Help me select my engine combo - budget build
02-13-2007, 06:47 PM
#1
Help me select my engine combo - budget build I need help selecting the right head/cam, etc. to make my project go.
Here are the specs:
85 Corvette
3.07 rear gear
2001 4L60E trans
LS1 from a Corvette
Requirements:
1. My wife will be driving this - so, it MUST idle well - but performance is crucial.
2. 1/4 mile performance at 12.5 or better
3. It must run cool and allow for the a/c to run full blast (we live in Florida)
What I currently have:
LS1 block (98)
Pair of 2001 LS1 heads
LS1 Vette (non-EGR) Intake
1" 5/8 Pacesetter shorty headers
I like the idea of the Patriot heads and cheater cam...but am open to suggestions, quality used parts...or other ideas to keep the total engine build price LOW. Part of the fun in doing this project is minimal expense.
I plan on installing a TRANSGO kit and plan on using a stall converter (used if at all possible).
Fire away!
If you have 20 minutes to kill...the whole story and pics of the LS1 build are here:
http://www.mcspeed.homestead.com/Frankenvette.html
Here are the specs:
85 Corvette
3.07 rear gear
2001 4L60E trans
LS1 from a Corvette
Requirements:
1. My wife will be driving this - so, it MUST idle well - but performance is crucial.
2. 1/4 mile performance at 12.5 or better
3. It must run cool and allow for the a/c to run full blast (we live in Florida)
What I currently have:
LS1 block (98)
Pair of 2001 LS1 heads
LS1 Vette (non-EGR) Intake
1" 5/8 Pacesetter shorty headers
I like the idea of the Patriot heads and cheater cam...but am open to suggestions, quality used parts...or other ideas to keep the total engine build price LOW. Part of the fun in doing this project is minimal expense.
I plan on installing a TRANSGO kit and plan on using a stall converter (used if at all possible).
Fire away!
If you have 20 minutes to kill...the whole story and pics of the LS1 build are here:
http://www.mcspeed.homestead.com/Frankenvette.html
02-16-2007, 03:25 PM
#4
CheaTR cam is better for applications with exhaust manifolds. While it works well, I'd think you may be leaving some torque on the table. With your wife driving, and idle quality in mind, best compromise for power and drivability would be with -15 to -10 degrees overlap at .050" lift. Cams that meet that:
210/216 114 LSA = -15
212/218 114 LSA = -13
210/216 112 LSA = -11
208/214 110 LSA = -9
All should make excellent torque down low. The 212/218 would probably make the most peak HP at the highest engine speed. 208/214 would make the most possible torque in the daily driving range. Honestly, you could probably make do without a converter with cams of this size, but that may make it toughter to get your 12.5 ET.
Remember, you are replacing an engine that made ~ 225 fwhp, with one that should make close to 400 fwhp with those heads, exhaust and a tune. You won't need a lot of cam to make 430-440 fwhp, which should put you over 380 rwhp, plenty for a 12.5 with good traction.
210/216 114 LSA = -15
212/218 114 LSA = -13
210/216 112 LSA = -11
208/214 110 LSA = -9
All should make excellent torque down low. The 212/218 would probably make the most peak HP at the highest engine speed. 208/214 would make the most possible torque in the daily driving range. Honestly, you could probably make do without a converter with cams of this size, but that may make it toughter to get your 12.5 ET.
Remember, you are replacing an engine that made ~ 225 fwhp, with one that should make close to 400 fwhp with those heads, exhaust and a tune. You won't need a lot of cam to make 430-440 fwhp, which should put you over 380 rwhp, plenty for a 12.5 with good traction.
02-17-2007, 08:11 AM
#5
Originally Posted by hammertime
CheaTR cam is better for applications with exhaust manifolds. While it works well, I'd think you may be leaving some torque on the table. With your wife driving, and idle quality in mind, best compromise for power and drivability would be with -15 to -10 degrees overlap at .050" lift. Cams that meet that:
210/216 114 LSA = -15
212/218 114 LSA = -13
210/216 112 LSA = -11
208/214 110 LSA = -9
All should make excellent torque down low. The 212/218 would probably make the most peak HP at the highest engine speed. 208/214 would make the most possible torque in the daily driving range. Honestly, you could probably make do without a converter with cams of this size, but that may make it toughter to get your 12.5 ET.
Remember, you are replacing an engine that made ~ 225 fwhp, with one that should make close to 400 fwhp with those heads, exhaust and a tune. You won't need a lot of cam to make 430-440 fwhp, which should put you over 380 rwhp, plenty for a 12.5 with good traction.
210/216 114 LSA = -15
212/218 114 LSA = -13
210/216 112 LSA = -11
208/214 110 LSA = -9
All should make excellent torque down low. The 212/218 would probably make the most peak HP at the highest engine speed. 208/214 would make the most possible torque in the daily driving range. Honestly, you could probably make do without a converter with cams of this size, but that may make it toughter to get your 12.5 ET.
Remember, you are replacing an engine that made ~ 225 fwhp, with one that should make close to 400 fwhp with those heads, exhaust and a tune. You won't need a lot of cam to make 430-440 fwhp, which should put you over 380 rwhp, plenty for a 12.5 with good traction.
Great info....what heads/head mods to you suggest for this cam range?
02-17-2007, 10:55 AM
#7
Simply add a larger short block (408+) with a cam just large enough to pull high idle vacuum numbers (you can use your stock un modded heads for this). This combo will be more street friendly and will develop lots more torque which is what you want with your stock ring gear.
There is no replacement for displacement (well...dry nitrous maybe)
There is no replacement for displacement (well...dry nitrous maybe)
Last edited by gollum; 02-17-2007 at 11:00 AM.
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02-17-2007, 11:35 AM
#8
Originally Posted by gollum
Simply add a larger short block (408+) with a cam just large enough to pull high idle vacuum numbers (you can use your stock un modded heads for this). This combo will be more street friendly and will develop lots more torque which is what you want with your stock ring gear.
There is no replacement for displacement (well...dry nitrous maybe)
There is no replacement for displacement (well...dry nitrous maybe)
02-17-2007, 04:54 PM
#9
I don't know that I'd call a 408 a budget engine, especially since you already have a LS1 shortblack to start with. More displacement will always make it easier to acheive your performance goals, but at what cost? Most of the time I see $3000 - $3200 thrown around as a base price from sponsors here for a budget 408 shortblock. The problem is 'options' can chew up your budget in a hurry. Better crank, rods, pistons and heads support more power, but can double the price.
I think your performace goal is reasonable enough to achieve with stock cubes. Before you spent that kind of money on a short block, I'd spend it on good quality aftermarket heads to enhance what you already have. Patrick G was able to make 433 rwhp through an M6 using AFR 205 heads, long tubes and the CheaTR cam. While he has used excellent preparation and an electric water pump, attention to the details could get you over 400 rwhp through your A4.
The CheaTR was designed to idle and drive like stock, and does so through modest durations and a wide lobe separation angle. A by-product of that configuration is a late intake valve closing point that drives the power peak higher. That cam peaks at 6300-6500, higher than you'll want to push that tranny without some hard parts to beef it up. Tightening the LSA will bring the IVC back and increase low and midrange punch. But it will increase overlap, unless we decrease the duration. That hefty exhaust duration is there to work with manifolds, but since you are using headers, it is a crutch we don't need.
Keeping the intake duration at 214, we can go as tight as 112 with an exhaust duration of 214 and still have -10* overlap. I think that cam would be about the best compromise between performance and stock-ish manners. PP heads would work well with this cam, but a high flowing head like the AFR's with small ports would work very well.
I think your performace goal is reasonable enough to achieve with stock cubes. Before you spent that kind of money on a short block, I'd spend it on good quality aftermarket heads to enhance what you already have. Patrick G was able to make 433 rwhp through an M6 using AFR 205 heads, long tubes and the CheaTR cam. While he has used excellent preparation and an electric water pump, attention to the details could get you over 400 rwhp through your A4.
The CheaTR was designed to idle and drive like stock, and does so through modest durations and a wide lobe separation angle. A by-product of that configuration is a late intake valve closing point that drives the power peak higher. That cam peaks at 6300-6500, higher than you'll want to push that tranny without some hard parts to beef it up. Tightening the LSA will bring the IVC back and increase low and midrange punch. But it will increase overlap, unless we decrease the duration. That hefty exhaust duration is there to work with manifolds, but since you are using headers, it is a crutch we don't need.
Keeping the intake duration at 214, we can go as tight as 112 with an exhaust duration of 214 and still have -10* overlap. I think that cam would be about the best compromise between performance and stock-ish manners. PP heads would work well with this cam, but a high flowing head like the AFR's with small ports would work very well.