How long at WOT for 460

[wet77]

Now I know this ? may have many answers and variables but I have a 460 ford .030 over mild cam 750 carb tunnell ram intake fairly stock valve train and bottom end,also only a stock oil pan not a 10qt. And am running 20-50wt oil.
I run 4800 rpm WOT with a A cut impeller on a rebuilt berk.
Now I usually cruise at 3800 rpms or 43mph
How long would I be asking for trouble with this set up to keep it at 4800rpms??
Just lookin for opinions!
Any small changes like roller rockers would be going in the right direction??
Thanks in advance!

[Taylorman]

Haven't you been listening to everyone's opinion. You have to have a Chevy to run at wot.
[ August 22, 2003, 01:04 PM: Message edited by: Taylorman ]

[Blown 472]

Well the fords like to pump the valve covers full of oil, and having a small pan like yours you might be asking for trouble.
The drain backs on the fords are small so you might be starving the bottom end if you run it wot for a long time.

[LakesOnly]

I've done 25-30 second bursts, but with 13 quarts of oil.
LO

[LakesOnly]

wet77:
...I have a 460 ford .030 over mild cam 750 carb & tunnel ram, stock valve train and bottom end, stock oil pan, not a 10qt.
I run 4800 rpm WOT with a A cut impeller on a rebuilt berk.
...Would I be asking for trouble with this set up to keep it at 4800rpms??
Well....let's see if I get slammed for this one:
Stock oil pan in a marine application? I always advise run one additional quart in the engine. Marine engine rpm's are usually consistently higher and this helps compensate for drainback time.
Really, don't even get back to me about dipping crank throws into oil or parasitic drag....re-read the above paragraph.
LO

[Floored]

I guess you have to ask why? the longer at WOT the more chances of getting to diagnose what that noise was you never heard before or posting a way cool pic to ask if we'd ever seen a rod go out the pan and through the hull before, after draining the boat. I've gotten to where I enjoy driving much more than fixing. cruising the river or lake enjoying a frosty Root Beer, and seeing the wife in a swimsuit, thats livin

[Jet City]

Actually LO, I agree with your your theory. I have run my mild (and well worn) 460 at 4500+ rpm for several minutes on many occasions, with stock pan no less. This is one of those "don't try this at home" deals, but it survives it every year. I would really recommend a marine pan for this, but if I loose my engine I'm only out a junk-yard shortblock (my excuse to build a hot 460), thats why I take the chance. I also run Kendall 40wt, which I've found maintains better pressure than 20w50 on hard runs, and I change it frequently. I've never been a Ford guy, but the durability of the 460 is nothing short of amazing. I'd say you'll be fine if you keep your WOT blasts to 10-15 seconds, but always keep an eye on that presure gauge.

[Squirtcha?]

Well, guess I'll jump in the fray here. I run mine at 5200 rpm for as much as a minute (sometimes even more). I'll run it 5600 rpm for 30 seconds at a time with the NOS. I've never had any problems. I am running the Edelbrock Performer RPM heads though and they might have larger return holes in em. I'm not sure.
I second what Jet City Rebel said. I ran my stock 460 really hard for five years (who knows prior to that) and it ran perfectly. I just rebuilt it to go faster, not because there was anything wrong with it. In fact, the crank only had to be turned .010" and the bores had no scuffing or scoring and were pretty much still round. It may have even been the original motor. The BBFs are some pretty tough motors.
[ August 22, 2003, 03:23 PM: Message edited by: Squirtcha? ]

[wet77]

glad you brought up the oil issue I have been using QS 20-50 and switched to part synthetic and I noticed my pressure dropped to nothing higher than 42psi??
Would the 40wt synthetic be the way to go??
Or I seen some mobil 1 10-50 synthetic also??
Any suggestions for this motor setup?
Thanks Guys!

[wet77]

Also can I send some pics of my boat to someone to post on the jet page??
Thanks Jason

[Jet City]

Wet77, you will hurt nothing by trying a different viscosity, I have tried all of the reasonable weights for this application and find that straight 40w maintains better pressure when the going gets tough, I also believe that straight weight oils thin less under high heat (maintains its original viscosity better) than multi's. When using 40w, it is important to bring the oil up to temp by cruising (1800 rpm or so for 5-10 minutes) before running harder (you should anyway). I know there are many who feel 20w50 is a better weight for this application, I wonder how many of them actually tried 40w themselves to determine this, I find a dramatic difference between the two. I would only use straights in my jetboat, drag car, air compressor and lawn mower, the daily drivers get multi's. I'd like to see your boat, but I am also picture posting illiterate.

[hack job]

in my bbf (501 cid) i run straight 50w VR valvoline oil it is what i have been told to run by my builder. it has never been better old oil i saw veriing pressure with my 50 wieght and a clay smith pump it never comes below 70 psi most time s its at 80psi wink

[Danhercules]

Squirtcha?:
. I'll run it 5600 rpm for 30 seconds at a time with the NOS. I've never had any problems. See LO!!!!!!!! I need NOS!!!!!!!!!

[Snorider]

Ive run my stock 460 w/ a stock pan @ WOT (4900rpm) for 10minutes nonstop.
Granted I only did that once, (was trying to outrun a lightning storm), i still had good oil pressure (20 @ idle, 50 @ wot), and havent heard any tell-tale noises as of yet.
I have had no problems turning 4900, and every time i take the boat out i hold it to the floor for at least 3-4minutes nonstop - its just half the fun of it!
20w50 oil seems to be holding up fine...
A couple of times i did launch the boat @ 4900rpms, which caused the pump to cavitate, which buried my 6000rpm tach jawdrop
that was alittle scarey, and i try not to do it in purpose, but it still holds together.... 100% stock parts, no internal parts changed in at least the last 15 years or so, the motor has probably never ever been torn apart, and its a 1978...

[77charger]

the last time i drove my old jet boat with a bbf.I held it wide open for 5 minutes at powell dring around in smooth water.I was going to look for a new boat anyways and decided to test the durability(didnt matter to me if i blew the motor).
Did i mention that i would hit the nos for 15-20 seconds strait at times also.All this with a stock lower end,and cast pistons.Boat is still running strong my brother now owns it.

[Hallett19]

I kept mine wide open the other day for over a minute and it holds up fine, I remember I held it open all the way across havasu, from site 6, along crazy horse and into the channel at night. As long as you have good oil, and enough of it, as long as the motor is setup right, you can hold it open for as long as you want I'd guess.

[Elk Chaser]

It's a simple calculation.........
RPM divided by the percent of adrenalin in your blood stream divided by the number of teeth you have showing at that time .......... idea
for instance.....
5000 RPM / 75% / 15 Teeth = 4.4 minutes
or
4800 RPM / 50% / 10 Teeth = 9.6 minutes
or
4000 RPM / 40% / 5 Teeth = 20 minutes
:D

[LakesOnly]

Look at you guys! :D :D
"...the last time i drove my old jet boat with a BBF, I held it wide open for 5 minutes….
Did i mention that i would hit the nos for 15-20 seconds strait at times also? All this with a stock lower end,and cast pistons. Boat is still running strong…"
"I kept mine wide open the other day for over a minute and it holds up fine; I remember I held it open all the way across havasu…"
"Ive run my stock 460 w/ a stock pan @ WOT (4900rpm) for 10minutes nonstop. I have had no problems turning 4900, and every time I take the boat out I hold it to the floor for at least 3-4 minutes nonstop…it still holds together....100% stock parts, no internal parts changed in at least the last 15 years or so, the motor has probably never ever been torn apart, and its a 1978..."
**** yes!
I love these engines!
LO
:)