Bader-X

iTrader: (2)

car has 98 heads (ported localy with no gains) might be slightly milled to be flat with low lift 562 562 224 224 114 TR cam 918`s , T56 swap with 2007 ZO6 clutch kit ls6 intake , ported stock TB , UD pulley , LT ORY and stock Muf and 3" cutout , Lid and holley filter and FAI ... car made 353 or 362 RWHP dynojet SAE tuned.


now a used 418 ci (for 2250$ installed labor and parts with exchange - Aha that`s why ! ) (4.100 6.125 and 4.030 pistons unknown cc) with about 12 to 0 compression with the previous owners heads unknown cc chamber are being installed , gonna try to tune it with 94 oct fuel and see if it`ll work and keep you posted.



once I get the pistons CC I`ll be Asking:

1-how much is my current compression and is it tunable with 94 fuel?

2-what cc pistons to order to make the compression about 11 to 1 with 62cc heads? or what will 70cc heads make the compression?

3-in general do people tune with the cutout open or closed?

Future plans :

Heads (still seeing the options and might find good used ones locally - Shipping Prices suck! )
cam 228-234 235-246 114-118 LSK intake XER Ext lobes
Timing chain and maybe pushrods

we`ll see if it`s a lesson learned not to do what I did

KCS

iTrader: (20)

Also, find out...
1) what head gaskets you're gonna use (gasket bore size and compressed thickness)
2) the chamber volume in cc's
3) whether the piston is in or out of the hole, and how far

That info, along with the piston dish/dome cc, should help us get a little more accurate.

Bader-X

iTrader: (2)

saw the build sheet .... the bad news is the current compression is 12 to 6 with the current 70cc heads
and the sheet is not with me to know if the pistons are in the hole or out sorry ...


the pistons are Dome +5 and the gasket was cometic .40 something like that ...

now all these questions was based on the propability of his heads being 59-62 cc .... so new pistons is a must for using 94 oct fuel. (my bad bought and installed on assumptions)

1-so what Dish cc is required for a piston for 4.100 stroke with 6.125 rods and 4.030 bore that will give me 10 to 8 up to 11 to 0 compression with 62 cc heads using stock 6.0 L gaskets ?

2-and can I just order the same size pistone (4.030) and replace the current pistons or a 4.040 is a must?

3-the cheapest off the shelf forged pistons for my application are what brand and from where to order?

now I`m gonna start it on what I think is 100 oct fuel and just drive it home and park it untill I order the parts and recieve them.

1-thought the compression is 12 to 0 based on his words but my bad didn`t request to see the sheet .... and thought that his heads is less than 64 cc and he told me the pistons are maybe dome as he`s been told.

clubber

What in the hell is 12 to 0 or 12 to 6 compression ratio?

Pro_built7

iTrader: (9)

12:6:1 I think he means ^^

KCS

iTrader: (20)

Read this

12 to 0 is not a realistic ratio, neither is 12 to 6. 12 to 6 would actually be a 2:1 compression ratio, which I doubt would even run. I think you actually mean 12.0:1 or 12.6:1, and your target is between 10.8:1 and 11.0:1.

1) Assuming the piston is at zero deck (neither in nor out of the hole), Wiseco has a 4.030" piston with a 14cc dish (K454X3) that would put you at ~10.85:1 with 62cc heads.

2) It's possible, you could use 4.030" pistons, but you have to be sure that the piston-wall clearance is within spec and that there is a fresh crosshatch on the cylinders for the new rings. It would be best to go with a larger piston, and have the cylinders honed for that size so that it's not so shoddy. Plus, it'll give your machinist room to clean up the cylinder in case it's scratched/out-of-round/etc.

IMHO, I'd make sure you know EXACTLY what engine you have before you go ordering any parts. Your very next step should be to verify what pistons you have and what the actual compression ratio is. From the sound if it, you could have a stock 5.3L iron block and you wouldn't even know it...

Bader-X

iTrader: (2)

hahaha yeah it`s 12.6:1 and it states 6.0 Litre block on the build sheet ( I remember) and 6.0 L on the block and it is iron ^_^ and the pistons are Diemond and the Dome is +5 and the pistons are 4.030 .

thanks for the info saw the wiseco chart and saw the pistons you mentioned but they are 4.030 and didn`t find 4.040 for 4.100 6.125

KCS

iTrader: (20)

Yeah, 4.040" bore and 4.100" stroke may not be an off the shelf piston. I'd call and ask how much it would be. Call Wiseco, or get ahold of a guy named "brian nutter" on here. I think that they have all of their piston blueprints in CAD files, so they can take one design and cut it for a 4.040" bore size for a small upcharge. Kind of like just blowing up a picture to fit a larger sheet of paper.

Hilton

iTrader: (36)

I wonder what stock LQ4 piston would do to your setup.

I wonder what your pistons would do to my stock displacement LQ4 with 64cc heads.

:ah:
I see you have 4.030 pistons. Is it even possible to fit the LQ4 pistons in your block?

I'm still interested in what your pistons would do if I had my block bored to 4.030.

Bader-X

iTrader: (2)

keep the interst as if the engine runs ok I`m parking it until I order new -14 or so dished ones to lower my compression and I might look for a buyer in the USA for the +5 domes ^_^ but they are designed for 4.100/4.125 stroke with 6.125 rods
and the LQ9 has 4.000 bore I think so they won`t fit as the bored block is much bigger than the stock pistons.

and thanks for the info and your time KCS ^_^

Bader-X

iTrader: (2)

found another way to not change the pistons and lower my compression to the target I want

saw sold heads in the classified section here for a pair of 317 (LQ9) that its chambers been opened to 79cc !!!
didn`t know that this can be done.


so I`ll be contacting PRC for their 6.0 2.5 heads and see how much it would be for opening the chamber to 80-83cc if possible and I`ll use .051 or so head gaskets 10.6:1 - 11.2:1
and how much for 2.055 intake valves instead of the 2.02 with their 675 Lift EHT springs (LSK Lobes in mind)

or the same heads from Patriot but I really want the PRC`s but will see how much of a difference $ wise.

thanks for the help ^_^