z28jason

Does anyone know how much a stock head can be ported and how much the max flow w
You can get out ot them

JohnS Z28

iTrader: (1)

theres not a lot of gain to see, your money is better invested in a pair of stock 243's and maybe later send those off to be ported.

gMAG

iTrader: (1)

I think the question might be, how does the flow of ported heads match up with cam @ given rpms, rather than just peak numbers.
Which heads do you have?

thunderstruck507

iTrader: (18)

Professionally ported ls1 heads will outflow stock 243/799 heads.

I have seen claims of over 300cfm on ported ls1 heads, which is more than amateur ported 243s will get you.

I don't know where this new rumor is coming from that ls1 heads are junk and can't be ported to outdo stock 243/799 castings, but it's getting old already.

Here is some ls1 junk making 41rwhp (stock 243 might get you 15rwhp):
https://ls1tech.com/forums/dynamomet...ck-valves.html

wildcamaro

iTrader: (15)

243s are better no doubt about it...I would spend the 350 to get those then I would invest 6-700 in cnc porting them...you can get good flow with ls1 heads, I just can't justify starting with the inferior platform...however if on a budget I thought I saw somewhere that ports ls1 heads for under 500, I'll see if I can find the name

3rdCoastPowerSports

iTrader: (5)

i agree with thunderstruck. look at it this way the 243 head is basically an improved version of the 241 head. they fixed some of the things that they needed to be fix on the 241 head (i.e. they raised the floor, removed cooling bump, ext.). the 241 ported will outflow a stock 243 all day long. PERIOD. A professionally ported 243 will outflow any pro ported 241. hope this helps

wildcamaro

iTrader: (15)

You can't compare a ported ls1 241 to a regular 243, obviously it will flow more, heck a ported 806 will beat a stock 243...

3rdCoastPowerSports

iTrader: (5)

i was comparing ported 241 to stock 243's because they are both in the same price range. for example you can pick up a 2nd hand set of 243 heads anywhere from $350-$500. you can also pick up a 2nd hand set of decently ported 241 heads for right around the same price.

z28jason

ok thats good to know...i just have the stock ls1 heads on my car now..my buddy was telling me that you could port and polish a stockset of ls1 heads and they would flow just about the same maybe little better than his patriot stage2 heads he had a few years ago.

garygnu

the are some threads with pics of DIY head porting .get some 5.3 heads for free or cheap to practice with.read up on where you can safely remove material from in a head runner.do you have access to flow bench.also check the price TSP ported heads.

ls1 down under

my 2 cents worth.....i recently went down the path of getting 241's ported and polished to suit my cam that i already put in nearly 12 months ago. I choose the cam based on size that trickflow use to match their heads (220/224, 575 lift , 112 lsa). I used a cylinder head place that had a good reputation and been around since begining of ls1 so had done many 241 heads. He didnt just go all out and say 'i will fully port and charge u a bucket load of cash'. Instead he asked what sized camshaft i was using, what sort of power i was after, what my whole set up was and of course my budget. He advised me what he would do to the heads so that it would suit my application. In the end as my cam is relatively small, he washed and reconditioned the heads and then proceeded to shave/mill the heads 30 thou (raise compression), 3 angle grinded the valves and seats as well as blending and porting the bowls. Isky ovate wire beehive springs, locks and retainers were used. Trickflow MLS 0.45 thou head gaskets were used to install. 36lb injectors were thrown in at the same time, efi live was used to tune mafless (no air flow metre). Seriously man, the difference the heads have made to before when it was just a cam is amazing. It has so much better response , there power throughout the whole range on tap, fuel economy is not affected when crusing along, the car is as quick dropping it at 80km/h now as it is taking of the lights from a stop start. Plus it sounds friggin awesome, it changed the sound the car was making with just the cam, ppl know that there is something angry under your hood when you are sitting there at the lights. what i'm saying is, that sometimes fully ported highes flowing heads may not be required for your aplication. Be wise, seek advice from a pro, and you will have a great street combo

bww3588

iTrader: (49)

how do you figure it is "inferior"?

Maybe his engine build does not negate a set of 350 dollar LS6 heads...

I agree this rumor of LS1 heads being junk is getting real old real fast.

Almost as bad as the rumor of one LS1 head being better than another LS1 head. All LS1 heads perform the same, yes they had some differences in casting methods that makes one head slightly cleaner than the other, but in the end, its an LS1 head and you will NEVER see a difference. EVER.

izzy_6

Im geting my stock heads ported but I was thinking about what cam can I use with the stock heads.

gtotoocool1

iTrader: (6)

this is the most intelligent post I've seen in awhile.

wildcamaro

iTrader: (15)

Inferior means Port job for port job the 243 make more power that ls1 heads...but considering that you can get ls1 heads at 1/4 the price of ls6 heads they care a good budget option...but don't sit here and say if you had your choice of ported243 or ported 241 you would take the latter, you'd be kidding yourself

gtotoocool1

iTrader: (6)

Yes the 243s are better,the biggest advantage being the improved SSR .but don't kid yourself,there are some very stout engines running 241,806s,etc.for most street builds it doesn't make that big of a difference which one you go with,assuming they are properly ported.now when HP levels go beyond a certain level,the 243 has a decided advantage.

wildcamaro

iTrader: (15)

I don't doubt that...you could port an 806 head to outflow a stock 243 if you really wanted to...but there's a reason gm started using 243/799 on z06 and newer trucks

gtotoocool1

iTrader: (6)

yep,there is.but it doesn't mean the LS1s are obsolete.i've seen too many fast cars with "inferior" LS1 heads.all i'm saying is that if you already have a set of LS1s,and your not looking for a max effort deal,your money ahead by just getting those ported.and I mean by someone that is good.
i'm probably not going to win the argument with you,your mind is made up.but I've been down this road before,spent way too much money on parts I didn't need,listening to "experts" on the interweb.

gtotoocool1

iTrader: (6)

first,ask yourself what is your goals for the car?second,don't get hung up on flow #s.a properly ported 275cfm head will outperform a improperly ported 300cfm head all day long.flow #s have their use,but are used as a marketing tool to sell heads way too much these days.
you would be surprised at how much more power you get from just a VJ and bowl blend,even if the flow #s aren't that impressive.

X-Bomb Racing

iTrader: (1)

Im having a set of 862's ported right now. We will see some flow numbers soon. I will report flow numbers back here when they're done.