52172

iTrader: (2)

Which flows better? I just had my heads ported out to stage two and the head porter said the 2.02 are the way to go with a stock bore as there is really not enough room for the 2.05 and they are too close to the gasket which effects the quenching of the combustion chambers? This is on a stock bore. Should I have made him install the 2.05's? My heads now flow 306 cfm at .650 and 300 at .600 which is pretty good.

FASTONE

You can go to the 2.02 valves with the stock seats,2.05 needs new seats=more money.Those flow numbers look plenty good!!

SAM98WS6

2.02 on stock bore and they work great....my 2.055s are sitting on the shelf.

Hysteria

The stock seat barely has enough room for a 2.02.

NataSS Inc

iTrader: (9)

I am running a 2.05 but had the seats upgraded to make them fit

kumar75150

Back a year and a half ago when I had my heads done, everyone told me I had to go with 2.02s.

Recently, a month ago, I had my heads redone. I went with 2.08 valves this time and picked up power from before.

52172

iTrader: (2)

you are running 2.08 valves on a stock bore?

Need2gofaster

yes i would like to know this to.....2.08 on a stock bore with no flycutting?

LSUxBlake

iTrader: (3)

I have 2.05's with upgraded seats.

52172

iTrader: (2)

what do your heads flow and are they ls or ls6 heads?

kumar75150

yes

no flycutting

244/250 .625 lift on 112lsa cam

I have valve reliefs in my pistons.

cyphur

iTrader: (10)

um, i was under the impression valve reliefs in your pistons.....is the same thing as flycutting? acheives the same goal anyhow.....

goober35

iTrader: (1)

He could have forged pistons. The they are vavle reliefs and not flycut. I think

Dustin 98TA

I have the 2.055 with the stock seats, no problems whatsoever.

wait4me

iTrader: (10)

i like my stage 3 2.08 heads and my motor is stock bore "for now" , i got mine from pete at cnc heads in florida, they cost 2900 bucks though........

TD's z

we use 2.055 in our new 2.5 5.3 heads we've been consistantly seeing numbers in the 320s at .600 with good low to mid numbers aswell that tells me a 2.055 is not too big for a 3.9 bore

kumar75150

what he said

Lunati pistons that came with valve reliefs

Cary@Perf-Induction

iTrader: (1)

IF YOUR VALVE JOB IS CUT TO 2.055 ON STOCK SEATS, YOU DO OR WILL HAVE PROBLEMS. YOU WOULD BE SEATED MORE THAN 50 PERCEN INTO THE ALUMINUM. WE RUN OUR 2.055 VALVE ON A 2.160 SEAT INSERT. 2.055 WORKS FINE ON A STOCK BORE. THEY JUST FALL OFF IN THE FLOW CURVE A LITTLE SOONER, OURS ARE THE SAME THROUGH .450 LIFT AS THEY ARE ON A 4" BORE.

Sport Side

iTrader: (6)

Is there really any reason, to go over stock size? Proof, I mean? Or is this just part of that bigger is better mantality that this site has?

Just curious, thats all. Guessing valve diameter choice has to do with the setup.

Ed Curtis

That comment will getcha in trouble...
Valve sizing and what is correct is based on a lot of things..

Engine requirements
Physical block restrictions
Chamber design
Port design
HP requirements

Still in all, you are on to something.
It's really a balancing act between what works and what is "supposed" to work...

Ed