scoobysnax83

I guess you missed my point. My point was simply that when comparing two heads from the same company the only difference is flow numbers. They are not going to change their porting technique ("port size" as you elliquently put it) from one head to the next. And as far as combustion chambers... What exactly do you mean?

1 Nasty Bird

You said peak flow #s were "Everything" in a head. That is far from true. I just want everyone to know the velocity of the port is just as impotant. A smaller port size (cc's) that has the same flow #s is alot more efficient cause its moving air at a much higher velocity, effectively filling the chamber more effectively. If you were carb'd it owuld also help with getting a signal at the carb and helping the car run smoother and waste less gas. Another very important part of the cylinder head is the combustion chamber. The overall shape and andy sharp edges al effect perfomance. Such things as smoothing out raised edge's (such as that on the GT40 ford head near the spark plug) and unshrouding the area around the intake and exaust ports is possible with most heads. You can read books hundreds of pages long on stuff like this. All im saying is there is ALOT more to it then flow #s. People just find it easier to compare flow numbers cause we dont all have a CAD program or something like pro-engineer, to compare and modify our exact port shapes and combustion chambers, so we go by flow #s.

FASTFATBOY

See this guy

www.killiansportingservice.com

He can get 270@.600...price $450 for portwork and flow one hole. You really need 280 CFM plus to support a 383 IMO.


David

1 Nasty Bird

270 CFM at .600, but whats the intake port size? 330 CCs?

Like i said earlier getting big #s isnt all that hard, getting big flow #s that will make big power is a lil more tricky. and for $450 he must not be spending the time to really do what needs to be done. Or he is selling his skills for WAY too cheap IMO. but thats just my opinion.

Fastbird93

Whoever said velocity is right. Flow numbers are NOT everything in the heads. You can have too much porting and stall out the air on it's way in.

What I'd be doing is asking for a direct comparison between the two different versions of the porting. What are the intake runner sizes, comparing the flow numbers across the board for each port job, seeing just how big the differences are. Get the heads whichever you go with, and make a cam descision with some guidance from someone who knows how to spec one out to match your heads good.

Valkyn71

Its a 205 cc intake port, not sure on the combustion chamer size. I would imagine stock tho, is there any benefit to going with a larger combustion chamber?

NightTrain66

If the $500 is for "the extra porting" only and you still need to buy the larger valves, extra machine work, etc, that could add up pretty quick but depending on your budget/goals, it might still be worth it.

If the $500 includes the extra porting, supplying the valves, machine work, etc. it is probably a VERY good deal.

If the $500 includes all of this plus better springs, retainers, locks, etc, than it is a steel.

They might be charging the same for the portwork but the extra $500 might be paying for larger valves, springs, Ti retainers, etc. These parts can add up pretty quick. If this is the case, you could possibly get away with some less expensive parts and get the better flowing head that will work with the cam that you have chose.

Lloyd Elliott
NightTrain66

jkipp84

Is this a comparison of the LE1 and LE2 packages? I think the LE1 is $1100 and the LE2 is $1600.. $500 difference. Just wondering if these are what you're talking about. Both of those prices include the cam, so if it's without the cam, minus it's price, you're still left with a $500 diff.

Just curious..

Valkyn71

Yes this is the LE1 and LE2 package. Im planning on running the LE1 cam with LE2 heads.

So yes the $500 includes the valves, better springs, retainers, extra porting, ect.

jkipp84

I believe getting the LE2 heads with the LE1 cam is the way to go then. If sometime in the future you decide to go with a larger cam than the LE1, then your heads will be ready to support what it wants to do. If you go to a 383 and can't swing the price of AFR's (which I think would be the better choice - also ported though), the LE2 heads will support that better as well.

$500 to basically avoid future regrets and make the most out of what you are able to afford later. Makes sense to me.

BTW - I'm going with the LE2 package myself

Valkyn71

How much are a set of AFRs? ~$2000? Then a $1000-1500 port job on top of that? too expensive for my blood (and college budget)

How do you think these heads would work with a forced induction engine? I think if i ever go crazy and do an engine it will be a supercharger 355 w/forged bottem end.

jkipp84

I don't know much about FI applications... If rskrause doesn't chime in on this thread, I'd PM him about it.

SStrokerAce

I'm a big fan of aftermarket heads on a 383 or boosted motor since the AFR/TFS/LT4 can really support the extra cubes.

On boosted motors you can see gains from going to 260cfm flow to 290cfm flow (IE stock LT4 to AFR 210) in the range of 30-50hp. The heads are not as critical but they do help, and the port size is just as important there.


The port size is also relevant to the motor, a optimum port for a 383 is not the same as a 350, so that's something you should think about.


Bret

1 Nasty Bird

Hope we didnt scrae this guy with all the tech. You have a good idea with the LE2 heads and LE1 cam, you should be happy if you want a quick but very streetable package. You have good room to upgrade more later if you want. That package should work well. and from what ive heard about how much everyone here likes the LE heads theyre a good deal.... that 450 dollar port job looks like somethings wrong there though.

scoobysnax83

seems like more than just the thread starter was educated here. Thanks for setting me straight everyone. I was simply trying to over simplify an obviously complex question.