Chevy86 IROC-Z

iTrader: (17)

hi guys. Ive got a set of swirl port heads in my IROC. I read in many internet sources that these are very poor heads. So now that we are close to 1/2 ways into the year, I want to start investigating into buying some good, but affordable heads. Im not sure if I want to go with cast iron, or aluminum. I realize that aluminum is hella lighter, but here in 110* degree summers, Im afraid of warping the heads. Now with cast iron, i would be set, but I would of course add much more weight to my weekend warrior. Any suggestions on some 350 heads? Thanks guys.

88gta3508

ALUMINUM <> patriot or similar
get a high flow water pump <> drop your thermostat 180 or 160 if needed
upgrade your radiator copper 2 - 3 row
stock is single

Chevy86 IROC-Z

iTrader: (17)

OK. Thanks 88gta3508. Anyone else?

Blown84Bird

Aluminum. .. plus it's shiny lol

Chevy86 IROC-Z

iTrader: (17)

Shiny? Thats cosmetic. Im looking for durability, reliability, and performance.

Blown84Bird

Shiny. Hands down that will make it fast LOL. aluminum heads will produce more power as far as 110 summers wouldn't worry about it combustion chamber temps are well over 110. Plus when you and them on you have two big aluminum heat sinks to help dissipate heat. Plus they are lighter about 1/2the weight of cast. And they are shiny

DeathStarr89

iTrader: (1)

typically Aluminum heads are much better designed, lighter and flow better.


What is your budget?



The Edelbrock Performer RPM heads are pretty nice for the price but without upgrading the rest of the top end a pair of good heads is a bit of a waste.

Chevy86 IROC-Z

iTrader: (17)

Edelbrock heads? ok. Well my budget is nothing more than $1000. So along with the heads, I might as well get a aftermarket intake such as this Edelbrock

I also thought about getting a 58mm T.B. and a air foil for the T.B.. Is this the best way to go for a quick out of the box power upgrade?

88gta3508

the heads are a great choice for power
FORGET about that intake <> just port yours and open up the plenum throttle body area
PS.. a performance throttle body.. will have the air foil incorporated...
your going to need a prom tune

tater

iTrader: (10)

Throw some Vortec's on. Pretty good "bang for the buck".

87WS6

iTrader: (1)

I'd just port your existing intake. If you feel you need to I'd upgrade to SLP runners. It is my understanding that the 58mm throttle body is too much for most cars. If you want to make some decent power your best bet is a cam and some heads. The cam is really fairly cheap all things considered but more time consuming to install than most parts because of where it is in the car.

Saabster

iTrader: (2)

Aluminum heads are going to warp if you overheat them, not from regular operating temps. Your fears seem to be based in old school knowledge. Today's aluminum heads are built on much more proven designs. I don't think chevy even still makes engines that don't have aluminum heads on them. Iron blocks, however, are making a come back in some applications (boosted).

Chevy86 IROC-Z

iTrader: (17)

I already have a 94 Z-28 roller cam inside. I strongly believe that my swirl port heads are limiting my full potential. So around what temp can a aftermarket alum heads begin to warp when overheated?

Chevy86 IROC-Z

iTrader: (17)

Are aluminum vortecs just drop in and go, or do I need any other mods?

Chevy86 IROC-Z

iTrader: (17)

I already have the Hypertech PROM in the ECU.
Hypertech 157312

InfernalVortex

iTrader: (4)

You'll need a new intake or intake base. The intake ports on the head are taller and narrower.

Chevy86 IROC-Z

iTrader: (17)

I'll have to pass on the vortec heads. I dont want to change my upper intake. I love the TPI look (plenum and runners). They are unique and one of a kind.

I want to keep my Camaro as close as possible to an IROC-Z without compromizing it's unique intake signature look.

aremy10

iTrader: (3)

i didnt know this till last week

i watched a show on aluminum vrs steel heads

out of all the experiments it turned out that aluminum didnt have barely any performance advantage. it was a very interesting show, cause i always wondered if alumin was better. but as it turns out you can get the same power either way, the only difrence is the steel is much more durable ( obviously ) so when i upgrade ide go with steel. even though alum is "pretty" and lighter . it really doesnt make much difrence other then the aluminum does swell and shrink when heated and cooled.

dont get me wrong,, i wouldnt say no to a new set of alum. for a good deal. just tellin ya what the statistics said. they put the graghs of all the power curve and hoursepower etc. side by side ,comparing the steel with the aluminum. they were practicly the same, so in the end of the show it all came down to witch were stronger and more reliable. the cast iron took the gold. i was really suprised, cause i always thought that aluminum was way better

DJ_91RS

There are some good iron options out there. If yours is a street car, look at the mid lift flow rates. Some people look at the max w.o.t. flow, where on a street car it spends so little of it's time.

Dave

Thirdgen89GTA

iTrader: (5)

I will choose aluminum heads for their weight savings. Its worth it for me to drop 50lbs off the front of the car, especially so high up. Because reducing weight is very important to me.

The car is already running 13.5s @ 102mph in bad air with nothing more than a B-body LT1 (iron heads, baby cam), this includes the PCM pulling 5* of timing due to false knock thanks to a small leak at the header. And the engine is only rated originally at 260hp from the factory.

Chevy86 IROC-Z

iTrader: (17)

Well then. I believe Im interseted in cast iron then since there is no big difference other then looks, weight, material, and tolerence to heat. So is there any good suggestions for any iron center bolt heads? I searched jegs and all I got for a 87 IROC-z where 3 Edelbrock alum heads. http://www.jegs.com/webapp/wcs/store...Id=10002&Nty=0

Summit dont even have just heads. All I can find where head combos.
http://www.summitracing.com/search/Y...k%7cAsc&GRC=96

Chevy86 IROC-Z

iTrader: (17)

I found these on summit.
http://www.summitracing.com/parts/SUM-152123/

will these heads give me more power, or will they perform like stock heads?

DT1987RS

Brodix IK 180 is a good choice for a 350 A little over $1,000.00 but well worth it as they will outflow the vortec heads by about 18 cfm @ .500 and it is dressed with ss valves screw in studs and guide plates.

Chevy86 IROC-Z

iTrader: (17)

They look good but I'm leaning more towards cast iron. I understand that they are heavier, but Id rather have them last rather than warp in the event of a unitentional overheat. Thanks though for the suggsetion though.

DT1987RS

The next choice would be the cast iron RHS vortec head check them out.
Good luck

Chevy86 IROC-Z

iTrader: (17)

As another member posted, the vortec heads are slightly different and will require a different intake manifold. That alone would make my wallet lighter. Undecided .

Chevy86 IROC-Z

iTrader: (17)

Yup. I dont need vortec heads. Look at the difference in the bolt patterns. That would mean that I would have to junk or sell my TPI system and get a newer one that would fit correctly.

87WS6

iTrader: (1)

You only need to change to a Vortec TPI intake manifold. The plenum and runners, fuel rails etc stay the same. It wouldn't look any different than the stock setup really. Not unless someone really scrutinizes it and knows the difference. As for aluminum vs. iron, well both metals behave differently when exposed to severe heat. However under normal operating temperatures the only difference is weight. 50lbs. is a hefty weight savings and aluminum heads are one of the easiest methods for lightening the load in the front of your ride.

Chevy86 IROC-Z

iTrader: (17)

I had no idea that there was a vortec intake TPI manifold. So then a good set of vortec heads, along with the Vortec intake manifold (Edelbrock 3861 High-Flo Intake Manifold Base), would give me outstanding results right?

InfernalVortex

iTrader: (4)

I hate to jump on the TPI bashing parade, but that intake isnt good for anything but pulling stumps and looking pretty. It's far too RPM limited for making real power. You have to rely on heads almost exclusively to make power since you're so limited on cam durations, not because it's EFI, but mostly because TPI's usable RPM range is only 1000 to 4500 or so. You can make it acceptable by paying a lot of money, or just trying to make as much torque as possible to get the hp figures out of it. I mean you can make a lot of power with TPI, but I wonder how much more power those guys would be making with an intake that wasnt tuned for low RPMs.

Im not really a fan of that intake for anything other than a table ornament. It just seems like a great way to waste huge investments in performance parts by putting a TPI on it.

Also, overheating any engine is bad for it, aluminum or iron. Iron cracks, aluminum warps. Factory heads are aluminum these days. They will warranty it, I woudlnt stress too much over them overheating. As far as making power, aluminum and iron are about the same, but aluminum needs a higher compression ratio. The advantage is that aluminum is a much more workable metal and its easier to work with for porting, so a lot of high-end, high-flowing heads use aluminum. Also the weight savings are huge. It's HARD to pull 50 lbs out of a car, and especially hard to pull 50 lbs out of the front of a thirdgen any other way. Ditching the A/C, going to a ministarter, and relocating the battery all together may not even net that much off the front of the car.

MotorMouth

Here is a bunch from Summit around your price range. Just make sure you pay attention to it saying each or pair.
http://www.summitracing.com/search/D...?Ns=Price|Desc

J91

Like he says...TPI, not for me! Aluminum heads are for me.....

J91

As far as suggestions for heads- RHS

Pocket

iTrader: (24)

I cant believe anyone hasnt posted this yet

Swirl ports only came on TBI engines. You have a TPI correct? Then you dont have swirl ports

The benefits of alum for cyl head material is improved heat dissipation and weight savings. Generally factory engines with alum heads have a higher compression than their iron headed counterparts because of the dissipation. B-body vs F-body LT1s are a good example of this

You wont go wrong with RHS heads, either iron or alum. Ebay heads are also good for the money, just dont expect AFR numbers from them

The guy who suggested simply porting out the stock TPI base has never looked them over. There really isnt much material there to remove. Real flow from a TPI is aftermarket parts. Read over the various better TPI stickies for more in depth info on those

88gta3508

yes I have Looked at Many.. TPI bases runners & plenum's I ported a few sets
there is plenty to open UP
purchasing the pretty SLP or any brand after market TPI base, runners, plenum
is a waste of money your still limited to the same RPM range
unless you custom weld your runners like other post's have , now for all that kind of work
install a LT1 base have it drilled for a Dist ... your still factory.. the TPI does look cool
but a pain to take apart.. sell it sell it quick

Chevy86 IROC-Z

iTrader: (17)

I cant believe you havent read my description under my avatar yet. Notice that I have a 350 in my 86 IROC. 1986 IROC's came out of the factory with a 305 to the public. According to other sources, only 50 350 blocks where produced for testing.
And yes, I do have swirl port heads. It came with the block that I bought from a retired mechanic. Look at my profile pictures. You'll see that me and my uncle rebuilt my engine if you dont believe me. I couldn't use the other heads (350 because one had cracked which I believe was a leading cause for my complete engine failure ( http://www.youtube.com/watch?v=nHja0312gSo ). I am considering after market parts. Dont take my reply personal. We are here to help eachother. I also make mistakes and I very often overlook obvious things.

Chevy86 IROC-Z

iTrader: (17)

Sounds good. Thanks for the info bro. It's just confusing when you begin to weigh the pro's and con's of both materials. I'll take a look around. Agian thanks.

86White_T/A305

Also just so you know,if you really wanted to use vortec heads and use your stock tpi base it take a bit of time but a nice grinding tool of some sort and a steady hand can easily grind a new bolt mating surface for the proper bolt angle.

Ive dont this myself so that I can use my tpi on both vortec or no vortec heads.Now that Im switching to hsr Ill be selling my tpi for someone else to enjoy all that low grunt torque and trade for a more broad balance power band.

As for the iron vs alum head..either way you look at the pros and cons of heat,as mentioned before..once they over heat to the point of damage..you will need new heads.If your truly after 500hp even at the crank..keep in mind..the lighter the drivetrain..the less rotating mass..means more power but more importantly..much better response.

I dont know but some of you guys but I instantly noticed my weight savings on the front end going from iron to alum..and I can see it since my car has eibach pro kit and lifting back up a little.Steering response improves aswell as shock rebound.

Shaving weight matters..even if its a few lbs here in there..they add up in the long run to making a better overall package.Its not just all about hp/tq

Pocket

iTrader: (24)

This required a raised port intake at minimum. Stock for stock it wont cover

CamaroIROC88350

iTrader: (1)

You could get some aluminum heads out of a LT1 Camaro or an LS1.

Thirdgen89GTA

iTrader: (5)

Most definitely not out of a Gen 3 and up motor, LS1's are completely different and almost none of the parts interchange. The only parts I know of for sure are the lifters, and the pushrods if they were the right length. The Gen 3 and up motors use a completely different bolt pattern.

LT1s will work on a SBC, but require a remote mount thermostat, and modification to the heads. The information on the modifications needed can be found on these boards. They are not a simple bolt-on.

Chevy86 IROC-Z

iTrader: (17)

Are the 4th gens heads vortec style?

Thirdgen89GTA

iTrader: (5)

Vortecs and LT1 heads are similar, but not interchangeable.

A few passages need to be welded over to block them off, and 2 holes in the back must be drilled and tapped for steam tubes since LT1 heads are reverse cooled. If you can do the work yourself, its cheap.

If not, they aren't a great investment. Might as well spend money on AFR or another aluminum head.

Orr89RocZ

iTrader: (20)

Since aluminum heads are easier to port and cut, 90% of aftermarket heads are aluminum Easy to setup CNC processes to cut these castings. Iron would take a good bit more work since its much harder material.

Most of the as cast iron heads available arent that great flow number wise but leave room for good improvement with the right porting.

I dont know many people using an iron head on a street car who are running fast times. I see it all the time, a huge cammed setup that sounds like it will turn 10s on motor but only breaks mid 12's....maybe a big mismatch but factory iron heads dont seem to flow well and would require alot of time and money to port to acceptable levels. The out of the box aluminum heads seem to kick Iron heads butt, in bang for buck.

Many years ago, there was a thread on porting L98 iron heads and the man was able to achieve 270cfm on the intake and near 200 on the exhaust I believe all said and done. That was with larger cut valves and extensive porting. This wasnt your DIY simple quick port job. If you couldnt do that yourself which most of us cant, then you would have to pay big bucks. Could buy a set of heads for that.

RHS seems to have some good Iron castings, even the bigger dart platinum Iron eagles seem promising, but i'd spend the money on aluminum simply because you will save 50 lbs!!! Weight loss is same thing as adding hp. Take advantage of it.

Atilla the Fun

This thread is getting awfully long for no decision yet. Bite the bullet and get some heads already.
Vortecs can be had used for $76/pr. Best value per dollar. Love exh. porting.
Alum. L98 heads can move serious air if ported correctly.
There are also new aluminum heads available as low as $550/pr. bare. They're probably Chinese, but they should be okay with good porting.
To step past that, Brodix offers their IK180 heads, with either 64 or 70 cc chambers, for $710/pr. bare.
If you're willing to spend more for more flow, the best there is for SBCs is the Competition-ported version of AFR's 180 Eliminator head. These will feed a 400 to 6500 rpm, delivering over 530 horses.
Or just put a turbo on a 305 and have a whole different set of considerations.

Orr89RocZ

iTrader: (20)

These would be something like the procomp heads. From what i hear, the castings are ok, but could use clean up. The components they use in their heads however are junk. Its best to buy them bare, inspect the casting and do some mild clean up work and then build them up with your own components.

mikesanto70

only your lower intake, not the TPI, edelbrock sells one

Chevy86 IROC-Z

iTrader: (17)

uuhhhhh..... What? The thread concentrates on the heads.

86 LT1

the options are endless depends on what you wanna spend,Brodix and Dart are what we run

86 LT1

no reverse cooling different,but you could always do the lt1 swap and make some real nice power!