19doug90

Well i had budgeted enough money for some dart iron eagle heads and have managed to scrounge up an extra couple bucks.

both heads are essentially the exact same, only one is aluminum, and they will both fall off power wise after .52 lift

The cam im going to be running would be able to make lift in the .54 range with 1.6 roller rockers, but only makes .510 with 1.5's

If you could only afford either slightly ported iron eagles, or go for the aluminum heads, which would you do. Keeping in mind that for the next 5 years at least i dont plan on changing anything to do with this motor.

Dialed_In

iTrader: (3)

those heads are not the same. Runners and chambers are different. Out of the box they may perform close to the same, but the Pro 1's have more potential.

1989GTATransAm

iTrader: (3)

My 200cc Dart Pro One's do not fall off up to .600 lift as that is what they were flowed to. They are a very good head. Then select a cam that can utilize the flow.

onfire

I was lookin into those dart pro 1 with the 200cc intakes ... theyre a great head.... these are a few things i would check out when comparing the 2....
--keep in mind what size rocker arm stud they come in
--if you got a 400 block to drill the steam holes
--the aluminum will displace heat better
----> if you are running 1.5 rockers now and your cam is at a 510 lift
and the spring will handle up to 520 i think it would be pushing it ... it will work for some time but will wear out faster especialy when your up in the 5500+ rmp area... for me i usualy go with a cam that is .020 lift below the max spring lift capacity.... as a general rule of thumb that is for longer spring life
and forget it if you already have 1.6 rockers...
if you realy wanted to run 1.6 get the bear head and put some matched springs for that cam to handle .540 a rough estimation i would have to say you could use a spring of 100 lbs closed(seated) and 280 lbs open ****mind you this is just roughly speaking talk to the cam manu for a more specific recomendation for that type of matchup****
so if your running a 350 with 1.5s i would check the stud size and if that matchs up
try to see if you cant get the alumin set with a slightly stiffer spring for that .510 cam because they will work for now but typicaly speaking they will wear out if your only .010 away form the max lift that the spring can handle.....

--->though it shouldnt be a problem if you go with the 1.6 and that cam with the head off put some putty on the top of piston 1 fit the head on without the gasket and put the intake and exhaust rocker on and tighten them acordingly ... then turn the moter over by hand till you see the intake and exhaust open and close twice pull the head off and measure how deep the groves the valves left in the putty ... and hope you dont have valve/piston knock no fun!!
anyhow
hope i didnt confuse you its a bite to think about but better safe than an overloaded credit card

good luck man

11 Flat

Do you mean they are loosing Flow? If so, get the ones that will leave you enough money to get them ported after. Dropping flow is one of the signs of a turbulent or inefficient port... In addition, you are going to want to get them fixed

Or do you mean one of them is ported but it drops flow after .520 lift? If thats the case stay away from it because its a bad port job. It could be fixed very easily, or it could turn into a nightmare.

19doug90

oh shoot sorry forgot to mention im using the 180cc head, anything else would be too big for my motor.

And dialed in i know the pro 1's have more potential, but i dont plan on porting the pro 1's for monitary reasons.

My choice is either ported iron eagles, or out of the box pro 1's

Trying to make up my mind which is a better decision.

Out of the box, they will both fall off around .52. And the springs on the head will be able to handle over .60 lift

As a side note if im only using .510 lift and the springs are good for way more then that, am i running too heavy of a spring and will that have any negative effect on the motor?

Dialed_In

iTrader: (3)

Get the pro 1's, and when you have some more money you can pull them off and do some work.

onfire

well it would be better to get the pro 1s and use 1.6 rockers ... what type of lifters are u using?

rjmcgee

Might want to just figure on getting the correct valve springs from the get go. My Pro Action heads had springs good to .600" lift and while I don't have bind issues it does float the valves at 5500 rpm. I don't think these guys that assemble the heads use the best springs available.

Dialed_In

iTrader: (3)

They don't use the best springs, they don't set the seat pressures, and the valves are heavy. You get what you pay for.

Just like I told you in that PM, whatever you get, you're going to want to take them apart and clean them real well. Then do a valve job and set all the spring pressures as you're putting them together.