89fbrestor

if its worth a shot ... do they crack? will i be rebuilding the bottom end with in a couple years. my car will be a street car but i live in the country and i do plan on enjoying my car. i know i'm using forged crank and H rods but if i can get hyper pistons and be safe then i will but if i'm going to be rebuilding... i'll spend the extra $

Orr89RocZ

iTrader: (20)

Just like any motor, if the tune isnt right they will break. They are not as forgiving as forged pistons since they are a harder material that is more prone to cracking than just deforming/melting down.

If you already have a forged crank and H-beams, might as well go with forged pistons. I'd rather see cast crank/i-beams with forged pistons for budget builds. Rods/pistons USUALLY go before a crank will. Spend money on good rod bolts and good pistons to be safe, since tuning can be tricky and any small mistakes can show up with disaster. Need to be careful.

But look at what stock internal lsx's are doing. They have some sort of cast or hyper piston in it and they live just fine with good tune.

For a milder build, go for it. they should live at 500whp no problem with good tune. Guys have run zz4/Lt1 motors with big nitrous shots to those hp levels and nitrous is harder on pistons than boost.

89fbrestor

well this is pearl's thread and i don't want to hijack (sorry pearl if i butted in) but i wish there was a concrete guide to go by. i want my car to get into the mid 10's so i think I'll wait to read up more before i purchase the pistons just so I'm confidant with my buy.

i to am using the ebay gt45's I'm going twin and i just want the best i can get out of my set up.

Orr89RocZ

iTrader: (20)

Mid 10's is 500-550whp in a 3400-3500lb car assuming strong launch. Hypers can do that just fine, but forged would bring more peace of mind

89fbrestor

orr you the man hyper it is lol orr do you think mid 10's could be achieved with camel hum 2.02/1.60 heads? i do plan on upgrading but i have these now and would rather use them till i can afford some nice heads. with the turbos and the heads being worked. the heads would be the only thing lacking in my set up. suspension, trans, everything else is top of the line stuff, or close to it.

pearl again sorry if I'm putting stuff in your thread that you don't want. yours is further along then mine and i cant wait to see what you think of the turbo once you get it up and running. that thing is getting VERY GOOD reviews over at the turbo forum. i think the only down side I'm going to have running two of them is room... gonna be a tight fit.

Orr89RocZ

iTrader: (20)

Well its easier to make power with better heads. Likely can make camel humps get into the 10's with enough boost. Just keep an eye on the tune and keep chamber temps down. Run a colder plug and good gas, maybe some meth injection. That all should help.

Just be sure you run the proper ring gap on those pistons. They have different expansion rates than some forged pistons so they may want a wider gap. I run .022-.023 on my 401 with forged pistons and seems to be doing well. I'd talk to the piston manufacturer or an experienced builder who uses those pistons to see what they recommend.

89fbrestor

the tune, gapping, meth etc. i started my build but i'm not to the motor yet i'll be posting lots of questions when it get to that point. i'm planning nitrous, meth etc. i short of the heads(for right now) i plan on going all out on this build thanks orr

pearl01chevy

89fbrestor its fine your asking questions on here cause some things your asking is helping me out.. Im just so lost with so many mixed opions on cam/pistons and rods.. as of right now i have the cast crank from orileys, since i spun a bearing within first 1,000 miles of the first build it tore up the crank.. So i ended up buying the cast crank from orileys and i have maybe 3,000 miles on it if that. So i should be good with that.. i was more worried bout my rods though, are stock rods cast?? and will those be fine?? they were checked for cracks and all that and came back compeltely fine..

89fbrestor

pearl there is some serious gurus on this site. guys like orr, street lethal, gary1 etc. when they give there opinion i take it for truth. I'm sure you'll get a solid answer. me personally.. and I'm far from a guru i hear of rods going more then anything else. that's what prompted me to go with forged H beam rods. $230 on ebay which I'm sure some will say ebay stuff is junk but those rods will be stronger then stocks and not bad at all for a price.

as far as cam, orr and someone else chimed in on the cam i used in my green camaro and when i was finished it performed much much better then i anticipated. I'd trust the opinion of a few guys here over the sales men at summit unless your going to deal with a place that will do the work there selves and not just pull one off the shelf. that's my 2 cents

Orr89RocZ

iTrader: (20)

lol not a guru but sharing my experience on what i've seen so far.

Stock older rods are kinda weak. The powdered metal rods in the LT engines and zz crate motors are decent for a budget rod. The newer scat I-beams with 7/16" bolts are pretty decent rods. H beams are best with the ARP 8740 or 2000 bolts. They can hold some big power and some rpm. If you dont turn alot of rpm you have a better chance at the stuff living.

If you want nitrous on top of boost, i'd go forged piston. For your mid 10's goal you wont need spray, just keep it meth injected for cooling and octane increase. BUT if you ever get tired of mid 10's and want to turn the boost up, change heads/cam for more power, its nice to know your bottom end is strong and can support it if you had Forged crank/H beam rods/Forged pistons But then again, after 600whp, the factory blocks start to become a stressed point...guys have pushed them to 1000hp and such but thats pretty iffy and does require a half-fill on the block to give it some strength. Splayed 4bolt main conversion from 2 bolt block is best for this, but much over that power you will want an aftermarket block if you want it to live along time. IMO.

If you go forged pistons, you have 2 choices in material. 2618 and 4032. 2618 has a higher tensile strength but also has a higher expansion rate. The piston to wall clearance must be made wider to allow for the expansion thus increasing the probabilty of "piston slap" on cold startup. 4032 has a lower tensile strength but expands much less so the piston to wall clearance can be closer, lowering the chance of "slap" on cold startup. For mild boost setups you can get the 4032 alloy metal. For much higher hp conditions with higher chamber temps, the 2618 are advised. Extra insurance would be in the 2618 pistons. Thats what I'm running in my car I do believe. JE pistons but they are pricey at 800 bucks.

project89

iTrader: (1)

.007 top ring gap per inch of bore size i.e 3 inch bore = .021 gap 4 inch bore = .028 top ring gap thats what i use on hyper pistons and hell my v6 motor has seen just shy of 30 psi

forged pistons will work good with a .005-.006 ring gap per inch of bore personally on a forged piston depending on how high up the top ring land is id go .005 unless the top ring land is way up top of the piston then id open it back up to .006

gap the second ring as u normally would except do not use a gap-less second ring on a hyper piston

pearl01chevy

geeze oh geeze.. im getting way overwhelmed here.. not because of you guys, just so many choices on what to get/buy.. i started looking at some scat kits, but theres 4 choices on pistons and not sure which is best here.
Flat top, with two valve reliefs
Dome, with two valve reliefs
Dish, with a D-shaped cup
Dish, with two valve reliefs

but on another note, i was checking around ebay and seen this kit :http://www.ebay.com/itm/SBC-CHEVY-35...sories&vxp=mtr

I honestly dont know what to do, either peice something together or to buy part by part.

Orr89RocZ

iTrader: (20)

Keep the compression down. Use a D-shape dish.

pearl01chevy

so after working on my buddys truck for a few weeks, it was time to get some much needed work in on the truck. Finished up cleaning the frame.. and i will never ever again paint a frame with a brush, what a pain in the *** i must say.. 2 hours to do all this and i will still need to do another coat tommorow night.. im kinda iffy on the results but ill wait till morning when its dry to make a real comment on it.. I think im to picky and i didnt tear it down enough to get into detail.. bleh

This is a quart and i still have little less the 3/4 left..

89fbrestor

looks nice.

pearl01chevy

well he offered rods to for a couple more bucks.. what you guys think? pistons have 1000miles on them, http://www.summitracing.com/parts/SLP-WL2403NF30/ from this pics they still look almost brand new and said he will get any pictures i want.. what do you guys think? btw this is the email i got from him.. not trying to bash anyone or anything, just wanna make sure this is what i do need.

I have to tell you that the rods have been ground on in several places by the previous owner to allow for block clearance. They are stock L98 rods with ARP bolts. I will throw in the rods for an additional $20, but they are real heavy so shipping costs will go up.
$220 + shipping will get you exactly what you see in the pictures.

pearl01chevy

finally got to roll the truck outside, its like 45degrees out and its soo nice out.. great feeling seeing her outside and the work of the frame payed off..

pearl01chevy

hey guys.. could really use advice on the motor.. im ready to buy everything just still unsure on what to actually get.. i can get these for 200bucks, this will work correct? there forged .. http://www.summitracing.com/parts/SLP-WL2403NF30/..
now what rods should i go with?? once i get all that i can start reasembly.

edit... been searching.. these look good? http://www.summitracing.com/parts/SCA-26200716/

project89

iTrader: (1)

dont get those rods they are 6.2 inches long not the stock 5.7 inches long
also dont get those l98 rods that have been ground on i wouldnt trust them . i would ask ur local machine shop how much for a set of recon rods with arp bolts vs a set of proper scat rods or eqiv

pearl01chevy

ok thanks for the info. rods are coming with the deal now, so ill just scrap them or sell them cheap.. i dont have many shops around here who wont screw me over either.. Rockford racecraft was right down the street but have shut down.. i got one other guy i can maybe goto sometime this week.. never heard of recon rods

project89

iTrader: (1)

recon rods = reconditioned rods its just a stock rod that has been machined to bring it into factory new spec

typically they shave the big end then install the new bolts and then bore the big end back into spec
magnafluxed to check for cracks shotpeened and stress relived etc etc etc

pearl01chevy

searched a little differently.. this doesnt look toooo bad.. pistons arent forged though http://www.summitracing.com/parts/ESP-B13403E030/

89fbrestor

have you decided yet?

pearl01chevy

noo sorry.. i just went and talked to the only engine builder in town i trust, he checked my old rods for me last build and all that.. Been a real helpful guy, but anyways.. he said everything on that assembly i posted above looks fine "besides" the pistons since there not forged.. soooo back to looking..

project89

iTrader: (1)

depending on what the chamber size is on the heads ur using

http://www.ebay.com/itm/SBC-CHEVY-38...item2c6076ff95

though im sure they have a kit with dish pistions its also a 383 stroker kit

pearl01chevy

i did see that kit before.. its nice to see everything is there even the flexplate and balancer.. i plan on using my vortec heads. but that kits for a 383 and isnt dished pistons.. could i really do a 383 with the turbo??

pearl01chevy

just found this kit, http://www.ebay.com/itm/SBC-CHEVY-35...item56454ce7f0 Hows that look??

89fbrestor

is that whole kit forged or just the pistons? have you considered buying everything separate and just having your local shop balance them. thats what i plan on doing. couple hundred bucks for a used forged crank(have it turned), $200 for a set of forged h-beam rods, $360 for set of forged sealed power dished pistons then the flywheel and balancer would probably be close to the same price your looking at for these kits but it would all be forged. my local shop will balance for $120.

pearl01chevy

trying to find good used sbc parts around here is nearly impossible, especially forged.. And if you do find them your just better off buying new for the price. Im sending the company that list that kit a email to see if its all forged or not.. Would be nice if someone on here would like to sell me all the parts i need lol

edit.. where the heck did you find h-beams for 200bucks?? or you talking used ones? and technically i wouldnt need a new flywheel and balancer if i left it 355 right?? i can use what i already got for that?

pearl01chevy

just bought my pistons thanks to perryrj! now looking for crank and rods and hopefully can get this thing moving!! Btw tax return season coming up very soon.. wanna start looking into whats a good wideband and what i can do about carbs.. i have a edelbrock 750 currently, has anyone converted to a blowthrough? or am i kinda stuck with using a holley?

pearl01chevy

hey guys need a little help.. im confused on this.. im ready to torque down my mains.. but when looking at the specs i see
7/16 inner 70lbs
7/16 outer 65lbs

but what are the 3/8 outer main cap 40lbs?? all the bolts for the mains look the same

89fbrestor

i have the torque specs somewhere out in my garage but i would think a quick search on yahoo or google would show them. any pics of recent work? good to hear things are moving along for you.

pearl01chevy

i dont need the torque specs, just wondering what the 3/8 bolts are, or if i even need to worry about them.. and no major progress.. just got the block painted and thats bout it

pearl01chevy

been a while since ive update.. havent done much lately just getting parts.. i painted the block last weekend to a grey, i wanted something different then black like the last time around and i think this will make the engine bay pop a little more.. also got my crank in and torqued.


Next came the pistons/rods i bought from a member



Just to be safe this is in the correct range right? ive only plastigauges 1 rod so far

pearl01chevy

next... i bought this tonight for a steal, 50bucks and i seen it run on the truck it came off of. its a holley 3310-2 carb which is a 750 double pumper vac secondaries, from what im reading this will be a perfect carb to covert to blowthru




and one of the truck sleeping away

pearl01chevy

will be using this link to covert carb to blowthru
http://www.hangar18fabrication.com/blowthru.html

89fbrestor

looks good.

pearl01chevy

sooo.. im down there tighting and torqueing the rod caps.. did one, went to 3.. i realized i can move the crank back and forth in the rod bearing holes without the rods actually moving.. extremely hard to explain but seems there is was to much clearance inside there allowing the crank to move around.. but im confused since i checked the tolerances and they were within spec on the 2 rods.. any advice?

gcpoland

iTrader: (18)

You can't convert a vac secondary carb for blow through.

fast82z

iTrader: (1)

Are we talking thrust clearance as in the crank can move front and back in the block, because there should be some movement that way in the order of some thousandths. There should only be a few thousandths of clearance between the diameters of the crank journal and rod bearing, so the rods have to move up and down with the crank...or more of rotation if at top or bottom of stroke.

I've also seen a guy running an edelbrock blow through, although I haven't done one. It should be the same kind of deal where you need the foam style floats and jet up for more fuel.

I've been running an AEM wideband for some years now, and it has always been good to me.

pearl01chevy

nooo fast82z.. if the crank is not moving, and i have the rod torqued to the crank, i can move the rod around with play.. its not tight at all.. seems i could almost stick a paperclip between the crank and the rod bearings.. its like this on the 2 rods i've tried.