10:1 and Forced Induction?

boffy81 · 06-22-2008, 09:59 PM

i have a 79' 350 with 10:1 flat tops,bored 40 over, with vortech heads, and a strong bottom end, is ti possbible to run forced induction or will i have to change out my pistons?

2500ak · 06-22-2008, 10:25 PM

I'm pretty sure the answer is yes. But you will have to run lower boost or higher octane fuel. Low CR means a few good things that are favorable for boost, like a wide tq band, less tendacy to knock with more timing etc... You might throw in a cam with a really wide LSA and high durations to bleed off some of that compression.

cb_silverado · 06-23-2008, 04:19 AM

yeah you deffinitely can run boost..but not more then like 8 pounds with 10:1. With good flowing heads, and a good breathing cam, it whould be pretty nasty..

blown68ssrs · 06-23-2008, 07:03 AM

An option is to swap the vortec heads with smog heads (72cc deal) to lower the static compression so you can run pump gas.

bankspowered98 · 06-23-2008, 09:43 AM

Yes you can run boost. My suggestion would be to contact NODIH. He is the man of mathematics. He will be able to tell you the maximum levels you can achieve without damaging your engine. GOOD LUCK!

Pauly · 06-23-2008, 01:08 PM

I wouldnt switch from Vortec heads to be able to run a blower. I owuld switch to a dish piston before swapping out the highest flowing stock GEn 1 heads GM ever installed on a stock vehicle.

Intercooling, meth/H2O injection, proper cam and retarded timing will all help to run a blower on Vortec heads with 10:1 comp ratio.

peace
Pauly

bankspowered98 · 06-23-2008, 01:11 PM

If you decide to run water/mth injection let me know. I can set you up with some folks that will be able to have you injecting all kinda of things

S/C Z71 · 06-24-2008, 07:05 AM

Quote:

Originally Posted by Pauly

meth/H2O injection,

boffy81 · 06-24-2008, 11:19 AM

thanks for the info i guess i forgot to mention i have a cam aswell, im running an rv cam. and yeah, id rather not switch out the vortec heads cause i just paid some big coin to buy and have them ported. i wouldnt run much boost, more for a show appeal than for power

bankspowered98 · 06-24-2008, 11:40 AM

You say that now. However, trust me on this, it is addicting. You keep wanting more.

S/C Z71 · 06-24-2008, 11:55 AM

Quote:

Originally Posted by bankspowered98

You say that now. However, trust me on this, it is addicting. You keep wanting more.

x2

xtremejimmy · 06-24-2008, 08:25 PM

really, depending on what setup you built your motor with is what determines it all. On my 01 zo6, i had an all forged 347 running 10.5 to 1 compression ratio, and I was running 14 psi making 730whp. It help find and even held up to my 200 shot on top of that without a problem. The trick is to keep IAT's down and have good fuel with a heck of a tune. Make sure to use meth injection. That is a great thing to have for any forced induction setup. I remember seeing my IAT's drop from 175 down to ambient as soon as the meth started spraying. I wouldnt go more than 8-9 psi though on your setup if you want to remain reliable. If you start making big power like I was, you start to realize that everything behind the motor starts to fail (clutches, tranny's, rears, axles, tires and more tires!!!)

blown68ssrs · 06-25-2008, 11:58 AM

Wow. Here is the equation to calculate effective compression ratio. E = C((B / 14.7) + 1)
Where E= Effective Compression, B= boost psi, and C= Static compression.

S/C Z71 · 06-25-2008, 12:33 PM

Math.

Boosted-Z71 · 06-26-2008, 02:34 PM

I would not even consider more than 7-8 psi unless you have a steel crank & definately No cast pistons. Meth injection can help alot with IAT's, it wont make up for a shortage of fuel. I am at a Cr of 10.5 / 1 on my 350, Aluminum heads will help with detonation, of course you already have vortecs which are great heads & want to keep using them. Your going to need some good fuel 91 oct or better. Street Blower motors tend to like cams in the 113-115 LSA range on computer controlled EFI. You can always call Comps Cams & talk to a rep, they will be glad to recomend a cam for you. by the formula above I am 18.3/1 Cr on pump gas under full boost. As mentioned before a great tune is going to make all the difference in the world

Boosted

XLR8N · 06-26-2008, 02:36 PM

Quote:

Originally Posted by S/C Z71

Math.

I'm with him on this

XLR8N · 07-16-2008, 07:06 AM

Quote:

Originally Posted by Boosted-Z71

Street Blower motors tend to like cams in the 113-115 LSA range on computer controlled EFI.
Boosted

I am trying to learn some FI knowledge, but wouldnt it be more reasonable to run around a 118-120 LSA? dont hate me for being dumb.

06-22-2008, 09:59 PM	#1
boffy81 Registered User Status: Offline Join Date: Jun 2008 Member ID: 90768 Pics: My Gallery Location: parksville b.c. Age: 19 Posts: 6	10:1 and Forced Induction? i have a 79' 350 with 10:1 flat tops,bored 40 over, with vortech heads, and a strong bottom end, is ti possbible to run forced induction or will i have to change out my pistons?

06-22-2008, 10:25 PM	#2
2500ak Registered User Status: Offline Join Date: May 2007 Member ID: 68421 Pics: My Gallery Location: Alaska Age: 20 Posts: 679	Re: 10:1 and Forced Induction? I'm pretty sure the answer is yes. But you will have to run lower boost or higher octane fuel. Low CR means a few good things that are favorable for boost, like a wide tq band, less tendacy to knock with more timing etc... You might throw in a cam with a really wide LSA and high durations to bleed off some of that compression. Last edited by 2500ak : 06-22-2008 at 10:27 PM.

06-23-2008, 04:19 AM	#3
cb_silverado Baggin it Soon Status: Offline Join Date: Feb 2008 Member ID: 83627 Pics: My Gallery Location: Daytona Beach, Fl Age: 25 Posts: 39	Re: 10:1 and Forced Induction? yeah you deffinitely can run boost..but not more then like 8 pounds with 10:1. With good flowing heads, and a good breathing cam, it whould be pretty nasty.. -Don't worry its only A Chevy..

06-23-2008, 07:03 AM	#4
blown68ssrs turning 10's Status: Offline Join Date: Jun 2004 Member ID: 15395 Pics: My Gallery Location: Canada Posts: 747	Re: 10:1 and Forced Induction? An option is to swap the vortec heads with smog heads (72cc deal) to lower the static compression so you can run pump gas. A bunch of 1st gen big block Camaro's

06-23-2008, 09:43 AM	#5
bankspowered98 Registered User Status: Offline Join Date: Dec 2005 Member ID: 38660 Pics: My Gallery Location: Independence MO Posts: 367	Re: 10:1 and Forced Induction? Yes you can run boost. My suggestion would be to contact NODIH. He is the man of mathematics. He will be able to tell you the maximum levels you can achieve without damaging your engine. GOOD LUCK! 454 Vortec, Whipper Charger, Banks Powerpack Exhaust, DevilsOwn alky/water injection, MSD Ignition, 454HO Cam, Roller Rockers, 42lb injectors, 20x10 305/50-20's


Home Forum Gallery Rules Downloads Supporting Member Ebay on FSC!

06-23-2008, 01:08 PM	#6
Pauly Registered User Status: Offline Join Date: Oct 2004 Member ID: 19647 Pics: My Gallery Location: Woodstock Ontario Canada Age: 32 Posts: 5,311	Re: 10:1 and Forced Induction? I wouldnt switch from Vortec heads to be able to run a blower. I owuld switch to a dish piston before swapping out the highest flowing stock GEn 1 heads GM ever installed on a stock vehicle. Intercooling, meth/H2O injection, proper cam and retarded timing will all help to run a blower on Vortec heads with 10:1 comp ratio. peace Pauly 97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

06-23-2008, 01:11 PM	#7
bankspowered98 Registered User Status: Offline Join Date: Dec 2005 Member ID: 38660 Pics: My Gallery Location: Independence MO Posts: 367	Re: 10:1 and Forced Induction? If you decide to run water/mth injection let me know. I can set you up with some folks that will be able to have you injecting all kinda of things 454 Vortec, Whipper Charger, Banks Powerpack Exhaust, DevilsOwn alky/water injection, MSD Ignition, 454HO Cam, Roller Rockers, 42lb injectors, 20x10 305/50-20's Last edited by bankspowered98 : 06-23-2008 at 01:14 PM.

06-24-2008, 11:19 AM	#9
boffy81 Registered User Status: Offline Join Date: Jun 2008 Member ID: 90768 Pics: My Gallery Location: parksville b.c. Age: 19 Posts: 6	Re: 10:1 and Forced Induction? thanks for the info i guess i forgot to mention i have a cam aswell, im running an rv cam. and yeah, id rather not switch out the vortec heads cause i just paid some big coin to buy and have them ported. i wouldnt run much boost, more for a show appeal than for power

06-24-2008, 11:40 AM	#10
bankspowered98 Registered User Status: Offline Join Date: Dec 2005 Member ID: 38660 Pics: My Gallery Location: Independence MO Posts: 367	Re: 10:1 and Forced Induction? You say that now. However, trust me on this, it is addicting. You keep wanting more. 454 Vortec, Whipper Charger, Banks Powerpack Exhaust, DevilsOwn alky/water injection, MSD Ignition, 454HO Cam, Roller Rockers, 42lb injectors, 20x10 305/50-20's

06-24-2008, 08:25 PM	#12
xtremejimmy Registered User Status: Offline Join Date: May 2006 Member ID: 46928 Pics: My Gallery Location: Miami, FL Posts: 48	Re: 10:1 and Forced Induction? really, depending on what setup you built your motor with is what determines it all. On my 01 zo6, i had an all forged 347 running 10.5 to 1 compression ratio, and I was running 14 psi making 730whp. It help find and even held up to my 200 shot on top of that without a problem. The trick is to keep IAT's down and have good fuel with a heck of a tune. Make sure to use meth injection. That is a great thing to have for any forced induction setup. I remember seeing my IAT's drop from 175 down to ambient as soon as the meth started spraying. I wouldnt go more than 8-9 psi though on your setup if you want to remain reliable. If you start making big power like I was, you start to realize that everything behind the motor starts to fail (clutches, tranny's, rears, axles, tires and more tires!!!)

06-25-2008, 11:58 AM	#13
blown68ssrs turning 10's Status: Offline Join Date: Jun 2004 Member ID: 15395 Pics: My Gallery Location: Canada Posts: 747	Re: 10:1 and Forced Induction? Wow. Here is the equation to calculate effective compression ratio. E = C((B / 14.7) + 1) Where E= Effective Compression, B= boost psi, and C= Static compression. A bunch of 1st gen big block Camaro's

06-26-2008, 02:34 PM	#15
Boosted-Z71 This is All You'll See Status: Offline Join Date: Mar 2002 Member ID: 1342 Pics: My Gallery Location: Greentown, Indiana Age: 46 Posts: 1,028	Re: 10:1 and Forced Induction? I would not even consider more than 7-8 psi unless you have a steel crank & definately No cast pistons. Meth injection can help alot with IAT's, it wont make up for a shortage of fuel. I am at a Cr of 10.5 / 1 on my 350, Aluminum heads will help with detonation, of course you already have vortecs which are great heads & want to keep using them. Your going to need some good fuel 91 oct or better. Street Blower motors tend to like cams in the 113-115 LSA range on computer controlled EFI. You can always call Comps Cams & talk to a rep, they will be glad to recomend a cam for you. by the formula above I am 18.3/1 Cr on pump gas under full boost. As mentioned before a great tune is going to make all the difference in the world Boosted 98 Ext Cab Chevy-Z71, 5.7, Built Front to Back. 87 SB 5.7 Vortec / TBi Combo, Getting Faster Everyday

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