Re-building an older FI motor
12-30-2010, 07:41 PM
#1
Re-building an older FI motor Application: 97 corvette. 142K miles 97 LS1 w/ Vortech V2 S-trim 6 PSI (the vortech cog-belt kit not the A&A setup) Automatic w/ 3.15 gears
Other modifications:
- Vararam cold air intake
- ported LS1 throttle body
- LS6 intake manifold
- 1.8 yella terra rockers w/ comp 1218 springs
- LG Super Pro long tube headers w/ cats and x pipe
- Borla Stinger exhaust
Getting a considerable amount of blowby to where i'm only getting 4psi max according to my boost gauge. Aside from a lack of boost, everything is running smooth and quiet.
With the engine being the weakest link in my drivetrain, I'm considering re-building the motor to take full advantage of the boost as well as adding an ECS mild blower cam and up to about 7-8psi.
Questions:
1) Assuming I rebuild my existing motor, what components would I be looking to replace? Type, brands etc? Any extra components i should add for strength?
2) Assuming seperate costs for engine removal, parts, machine work, part installation, and re-installation of motor, what cost range would I be looking at?
Goals:
- This car is a street car/daily driver only, but it driven on freequent spirited cruises. I'm not looking to set track records, but i want to be able to back up my boasting.
- 500 rwhp range on conservative tune (currently sitting the 385 range according to dynojet)
- No less than 22 MPG fuel economy with cruise control at highway speed (70-80mph)
Thanks for the help.
Other modifications:
- Vararam cold air intake
- ported LS1 throttle body
- LS6 intake manifold
- 1.8 yella terra rockers w/ comp 1218 springs
- LG Super Pro long tube headers w/ cats and x pipe
- Borla Stinger exhaust
Getting a considerable amount of blowby to where i'm only getting 4psi max according to my boost gauge. Aside from a lack of boost, everything is running smooth and quiet.
With the engine being the weakest link in my drivetrain, I'm considering re-building the motor to take full advantage of the boost as well as adding an ECS mild blower cam and up to about 7-8psi.
Questions:
1) Assuming I rebuild my existing motor, what components would I be looking to replace? Type, brands etc? Any extra components i should add for strength?
2) Assuming seperate costs for engine removal, parts, machine work, part installation, and re-installation of motor, what cost range would I be looking at?
Goals:
- This car is a street car/daily driver only, but it driven on freequent spirited cruises. I'm not looking to set track records, but i want to be able to back up my boasting.
- 500 rwhp range on conservative tune (currently sitting the 385 range according to dynojet)
- No less than 22 MPG fuel economy with cruise control at highway speed (70-80mph)
Thanks for the help.
12-31-2010, 05:24 AM
#2
TECH Senior Member
What is your budget? Being in TX, you have the choice of quite a few engine builders. I've dealt with LME and they have always done great work for me.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
12-31-2010, 08:51 AM
#3
What is your budget? Being in TX, you have the choice of quite a few engine builders. I've dealt with LME and they have always done great work for me.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
12-31-2010, 04:54 PM
#6
What is your budget? Being in TX, you have the choice of quite a few engine builders. I've dealt with LME and they have always done great work for me.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
In your place, I would just get a forged shortblock and some fresh heads (or rebuild yours).
You are looking at around $3500 for a decent forget 347.
You will need larger injectors and a good fuel pump for 500 rear wheel HP. A rebuild on the Vortech wouldn't hurt either if the unit has high miles. I am in the middle of rebuilding my '01 LS1 shortblock with forged internals as a 347 and went with a 3.905 bore, Diamond -8.6cc pistons, forged connecting rods (SCAT is the cheapest I'd go, Callies/Lunati preferred), ARP head studs (more PSI = potential to lift heads from block), ARP main studs (to prevent cap walk), high flow/volume oil pump, stronger timing chain (I went with the SLP double roller/SLP oil pump combo), and medium-high grade Clevite bearings. I am shooting for 350-400 NA, 550-700 FI, reliably.
Last edited by ZexGX; 12-31-2010 at 05:05 PM.
01-01-2011, 01:38 AM
#7
Another question: How do you guys feel about fuel pump boosters versus just replacing it with a high-flow unit? I'm pretty sure that bump boosters are just to keep from digging into the fuel tank and will eventually wear out the stock pump, but I want to make sure.
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01-01-2011, 04:50 AM
#8
TECH Senior Member
Racetronic PnP fuel pump units with harness is what I used and they fed mine to over 600 Hp comfortably.
An in line fuel pressure regulator with return is something many fail to address. This will maintain cosistant pressure, especialy in higher rpms which will feed your injectors and allow them to reach their true potential.
An in line fuel pressure regulator with return is something many fail to address. This will maintain cosistant pressure, especialy in higher rpms which will feed your injectors and allow them to reach their true potential.
01-01-2011, 10:05 AM
#9
Racetronic PnP fuel pump units with harness is what I used and they fed mine to over 600 Hp comfortably.
An in line fuel pressure regulator with return is something many fail to address. This will maintain cosistant pressure, especialy in higher rpms which will feed your injectors and allow them to reach their true potential.
An in line fuel pressure regulator with return is something many fail to address. This will maintain cosistant pressure, especialy in higher rpms which will feed your injectors and allow them to reach their true potential.
