1999 Stock 350 Vortec compression ratio??? - Chevelle Tech

Performance Our High Performance area

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 18 (permalink) Old May 15th, 09, 12:52 PM Thread Starter
Tech Team
Brian
 
Join Date: Mar 2006
Location: Los Angeles, Ca
Posts: 119
1999 Stock 350 Vortec compression ratio???

I just picked up a complete 350 vortec engine out of a 99 (old body style) Escalade. It is the same engine as the chevy trucks, tahoes and suburbans had in them from 96-99. The engine looks good inside so I'm just going to run it as is except for a cam upgrade. I'm just wondering what the compression ratio is on this engine? Thanks.

1998 Chevy Z71 Full Size Pick-up Vortec 350

1998 Buick Regal GS Supercharged V6. Smaller SC pulley, SLP cold air box, TB spacer

68 El Camino 350, B&M TH350, 12 bolt posi 3.73's. SOLD
71 El Camino 350/350
SOLD
70 El Camino 350, Vortec heads, Lunati 60103 cam. SOLD
69 El Camino parts car. SOLD

Jesus is my Lord. God Bless.
bigbird90650 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old May 15th, 09, 1:00 PM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: 1999 Stock 350 Vortec compression ratio???

9.4:1 i believe.
swap a cam into it, with upgraded springs and cut the valvr seat guide area down, and have a blast.


aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
post #3 of 18 (permalink) Old May 15th, 09, 1:13 PM Thread Starter
Tech Team
Brian
 
Join Date: Mar 2006
Location: Los Angeles, Ca
Posts: 119
Re: 1999 Stock 350 Vortec compression ratio???

Quote:
Originally Posted by BowtieAaron View Post
9.4:1 i believe.
swap a cam into it, with upgraded springs and cut the valvr seat guide area down, and have a blast.


aaron
I have a set of Vortec heads that have machined guides already, 202 valves, oversized springs and screw-in studs and guideplates all ready to be slapped on this engine. The stock heads that came on the motor had some hairline cracks between the valves so I trashed them. I was just wondering if I should have the heads surface machined down a little in increase the CR. What do you think? We only have 91 octane out here in California.

1998 Chevy Z71 Full Size Pick-up Vortec 350

1998 Buick Regal GS Supercharged V6. Smaller SC pulley, SLP cold air box, TB spacer

68 El Camino 350, B&M TH350, 12 bolt posi 3.73's. SOLD
71 El Camino 350/350
SOLD
70 El Camino 350, Vortec heads, Lunati 60103 cam. SOLD
69 El Camino parts car. SOLD

Jesus is my Lord. God Bless.
bigbird90650 is offline  
post #4 of 18 (permalink) Old May 15th, 09, 1:51 PM
Senior Tech Team
Paul
 
Join Date: Jan 2001
Location: Columbia, MO, USA
Posts: 14,690
Re: 1999 Stock 350 Vortec compression ratio???

Maybe a .005" cut and then install .015" or .020" thick shim headgaskets.

pdq67

Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
pdq67 is offline  
post #5 of 18 (permalink) Old May 15th, 09, 2:14 PM
Senior Tech Team
Matt
 
Join Date: Dec 2005
Location: Mt. Prospect, IL
Posts: 2,609
Re: 1999 Stock 350 Vortec compression ratio???

Quote:
Originally Posted by BowtieAaron View Post
9.4:1 i believe.
Yup,

Scroll way to the bottom:

http://autos.msn.com/research/vip/sp...model=Escalade
bochnak is offline  
post #6 of 18 (permalink) Old May 15th, 09, 3:08 PM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: 1999 Stock 350 Vortec compression ratio???

thats all i run is pump gas.. i had 62cc '461 camel humps with stock 4valve pistons, probably somewhere about 9.8:1, maybe a little more. ran good. no ping.

i run just about 10:1 with aluminum heads and 38* timing with a large cam, and no ping.
my stock lt1 trans am has 10.4:1cr and alum heads, and only has slightest bit of ping when hot with stock crappy tune.


aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
post #7 of 18 (permalink) Old May 15th, 09, 4:27 PM
Lifetime Premium Member
 
Join Date: May 2005
Location: Coon Rapids, MN
Posts: 5,679
Re: 1999 Stock 350 Vortec compression ratio???

I did the same thing as you. I left the short block as-is from GM, had only 19K on it.

{OO Malibu OO}
1999 350, Vortecs, GM's HOT cam, Holley Stealth Ram, 700R4, 4:10s
car: http://i168.photobucket.com/albums/u...ps8c002323.jpg
engine: http://i168.photobucket.com/albums/u...s/DSC03416.jpg
Bowtie-72 is offline  
post #8 of 18 (permalink) Old May 15th, 09, 7:14 PM
Tech Team
matt
 
Join Date: Jun 2000
Location: meridian idaho
Posts: 547
Send a message via AIM to 300hp
Re: 1999 Stock 350 Vortec compression ratio???

i did the same thing. i have a lunati voodoo hyd roller, threw on shim gaskets, should be around 9.6:1

matt wilson
1968 gmc 2wd short bed-385/th400/9in
1972 fj40-6.0l lifted on tons
300hp is offline  
post #9 of 18 (permalink) Old May 15th, 09, 9:54 PM
Super Mod
Mr Bill
 
Join Date: Aug 1998
Location: Waldorf Md. USA
Posts: 10,197
Re: 1999 Stock 350 Vortec compression ratio???

Brian,
Dont know what you are putting it in, but the one in my 99 Tahoe runs so good, I dont know if I would even do a cam change. It will spin right up to 5500 rpm and really pulls that 5000 lb brick around pretty good. It should haul arz in a 3600 lb car. And ... it got 21 mpg on a trip to Florida last December, probably averaging 75mph.

Its a shame you cant keep the fuel injection with it, I am pretty sure it is responsible for the awsome power and the fuel mileage.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Enginerepairshop.com

1971 Heavy Chevy - original owner
1984 Buick Riviera - original owner (Wife's car)
Team Chevelle #100
BillK is offline  
post #10 of 18 (permalink) Old May 16th, 09, 10:16 AM
Senior Tech Team
Matt
 
Join Date: Dec 2005
Location: Mt. Prospect, IL
Posts: 2,609
Re: 1999 Stock 350 Vortec compression ratio???

Is this motor a factory roller?
bochnak is offline  
post #11 of 18 (permalink) Old May 16th, 09, 10:22 AM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: 1999 Stock 350 Vortec compression ratio???

yes. factory roller.
made from 1996 to 2000.
1 pc rear seal
and has a hole for a mechanical fuel pump.

aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
post #12 of 18 (permalink) Old May 16th, 09, 10:27 AM
Senior Tech Team
 
Join Date: Dec 1998
Location: Lubbock, TX
Posts: 3,778
Re: 1999 Stock 350 Vortec compression ratio???

I rebuilt the one in my Tahoe with Speed Pro hyper flat tops, compression is right at 10:1, maybe a tad higher since I zero decked the block. I run the lowest octane pump gas with no problem, plenty of power and just short of 20mpg. The computer helps, but so does the fast burn chamber of the vortec heads.

Gary Adrian
The correct spelling is
HILLIARY
Busted Knuckles is offline  
post #13 of 18 (permalink) Old May 16th, 09, 12:12 PM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: 1999 Stock 350 Vortec compression ratio???

i also have speedpro hyper 4 valve flat tops. they are really close to the factory pistons, with zero deck and 64cc heads they claim 9.8:1cr, i think the part number is 345cp or something like that, i cant remember.

my dad had a 96 tahoe with the same motor, and it moved pretty good in that thing.
i have a 94 trans am with an lt1 in it. it is basically the same motor but reverse flow cooling and aluminum angle plug heads. the caprice lt1's had iron heads, and that is where gm based their vortec heads off of. my ta is rated at 275hp 325ftlbs and it runs damn good for a 3500lb automatic car. of course i have exhaust and some other bolt on/free mods, but 300fwhp is very fun.

aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
post #14 of 18 (permalink) Old May 16th, 09, 7:59 PM
Senior Tech Team
Matt
 
Join Date: Dec 2005
Location: Mt. Prospect, IL
Posts: 2,609
Re: 1999 Stock 350 Vortec compression ratio???

Quote:
Originally Posted by BowtieAaron View Post
and has a hole for a mechanical fuel pump.

aaron
Explain further. I though since it was EFI, the block was cast "shut", or with no mechanical pump provision. Or a block off plate?

So you can run a mechanical pump on these motors with no mods?
bochnak is offline  
post #15 of 18 (permalink) Old May 17th, 09, 10:10 AM
Senior Tech Team
Aaron
 
Join Date: Jan 2003
Location: Walnutport Pa, USA
Posts: 6,326
Re: 1999 Stock 350 Vortec compression ratio???

i thought they were shut also.
i know for sure the 87+ truck motors are shut.

mine had a block off plate, but a hole for the pushrod.
i am running a 130gph holley fuel pump (mechanical) on my 880 block (vortec block).

no mods were done to it.

hope you can make out the hole in there...









aaron

1971 Chevelle. 355, megasquirt efi. On3 7875 turbo. 4l80e, py3600, 355 gears. C5 brakes, SC&C stg2+, hellwig bars, 04-06 gto seats. 546rwhp/450rwtq with 28% converter slip on 18psi!

Little walk around video

http://youtu.be/D_B0B1RNmcc
BowtieAaron is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome