[aka Reckless]

Originally Posted by oldman

Are the LT4 forged? Either way I'd go with the LT4 piston and ring.

LT4 is, but I have an LT1

We sell drop in forged pistons for the LT1 that so not require re-balancing. They are the same weight and design as stockers, so they can be swapped without pulling all the guts out.

[oldman]

Originally Posted by 2SS_in_GA

LT4 is, but I have an LT1

We sell drop in forged pistons for the LT1 that so not require re-balancing. They are the same weight and design as stockers, so they can be swapped without pulling all the guts out.

I spend most of my time on 4 bangers which are completely and totally insensitive to reciprocating weight changes.

I wonder how much heavier a LT4 piston is? A little die grinding on the skirts can take off lots of weight.. Does GM use the same crank and rod on LT4 vs LT1?

[BradfordCamaro]

Originally Posted by oldman

I AM interested in the comp cam designs with the .560 lift on the low side to the GM perf Cam on the wild side. I have all the cams listed in my DD thread:

http://www.camaro6.com/forums/showth...=444879&page=3

Thanks. I lost track of that thread.

[aka Reckless]

Originally Posted by oldman

Does GM use the same crank and rod on LT4 vs LT1?

Pretty sure both have forged cranks, but the LT4 also has forged rods and pistons. I'm sure the stock rods are fine unless they will be under extreme duty. My car is a street car and cruiser. Might see the track once a year. We have several customers over 1000hp when we go to the track, so I have just as much fun watching and helping.

[oldman]

I with you, I'm just fine helping, I don't even autoX anymore the two kids do..

[JaxChris]

I think the only concern in the LT1, at least from the Corvette owners, is the pistons. That powdered metal soup can just falls apart under the increased pressure of boosted applications or when peak RPM is raised too far.

Vengeance offering drop-in LT1 pistons is smart for those that don't want to tickle the boom fairy when they get above the 600-650 mark.

oldman, the article you linked to on the 624-536-13 is odd. Their numbers are not quite what you would expect. For an aggressive cam profile, even on the shortened graph, I would expect to see the "after" showing the lower RPM power moved to the right and a harder climb after 3200 up to the new redline. Also, is it just me, or do every image I see of/about conical springs look like they compress unevenly under the retainers and do not maintain a cone shape? Beehives stand straight up when installed and don't have a wavy profile like conical do. Maybe I'm paranoid, but it doesn't seem like the potential for increased lateral oscillation would be a good thing when you're increasing RPM.

I think for those looking to avoid boost the best combination for a daily driver would be:
624-524-13 Comp Cam XFI AFM (or similar)
Ported Intake Manifold
Ported Cylinder Heads
Ported Throttle Body
Rotofab Air Intake (Dry Filter w/o Sound Tube)
1 7/8 Headers (Those I've seen install 2" lose power unless boosted)
2nd Cat Delete (Maybe even scrap AFM valves)
Mid-Pipe
Flex Fuel Kit
E85/93 Tune
HP Tuners
Installation

An owner that strikes the right deals for his parts could probably get this done for 5500-6000 all-in and I think it would get close to 550hp/500tq (not to the wheels). If you wanted to add a lot more labor and parts to strip AFM and go for a bigger cam, then I think 600/525 is possible with a 50% bump to the price tag. Gas mileage will suffer on E85, but pump price will make up for the lower economy.

I could be totally wrong, but I think I'm very close on the numbers/prices.

[DFW1LE]

Originally Posted by 2SS_in_GA

Pretty sure both have forged cranks, but the LT4 also has forged rods and pistons. I'm sure the stock rods are fine unless they will be under extreme duty. My car is a street car and cruiser. Might see the track once a year. We have several customers over 1000hp when we go to the track, so I have just as much fun watching and helping.

It is my understanding, but I could be wrong, that both have forged steel cranks and forged powdered metal rods, except there was additional machining done to those components on the LT4 for added strength and reliability. I have not checked to see if there are different P/Ns. The LT4's pistons are also forged aluminum which I do not believe to be the case for the LT1.

[oldman]

comp -13 is a 222 / 234 duration 118 lobe (very wide) .572" / .529" power 2000 -7100

Not looking at any actual graph, I would say comp's claim on power on both ends is a little much. Texas Speed cams have power into the 7000s and they are HUGE cams with aggressive lifts and lift profiles and no way work with AFM.


I would agree this really look with no numbers more like a milder cam as peak HP is 6000 and it is dropping. If you look at the pre CAI that is a more normal mid duration 3/4 cam curve as it is pretty flat from 6100 to 6300 and still is relatively flat to 6600.. Nut shell conclusion if you put a CAI on the car and it gains 20 HP from 5500 to 6000 and is back to pre CAI power at 6600, somethings is WRONG. So use the pre CAI curve if you want to evaluate the cam itself and then it looks about right.



I did mention in my DD that Chevy performace cam which is about the longest duration sub .600 lift cam on the market at: 228 / 248 with .577 lift has a power peak of 6200 and a 6600 max rpm rec.
http://www.chevrolet.com/content/dam...dyno-chart.jpg

This is a pretty impressive package with stock manifolding. I have just one minor quibble and it is minor, I think the larger CNC heads and a little too much exhaust duration muddies up the mid range a tad more than needed. I would speculate a mild porting more of a clean up and a good three angle and a compu cam setup could yield +60 HP and have a more stock like mid range torque for a cheaper price point.

That said actually driving a car nearing FBO, it got more than enough torque in 1st, 2nd and even now that it is 22 degrees out 3rd gear is iffy with traction control off. So what is an extra 20 ft lbs from 3200 to 4600 LOL.

Really cheap would be one steup milder comp cam is it the -12 that would be too easy, no springs, port clean up and pro three angle for dunno say $1000 DIY (not the three angle)

[BradfordCamaro]

I Will Bump this instead of starting a new one.

Had a quote from the Shop around here that does Corvettes/Camaros and knows the LT1. Champions

Cam - Valve Springs/Push Rods - Installed and Dyno Tuned ..... $4200
So before ya'll scream - That is CDN$, that would equal $3150 USD.

I will have to go by their shop and go over their numbers and exactly what is done.
The price has me interested. (no one here has given a price)

[7stringtheory]

oldman I'm not sure how far you are willing to drive but Frankenstein Engineering Dynamics in DFW custom grinds camshafts and ports / machines heads as per your application. I have spoken with them and their prices seem really good, you should contact them for a quote on what you are looking at.

[oldman]

I should, it is race season and I have two kids the autoX / road race, and one into go carts, the oldest is looking at east cost college where my out of pocket may range from zero to 1/4 a million+ (if it were me I'd take the free ride, plus summers, plus Europe for 6 months at a top 20 University... daughters... LOL), the only bright side is she will leave her Civic at home so I get a daily driver!

Back on subject, I do think any cam that is designed for the AFM lifters is going to be a compromise at best in ramp profile. I'm thinking it maybe best to do ported heads, change out the AFM lifters and add a decent conical spring.. say 16 hours. Then later on change cam, 9 hours. That way the cam choice is not limited to the AFM lifters...

[oldman]

Originally Posted by JaxChris

I think the only concern in the LT1, at least from the Corvette owners, is the pistons. That powdered metal soup can just falls apart under the increased pressure of boosted applications or when peak RPM is raised too far.

Vengeance offering drop-in LT1 pistons is smart for those that don't want to tickle the boom fairy when they get above the 600-650 mark.

oldman, the article you linked to on the 624-536-13 is odd. Their numbers are not quite what you would expect. For an aggressive cam profile, even on the shortened graph, I would expect to see the "after" showing the lower RPM power moved to the right and a harder climb after 3200 up to the new redline. Also, is it just me, or do every image I see of/about conical springs look like they compress unevenly under the retainers and do not maintain a cone shape? Beehives stand straight up when installed and don't have a wavy profile like conical do. Maybe I'm paranoid, but it doesn't seem like the potential for increased lateral oscillation would be a good thing when you're increasing RPM.

I think for those looking to avoid boost the best combination for a daily driver would be:
624-524-13 Comp Cam XFI AFM (or similar)
Ported Intake Manifold
Ported Cylinder Heads
Ported Throttle Body
Rotofab Air Intake (Dry Filter w/o Sound Tube)
1 7/8 Headers (Those I've seen install 2" lose power unless boosted)
2nd Cat Delete (Maybe even scrap AFM valves)
Mid-Pipe
Flex Fuel Kit
E85/93 Tune
HP Tuners
Installation

An owner that strikes the right deals for his parts could probably get this done for 5500-6000 all-in and I think it would get close to 550hp/500tq (not to the wheels). If you wanted to add a lot more labor and parts to strip AFM and go for a bigger cam, then I think 600/525 is possible with a 50% bump to the price tag. Gas mileage will suffer on E85, but pump price will make up for the lower economy.

I could be totally wrong, but I think I'm very close on the numbers/prices.

seems to sum it up...

[DFW1LE]

I wonder if Katech sells these parts separately and what the spec is on their cam:
Stage 2
600Hp* **
523lb-ft* **
Air intake system
CNC port throttle body
MSD Atomic Air Force LT1 intake manifold
Katech Camshaft
VVT limiter
Katech CNC ported cylinder heads
Katech AFM delete billet valley cover
High speed lifters
High Lift valve springs
Valve spring locators
Intake valve seals
Exhaust valve seals
Titanium valve spring retainers
C5-R timing chain
160 thermostat
Chassis dyno calibration
Serialized plaque
Price:
2016 $8,731
2017+ $8,831 (manual), $9,331 (automatic)

[oldman]

interesting the manual is cheaper to install? I'm sure they are .630 or so lift cams, I'm still unsure of the 100K miles for this type of cam, note I DON'T know. For me and this is just me I stick with the 20 HP less and the .571 lift cam with mild valve springs.

I think katech uses STP RWHP so that is about 650 engine HP. The GM heads / cam hot cam that also is a AFM delete is rated at 580 HP.