400 sbc rpm
02-24-2011, 09:15 PM
#1
Teching In
Thread Starter
iTrader: (2)
Join Date: Sep 2009
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
400 sbc rpm i am new to 400 sbc motors being a long time ford lover, i bought a motor from my uncle, it has 12-1 compression, a .630 solid roller cam set up, h-beam rods,victor intake right now it has ported 291 casting heads i now have some brodix heads for it, it ran 10.70's in his vega with a 750 carb and tiny 1-1/2 headers , now it will have some 1-3/4 step 1-7/8 headers and a 1050 dominatoer my question is just how hard can you turn a 400 i have some 4.56 gears in my car which is a 1980 notchback mustang and 28 inch tires,
02-25-2011, 07:51 PM
#2
TECH Regular
Join Date: Oct 2004
Posts: 411
Likes: 0
Received 0 Likes
on
0 Posts
cast crank seems to be the limiting factor? I've seen 8500 rpm out of a stock crank/rods/block but I wouldn't recommend it because i've never done it personally.
Ask your uncle where he shifted it... my guess is that cam is happy at 4000-7000 rpm.
Ask your uncle where he shifted it... my guess is that cam is happy at 4000-7000 rpm.
03-01-2011, 09:20 PM
#3
Teching In
Join Date: Dec 2007
Location: ATL, GA
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Rpm's for 400 SBC I would not turn over about 6500 with a stock cast crank making close to 500hp, it will flex and cause your oil pan to fail to hold the connecting rods in...
Bad joke but I have seen it a thousand times, thats why 400 stuff is hard to come by, it has all been scrapped. The newer Scat LW is a good piece as it is around 50#, most of the other 400 aftermarket cranks are close to 60# and too heavy for their own good.
I personally love them and my house dirt engines are all 400 based, but I always splay the caps, and use main studs. I try to get the best crank I can and balance it perfect cause the slightest unbalance on a 400 will shake it apart. I would also get the best rods I could and the best rod bolts. If you want to turn over 7000rpm, your best combination is to de-stroke with a stock steel chevy crank if that is the best you can afford.
Bad joke but I have seen it a thousand times, thats why 400 stuff is hard to come by, it has all been scrapped. The newer Scat LW is a good piece as it is around 50#, most of the other 400 aftermarket cranks are close to 60# and too heavy for their own good.
I personally love them and my house dirt engines are all 400 based, but I always splay the caps, and use main studs. I try to get the best crank I can and balance it perfect cause the slightest unbalance on a 400 will shake it apart. I would also get the best rods I could and the best rod bolts. If you want to turn over 7000rpm, your best combination is to de-stroke with a stock steel chevy crank if that is the best you can afford.
03-11-2011, 08:50 AM
#4
call me lucky(so far anyway) but i rev my little 406 to 7200(well i bump the 7200rpm pill in my msd box)regularly. it has a cast crank from eagle, factory rods w arp bolts and hypo pistons. i run 11.4 comp on pump gas and its a 2 bolt main. with a flat tappet solid comp cam and cast iron pro top line heads. in a 68 camaro on drag radials w th350 and a way too tite converter and 4.10 gears it runs 11.30 at 120 w 1.7 60ft. if everything is clearanced rite i dont see a problem w 7000-7200rpm .
