engine rebuild
Thread Starter
Instructor
Joined: Jan 2005
Posts: 146
Likes: 1
From: Roanoke Rapids NC
engine rebuild
hey fellows,
i have a 74 convertible with the original L48 in it. I want to rebuild the engine with some power. I saw a performance kit that Holley makes called a Systemax 2 system consisting of new heads, cam, intake manifold, pushrods, and a double roller timing chain. is there any reason why this kit wouldn't work with my engine? If it will, i noticed some of the requirements for the kit are forged steel crankshaft 4 bolt main and GM "pink rods". does my engine have either of those now, assuming everything internal is original? I was told i might need new pistons, rings, bearings, gaskets... what else might i need for an engine rebuild with the Holley kit? i'd appreciate any help i can get.
Thanks,
Brad
i have a 74 convertible with the original L48 in it. I want to rebuild the engine with some power. I saw a performance kit that Holley makes called a Systemax 2 system consisting of new heads, cam, intake manifold, pushrods, and a double roller timing chain. is there any reason why this kit wouldn't work with my engine? If it will, i noticed some of the requirements for the kit are forged steel crankshaft 4 bolt main and GM "pink rods". does my engine have either of those now, assuming everything internal is original? I was told i might need new pistons, rings, bearings, gaskets... what else might i need for an engine rebuild with the Holley kit? i'd appreciate any help i can get.
Thanks,
Brad
Pro
Joined: Aug 2003
Posts: 673
Likes: 0
From: Jackson Ms
just finished building this kit and only have a few miles on it 
i think that's Recommendations not requirements. your 2 bolt main block will work fine. thay did bore to 30 over to make those horspower #.
you'll need new pistons, rings, bearings, gaskets, rocker arm's, oil pump.
if your old dist. and carb are good, if not may need new.
what i did is went to local shop and got a short block that had been redone and got lucky and found a 4 bolt 30 over block with forged rod's and crank and all new pistons and bearings in it.
see my post of the video made it sunday
http://forums.corvetteforum.com/show....php?t=1032824
i think that's Recommendations not requirements. your 2 bolt main block will work fine. thay did bore to 30 over to make those horspower #.
you'll need new pistons, rings, bearings, gaskets, rocker arm's, oil pump.
if your old dist. and carb are good, if not may need new.
what i did is went to local shop and got a short block that had been redone and got lucky and found a 4 bolt 30 over block with forged rod's and crank and all new pistons and bearings in it.
see my post of the video made it sunday
http://forums.corvetteforum.com/show....php?t=1032824
Instructor
Joined: Dec 2004
Posts: 230
Likes: 6
From: Washington DC
I new to this game and was thinking of the same packages. However, if you have to buy new pistons, rings, bearings, gaskets, rocker arms, oil pump, then is a new ZZ4 a better choice? What kind of HP and TQ will the Holley package make?
http://www.gmpartsdepot.com/?src=ggmcre
http://www.gmpartsdepot.com/?src=ggmcre
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Originally Posted by Al77Vette
I new to this game and was thinking of the same packages. However, if you have to buy new pistons, rings, bearings, gaskets, rocker arms, oil pump, then is a new ZZ4 a better choice? What kind of HP and TQ will the Holley package make?
Pro
Joined: Aug 2003
Posts: 673
Likes: 0
From: Jackson Ms
let's see...zz4 $3779.00 355 horsepower at 5250 rpm
or
local shop rebuilt block $600.00
holley kit $1400
gaskets $ 100 kit
rocker arms $100 summit roller tips
oil pump $40
what $ 2300 there about?
425 horsepower at 6150 RPM
leaves about $1400 to play with.
i'm a cheap'o so got the kit.
i allso got hooker headers and header back pipe kit and a holley 750.
got it in the car and running for under $3000.
but it's your car so do what works for you and good luck!
or
local shop rebuilt block $600.00
holley kit $1400
gaskets $ 100 kit
rocker arms $100 summit roller tips
oil pump $40
what $ 2300 there about?
425 horsepower at 6150 RPM
leaves about $1400 to play with.
i'm a cheap'o so got the kit.
i allso got hooker headers and header back pipe kit and a holley 750.
got it in the car and running for under $3000.
but it's your car so do what works for you and good luck!
Instructor
Joined: Dec 2004
Posts: 230
Likes: 6
From: Washington DC
Here’s my problem. I have purchased 77 with a number of updgrades:
Engine block; 14101074 80-85 truck
Heads; 14102193 87-95 Swirl Port
Intake 14101074 can’t find specs.
Stock Q-Jet
Stock 3.36 rear
I added long tube Headers, MSD 6AL, New Distributor and sent the car to a speed shop for ½ day of dyno-tuning to achieve a whopping CWhlPwChp =209Hp, SAETrq 334Tq and SAEPwrCHp 256. I love the car, I look good in the car, but I am afraid that a family sedan will blow my doors off at the track.
If its possible to get a good $600 engine block that will work, then $1400 in my pocket looks a lot better.
Thanks
Engine block; 14101074 80-85 truck
Heads; 14102193 87-95 Swirl Port
Intake 14101074 can’t find specs.
Stock Q-Jet
Stock 3.36 rear
I added long tube Headers, MSD 6AL, New Distributor and sent the car to a speed shop for ½ day of dyno-tuning to achieve a whopping CWhlPwChp =209Hp, SAETrq 334Tq and SAEPwrCHp 256. I love the car, I look good in the car, but I am afraid that a family sedan will blow my doors off at the track.
If its possible to get a good $600 engine block that will work, then $1400 in my pocket looks a lot better.
Thanks
Last edited by Al77Vette; Mar 9, 2005 at 10:57 PM.
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Pro
Joined: Aug 2003
Posts: 673
Likes: 0
From: Jackson Ms
you running a auto trans??
may want to check it out. problems there will kill hp.
that 3.36 gear not helping you eather.
if motor run's good and trans is ok i'ed look in to a gear, maybe 3.55 or 3.73
that'll bring it to life! suck a lot more gas thow.
what family sedan is that? there some fast ricer stuff out there!
may want to check it out. problems there will kill hp.
that 3.36 gear not helping you eather.
if motor run's good and trans is ok i'ed look in to a gear, maybe 3.55 or 3.73
that'll bring it to life! suck a lot more gas thow.
what family sedan is that? there some fast ricer stuff out there!
Last edited by grayhook; Mar 9, 2005 at 10:38 PM.
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Chances of finding a complete redone, forged shortbolck for $600 is being real optimisic. The cost of a block and preperation will run $600; cleaning, boring, honein, line bore etc.
The SytemMax kit sounds good. They picked parts that should work well with a stock bottom end. This is a top end rebuild. The bottom end of and engine does increase performance per say. Spending money on the bottom end is done to ensure that things will not break dur to the increase in horsepower from the top end.
As for changing gears, it will make a difference and is relative to how much of a change you make.Going from 3.36 to 3.55 would be minimal and not worth much in my book. Going to 4.11 ratio would make a difference but hard to justify if the car is driven a lot on the highway.
The SytemMax kit sounds good. They picked parts that should work well with a stock bottom end. This is a top end rebuild. The bottom end of and engine does increase performance per say. Spending money on the bottom end is done to ensure that things will not break dur to the increase in horsepower from the top end.
As for changing gears, it will make a difference and is relative to how much of a change you make.Going from 3.36 to 3.55 would be minimal and not worth much in my book. Going to 4.11 ratio would make a difference but hard to justify if the car is driven a lot on the highway.
Race Director
Joined: Jun 2000
Posts: 10,037
Likes: 668
From: FL
Cam specs for the Systemax2 off the Holley site:
Camshaft Specifications
Intake valve gross lift/duration: .490"/290°
Exhaust valve gross lift/duration: .490"/297°
Intake valve duration @ .050": 235°
Exhaust valve duration @ .050": 240°
Rocker arm ratio: 1.5
Intake valve lobe centerline: 107°
Lobe separation: 112°
Their dyno curve shows:
Horsepower: 425 @ 6150 RPM
Torque: 425 ft./lbs. @ 4250 RPM
That is a rev motor and a pretty radical cam for a daily driver on the street.
I am not too sure that a stock L-48 with cast crank and pistons will live too long above 6000 rpm.
Personally, I built a torque motor that makes over 400 ft/lbs at 2500 rpm. Now that is performance you can feel.
Camshaft Specifications
Intake valve gross lift/duration: .490"/290°
Exhaust valve gross lift/duration: .490"/297°
Intake valve duration @ .050": 235°
Exhaust valve duration @ .050": 240°
Rocker arm ratio: 1.5
Intake valve lobe centerline: 107°
Lobe separation: 112°
Their dyno curve shows:
Horsepower: 425 @ 6150 RPM
Torque: 425 ft./lbs. @ 4250 RPM
That is a rev motor and a pretty radical cam for a daily driver on the street.
I am not too sure that a stock L-48 with cast crank and pistons will live too long above 6000 rpm.
Personally, I built a torque motor that makes over 400 ft/lbs at 2500 rpm. Now that is performance you can feel.
Pro
Joined: Aug 2003
Posts: 673
Likes: 0
From: Jackson Ms
Chances of finding a complete redone, forged shortbolck for $600 is being real optimisic
, no cam, chane or gears. sold the heads for $100 to a bud so got $600 in it. even if it turn's out to be $800 for a shortblock it cheaper then a crate motor.
pretty radical cam
stops make'n tq at 4200 rpm.
i dont think it will see 6000 rpm for long on the street anyway. i've seen a few build's with a lot more radical setups on a 2 bolt block that did fine.
400 ft/lbs at 2500 rpm
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
I would agree with Steveg75 and in a way Grayhook did too. Cam that engine to reach its peak a little lower in the rpm range say 5500 to 5800. You will also have more torque at lower revs which is a good thing on the street. Don't forget the torque converter part of the equation. Last week a forum member told about his stock converter causing idle issues with his new engine ie. go with a higher stall.
