what ring to use with KB pistons

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Darren

Darren

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hey guys i am buying a set of KB pistons part # KB 400. Should i get the kit with the rings or get the rings seperate? If so what rings should i get? I know i will need file fit rings. The engine is a 383 4 speed and will be street driven. Thanks
 
No reason not to get the rings with the kit if you can save some dough. Just make sure they're moly faced.
 
I have that same piston going in my 383. I got JE low tension rings.
 
80fbody said:
No reason not to get the rings with the kit if you can save some dough. Just make sure they're moly faced.
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Pretty sure in the kit only the top ring is moly faced. And for some reason in the kit the rings state "no" for fill fit. Can they still be filled? Thanks
 
Darren said:
Pretty sure in the kit only the top ring is moly faced. And for some reason in the kit the rings state "no" for fill fit. Can they still be filled? Thanks
Click to expand...

If you measure the end gaps..and they are too tight...yes..you can file them....but File to Fit rings are .005 larger then the intended bore size.....and NON File Rings are not....
 
I'd go with good Molly coated rings. might be worth a call to the supplier to make sure they are.
 
The rings that KB offers for there pistons are iron. The top ring is moly faced and second ring is castiron faced and oil rings are stainless steel. Would these rings be good for a mild 383 build? Thanks.
 
Thanks boys. Iam going to post my bottom end combo before i order it all for some thoughts. Thanks
 
You will need to file the rings regardless because of the pistons so I'd just get the stock-type replacement, moly top ring set. Whosever is cheapest.
 
Hey guys this is the combo i got so far. 68 block bored. 30. Polished steel crank. Clevite 77 H series main and rod bearings std size. Stock rods with ARP bolts. KB 400. 30 pistons and rings. I will see if i can have the machine shop deck the block just to make sure the block is sqaure. This engine is being built for a matching number 68 barracuda 4 speed. So thats why i want to keep it as stock as i can, so what do you think? Thanks
 
May want to have the block bored first, mock up the crank with a new piston, install a gasket & the head you're going to run to check for piston to head clearance. Once you know that, you'll be able to deck the block to the correct measurement for your needs.

It's certainly more time consuming but would make for a nicer build with proper compression, etc.
 
Looks ok. i disagree with the bearings especially given the polished (not cut and polished) crank surfaces but that's just me.
Also - "decking" the block will not mean it's square (parallel to the crank centerline and perpendicluar to the bore centerline). It will mean it's been cut to flatten it. You need to have a shop "square deck" it an in order to do that, the shop needs the right fixture. So if your goal is to "square up" the block you should make sure you knwo what you're looking at in terms of equipment, and ask to see it. Many shops say they square deck and charge appropriately, but can't because they don't have the fixture.
Also don't forget you'll need to file fit the rings per KB's instructions.
 
moper said:
Looks ok. i disagree with the bearings especially given the polished (not cut and polished) crank surfaces but that's just me.
Also - "decking" the block will not mean it's square (parallel to the crank centerline and perpendicluar to the bore centerline). It will mean it's been cut to flatten it. You need to have a shop "square deck" it an in order to do that, the shop needs the right fixture. So if your goal is to "square up" the block you should make sure you knwo what you're looking at in terms of equipment, and ask to see it. Many shops say they square deck and charge appropriately, but can't because they don't have the fixture.
Also don't forget you'll need to file fit the rings per KB's instructions.
Click to expand...

What would you recomend for the main bearings? I would like to stay clevite. Thanks
 
I ordered my parts. i ended up getting the clevite P series rod and main bearings. And i went with sealedpower 4.280 top moly faced rings. good choice? Thanks.
 
I have a feeling moper is going to reply and say you should've picked the Speed Pro M type bearings...
 
Thanks guys. Seeing that i allready have the p series clevite bearings on order i will be running them. I will confirm with the machine shop with there thoughts. Thanks guys for your help.
 
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