Quote:
Originally Posted by ho428
Oil temps have been a problem with some people road racing with the 3.25 main. Oil containment is an even bigger problem with a stock pan, and even with the Canton pan, especially under hard braking.
HPDE and Time trials are short runs, usually 15-20 minutes. It might could handle the temps with a good oil cooler. I wouldn't run it anywhere near 7000 rpms though. More like 5800 until you know more about the cam and valve springs. I generally shift my solid flat tappet 400 at 6200, only occasionally take it to 6500. You can feel it fall off so no reason in the world to wind it up further.
I'm putting together a 7000 rpm 433, we had to put a lot of thought into the valvetrain for that, along with a splay capped 3" 400 block with forged everything.
Once you get the KRE's and new cam you might can move the RPM's up into the low 6000's.
Weight is also a big problem, I see a 69 Bird in your signature. With a steel flywheel, 11" clutch and quick time bellhousing the 455 will weigh in at over 650 lbs. Aluminum heads will help some, but the hood and front bumper assembly is well over 100 lbs if it's all steel.
You'll need some serious front springs and brakes with cooling for late braking if you want to compete in Time trials.
I've gone lightweight on everything and it's still nose dives under braking.
I'd take it out for some HPDE runs, keep it conservative, monitor everything and evaluate it after each session. Run an oil pressure light and gauge, by the time you notice a gauge it's too late. If you switch to a Canton pan they come with a bung for measuring oil temp.
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Yeah I'd definitely be making some upgrades before taking it out for any events. I'm honestly not sure how the engine lives right now with the #62's on top. I've never had audible pinging and the engine doesn't run hot. I'm sure the altitude here in Colorado is helping it survive on 91 pump gas.
At any rate, I'd be looking at a minimum of a head and cam change (or at least finding out what cam is in it), along with a canton pan at the least. Right now it makes about 42psi at idle when cold and drops to about 38psi at idle warm on the oil side.
The plan does include a fiberglass hood to save some additional weight off the front end.
Those things I can sort, I'm more worried about a bottom end. If I need to, I don't really have a problem with taking the engine out and rebuilding it. But if a 3" main block is desirable for this type of situation, I might as well just continue to have fun with the engine in the car and piece together a new engine on the side.
Heck I could limit my sessions for a season or two while I do that and focus on tuning the chassis and suspension.