Holy Macrkeal! 500hp?!? Wouldnt parts start flying with that much, escpaially if you were racing?

 

I guess its safe to say that the long rods can handle 400 hp I wonder what compression its getting.

 

I guess the 500hp systems are for all out racers such as the pro streets etc.

 

So it's probably safe to run a 250? Lets see, 390hp + 250hp = 640hp??? Something's gotta break!

Oh skinsey, now we know the long rods are good for 450hp! Thanks for proving that for us!

 

i probably wouldnt go over 250. thats just me. i would probably want steel crank and rods with a bigger shot. what a kick in the pants 250 would be though!

 

glad to see you getting away with that.
typically, popular mytholodgy says cast pistons and n2o make a recipe for disaster.
I went with cast pistons, thinking I've never want n2o... but, of courese, seeing you run a 13.9 makes me all crazy... Now, a heavier 250 isn't gonna run as quick... but 14's would be a hoot!

What timing are you running while on the n2o?
Are you running the recomended fuel jets with the 150 juice jets?, or have you had to experiment?
Any idea what your a/f is when running n/a?

 

Without being an "expert" on NOS, I looked over your build, and I think you're going to have to 4-bolt the main caps, even with only a 150 shot. For a 250 shot? Sheesh, these guys are trying to run their experiments through you!

My machinist told me my 390 could stand a small shot, like around the 100-150 range, but I never had the nerve to try it. And it was in the same range of performance as what you are building, right down to the same exact TRW pistons.

The reason I didn't have the nerve was main bearing squirm, if that was taken care of, these guys might be right, it could take a 250 shot But somehow, I think a steel crank is in order - what the heck? You just need a 391 crank with the snout turned down - what's another couple hundred bucks ?

art k.

 

You're probably right. The only problem is that I already have it put together. That'd mean I'd need to take it all apart again. PITA.

Wasn't the main cap walk more of a RPM induced problem on circle track racing 406's and 427's? Mine will probably never see the far side of 5500rpm.

 

I hope to get my non-NOS 69 F250 into the 13s Wed. night. I think Strokster is coming to help with the carb tuning. It already ran 14.5 with a fuel supply and/or ignition issue I've yet to diagnose.

you guys cross your fingers. If not 13s, maybe a few good solid low 14s, and to get home under it's own power would be nice.

I wonder what it would run with some NOS???? I'm running a SCAT crank, eagle BBC racing rods and Ross racing Pistons.. I guess the 428 block is my weak spot..

I hope to get to the track early, and possibly run the Camaro and/or the bike if I can figure out how to get them all there....:-) Hopefully. I'll have all good things to say tomorrow night.....what are the odds? :-)

 

So what's another couple grand...

I guess it's really not a big deal, but I got nervous thinking about it in my own motor, but I'm squeamish...

 

Ya, that is impressive indeed Gtex... I've got no misconceptions of my build running anywhere's near yours... heck, even with a 150 shot you'd likey whoop me n/a. haha...

Hope you're able to chase down your gremlins...
I've not been visiting in some time, what is the issue anyways... post link?
Good luck tomorrow night... get video!!!

 

It just seems like it's running out of gas on the back end of the track. It could be ignition, but it really seems fuel related. I should know more tomorrow night. I'll have a couple folks to help diagnose the problems and maybe do some tuning.

 

Greg did you ever put a different fuel filter on that?

 

I had a problem like that with my 67 mustang last year. Turned out to be the distributor gears being bad. Too much play in it. I replaced the gear, and it pulled fine. I ran a 125 shot on my 302 in my mustang with cast pistons for almost two years with no problems. Then I built a bigger motor and sold the 302.....It ran fine before I took it out though. Soooo, I would say you should be fine with a 150 to 200 shot. Just make sure your fuel and your ignition are in tip top shape or you'll have a better understanding of what it's like to have a backfire through the intake. If it happens, it may blow the intake completely off the motor. YIKES! Only seen it happen once, but hey...my buddy wasnt the sharpest knife in the drawer. Just my 2 cents worth.

 

funny... that echo's my pm...