custom pistons

[k92]

The engine builder doing my ls6 engine has found that all of it's cylinders show no wear,save for #5 which shows 5 thousanths wear.I was planning on using some h beam rods which are full floating,however TRW does not make stock pistons that are full floating and/or are for 5 over bores.So I can get my stock rods redone with new ARP bolts and go 30 over and use stock TRW's, or get H-beam rods and custom pistons and leave the bores alone, or even go the custom route and still go 30 over.I was told that the custom pistons and h-beams are a lot lighter than stock,are made better, can use smaller/lighter rings.So if I go the custom route,would I be better off boring it 30 over or leaving it alone? The difference between the h-beams and ARP bolts,labor for rebuilding the stock rods is less than 200 dollars.The difference between the TRW pistons and custom pistons is around 200 dollars also.Any thoughts or suggestions?

[Chevy454]

The difference between a set of TRW and a good set of CP or Ross or JE pistons is like night and day...if ya don't believe me, just ask my burette! When I cc'd a set of NHRA legal TRW's, they came in around 28-29 cc dome...when it's *supposed* to be 34cc...our set of CP's were right on the money. The TRW's are cheaper for a reason...

What are your plans for the car?

[k92]

I don't have any plans on drag racing the car,mostly car shows,cruise-ins,short trips where I'll lean on it some.

[Chevy454]

What octane fuel you shooting for, that is, what compression ratio? If you're not gonna be racing it, then you'd be hard pressed not to get the TRW's and keep the $200+ in your pocket...

[indyjps]

depends on how much youre putting into the engine, if blueprinting everything and planning on going racing, the better pistons will show their benefit. if youre just going to drive the car and occasionally wind it up the stock set up will be fine. another consideration woudl be do you want to go .030 over now or spend the extra $ on better pistons and save the bore for later. good luck.

[olredalert]

-------First of all, why the H-beams??? My old LS6 race-car (a record holder in its day) never had any thing in it for its entire history other than the original dimple-rods. Final engine when sold had 14to1 compression, and never a hint of failure. Ran low 10s at a weight of 3950 going off. My opinion,,,stick with the dimples!!!
-------On the pistons; If you cant figure out a way to keep the standard bore and cant find a set of 20s then go to the 30s and balance the entire rotating assembly, including the clutch, and even the driveshaft if there is a hint of a question-mark. Personally I dont think you need floaters on the street the way you say you are going to use it. Racing stuff on the street is vastly over rated. You wouldnt be happy with the piston slap when cold, at least I wouldnt. Hope this helps.........Bill S

[JoeG]

I agree Bill-- especially the balancing---

[k92]

By the time that I buy new bolts,have the stock ones rebuilt and balanced I will have spent what I can get new rods for.Pistons are the same way, I won't have to bore the block and will get better,lighter pistons to go with the lighter rods.My builder is a top notch pro-stock racer named Animal Jim Feurer and is very good at the little details.The good news is that the deck is totally flat and wont need decked so I can keep the numbers w/o problems.

[Chevy454]

You'll have to have all the new stuff balanced too, so you can't count that as an additional cost...what hard parts do you already have? I agree with Bill, if you already have the stock rods, they'll be more than adequate, and cheaper to boot...I would personally try and keep from boring it if possible, so you're probably gonna have to opt for some custom pistons.

[olredalert]

-------Jims credentials would certainly not be knocked around here. You have chosen wisely, grasshopper. Im a little surprized that Jim would push the full floating pistons, however. Did he, or did he just offer alternatives??? Really, thats the part of your build-up that I dont think you will enjoy over the long run. What does Jim say the rods and pistons will do, seat of the pants??? Id be interested in knowing........Bill S

[k92]

Jim did not push anything, like you said he told me all of my options.He also just said that the weight savings of the new pistons/rods can make a difference IF you take the same approach on the rest of the engine, like lighter valves, retainers, flywheel etc...I'll check with him on Monday and see if he's ordered the new pistons/rods yet? So you guys think that I should not bore the block, go with custom pistons and just use the stock rods that I already have with good ARP bolts and have them rebuilt? He said that he likes the full floating pistons because of the fact that they have spiral locks etc..., I would've just used stock 30 over TRW replacements, but they dont make them full floating.