as well begin with the front bearing, and if things look "real bad", then you've already got the front parts off, and then you can continue with pulling the whole motor out. I think that when you see the timing chain there, see if there's play in the lower (front) bearing, as well as on the cam. The lower (larger) sprocket will wobble noticeably, when the chain is off of it. If you DO get into the timing chain, make sure you know where the cam and crank are lined up, before you put things back together.

It depends on how many miles--and age of your motor, and if it's gonna hang together for a few more years, before you take the big plunge.

Heck, let's all converge over at Arlie's, have a "BBQ and motor-yankin' party"!

LOL!

Good Luck,

Paul N.

 

[Mosesatm]

Ah, yes, tearing down the front of the motor again.

I just replaced the timing sprockets and chain, the fuel pump, oil pump, water pump, distributor, lifters, pushrods, transmission filter, all the hoses and belts, and cleaned and painted everything. Used a case of paper towels, a gallon of lacquer thinner, and a few cans of Ford blue.

The annoying thing is that it now runs great, it just makes that troublesome noise, which it made before I did all that work.

Oh well, at least this time I'll just spill antifreeze all over the garage floor instead of antifreeze, and oil, and transmission fluid, and I won't get nearly as greasy!!!! And why in the world did Ford place the radiator drain over the dang frame?

Arlie--

"IF" it's the front main bearing, as you may know....that would be a lot easier than pulling the whole motor. It involves removing the radiator, water pump, all brackets, the timing cover, and oil pan. Old, stock timing gears have plastic (nylon) on them, and they degrade over time. It might be time for a new, better, all metal timing chain. After 100K miles, they get sloppy, and the timing never gets right....

Besides, if you're going to do "something", you might as well begin with the front bearing, and if things look "real bad", then you've already got the front parts off, and then you can continue with pulling the whole motor out. I think that when you see the timing chain there, see if there's play in the lower (front) bearing, as well as on the cam. The lower (larger) sprocket will wobble noticeably, when the chain is off of it. If you DO get into the timing chain, make sure you know where the cam and crank are lined up, before you put things back together.

It depends on how many miles--and age of your motor, and if it's gonna hang together for a few more years, before you take the big plunge.

Heck, let's all converge over at Arlie's, have a "BBQ and motor-yankin' party"!

LOL!

Good Luck,

Paul N.

 

[PNewitt]

If you know a doctor, or someone with a stethescope (sp?), I'd remove the fan, and any other obstructions, and get a good listen here and there for where exactly that noise is coming from--while the engine is at low idle...

It just might work.

Paul.

 

[Perkchiro]

" Old, stock timing gears have plastic (nylon) on them, and they degrade over time. It might be time for a new, better, all metal timing chain. After 100K miles, they get sloppy, and the timing never gets right....
Paul N.

Now that's a new one on me. I didn't know they used nylon or plastic on the timing gears. When I dismantled my engine, I didn't see any sign of plastic or nylon on the timing gears or the chain. They were solid metal castings. I'm curious, was that some sort of coating that Ford applied? That's an interesting tidbit I'd like to know more about.