[oldman]

Originally Posted by KingLT1

Over the weekend I was out at the last car meet of the year and there was a guy that has a built NA 6th gen. It's a 14:1, CID heads, GPI track attack cam, Hi ram, 4500 stall car. He said he very seldom drives it anymore. While it's fast, he claimed that it was no longer any fun to drive on the street. He wants to switch to a mild build with boost.

Somebody built a race car for the street and was not happy with the results, no surprise there. No surprise with the "mild boost" making a good all around drivable package. IMO there are 10x more guys with the "mild boost" rapidly turning into a big boost parts breakage money pit vs I built a performance NA car for the street. I don't know about fun, but all within a driver's race given 220+ wear street tires. In general, one is not going to get into parts breakage with heads and a reasonable lift street cam, one rapidly gets into powertrain failure with increase boost and / or traction. That's what torque does. One can rapidly get into a money pit with boost, while a reasonable heads and cam package is a once and done deal. Boost is addicting. Sure it is a big world and there are guys that went off the deep end with NA, IMO it is way easier to go off the deep end with FI.

to the OP, I am completely happy with a heads and cam setup on my M6 and it is no faster or quicker than my blower setup on street 220+ wear tires (lets just call it a driver's race). The head and cam setup IMO has these advantages:
1) sounds better
2) sounds better thru the gears
3) is way lighter
4) builds way less heat ( I toasted 2 starters in Texas with my supercharger)
5) mild lift cam seems to be near stock dependability
6) for me it has been a one and done deal, I never wanted to go with a bigger cam etc
7) since I do my own work, it was reasonably cheap for me. About $2500 all in ( I already had FBO).
8) I feel on a M6 the heads and cam package just made my car just that much more fun
9) plays well with bolt-ons

Disadvantage or heads and cam
1) less eye candy
2) can't remove to sell when I'm done with the car and it does not really increase resell value of car.
3) Probably not as fast as a FI setup given DR or better traction
4) I personally like the centri FI on my Camaro M6, I felt the more linear power and torque band to be a good match for just all around. Just wish it had a little more RPM.... and then the slippery slope starts.
5) in daily use the procharger is like a stock car.
7) super easy to DIY on the procharger


the two huge disadvantages on FI IMO are
1) slippery slope of boost = traction = parts failure, if you can keep at the base boost you're a strong man.
2) Once you get into big boost numbers it can get really expensive really fast and that is engine, fuel, drivetrain and traction problems ( the last even more so on a M6)

[DaveC113]

Originally Posted by oldman

Somebody built a race car for the street and was not happy with the results, no surprise there. No surprise with the "mild boost" making a good all around drivable package. IMO there are 10x more guys with the "mild boost" rapidly turning into a big boost parts breakage money pit vs I built a race NA car for the street. I don't know about fun, but all within a driver's race given 220+ wear street tires. In general, one is not going to get into parts breakage with heads and a reasonable lift street cam, one rapidly gets into powertrain failure with increase boost and / or traction. That's what torque does. One can rapidly get into a money pit with boost, while a reasonable heads and cam package is a once and done deal. Boost is addicting. Sure it is a big world and there are guys that went off the deep end with NA, IMO it is way easier to go off the deep end with FI.

to the OP, I am completely happy with a heads and cam setup on my M6 and it is no faster or quicker than my blower setup on street 220+ wear tires (lets just call it a driver's race). The head and cam setup IMO has these advantages:
1) sounds better
2) sounds better thru the gears
3) is way lighter
4) builds way less heat ( I toasted 2 starters in Texas with my supercharger)
5) mild lift cam seems to be near stock dependability
6) for me it has been a one and done deal, I never wanted to go with a bigger cam etc
7) since I do my own work, it was reasonably cheap for me. About $2500 all in ( I already had FBO).
8) I feel on a M6 the heads and cam package just made my car just that much more fun
9) plays well with bolt-ons

Disadvantage or heads and cam
1) less eye candy
2) can't remove to sell when I'm done with the car and it does not really increase resell value of car.
3) Probably not as fast as a FI setup given DR or better traction
4) I personally like the centri FI on my Camaro M6, I felt the more linear power and torque band to be a good match for just all around. Just wish it had a little more RPM.... and then the slippery slope starts.
5) in daily use the procharger is like a stock car.
7) super easy to DIY on the procharger


the two huge disadvantages on FI IMO are
1) slippery slope of boost = traction = parts failure, if you can keep at the base boost you're a strong man.
2) Once you get into big boost numbers it can get really expensive really fast and that is engine, fuel, drivetrain and traction problems ( the last even more so on a M6)

Thanks! How much labor would you estimate to install new cam and lifters? Shops want a small fortune... Do you feel like it's worth it to install lighter valves and a bit more spring at the same time? The head work can add some significant costs depending on how far you want to go.

Another big advantage of doing the heads/cam is increasing reliability by getting rid of the DOD/AFM lifters.

People are definitely charging significantly more for a car with heads/cam done. Not $10k more, but you'll get at least a few grand back ime.

[oldman]

I could not whiggle the cam gear off the cam, so I had to drop the pan, if you can do that I'd expect 10 shop to 15 hours or $1200 to $1800. It IS a pain to set the preload on the lifters. Drop the pan or pull the engine is going to add say $500, it is a pain to pull the engine on a manual BTW.

this is just IMO, I like and will only use sub .600 lift cams, been through all the LS1 cam / head / valve / spring wars, said OK maybe I don't know anything, had a .660 lift cam failure and said not doing this again.

Johnston lifters (probably overkill on sub .600 cam), I'd look at some conical springs (can get away with singles springs really) on the milder side and make sure the shop actually does the preload on the lifters, not just throw in a set of thick wall pushrods. Since my cam is sub .600 lift, I'm not too worried about needing all that much spring pressure. The GM hot cam used stock LT1 valve springs to 6600 or was that 6800 RPM (LT1 intake valves are hollow). Z/28 springs are mild in comparison to aftermarket dual springs (titanium intakes). There are so many advantages to sub .600 lift cams, sure make less power....

I think I mentioned the lifter preload?

Here are some springs:
https://www.psisprings.com/products/1500-series/
sub .600 lift cam probably can get away with LS1511s, I'd check with the cam grinder as it is lobe dependent (and type of intake valve)... about $300 bucks

[oldman]

This video addresses King's claim of "stripped" NA cars. This is FBO only and Pray does talk about how much weight is "stripped"... Partial stripped, still A/C the car did 9.9x, it was doing 10.1X with mild weight reduction.



Clearly heads and cam would need even less weight reduction... um 9s is 9s
I would speculate this stock engine would break a whole lot less drivetrain parts vs a FI setup...