Ryans99ls1

iTrader: (16)

OK ive been trying to decide what to do for awhile now.. I know its time to upgrade the heads on my car and i wanna know the best way to go about it is. i wanna know if i should pick up a set 243's and get them ported or if i should just take my 853's to get ported? I plan on spending about $800. So if i get the 243's for about 400 and spend another 400 on porting will they outflow my 853's if i just spend 800 on porting those? the flow numbers im shooting for are 300+cfm on the intake side and 230+cfm on the exhaust side. Can 853's even be ported to flow that much? full details please

i know people are going to say just save up and buy TEA's or AFR's or PRC's, but i can get some 243's for pretty cheap and i really kinda wanna do this as an experiment.

keep in mind, i have NOT looked up porting prices, i know they are expensive but im just trying to get a feel for which direction i should head. If 800 wont get me the numbers i want( im pretty sure it wont) thats fine, then disregard the price ive put on it.

speedthrillsme

iTrader: (2)

Its my understanding that once 853's, 241's or 243's are ported they all flow about the same. I could be wrong and I am sure I will find out if I am.

NemeSS

iTrader: (127)

TSP has a program whreu can send in your good cores and they will cnc port them and have a few options as well

outkast6991

iTrader: (34)

243's will slightly out perform 241/853's when both ported

lemons12

iTrader: (71)

YOu can get a set of used PRCls6 stg 1 heads for around 800+shipping w/ springs.. That will be over your 300cfm flow goal as well.

01'SSLSX

where can u get 243's for $400?

243's are the way to go.

outkast6991

iTrader: (34)

you can find some used one's in the classifieds for 400-500. i paid $550 then sold the springs so i ended up paying $350 for the castings with valves. you can get new from SDPC for just over $600

Ryans99ls1

iTrader: (16)

local guy and theyre bare

socal

iTrader: (1)

the cnc program my friend uses cuts them all to be the same and then he just hand blends them

98z8uup

iTrader: (7)

Do you mean that stock 243's will out flow ported 241/853 heads. Or ported 243's will out perform them a little better.

02*C5

iTrader: (1)

243s will out flow and out perform 241s. I know this because I fought this battle. I had a set of 241's ported, deck milled .030, and 59CC chambers. I went with a different set of heads, 243s, cnc, ported, deck milled .005 and standard 64CC chambers with the same cam I gained 20rwhp with a larger cam I ended with 450+ rwhp on an A4 so that should tell you what a difference 243's make.

This is on an LS1 engine w/ over 80K on the clock.

LilJayV10

iTrader: (39)

So you put the 243 heads and a bigger cam on the engine at the same time?

lemons12

iTrader: (71)

No, not if I understand him correctly... He put the 243s and picked up 20Rwhp and then put a bigger cam in and made 450Rwhp with the 243s.

outkast6991

iTrader: (34)

the 243 is a better casting all around. if you port a 241 and a 243 the 243 will come out ahead assuming you have a head guy that knows what he's doing

98z8uup

iTrader: (7)

So the best thing is to get a set of use 243 and use them stock and, until he save some money to get them ported.

Damian

iTrader: (89)

If I was in this situation I'd take a 243 casting, cut a good valve job in it, do a good blend, deck them .015 and put it on the car. You can get this all done under $1000 (including the price of the heads) and have more compression than a 5.7L head, more piston/valve clearance.

I've done a couple of cars with 243's done the way I described, a custom cut cam, and normal bolt ons making 430-440rwhp with a nice flat TQ curve.

outkast6991

iTrader: (34)

this is exactly what i did. 243's with a hand blended VJ, throats opened to **% of the valve and blended. without the valvetrain i'm into them for $1200($350 for castings+$850 for the machine work)

02*C5

iTrader: (1)

You got it.

Ryans99ls1

iTrader: (16)

that sounds like a good plan. i still got a good amount of research to do but thats good advice.

SweetS10V8

iTrader: (4)

Your best bet is to just save about $200 more and buy a set of CNC ported 243s. Texas speed starts with new castings, flow what you want, and are like $1025.

http://www.texas-speed.com/shop/item...d=649&catid=20

having someone port your heads isnt a good idea unless they flow them before and after to prove they didnt screw up their heads.