built engine completed

Purchased a long block out of the classifieds here and it had quite a few issues with it. After cleaning up the heads, and freshening the shortblock, its finally up and running.

Prior to this, I had:

Stock block, heads, cams.
Kenne Bell 2.6L - 9lbs boost
Kooks LT headers.
Dyno @ 439/427

With the suspension and misc upgrades, my best time is 11.47@122.

Changes:
9.0:1 compression forged 4.6 shortblock.
3.25 pulley - making 15lbs boost
Comp 127550 cams
Phaser lockouts.
FRPP 62mm TB

found the lower compression while tuning and not too thrilled as it was advertised as stock 9.8:1. will make due with it as I may just get a smaller pulley for more boost.

Final pull I was 517/461, i believe it was only 15 degrees timing and steady 11.7 A/F, so it is a little conservative.

So 78hp/34tq gain which should do me ok. I was expecting more, but maybe with the lower compression and the lockouts, it is probably losing some.


Hoping it can give me a 10 sec slip and I will be happy with the car.

What rotating parts did you use? Can't wait to see some times.

08redgt said:

What rotating parts did you use? Can't wait to see some times.

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The parts were listed as cobra crank, manley rods, and JE pistons.

Awesome man! So much for us being a close match. LOL

Looking forward to seeing it run next spring.

Does anyone think my numbers are low? Had a couple friends question it, and I know the lower compression and lockouts have an impact, but i did kind of expect the 550 cams to have more of an impact.

I may get a second opinion on the tune too cause the current tuner was a bit hesitant to want to do anything because he does not seem to like the 5R55S.

I would think the lower compression would help it respond to boost and make more power.?

15* of ignition timing is very conservative.

You could probably either add boost at the same WOT timing or leave the same pulley on it and add timing. You'd probably see pretty big gains going from 15* to 18-19* of ignition timing (provided it doesn't knock- though I'm guessing it wouldn't).

I would think the lower compression would help it respond to boost and make more power.?

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Low compression doesn't make power. To make it really brief, it allows you to run more boost vs a higher compression motor, and with the right induction it CAN make more power...but reducing compression without compensating for it with added boost usually results in losing power, not gaining it.

High compression makes power
Boost makes power
Advanced ignition timing makes power
Optimal AFR makes power
etc

Finding the optimal mix of all of these variables is the real goal.

Swarzkopf said:

15* of ignition timing is very conservative.

You could probably either add boost at the same WOT timing or leave the same pulley on it and add timing. You'd probably see pretty big gains going from 15* to 18-19* of ignition timing (provided it doesn't knock- though I'm guessing it wouldn't).

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Thats why I think i want a second opinion from a legit local dyno tuner instead of my shop working with basically amounts to an email tune.

I thought the timing was pretty low but the tuner told my show that was all he was willing to do with my boost level and 93 gas. I was thinking of just using a 3" pulley for a couple more lbs of boost.

Swarzkopf said:

Low compression doesn't make power. To make it really brief, it allows you to run more boost vs a higher compression motor, and with the right induction it CAN make more power...but reducing compression without compensating for it with added boost usually results in losing power, not gaining it.

High compression makes power
Boost makes power
Advanced ignition timing makes power
Optimal AFR makes power
etc

Finding the optimal mix of all of these variables is the real goal.

Click to expand...

Yeah, I understand high compression makes power, but I guess I was just thinking that I see people build low compression motors for high boost applications. - I realize without a power adder low compression is not what you want. I just assumed with the kenne belle that the lower compression would be a good thing for the amount of boost he's running. hmmm

cwhit23 said:

Yeah, I understand high compression makes power, but I guess I was just thinking that I see people build low compression motors for high boost applications. - I realize without a power adder low compression is not what you want. I just assumed with the kenne belle that the lower compression would be a good thing for the amount of boost he's running. hmmm

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Well my plans were for 15lbs on stock 9.8:1 compression. We didnt realize the lower 9.0:1 until starting the tuning.

Honestly, I was expecting closer to 550 with 9.8:1, so i would not have though it to be that far off. So I am not sure if better tuning will get it anywhere, or just simply throw more boost at it.

You'll probably need to retune anyway if you drop pulley sizes- since boost will come in earlier, you'd probably need to update your base fueling table to fatten up your AFR at an earlier RPM/load range.

Thats why I think i want a second opinion from a legit local dyno tuner instead of my shop working with basically amounts to an email tune.

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You could try Rodeheaver's (your shop's arch enemy...LOL)- believe he does in house tuning with SCT now.

how do those cams like the stock heads? are you happy with them?

They sound pretty awesome, but I can't speak to the performance vs say a ported head.

Driveability is still decent around town, and have not had terrible issues starting the car.

Boost wise, I am pullied for what should be 18 lbs according to KB estimates, even though they may be off. So between the cams and LT's, they are opening up 3lbs of boost. I would be curious to see what ported heads would do, but really dont want to dump much more $$$ into this 3v...

good deal, i'm currently putting together an f1a build. i'm going to start out around 20# and try to make my tranny last next summer. I might splurge for these cams now too, while i have the engine out of the car. once i get a T56, then the boost is going up!

The dude who sold me the motor had a procharger D1SC and said it made 630ish at 15lbs boost, so i bet the cams seem to like the centri SS better than my twin screw.

i bought the d1sc from the guy you bought the engine from.

Brezick said:

They sound pretty awesome, but I can't speak to the performance vs say a ported head.

Driveability is still decent around town, and have not had terrible issues starting the car.

Boost wise, I am pullied for what should be 18 lbs according to KB estimates, even though they may be off. So between the cams and LT's, they are opening up 3lbs of boost. I would be curious to see what ported heads would do, but really dont want to dump much more $$$ into this 3v...

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so is this saying you're loosing 3lbs of boost or gaining? I would think you're loosing it from my understanding, but my understanding isn't much and I stay more confused than informed.

The JE pistons for the 3v are a -17cc dish, I have them in my current setup. I think you will find, with our 52cc heads, they are 8.6 compression ratio. Unfortunately they require lots of boost to make any power. My setup only made a little over 600 at 15#. I was very surprised at the power levels and how doggy the engine is when not in boost. These are great pistons if you running 25# of boost in a race engine but not for a street setup. I am going back to -6.5cc Manley pistons when I redo this engine.


Earl

cwhit23 said:

so is this saying you're loosing 3lbs of boost or gaining? I would think you're loosing it from my understanding, but my understanding isn't much and I stay more confused than informed.

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Losing, which isnt to say its a bad thing, but expected.

retfr8flyr said:

The JE pistons for the 3v are a -17cc dish, I have them in my current setup. I think you will find, with our 52cc heads, they are 8.6 compression ratio. Unfortunately they require lots of boost to make any power. My setup only made a little over 600 at 15#. I was very surprised at the power levels and how doggy the engine is when not in boost. These are great pistons if you running 25# of boost in a race engine but not for a street setup. I am going back to -6.5cc Manley pistons when I redo this engine.

Earl

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Yeah, i know its pretty low, and I wil have to wait until sping to see if it is ok to stick with. I really dont want to tear the engine back up after it was just rebuilt. If anything, Ill just switch to a KB 2.8LC blower and pully up to 20+ lbs...