Working on motor

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Scamp it

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hi all
I’m refreshing what I believe is an 02
318 magnum engine
It’s mostly apart at this point
I have the pistons out right now and I’m wondering if there is a way to tell if the piston rings are still good?
Or if it’s out should I just replace anyway?
And how can I tell which ones I need to buy?
Thanks
 
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As a rule if your rebuilding an engine replace the rings and all bearings. The cylinder condition will give you a good indication of wear. The only way is to measure the cylinder bore diameter. I suggest you read/study a how to rebuild sb Mopar book. It's all about the component measurements compared to the listed specifications for those components. 65'
 
Get a cheap rebuild kit while have it apart, your engine will thank you!
 
Rings have at least 3 sealing surfaces, ALL of which are very important. Almost nothing spoils a rebuild faster than if the rings don't seal, And it's a really fast way to throw away power, and performance, neither of which the 318 can afford to do.
 
Before you take the rings out, use a feeler gauge and measure the ring side clearance; you do this by seeing how thick a feeler gauge can be slipped between a ring and it's groove. There is a spec on this; with old rings it ought to not be too much above the maximum; ti wil tighten up with new rings. The purpose is to see if the ring grooves are worn; if they are then new rings won't last that long.

New rings for sure. If I understand your question about what to buy, then plain cast iron will do but moly top ring sets will tend to break in faster/more easily.

You do know that you should hone the cylinders before installing the new rings?
 
New rings.
I had a friend in high school that lived by me, he was the cheapest sob ever, he fixed a 400 pontiac one time and only put rings on one piston.
It ran fine.
He still does stupid stuff like that to this day, just enough to get by.
 
As already stated, get a book that you can use to guide yourself thru this, study it hard. Be sure of the year of the model year of the engine you are working on, vin numbers stamped on the block will tell you that.

I am a firm beleaver that there is no such thing as being too clean while you are working on an engine........you can make 100 other mistakes, but not working clean does not have to be one of them.

Good luck!
 
If the bearings look good don't fool with them
get the correct rings
you have a late block and they wear better than the old ones so you could be ok with just a hone
engine in the car or on the engine stand?
put your money in the heads, guides, valve job
if bores are ok then get the correct hones to correctly hone for the rings you are going to get
if moly rings you will need at least two grits
then be prepared for LOTS of cleaning
what was your compresion before you tore it apart?
were you burning oil? most likely stems and stem seals
we could have told if it was rings but harder now
do all the rings rotate in their grooves? any broken rings, etc
 
And I forgot to mention.... the ring grooves need to be cleaned of old carbon etc, before putting in the new ones. There are tools for that, but, if you don't do this too often, you can break a ring in half, and use the square end carefully to scrape out the ring grooves.

Cylinder bores need to be cleaned after honing with ATF over and over, until a freshly ATF-soaked rag or paper towel comes out clean after a thorough wipe of the cylinder.
 
How to Hot Rod Small-Block Mopar Engines by Larry Shepard is a great reference for a rebuild. Lots of tips for things that could cause problems or might be overlooked if not familiar with Mopars. Also lots of info on various levels of upgrades. Many of these are inexpensive.
 
Then Hot Hot water (wear gloves) and tide powder
no solvent or wd-40 cus it forces tiny particles deep into the scratches - you want to float them up and out not imbed
then lightly oil and keep clean- spotless- hospital room clean
you are brushing out all the oil passages yet again if you have the block out of the car :)
but I've used an in car rod grinder and a re-ring with the block in the car and it ran for a long long time
lost a rod in 57 Nash 327 Hydromatic on way to 62 AHRA nationals in Cado Mills Texas (you could fit 8 adults in the Nash)
took foot of gas getting off ramp in Kansas City- rod started knocking- good OP and full of oil
Dealer there (call to my dealer in Whittier and a call from him to KC) got us back on the road in one day
That Nash Mortor was really tough- used by Chris Craft and Mercury Marine back in the day
I have / had a friend with a wood boat that still has one- and I have a core in storage all these years in case he needed it- but he never did- and since I lost him last year he never will. Found out we lost Mr Mopar good friend of mine and Roland Osborn when Chrysler Power was in Monrovia/ Duarte...
 
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