z383tpi

iTrader: (1)

Well, for sometime now I've been trying to sell my vortech supercharger to go N/A because I dont think my setup will hold, and I figured I could sell it and use that $$ to buy N/A parts and get it running. Since I ran out of funds years ago due to having a family. I WANT TO ENJOY MY CAMARO!! But after pricing good N/A setups and looking at the power outputs, Im not not sure what to do.
So PLEASE!! any engine builders and those with experiance with boosted motors, chime in.

Ok, I pulled the motor from my 1990 Iroc-Z(5.7 tpi) Clearanced the motor to a 383, The cylinder walls (thrustside) are thick enough to support high #'s, they were sonic tested but I dont remember the thickness. Here is the list of parts and my concerns with them in this build..

Eagle CAST crankshaft, (500 hp recommended limit=n/a)
Forged eagle H beam rods
Sealed power -110 dished hyperutectic pistons
double moly rings with end gaps at 24 thousanths
clevites H bearing (mains & rods)
All ARP hardware /studs where applicable.
**Note! Complete balanced assembly was done by myself with instructors help and was balance to less than a Gram!( .0?? - almost zero)
Camshaft is Comp's XFi 280. (and its recommended matching valve train components,=beehive springs, keepers, spring cups, retainer..etc.etc..)
Vortech heads @ 64cc
My concern now is with this setup, and the Vortech supercahrger @ 8psi, I'll be way over my HP expectations (was shooting for 500) and bottom end limits! Most parts were purchased before I better educated my self In what I was getting into.

Will I be ok? Or should I sell and go N/A? Its sad because I have all the parts to finish the motor w/ the S.C..but if It won't hold..
Help. thoughts and opinions welcomed..I want my Z running soon..Thanks

project89

iTrader: (1)

run it , ive seen guys with bone stock motors make alot more power then that

ZZ3Astro

I think you'll be ok for a while.. long enough to save up for forged pistons and maybe a better crank down the road. That's a fairly healthy cam so you will see some rpm with that combo. You've got good fasteners and rods which are your primary area of concern with that rpm/power combination. The hypereutectic pistons are a bit worrying, but if you are a conservative tuner you'll get away with that too.

My friend has a completely stock 98 vortec 350 except for cam and matching spring mods. First he ran a 150 nitrous shot and recently went to a V1 at about 5-6 psi non intercooled. He routinely turns it over 6000 rpm. Granted he's getting some blow-by now, but that's because he has no idea what his timing is doing (blow-thru, not f.i.) LOL. Probably got a ring land or two by now. Also the engine was probably over 100k miles when he put it in his car.

z383tpi

iTrader: (1)

project89; I value your thoughts in the subject since Ive read some of your post in boosting, and all your hard work in your own project. Thank you for your imput, as far as power..what # were you refering to?? Vortech promises a 40-45% increase in Hp(stock motor). So my setup(w/boost) is estimated at approx low to mid 600hp.

ZZ3Astro; Do you know of hyperu. pistons being a weak link in a setup like this? Sure they are not forged, but at 12%+ cilicone they're pretty strong, and run tighter clearances to the cylinder walls.(less Piston slap & less chance of blowby) btw..est compression ratio us 8 to 8.5:1..

ZZ3Astro

Detonation tolerance is the main issue. By their nature, hypers are brittle compared to even cast pistons. Just don't detonate and you will be fine!

z383tpi

iTrader: (1)

qoute from the vortech instruction manual
"..adjust the ignition retard **** until just beyond the point of Detonation, use third gear for testing in a safe road or area.."
So you're saying pistons go boom at this point??

junkcltr

iTrader: (1)

Those are some of the worst tuning directions I have read. You can run the hypers as stated as long as you don't rattle them. Yes they are stronger than forged but much more brittle and crack prone.
You probably want to run them a little looser in the bore than a natural aspirated setup too. More ring gap also. The compression seems a little low for just 600HP. Running 8.5 to 9.0 would make it run better when not in boost.

z383tpi

iTrader: (1)

ring end gap is @ 24tho as opposed to 16-17 for N/A, And the est comp ratio is at 8.5 with oem head gasket thickness.
Probably will go with boost and learn more about running methenol since vortech does not offer(nor came with) a intercooler. Too bad this forum doesn't have alot of info on methenol.
? sounds stupid but I gotta ask...is HP loss @ 45k+ rpm on stock TPI setup still an issue even when boosted?

Orr89RocZ

iTrader: (20)

I'd run more valvespring with those cams...they like to float over 5600-5700 rpm if you dont have good pressure. A good small diameter double spring like Patriot extreme golds are what I'd use but beehives should be ok if you dont go over 5800.

What intake you using? TPI? then you will be ok, as it wont make power above 5500. If you use a shorter runner intake then it may pull to 6K with that cam if the springs hold but the vortec heads will be the limiting factor.

8-8.5 to 1 compression is good. You have iron heads so it will be torquey still off boost but being a centri blower, it will come on in a linear fashion so car should always feel strong. Closer to 8 to 1 is safer on that setup but what dish size are those pistons? -110 is listed...is that suppose to be -11 cc or .110" dish?

Can you swap pulleys on the blower to make it more like 4-5psi to start out with? The tune is gonna be critical and with that, it will hold 8psi + but I would start out tuning with lowest pressure you can. EDIT: i see no intercooler....definately get a meth kit. Call one of the alky kit vendors and talk to them about your setup, they will get you a pump and nozzle kit to run on that motor. This will be crucial to fight detonation. OR get an intercooler and fab up your own tubing

8 psi on that setup is gonna be closer to 500whp...probably more

junkcltr

iTrader: (1)

I think he is talking about the Speed Pro H859 pistons which are 12cc dish and .110" deep recess.
As for the methanol I did a lot of pump testing and posted it a few years ago in the power adder forum. If you are just looking for basic amount to spray vs HP that is pretty much every where on the web. The shurflo 150PSI pump has worked well for me and pulse width modulated control from a GM ECM.

With H859 pistons, .028 stock gasket, .030 overbore, 64cc vortecs, stock deck height of .025, 3.75" stroke I end up with 10:1 compression

83 Crossfire TA

iTrader: (2)

Run a safe tune an you'll be fine, start pushing too close to the ragged edge/try to get every last hp out of it and you'll find your week points quickly. With good tuning hypereutectic pistons are the way to go for a street application, they just don't have the detonation tolerance of a good forged piston so don't push them till you're sure you have a good tune that does not go lean (I wouldn't tolerate any AFR's outside the 11-12 range, usually something around 12.5 will get you more power, but if you're trying to stay out of detonation and are really worried about breaking it I wouldn't go there).

The problem I have with recommending this is that this is the kind of thing that people get burnt on, and hearing that you built it yourself and "purchased before I better educated my self In what I was getting into" make me worry that everything isn't perfect and you'll think you got bad advice when it lets go... The fact is that most let go when you start pushing them hard enough for long enough, even with the best parts, and that cam should be able to turn some RPM (well, you should end up seeing the heads limit you just because of the cubes that you have it on) which will make things more prone to pop...

Don't take this the wrong way (I would be thinking the same thing of even most engines with the same parts built by a professional builder) If this was a well maintained, stock motor with reasonable miles I would be more confident that you won't blow it up.

You also don't say what the application is, is it going to see drag use every weekend or is it just cruising weekends? 600hp on every dragstrip pass puts quite a different load on things then having a 600hp motor on the street where you really can't use it and don't have the traction to heavily load it up...

83 Crossfire TA

iTrader: (2)

If that's correct then you have a different problem...

Orr89RocZ

iTrader: (20)

Yeah 10 to 1 on iron is alot for pump gas by itself, let alone adding booost

If you want 500 hp you can do that with heads/cam

junkcltr

iTrader: (1)

I was just guessing on the H859 pistons because he mention 383 clearance the block, speed pro pistons, and 110.
That adds up to a common H859 piston, but lets see what he really has in there. If he can balance an assembly then I would think he knows how to calculate compression. I am probably wrong on the pistons....I hope I am because he could have got an balanced ebay/scat/probe/ balanced assembly with 23cc dish forged for 860 shipped and ready to go that would support 600-700HP

z383tpi

iTrader: (1)

Thanks to everyone for each of your imputs....to answer some questions.
--Orr89rocZ; After inventoring my parts, it appears my valve springs are incorrect, I believe I was shipped the wong part# Ordered 26918 rcv'd 26986-16..Max lift .575. cam=.576. Looks like I gotta buy springs again..Heres a link
http://www.compcams.com/Company/CC/c...?csid=209&sb=0
Below is the part # & description..
Sealed Power #844-8-KH859CP30

383ci w/5.700'' Rod, Hypereutectic Pistons, .030'' Overbore
Piston Dia.: 4.030''
Piston Top: -12cc Dish, 2-Valve Reliefs
Pressed or Floating Pin
Comp Ratio: 10.28:1 w/58cc Heads, 8.65:1 w/76cc Heads
5/64'', 5/64'', 3/16'' Chrome-Moly Rings

--In the High performance/blueprinting class I took we did learn how to properly calculate Comp ratio...but that Was like 3years ago so Im rusty. But I do remember learning that Comp ratio is physically less then any calculated guess, since those don't take in consideration valve releifs(somtimes), gaps in ringlands, headgasket thickness V.E. etc..etc.. which is why im ASSUMING APPOX 8.5 TO1.
500wrhp sounds great! as stated before..I was just shooting for 500 @ the crank. Was hoping to take the stock designed tpi upto 6k Rpms max...So you dont think even presuriesd the tpi will choke High RPM V.E?

-- junkcltr..Methenol is being considered not neccesarly for more Hp but for detonation resistance. Maybe just a 50/50 mix. Still need more knowledge in menthenol...could you post a link to your thread? Also the most stressed point my instructor wanted to get accross to us is that quality control these days is CRAP! never assume out of the box performance is as best as can be or in some cases, acceptable condition. Many balanced assemblies purchased at my school needed work..Im talking poor uniformity. One we worked on was featrued on super chevy or camaro performance mag? it was a TPI 383 too..chaffey College/Sherm taylor & Albert Venagas built.. Ohh and most scat is china built cheap metals...ever seen one change all kinds of colors...I have.

z383tpi

iTrader: (1)

Part two..cuz^ that was a large post...

83 Crossfire TA- I understand where you're coming from, and wouldn't blame anyone but myself is somthing goes BOOM! After all, this thread is for advise and real world experrience that I need to consider before I tighten bolts. As for my statement about educating my self, I purchased the parts before I knew exactly what I wanted/ was getting into. Like Had I know better, I would have gone with a good 4 bolt main block, forged crank & pistons. After I took the High Perf / blueprinting class is when I realized I need to rethink & recheck my work, which is why the motor has been taken apart and sittin for 4+years
Im not looking to push this motor to its edge, just a strong beast. The application for this motor is just for a weekend toy, the occasional light to light warrior, and somthing I could take to a strip or roadcourse a few times a year and not be embarrased...not a daily or street permitted vehicle...But a illegal smog just for weekend cruising is on the wish list.
Tuning is a whole diff subject...I have no education in the subject matter and will deff be #1 priority berfore the key is turned!

Again thanks to all, and please feel free to share questions & knowledge, I need it and is the purpose of this thread.

Orr89RocZ

iTrader: (20)

-12cc dish with 383 and 64cc heads, assuming zero deck with .041" gasket, I'm getting 10.2 to 1 compression

If thats really the case, you cant turbo this motor

That 10.28 to 1 advertised with 58cc chambers is like they assumed the pistons to be below deck about 0.020" or so and then you used a standard .040" gasket. Not sure why they would do that.

z383tpi

iTrader: (1)

deck height is stock, head gasket is stock thickness...how are you calculating this??
I thought the dish would compansate for the diff in stroke...I suppose I could port the chambers? maybe de-shroud the valves...

junkcltr

iTrader: (1)

With the 64cc vortec heads, 383ci, -12cc dish you are at 10:1 or a little over depending on the block and gasket. I would not used forced induction and even in NA form the cam would have to be big and good fuel.
Even opening up the chambers will not allow forced induction with those heads. I would go with something that has a 23cc dish. Maybe check out the Probe FPS pistons.

Enter your numbers into this calculator.
http://www.kb-silvolite.com/calc.php?action=comp

Orr89RocZ

iTrader: (20)

could go with aluminum heads that have a 74-76cc chamber as well to bring compression down for boost.

Or run aluminum heads with 64cc chambers to keep compression where its at and run E85. It will run on low boost at that compression and make big power

z383tpi

iTrader: (1)

I wouldnt mind running E85, after all it will be a once in a while driver...
Or go 76cc, but $$ is gonna be a problem. I wont get anyhing for my vortec heads.

What are you guys running?? comp ratio / setups..and fuel?

junkcltr

iTrader: (1)

The E85 will require big injectors and larger fuel pump. If you compare the cost of those two items, cost of new 76cc heads, and pistons and then factor in the engine is apart then I would go with the pistons. It is your call though. If you haven't bought the injectors & pump then E85 would be the way to go if you can get it local.

Orr89RocZ

iTrader: (20)

Either way I dont think you can run boost on this setup at over 10 to 1 with iron heads without a high octane fuel...E85 may beable to handle a few PSI boost but this should be more like C16 race gas...

FWIW, my aluminum headed 400 is at 9 to 1 compression and i've been up to 18psi on 93 oct pump gas no problems. 10 to 1 maybe ok with aluminum for few psi boost, but on iron I wouldnt run it. Generally aluminum headed motors can run 1 point higher compression than iron. So 11 to 1 on aluminum is closer to 10 to 1 on iron. I wouldnt put boost on my old 11 to 1 383 I went with nitrous...cheaper and easier

z383tpi

iTrader: (1)

...My concern with new pistons is $$ and rebalance. would hate to have to add metal!
$$ is why I even considering the S.C sale, was hoping to use the $ from that to go/na and have a assembled motor...but I know Ima regret selling such an expensive part for little $ and knowing I could have had more power. Its looking more like Im going N/A...maybe trade for complete top end (aluminum heads as suggested) and some $$.

hmmm.. guess I gotta do some research and weigh my options.

junkcltr

iTrader: (1)

If you don't want to change pistons then the next best thing I think is to change the heads to a 72cc or bigger chamber. If it was mine I would rather use a junk GM head like an 882 to get the compression down and keep the SC before I considered selling the SC.

Orr89RocZ

iTrader: (20)

pistons and rebalance is likely less money than decent set of aftermarket aluminums but much more time consuming and PITA to do. Could shop around and see if you can find a set of aluminums in 72-76cc's but 64-65cc COULD work at 10 to 1 with alittle bit of boost...not much tho.

If you went n/a, the vortec heads will be holding that 383 back a good bit so you should consider swapping heads anyway.

z383tpi

iTrader: (1)

Thanks guys, Ima start looking for a set of (factory) aluminum 76cc heads and do some port work to them...any castings you guys would suggest??

Also, is there any 76cc allum heads that run vortech style manifolds? I have a bnib eldelbrock vortech manifold I'd hate to have to sell....maybe cast iorn 76cc V. style manifolds?...