I have a '76 225 with super low mileage. There is -NO- wear ridge and the head is currently off for "inspection". This engine sat TOO LONG. The 2 pistions in the open combustion chambers froze from rust. I was able to free things up with some oil, 220 grit paper and a great deal of working it a little at a time. There is very light pitting on one spot in one bore

I would like to run this engine as-is for a year while I re-build one of the steel crank motors from my car or truck. I just want it to run. I know it won't be great, but I'd like suggestions to get the most out of what I've got. My racing budget is BROKE till tax time, so I can only afford to install this motor if I can make it run without machine work.

Should I just assemble and run. Are there any cheap tricks to make this come back to life? Is it a comlete waste of time without replacing rings and overboring the one pitted wall? I can live with marginal compression in one cyclinder compared to all 6 in my existing motor.

This motor is otherwise the freshest /6 I've ever seen. It mocks me by never even being broken in, but needing the same work as a motor with 200,000 miles.

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1980 Aspen 225 super six

Run it.

D/W

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If it ain't broke, fix it!

It would be a good idea to pull-off the oil pan and remove one of the piston assemblies that was "frozen" and rusty in the bore. Remove the worst one first and check to see if the rings are stuck in the ring grooves.
It does not take much to have the rings stick in the piston grooves and if the rings are stuck, the engine will run rough and smoke / use oil.

You may be able to quickly free-up any stuck rings using solvent and tapping /pushing at the ring's gap. Worst case is you break the stuck ring(s), if so, pry-out the pieces and clean the groove(s) and install replacements. (I'll send you some good used rings if you can't afford a new set)

If the rings are free in the worst bore, put the pan back on and run it. If you do find stuck rings, free them up and go check the next "rusted hole" until you are satisfied that the rings are free.
DD

If you put the head back on and run it, you are taking a gamble, but it might just be fine. Drive it some, and stuck rings may even free up with some use cycles.... or pull the pan and disassemble (the right way)

D/W

Afterthought: I'm thinking this motor is in a car. If it is out of a car on a stand or on the ground, it would be foolish not to pull the pan and check things out - I shouldn't have made such an assumption without information on whether this motor is currently installed or not.

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If it ain't broke, fix it!

Seems like a reasonable next step.(and free! ) I'll see what it looks like and then post an update.

Dennis, it's sitting on the ground with only 4 bolts in the pan. I only bought the motor because I needed a pan for the motor that's in the car. (a dart pan wouldn't fit and it was almost race day!) $50 was the same price the guy wanted for the pan or the whole motor. I pulled the head as a core, but realized that this motor was in waaay better shape than the two I'm running if I could get it turning again.

I bet I can free up frozen rings by soaking them overnight in some kind of fluid. (after removing the assembly)

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1980 Aspen 225 super six

I pulled the piston out of the worst bore last night. The top ring was frozen, but not any more. Took about an hour of working at to get it free. I should have just busted it out and replaced it in hindsight.

I've rarely done internal engine repairs, but this bearing looks funny. The crank looked great ( in the dark )



There is an 1/8" wide strip of pitting about 1/3 the way from the bottom of the piece. I don't know what would have caused it, and I wonder if this is consistant with what the others will look like. Does this require replacement?

I've deceided to tear down a few more and see if they get any better.

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1980 Aspen 225 super six

Replace. (I would never consider reusing a rod bearing, anyway...)

That doesn't look great, but I've seen much worse and just did a polish job to the crank and replaced. What do the journals look like? Do you know how to use plastigauge?

D/W

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If it ain't broke, fix it!

In the dark with a trouble light, I could only find 1 imprefection. An 1/8 inch circle of mild 'spotting' where the hole in the bearing allowed air to reach the journal. If it was rust, it was worn away while I was turning the motor to get it free.

I never realized how soft the metal used as bearings was. I can scratch it with my fingernail? You're saying not to polish and reinstall any bearings even if they look better than this one? or just if they are flawed looking?

I've never used plastigauge, but I understand what it is and have read instructions to be: Lay plastigauge on journal, fit parts, torque to spec, remove parts, measure width with included guide.

Sound Right? I hear it's cheap, so I'll stop and buy some tonight to get a measurement.

I'm feeling pretty good about being able to refresh the bearings and rings. It only seems easy once you've done it. Otherwise it's a little intimidating. I'm glad this isn't a rush job. I am likely to pull all six and then I'll know exactly what I've got.

I'm VERY temped to get a flex hone and freshen up the bores now that I'm in there. A little water leaked through my tarp, and now I've got 3 days of light rust in 3 bores again. Any reason other than cost of the tool that I shouldn't give them all a mild cross hatch refresh? Any suggestions on what tool to buy or from who?

I'm dragging this block into the garage tonight, because I'm not gonna risk getting it rained on again and it's looking pretty usable at this point. Anybody got an aspen/volare oil pan?

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1980 Aspen 225 super six

as long as the crank doesn't have any scores i'd get a set of bearings and rings, do a hone job and throw it all together. should run real good and last too!

i wouldn't use the old bearings. definitely do the hone job, rent a hone from Autodrone (free) (ball type, use ATF for lube) (use with drill, run in and out at quick speed, don't run too long)

done.

Here is another "vote" for a new set of connecting rod bearings, the one you show is "toast". Check the ID on the back of the bearing to see if it is "standard" (STD) or oversize (.010, .020, etc.)

Give the crank journals a little polishing and lightly sand the mating surface of the con rod cap so you are sure it gets full contact when reinstalled / torqued. Make Sure the con rod caps go back on the same way they came off, bearing tab to tab, outside number to number

A hone is nice but you can also do a "poor man's" hand sand job on the bores, just to get a light scuff on the cylinder walls, work up & down for the cross-hatch, you won't need much if you are reusing the rings.
DD
[/i]

MMMmmmmmm... toast (in Homer Simpson voice)

The only markings on the bearing is an 'e' and 7-74 marked below.
I hope that means it's the origional bearing set and that this motor is actually a forged crank '74 motor. I'll clean the block and check the numbers against the info in the articles section to get a positive id. I noticed the big casting id was 'something-5' and 'BH'. I recall seeing that a 'BH' was a good find in the blocks article.

Against my own intentions, I've begun my first bottom end rebuild. I guess I've gotta learn eventually.

I'll give the crank a good inspection and pull a few more pistons tonight. I also have some plastigauge, so I'll test clearance on the next journal before I remove the piston.

Thanks for all the feedback guys!!

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1980 Aspen 225 super six

S-6 Ram,

Crank bearings are too cheap to risk damaging your crank by re-using scored beaings.

Yes, the bearing material (alloy of tin, lead, antimony) is quite soft, and trying to "Clean it up" would result in two things: 1) enough bearing material being removed to create excessive clearance, and 2) abrasive particles becoming embedded in the soft bearing material, and the bearing acting like sandpaper against your rod journal (really screwing-up your crank).

I'm glad you posted your initial question - I've had a 1960 Chrysler RB-383 big-block on the engine stand for about 4 years now, with the heads off, and the condition is much like you described - no ridge, clean cylinders, but now the walls have flash rust...motor was ripped down because of a coolant leak that contaminated the oil, and wiped-out all my bearings.
I want to finish pulling the motor down and get it to the machine shop, but want to clean those bores up so that I don't damage the pistons or rings trying to get them out of the block.

(This engine is an obscure '59-'60 Chrysler-only version of the 383, so new pistons and such are extremely expensive...I want to spend as little $ as possible on the thing, and get the old four-door Windsor back on the road!).

Good luck with your s-six !

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De Soto Frank

THAT'S cool. Very few people are even familiar with this engine. I bet it's fun to try to order pistons for! The stroke is 3.75" - what is the bore? I bet that'll make one torquey 383!

D/W

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If it ain't broke, fix it!

My old Motor's lists it at 4.0312, right tiny for a big block. Talk about "Torque of the Town"!
Here's the weird part; the hp/torque ratings given are identical for both B and RB 383s. Misprint? Creative marketing?

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O==\=/==O

"A mechanic is Somebody."
- Jim Preston

(Not meaning to hi-jack this thread... but...)


It would seem that the New Yorker and Imperials had the 413 RB engine, and that the "low-priced Chrysler (Windsor)" should have a "smaller", less powerful engine, that was yet "different" from the 383 B motor that was available in the De Soto...

So, they came up with an " under-bored 413"....in all other aspects, it's the same mill as the 413 - same heads, same valves, same crank & bearings...

I think Chrysler realized after two seasons, that this wasn't worth the effort, and just offered the 413 and the 361 ( still a "B" motor).
Pistons and rings are right pricey for the 4.0312 motor, so if the original bores and pistons are beyond help, I think I'm going to have it punched-out to a 426 or 440. At least the performance gains would justify the machine shop expense; doing a .020"-over rebore just isn't worth it in my book - not when those pistons are running $50 /slug.

I bought the car because it has a really solid body and nice interior...I hope I'll get it back together some day !

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De Soto Frank