Valve train comparison between 3.4 Supernatural vs stock vs 3.7 Supernatural. The 3.4 Supernatural parts where a bit heavier than stock and I was able to achieve good results. Now, the 3.7 Supernatural is a different breed. Much lighter spring, valve and hardware.
I believe I can get there with no problem and even higher, the question now is will the power be at that RPM. With the previous valvetrain I could feel a bit of power loss at 6900-7200RPMs and I knew the problem was the amount of mass the springs had to overcome as the RPMs climbed with the heavy SS oversized valves I was using. The engine had a peculiar sound, like valves floating. And could not get the best out of the camshaft at the higher RPMs. I'm pretty sure I could've gotten another 30whp but the valvetrain was the limiting factor. One of my worries at those RPMs was the stock rods I was using. They were ARP's bolt upgraded but still, my gut was wrenching when I saw the tack hit 7200RPMs. That's why I decided to go lighter and going with beehive springs. The beehive springs I run now are made for endurance (LeMans, Daytona, Sebring, etc). Every LS engine runing the IMSA prototype category uses the same part# and brand I'm using, they were not cheap.
OK, I wasn't sure if you were trying to hit a certain RPM goal.
Regardless, it'll reduce parasitic power loss, especially at high RPM. Also, valve float will be moved higher up the RPM range. But of course, you know these things. I'm just saying this for the benefit of other viewers.
What clutch? I know Spec makes spacers for different conversion setups.
Its for a Spec. I compare the Spec clutch vs the clutch I previously used and the stack height is different. The Spec is about 1/4 inch shorter in stack height. I've seen the spacers with the clutch kits from Spec but couldn't find the spacers by themselves.
[This message has been edited by La fiera (edited 01-24-2021).]
I wish I would have done that with my valve covers. My engine has the sheet-metal valve covers (very thin metal!). I was able to find a spacer, but needed 2 sets of valve cover gaskets (one under the spacer, and one between the spacer and the valve cover). Getting all that stuff lined up was kind of a pain. It also required longer bolts. Plus the sheet-metal valve covers use cork gaskets, which can be problematic.
I'm probably going to have a similar issue with the PTT clutch in an F23, but I'm not sure if I'll end up using GM's HTOB or PTT's or Tilton's or what.
If you don't already know, the F23 HTOB and input shaft seal are integral, so you will need a way to seal the input shaft if you use something other than GM.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
Going in!! Weather is nice so I think I'll have it in this week. I have to do some more installation of other systems for me to be able to start it. But overall I should be able to fire it up in a couple of weeks!
Well it's been 3 years since I started building this engine and I haven't taken the car to the track since 2013. Since I have easier access to track days for free I want to be able to track the Fiero as much as posible and develop the handling, braking and aero. The primary goal for this project is to compete in Time Trial events. First tentative track shakedown is April 30th to May 2nd at Summit Point raceway Main course.