Ok so i got a decent 350 out of 1995 chevy truck needs main and rod bearings. Fully dissassembled the motor looks pretty clean except for the bearings. I brought it to the machine shop and the guy fully cleaned, rehoned, plained the head surface to make sure no warping, and installed the cam bearings for me. Now that it is home i got to tinker on it alittle bit the new eagle crank is installed with the new bearings, and new main caps with new main cap bolts all torqued down pretty good crank spins freely with no problems. The new rods i got are eagle I beam rods with summit stock rod bearings which installed as well but are not in bolted to the crank yet my question is what are the stock piston rings size for a stock bore 350 so i can order these and get the bottom end together

 

Did you plastigauge the rod & mains?
They only honed but not bored the engine? What pistons are you using? That's where you get the ring specs from.

 

Yes i plastiguage the mains and rods the pistons im using are the stock 350 ones im just doing a stock bottom end refresh i got a nice set of tpi heads that i opened the valves up to flow better cam dont know what im gonna get yet also thinking of doing it tpi

 

Aftermarket pistons will want different tolerances than factory ones.

.... you did get your new rotating assembly balanced by your machine shop, correct?

 

Im going internal balanced with all of the bottom end seems like i missed alot of stuff think i should bring it down to him again and let him do the bottom end build

 

That's why we're all here man, to learn or help others.... or repeat incorrect information haha.

Just because everything is new doesn't mean it's correct or true in size. That eagle crank can be tapered from one end to the other and need to be cut for all you know. Your rotating assembly needs to be balanced with your flex plate and harmonic balancer. Your rings have to be gapped correctly, piston to wall clearance needs to be checked, cam might have to be degreed, etc.

My first motor I did a stock rebuild with a cam just to play it safe. I reused my crank, rods and pistons (machine shop polished my crank, checked my bores, I honed the cylinders, I gapped the rings, i put it all togethet and they did my heads). I've rebuilt several motors now but I am getting ready to disassemble my first set of heads.

 

Stock ring size is 4.000 to answer your original question.

 

IMO, id use Total Seal Gapless ring set. Generally you order your rings .005 larger than bore size to make sure you can fit them correctly. SO if your STD bore is 4.000, order 4.005. And yes you want to file them to manufacture specs.

Connecting rod side clearances should be between .018" - .026" side to side play.

IMO,I would recommend getting a good book on rebuilding a motor. A lot of people just slap stuff together and yes it will work, but for how long and how well. A good book will steer you and if you follow correctly, you will have a far superior engine. I have a book by "HP books" called Small-Block Chevy Performance, Author- Dave Emanuel. Think I payed 15 bucks for it. They worked with TPIS and other engine jedis when writing the book. However, you may like another book. Find what fits you but keep your eyes open. A lot of stuff will sometimes contradict its self so thats when you decide what works for you. Soon you will have a small library of books! lol. Good luck.

-Dan

 

I agree with all the above post BUT being your 1st rebuild I say do not over complicate this.

Yes file fit gapless rings are great, but NOT needed for a good mild build... Look at the stock engine.. Any of the common engines we use in these cars. NON had gapless rings.

Also if you read through a factory service manual the bearings clearance range is much wider than any performance recommendations.

Go do a weigh in of stock parts, you will be shocked. I have took apart engines that lasted 300K+ miles that had bob weights (piston, rod, rings, rod bearing package) will above 20 gram mismatch from lightest to heaviest

Now do not get me wrong I think blueprinting is great and 100% needed on race engines and very high performance street engines.

But for a 1st timer do your main clearance checks, use non file fit rings, etc and keep it simple.. You are already taking on alot of new info.. Focus on that, get this one up and running and learn more about blueprinted and build another one spot on.

I also say that because not many people on here out of the whole owns the tools to do percussion engine blueprinting anyway.

I have even seen "engine shops" use the common plasticgauge to measure bearing clearances... Yes this works, millions have been built with it but if you are not using a dial bore gauge, inside calipers, mic sets, etc etc to measure bearing clearance then why worry about .0001" ring gap, or .5 gram rod weight etc.

On a mild engine it will not mean much of a diff.

I again stress the fact blueprinting is a good thing and you should learn how to do it, but maybe not with your very 1st one

 

Ok everyone my machinist was wondering why i came back down again lol i told him that i need it to fully get checked through for all the clearances also to donthe bottom end work he laughed like hell and had a feeling i would come back with it all to bring it to him so like i said i got everything all set to him now im wondering about decent cam for a stock tpi bottom end to hold up to it. since this is a roller block and all how do all of you feel about the mighty LT-4 hot cam heard that cam makes a decent amount is there a kit i can buy for it to get the roller lifters, matching push rods, ans also for rockers what can i do those or should i just reuse the stock ones.

Another question is i know the piston ring size is 4.000 i need the actual size of the grooves that they sit in on the stock piston like is it 5/64, 5/64, 3/16

 

Cam, Im not sure. Night might know. Yes on the pistons. If you have 5/64, 5/64, 3/16 pistons, those are the ring widths you order.

 

Those Imperial sizes were what was used for a long time.

However at some point in the early - mid 90s, they switched to metric rings; not sure when, or in which motors.

Use feeler gauges in your ring lands, and a caliper if necessary, to measure their width. Be EXTREMELY careful with that surface, as the fit of the side of the ring to the ring land, is AT LEAST as important of a sealing interface, as the front surface of the ring to the bore. Even very small gouges or scratches or whatever, can DRASTICALLY affect blowby and oil control. Remove the old rings VERY carefully, with a ring expander tool, NOT your fingers, being careful not to let the ends of the old rings ding up the lands; and of course install the new ones the same way.