hectre13

iTrader: (4)

Hey All,

So my 350 setup right now has a set of crappy Stock L05 (193) swirl port TBI heads that have been rebuilt and are using crane valve springs. Crane Gold Race Full Roller Rocker Arms (1.5, non self aligning, narrow body). and Summit One piece forged chromemoly pushrods. I am also running a Comp Cams Thumpr Cam (279 and 297 duration, 0.479 and 0.465 lift (with 1.5 rockers), and 107 degree lobe separation, flat tappet hydraulic 279TH7 )

So I know that the 113 heads are 58cc heads vs the 64cc heads and that will bump up my compression ratio some, but does anyone see any major concerns with me swapping to these heads? from what I have read is that these stock support a max lift of .480 and that people were saying that with aftermarket springs that they can support up to somewhere around .525 without guide interference?

From what I have been reading is that the thumpr cams aren't all that great of cams.. and the whole reason we got them was because we tried getting the biggest cam we could to fit under those heads (which maxed out at .480 lift too because of valve stem seal interference).

I was wondering if it made sense to swap in the new heads and 1) stick with the same camshaft and just work with what I got. 2) put in a bigger camshaft that would give a little more performance (assuming that I'm not overlooking something with the left numbers) 3) swap out camshaft for a different recommendation (possibly smaller?)

Also, I know that I would need guide plates to run the rocker arms I currently have, would this affect my pushrods at all?

pound

iTrader: (7)

I wouldn't swap 193 heads for 113 heads. Thats a lot of work for not much if any gain. If you are willing to go through the trouble of a head swap, you might as well get some decent heads and a matching cam.

hectre13

iTrader: (4)

So you are trying to tell me that the cast iron smog restricted swirl port truck heads are equal in performance to the aluminum L98 heads from a 91 corvette? my car is on a budget build, and am getting a set of these heads for almost nothing vs $800+ to get aftermarket.. and it really isn't that much work to swap them on my carb'd motor. your response seems to be more of an opinion than any kind of actual advice.

Fast355

iTrader: (2)

I also agree with him. Not worth the time or gaskets to swap. The L98 heads don't breathe all that much better stock for stock. If you could find some ZZ4 heads they where an improved casting, have a revised valve job, and some pocket cleanup out of the box. A ZZ4 350 at 10:1 compression with a 208/221 @ .050, .474/.510" roller cam only makes 355 HP with a 750 4bbl carb and headers.. I was making about 330 HP (270 RWHP) from a 8.8:1 compression 350 with stock 810 swirl port heads and a GM 203/210 @ .050, .476/.480" lift LT4 cam running a 2bbl TBI setup.

pound

iTrader: (7)

You should read this thread - https://www.thirdgen.org/forums/tbi/...-headflow.html

If you are on a budget, then you may want to look into porting the 193 heads and doing the modifications to run a higher lift cam.

hectre13

iTrader: (4)

from what I read is that the aluminum L98 heads (128 heads) were not much better than the cast iron version, but that the later 113 heads were based off the ZZ4 setup and and had an improved exhaust port. I have a local machine shop that has given me a decent price on doing a rebuild, mild porting, and valve job for a really good price (I know the guy) on the aluminum heads. from almost everywhere that I have read says to ditch the L05's and now you guys are telling me I should keep them? this site is giving me all sorts of contradicting information.. ugh.

Fast355

iTrader: (2)

You got it backwards......The 113 heads ARE later alumninum corvette heads. GM released the ZZx series of engine in the late 80s/early 90s. The ZZZ, ZZ1 and ZZ2 had something like a 230/230 @ .050"/.480/.480" lift cam. When GM moved on to the ZZ3 and ZZ4 engines they revised the pistons, crankshaft, connecting rods, camshaft, valve springs, and worked over the 113 head design some.

What we are saying is stock 113 heads are not worth messing with unless they are ZZ3/ZZ4 heads or are worked over.

Orr89RocZ

iTrader: (20)

I'd buy a set of vortecs over 113's unless you like weight savings of aluminum like i do. 113's are great with port work, and guides cut down, better studs for stability, etc. but that is some money in work.

DynoDave43

iTrader: (11)

Fast355

iTrader: (2)

People under estimate the power you can make with a set of swirl ports. I saw another low compression build for a boat using a stock L31 Vortec cam that made 280 HP @ 4,500 rpm and 285 HP @ 5,000.

DynoDave43

iTrader: (11)

I'm not overly greedy. Something in the neighborhood of 300 horsepower would be plenty for me.

Sorry to take you off topic, hectre13.

hectre13

iTrader: (4)

No worries.. just trying to find the best budget friendly solution, I would prefer to get away from the L05 heads if possible. I may start looking into vortec heads.. but again.. that isn't going to be cheap either considering I would have to change out my intake too

Fast355

iTrader: (2)

I don't understand wanting to remove a head you are not even close to the potential of.

This was a 9:1 compression, .040" over 305 with flat top pistons, crane 272 H10 cam 216/216 @ .050, .454/.454" lift, 110* LSA, 64cc 350 810 casting TBI heads, 1980 chevy pickup aluminum dual jet intake and dual jet carb (front half of a Q-Jet), into shorty headers for a 1997-1999 C1500. Running a TH350 with a 2,600 rpm converter and 2.73 gears out back. Running in a 1980 C10 long bed pickup truck. The 85 mph speedo was pegged in less than 15 seconds from a stop, even spinning the right rear tire on launch.

hectre13

iTrader: (4)

I would have to pull the heads and have them rebuilt anyways, and have to do a pretty heavy porting job to do this, I was hoping to get this done for the cheapest/best bang for the buck (which is why I was gonna go with the 113's that I was gonna get for basically nothing), I understand that you favor the swirl port heads, but from what I understand is that a set of vortec's have much more potential (906/602), so why would I want to waste my time with these? especially since it looks like I can pick up a set of vortecs (used) around here for like $100-200

Fast355

iTrader: (2)

Well that changes things a bit. Didn't know you needed to rebuild your swirlies. In that case I would go with a 906/062. Just get them checked out before you put any money in them as they are crack prone. That being said I would go aftermarket aluminum over putting any money in 062/906. Edelbrock's Etec 170cc head can support over 450 HP out of the box and cams with up to .575" lift.

Pickup a core set of heads for $75 each.....Your in $150.00.....Now get them cleaned/surfaced/magnafluxed. Your now up to $150.00 each before you even touch the valve job. Cut the guides and perform a valve job, now you are up to $250-300 each. Finally pickup some springs, retainers, & keepers and you are up to $400-450 each. You can pickup a new in box Etec 170 for $661 each. To me it just doesn't make sense to not go aftermarket alumnium. You can run a full point higher compression with aluminum and gain 8-10 ft/lbs across your entire power curve.

http://www.jegs.com/p/Edelbrock/Edel...50168/10002/-1

hectre13

iTrader: (4)

it's easy to just suggest to buy aftermarket heads, but not all of us can afford that. like I said before, I know a guy who can give me a deal on machine work, so buying used and going from there isn't a huge deal, nowhere near your estimates on having them rebuilt.. I could probably have the set of heads rebuilt with a valve job for somewhere in the $200-$300 range, plus the cost of heads.. so potentially $300-500 for a used set, for rebuilt heads isn't bad.. vs $1300. Heck I can even go fully assembled vortec's on summit with a lift of .510 out of the box for $634 shipped. which may be the way I might go to not have to worry about finding a set of donor heads without issues.

Fast355

iTrader: (2)

Unless you do porting you are going to give up 30-40 HP so you might as well keep your swirlies.

hectre13

iTrader: (4)

are you trying to say that if I put on the summit vortecs I am going to lose 30-40 hp from where I am at currently?

8Mike9

Lemme pipe in if I may...based on something that I was involved with years ago.

I had a set of the swirl port heads that the OP has, a friend of mine needed a set so I gave them to him...he first had them flowed after clean up, he then ground out that "fin" in them, flowed them again...the change was minimal...I don't have the numbers anymore, but the gains were not worth the time it took with the die grinder.

Off to the internet we went, and what we found was many who tried to port the heads as they would do L98 heads, etc...and gains were minimal as well.

How anyone thinks the 193 heads are good for anything but pulling a boat out of the water, I'll never know.

Now let's take look at the 113's...immediately better flow than the 193's...plus the raise in compression, and ability to run more timing along with it...is an immediate improvent over the 193's.

Now let's do some port work...porting the 113's is a cinch, Al., goes away quickly and cleanly...somewhere I have templates for the L98 porting a member did here about 10 years ago...he ported them in 4 stages and flowed them, tweaked a bit, then made porting templates...I went to his "stage 2" port job using his templates, but never had them flowed.

Bottom line, bolting on the 113's will be an improvement, the tool to cut the guides down is about 50/60 bucks retail...probably cheaper if you search around.

The benefits of the 113's:
1/2 the weight
higher compression
better flow in the higher lifts
Much easier to modify
Much higher potential

Benefits of the 193's:
Will hold the door closed in a heavier wind.

cuisinartvette

Exactly those old iron heads are POS throw them in the trash where they belong. Let someone else waste their time with themand rave "but its stock stuff!" Who cares

Why eat an old ham sandwich trying to make it taste like the steak you got in front of you!

The 128 heads were used prior to the 113s on the L98

If you can spring for the Summit vortecs youre worlds ahead. Bonus is you get that awesome combustion chamber and an easy 20+cfm. Run a wider split on the exh if you change cams youll like it.

Be careful about taking the grinder to the Vortec heads you can go backwards in # real quick if you dont know how to get them to respond.

If you keep the aluminum ones the tool to turn the guides down is cheap, there are kits (Chris Straub sells them) that have the different retainer/keepers for the Vortec heads to run a bigger cam without all the hassle.

Fast355

iTrader: (2)

I have built numerous 300+ HP 350 engines with swirl port heads, some untouched factory castings.

I have used 601s/416/081s and 083/217 heads as well as 059, 062, and 906 heads.

That being said I would not waste my time with any stock GM casting if I wanted to go fast. Start with something aftermarket and aluminum. You can run more compression and gain flow out of the box not possible with the factory junk. Just about any head cast after 1973 will be a lightweight casting and more prone to cracks. I have a pair of cracked vortec doorstops that came off an engine that did not even get that hot after the radiator drain plug started leaking but yet still cracked.

Fast355

iTrader: (2)

That is the way I feel about ALL iron heads, iron = JUNK as far as making power on todays gas.

Aluminum rejects heat from the chamber much more effectively allowing for a higher compression ratio with less octane requirement.

8Mike9

I'm not quite sure what you are saying here, other than to go aftermarket, which isn't in the OP's budget.
I don't discount the fact you can make 300hp with swirlport heads, but you reach the limit of flow at higher lifts, and basically choke an engine that even if you were to run 083's on it instead, would make more HP...possibly less torque down low, but better breathing potential in higher RPMs and higher lift.

Depending on the price of the 113's, plus rebuild cost(what about 250-300)..I think with a bit of massaging the OP can still scoot along nicely, and keep 500 min in his wallet.
Not everyone can spring for AM heads, but can still go fast with some elbow grease.

TTOP350

iTrader: (8)

I did a set of 113s for a friend back in the day.
Picked up 6 tenths in the 1/4 with the 113s, a days worth of porting and 0 other changes to the combo. (stock iron L98 heads)

Never been a fan of the swirly port heads. Door stop, that's great! I'd get tired of moving those heavy things so Id use them as a 1 time use boat anchor. (and have b4!)

Orr89RocZ

iTrader: (20)

All stock irons or aftermarket irons? There are aftermarket iron castings in iron head classes that make big numbers, just not as popular. Bowtie large port vortecs are good castings and really can improve.