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  #16 (permalink)  
Old 07-21-2012, 01:53 PM
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Quote:
Originally Posted by Pupsvette76 View Post
I see so actually a restrictive head will cause more boost pressure even though it's not causing an increase in power
You got it . Start by ID ing the cylinder head. The casting number is under the valve cover, between the springs. As I said some of the stock heads really really suck.
Its a place to start.
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  #17 (permalink)  
Old 07-21-2012, 02:01 PM
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I would like to invest in a set of heads just can't afford them at the moment so I'm trying to work with what I got until I can buy them but I will try more time and/or more boost and see where that puts me
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Old 07-21-2012, 02:06 PM
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Adding a intercooler cools the compressed air, allowing more boost and timing and power per pound of boost, on pump gas. Water-methanol injection is another effective way to cool the air charge, again allowing more boost and timing on pump gas.

Also increases charge density (the charge air is thicker and cooler) making more power because there is more air to combust with fuel.
The cooler the temp of the air going into the motor the less likely it will detonate ping knock.

Detontation must be avoided.

Ideally you want to pick up cool air from the front of the car, compress it in the turbo and then cool it back off (thru a intercooler) before it goes into the engine.

if the inlet air cleaner is picking up hot under hood air you have already lost half the battle. Cool air is better.
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Old 07-21-2012, 02:18 PM
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Quote:
Originally Posted by Pupsvette76 View Post
I would like to invest in a set of heads just can't afford them at the moment so I'm trying to work with what I got until I can buy them but I will try more time and/or more boost and see where that puts me
you have to watch how much boost and timing you add on pump gas.
Detonation must be avoided or the engine will come unglued in seconds.

Some of the 76cc stock heads are not too bad once fully ported.
some are not even worth the time or effort.

ID the heads you got by casting number and i can advise on their power potential once ported
or weather a head swap to a better head is a better choice.
Of the stock 76cc chevy heads there are a few desirable ones that work pretty good once ported.
And a few stinkers that are best avoided.

If you want to add boost i would get a water-methanol injection system.
They are very effective. Or run higher octane gas.

Good gas is cheap compared to replaceing busted melted pistons.
If this motor has stock cast pistons it won't take much abuse.

Fuel octane and or charge air cooling ( weather its water injection or a intercooler) is your friend.

Remember add ing more boost to a very restrictive engine ( poor heads/exhaust) does not add much power/but braings the engine much closer to the detonation limit, requiring further ignition retard.

The higher the boost the hotter the charge air the more severe the detonation shock too.
Not comparaable to the engine knock on a stock vehicle that usually does not bust parts.
Detonation under boost is much more severe and eats engine parts fast.

Does this turbo motor have stock exhaust manifolds?

Once you improve the heads port flow you get a lot more go for 5psi boost cause it is actually going into the motor
to make power and the turbo speeds up as a result.
once you get the charge air temp under control you can safely crank up the boost and timing and make huge power.
Do a google search for water methanol injection.
There are many effective systems to choose from.

Last edited by F-BIRD'88; 07-21-2012 at 02:27 PM.
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Old 07-21-2012, 02:50 PM
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Ideally to run a lot of boost (10-12psi) on pump gas without a intercooler you want a low low 7.5:1 compression ratio.
Allows more boost and timing on pump gas.

a 9:1 cr definatly limited the amount of boost you can add on pump gas.

A intercooler or a water/methanol injection system is your best friend on this one.
Do a google search for autospeed and detonation and DIY.

Read the articles on home brewed engine ears- engine knock detector to allow you to listen for engine knock-detonation.
Build the knock detector- engine listener and use it. It works.
I build one for way under $100.
You build it using a $30 Radio Shack #33-1096 or #33-1097 listener amplifier.
The modification take about 1 hour to complete.

you need this simple cheap easy to build engine tuning tool if you want to experiment with more boost and timing.

you need to be able to hear the detonation before it destroys the engine.

i have seen cheap versions of these personal listener amplifers with ear buds, in dollar stores
for as little as $1..

Last edited by F-BIRD'88; 07-21-2012 at 03:07 PM.
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Old 07-21-2012, 08:23 PM
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Hey F-Bird that sounds pretty cool. I can never hear detonation on my car and this sounds like a good answer. What exactly do you do with the amplifier, mount it on the motor?
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Old 07-21-2012, 08:29 PM
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Originally Posted by bigblockragtop View Post
Hey F-Bird that sounds pretty cool. I can never hear detonation on my car and this sounds like a good answer. What exactly do you do with the amplifier, mount it on the motor?
Read the friggin articles on autospeed.com.

Give your head a shake.
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Old 07-22-2012, 06:56 AM
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I'll friggin do that right friggin away thanks for the friggin help and the friggin english lesson ! YOU MAD BRO!
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Old 07-22-2012, 03:01 PM
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Yeah lol I'm one on the right track I already have an intercooler and a snow water injection kit just have installed them yet I didn't wanna make things any more complicated just yet
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  #25 (permalink)  
Old 07-22-2012, 03:02 PM
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Currently I'm running 30 deg total what do u think I should crank it up to just to see if there's a difference
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Old 07-22-2012, 03:35 PM
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Things will get very complicated if when you lean on it too hard with just pump gas.

If you want to play:
Get some 110+ unleaded gas so you can up the boost and timing safely and see how it should be running.

Then detune it again for pump gas.

The car wil run much better with that big cam if you jsut lock out the spark advance 30 intial and 30 WOT under boost. The big cam will love intiial timing. The idle, low end , throttle response and boost response will improve. It will idle much cleaner too.

Big WOT timing, under boost requires octane or charge cooling . The heads are dead. Quit fuggin around and fix the heads.
Then you will see how a turbo motor really runs. Turbo motors need head flow too.
If you cannot afford race heads, max port the heads you got, yourself.

Build the knock detector/listener and use it.
if you can't afford heads you also cannot afford to smoke this motor...... right

Take a valve cover off and ID the casting number

You got a huge cam (for a turbo motor) and heads that suck. just adding boost will not help it, much.

Do you have a boost retard box?

Last edited by F-BIRD'88; 07-22-2012 at 03:46 PM.
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  #27 (permalink)  
Old 07-22-2012, 03:58 PM
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No definitely don't wanna turn this motor into soup I don't not have a boost retard box I was playing with the idea of an msd btm box but haven't made a move on getting on
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Old 07-22-2012, 06:01 PM
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cylinder head casting numbers are 462624 turns out its a 1.94 int valve with 1.5 exhaust valve....small valves!
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Old 07-22-2012, 07:48 PM
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been searching around trying to find a set of suitable heads and im thinking maybe instead of using a 76cc i could running a smaller more abundantly available size cc head and run a thicker cooper head gasket (.093 compressed thickness) i think a 64cc head is widely available and cheaper and the titan copper head gaskets seem to be a good choice as far as increase my cr in order to run more boost and to seem the boost better what-da-ya think?
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Old 07-22-2012, 10:35 PM
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Quote:
Originally Posted by Pupsvette76 View Post
cylinder head casting numbers are 462624 turns out its a 1.94 int valve with 1.5 exhaust valve....small valves!
No surprise to me. Just by your discripion and complaint of lame power
I know those are the heads you had.
They are the worst of the worst crap GM ever stuck on a SBC.

No amount of boost and good wishes will fix these dogs.

A 64cc head will require a piston change. A thich gasket will not work.
There are plenty good 72+++ cc chamber aftermarket high perf heads to choose from.

Not that hard to take any of these heads and open op the chamber larger to 78-80cc to get a low compression ratio.

Low cr is your friend if you want to run big boost on pump gas.
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