quote Originally posted by La fiera: Hello will! I didn't mentioned it before but I want to keep the "stock " long block look. I'm working on a 3.7 liter using the stock Camaro block. I know, I know, I can hear all the talk but you'll see it after is done. And I decided to stay with the iron heads because I want to keep the "stock" looking long block. And my goal is still 300WHP. Hard to swallow but I love challenges. I'll be selling the 3500 aluminum heads. They are being developed right now $1000 shipped Anybody? Flow numbers will come soon.

I never understood prioritizing looks over power, but it's your build. Just keep your expectations realistic. There's are reasons Northstars make more power than 4.9's that no 4.9 build can overcome no matter how much attention is put into the details.

I don't think you'll get to 300 WHP with the iron heads unless everything else in the build is perfect, including use of an aggressive mechanical ROLLER cam and more displacement. 3.7 liters from the Camaro block will be fun, too. There are ways to do it, but none of them are well-advised.

Without the extra displacement, you'll be getting into an RPM range in which the required spring load and valvetrain loads run a real risk of popping a rocker boss off the heads. If that happens, you'll never achieve your goal with that configuration.

quote Originally posted by La fiera: Now that's an unfair comparison, the LX9 has 500cc' over in displacement, better intake and heads that flow way better than the 3.4 and the advantage of the roller cam. So that engine you mentioned with 2 mods that made 240WHP, in reality it has 6 mods over the L32.

LOL! You're the one who gave yourself the handicaps
As noted, LX9 in a 3.5 liter, so displacement advantage is not 500ccs. However, it has a 2mm bigger bore than the 3.4, unshrouding the valves that much more.
Focus on engine building, not mod accounting.

quote Originally posted by turbo 3800: A 3900 iron block still has a factory longblock look to it if you put iron heads on it. Then you get advantage of stock looking block with increased displacement and roller cam.

This won't work. The LZ4 and LZ9 bore centers are moved outboard compared to earlier engines. The accompanying increase in bore size to 99mm means that the outer edges of the bore move 5 mm. This change caused GM to move the cooling jacket holes in the deck. Neither the chambers/bores nor the cooling jacket holes still line up between the old heads and the new blocks.

quote Originally posted by turbo 3800: You could use a 3400 iron block and use a roller cam too you know.

Exactly... I think he'll need to do that in order to hit his power goal.

quote Originally posted by La fiera: That's a good idea about using the 3900 block and use the iron heads! The reason I use a big mechanical cam is to make up for the lack of head flow of the iron heads.

A big roller would do even better, as aggressive ramp rates would result in more area under the lift curve and more time spent at max lift, comparing across the same max lift for flat and roller tappets.

quote Originally posted by La fiera: Back to the build! I upgraded the trans. I went from the M17 3.65 gears to the M19 4.10 performance gears 4 speed manual. And to make things more interesting the diff is locked. Now the driver input has a lot to do with it. You can't just floor it because you'll wrap it around a three. The reason I decided to weld the diff was because of my karting experience. If I can drive a kart and be fast I want my Fiero to be just like my kart.

LOL! Good luck with that. Your Fiero is NOT a kart.

quote Originally posted by La fiera: If you choose to use an aluminum flywheel DO NOT INSTALL the bolts with out hard steel washers. The reason being is that the bolts will eat the aluminum and the flywheel will get loose and damaged. Apply red locktite and torque to the recommended specs.

How many torque cycles are on those bolts? Reusing stock bolts more than two torque cycles is very sketchy.

If you want a clutch that enhances your car's performance, you may want to give serious consideration to a Tilton or Quartermaster 7.25" dual disk.

[This message has been edited by Will (edited 10-29-2017).]

quote Originally posted by Will: There was nothing ambiguous or open to interpretation about the assertion "Your Fiero is not a kart". Larger cars were not mentioned and therefore are not relevant. I didn't say it couldn't be done. You quoted me as not saying that. I did say that the rest of the build would have to be perfect in order to hit 300 WHP. This remains the case and is likewise not ambiguous. Let us know when you do a 250 WHP build.

I'll let you know when I try. Considering the weight of the wheels I'm turning, and the race I run, my builds have been about torque and I've already made 249 ft*lbs with a stock 3400 cam + Fiero intake on a Mustang dyno. I lost power [on the dyno] when I upgraded from 45 lbs wheel/tire combination to 54 lbs....yet still make over 200ft*lbs... Even at 45lbs, my rotating assembly was made higher than stock thanks to my 12" brakes and the thicker than stock Cobalt SS-based axles required by the F40 6-speed oh yeah and 1" aluminum spacer for the flywheel. Once again - the heads aren't the issue.
At the time, I remarked that my 3.4 build was slightly faster than my 4.9+allante intake 5 speed car with stock brakes and axles. Since going to bigger and wider and heavier wheels, it is most certainly not as future dynos have proven...however, the extra grip at the track still made the car faster overall on the oval-track racing that I do because I build that kind of engine for that kind of race. When you pay me to build a 300hp engine, I most certainly will. My drop-clutch rpm is in the 2000-2400 range and thanks to the gearing, I launch as good as slightly modified AWD cars but not as good as the more highly modified ones. My current engine is using the 480/480 cam from WOT-Tech which lowers the peak hp by another 300 rpm but gives me a slight bump in torque 400rpm sooner on the torque curve.

[This message has been edited by lou_dias (edited 11-02-2017).]