Never dynoed mine but I started having troubles with the stock crank flexing/bending and beating up main bearings somewhere around 950-1000ish based off ET/weight

 

That's around where I am this motor got a new stock crank in it and I'm having the same oil pressure issues as my last motor identical problems that led to a bent crank so thinking the same thing and need to just go forged

 

unless your having other issues . if a bearing gets hot enuff the crank will warp a bit. what about balance issues or convertor snout run out. just thinking outloud here. has the block had a sleeve?

 

It's a stock block forged pistons and rods stock crank. These last two motors are the only ones I've had issues like this. Also the only two ive really hammered on.

 

Im doing a forged on my new motor, I started seeing oil pressure go down, tore it apart had the stock crank checked and turned .010 under put it all back together and 10 passes later oil pressure was dropping 10 psi on each pass.

 

That's exactly what I'm seeing. Last motor had the identical issues and ended up being bent and cracked I'm debating on hammering it with 10more psi for a hail Mary pass but not sure if it's a good idea. 30psi idle 20psi WOT lol

 

I would refrain from hammering it harder. Knowingly pounding something you know is marginal at best, can end up with the car, and you, stuffed into a wall, or worse.

 

ya, I would take it that you found it out. And know what needs to be upgraded. It's not fun or cheap to just let it happen, and say the "its just stock stuff dosn't own me anything". its not some cheap camonly junk, its running fast! be safe,

 

What bearing clearances are you running?

 

.0025-.0028 in mine

some stock cranks just seem to be hit or miss on taking that kinda power.

mine lived a whole season at <800 hp

 

its it a drilled car, or non drilled truck crank?

 

Non drilled

 

We have done 200 or so passes with 1000+hp and numerous passes of those (50 or so) with 1300 plus, maximum power so far is 1450 weight shifted (5.06@3200lb). Had the motor apart recently as its going in a new car and is as good as the day it went in.

6BOOST

 

1/8th mile car can get away with a lot more. Gearing weight all not in my favor. 1450hp on a stock crank seems hard to believe.......

 

1450hp is not 5.06@3200lbs... Unless it was like 153-154mph....

 

I just took mine apart cuz of a cracked cylinder and mains 2,3,4 bearings where wore a bit but crank is fine

It is a drilled crank, been together 5-6 years

Spin to 7400

 

Its gotta be this weight it's lugging around tune wasn't too crazy timing wasn't high no detonation. Unless it's machine shop error from the last time the crank was bent. I'm either trading the car or I''ll just suck it up and pull the motor

 

99% of the cars passes have been 1/4 mile, has been 7.97@174@3200lb when it only went 5.16 to half track similar combo we did went exact same 5.06 to half we did on our 1/8th mile pb and went 7.71@181. If you don't work it out as 1450hp your using a different calculator to me cause it's been accurate for everything else.

Your lack of belief in what it does or doesn't do is about on par with my fucks to give for said opinion

6BOOST

 

Ps 1450hp is 150+mph to the 1/8th? What drugs you on son? You think top level X275 cars are only making 1450hp? ?

6BOOST

I just know that ive been faster with less hp and only a little less weight than you. I guess we are using different "calculators".

As for x275 it depends on the combo. A sbnos car trapping 152 @ 2600lbs prolly aint making 1450hp. But a bbnos car trapping 156 @ 3250 is prolly making over 1450.

 

Ps 1450hp is 150+mph to the 1/8th? What drugs you on son? You think top level X275 cars are only making 1450hp? ?

6BOOST

 

I lied, I stopped there this morning and made this

main bearings number five and one are in indicator is on main Journal Number three
http://youtu.be/XGHnOlJroic

 

Mine lived happy for four years and made 974hp. I had Numerous passes and miles on the Car it was also street driven, sold to someone in KC,MO and am told it is till cruising around...

 

So how much easier is 1/8 mile on a crank then running the 1/4? I will only be running 1/8th.

 

Can throw stock48's nova up there. It's around 3400lbs and been trapping 164ish for awhile now. Seems to be doing alright. Just drove it over 1000miles at drag week and took home the win.

We have done 200 or so passes with 1000+hp and numerous passes of those (50 or so) with 1300 plus, maximum power so far is 1450 weight shifted (5.06@3200lb). Had the motor apart recently as its going in a new car and is as good as the day it went in.

6BOOST

Just curious...Was this the filled block setup on methanol? What kind of bearing clearances do you run? Oil used?

-Thanks!

 

Can throw stock48's nova up there. It's around 3400lbs and been trapping 164ish for awhile now. Seems to be doing alright. Just drove it over 1000miles at drag week and took home the win.
!

Mmmhmm.

 

SBE 6.0 here 164mph traps @ 3400lbs

Seems fine as well

 

I wouldnt be worried about something catastrophic, but over time it is gonna beat bearings up

Mine was running for a long time, and still would be. Bearings beat up though

 

doug that sucks your hurt the motor least you got your 8 second slip though

Not to hijack the thread but kingcobra97

x275 bb n2o deals are making 1100hp on motor alone before they spray 600-800hp worth of dope.
http://treracingengines.com/x275e.shtml
http://www.steveschmidtracing.com/drag-racing-engines/the-hulk-nitrous-series/582-x275-legal

rons motor is prob close to 900hp n/a before he hits it with 500 or more.
grape apes tre 23 degree motor
http://www.racingjunk.com/Drag-Racing/182247508/X275-Ultra-street-Grudge-small-block.html

 

Not to hijack the thread but kingcobra97

x275 bb n2o deals are making 1100hp on motor alone before they spray 600-800hp worth of dope.
http://treracingengines.com/x275e.shtml
http://www.steveschmidtracing.com/drag-racing-engines/the-hulk-nitrous-series/582-x275-legal

rons motor is prob close to 900hp n/a before he hits it with 500 or more.
grape apes tre 23 degree motor
http://www.racingjunk.com/Drag-Racing/182247508/X275-Ultra-street-Grudge-small-block.html

I already agreed that bbnos cars make over 1450. Prolly well over considering their extra 650lbs and more mph than sbnos cars in X. But then again were talking about cars running low 4.50's. Not mid 5.0's....

You do know there is a 400-450rwhp difference between a 4.50 car and 5.0 car right?

 

1450 to the crank not the tire id assume. ive seen them live to about 1100 maybe a little more with a generous tune up. Mine personally lived to 5.65 to the 1/8. High 8s in the 1/4. then i changed routes

 

Guys I can take my car to billy Briggs up here in Michigan and it'll dyno 1115rwhp then I can take it to Lidio and it'll dyno 1250+. 6boost flywheel hp doesn't really help, there are so many variables. Converter slippage, IAT's, humidity, DAI all of that change pass to pass. Then you have to remember some dyno's don't produce enough load to lock up a converter (cough cough dynojet).

Moral of the story, We've gone 8.56 @ 161.82 in a 3473# car, with 104% injector duty cycle, 23# of boost, 17.6% converter slippage @ the 1000', a burnt up th400 the fluid looked like crude oil, the fluid smell would make you gag. Oh and mind you that's a stock block, stock crank and stock untouched 317's.

 

Actually no, flywheel hp is ALL that counts. Take 2 cars, one makes 1500 flywheel hp and has a short gear, big tyre, loose converter and lays down 1000rwhp. Same car swap engine to 1200hp, has tall gear, low profile tyre, tight converter, and lays down 1000rwhp. Your claim is they will both ET and trap the same? If your answer is yes then you haven't dyno'd many cars. The chassis dyno is a tuning tool and means 7/10's of sweet fuck all. But seeing as how everyone wants to continue the argument the engine has put down 1250rwhp on a dyno dynamics dyno which typically reads 5+% lower to a single roller style dyno.

6BOOST

 

I'm pretty sure he is saying flywheel horsepower is a more accurate figure, the reason why a 580rwhp car can make an 8 sec pass, what's it really make at the flywheel? Also I'm pretty sure nascar and prostock teams use engine dynos exclusively because they are much more accurate.

 

The stock crank can take a lot of power if things are right. Balance needs to be spot on, tune spot on, and rpm kept reasonable. once rpm gets past 7k with big power bad things are going to happen. I keep a 7k limiter on all of my stock bottom end, and stock crank builds. Some builders like to run loose clearance, I keep mine tight just like factory. If planning on 1000+ hp and over 7000 rpm I would put a good crank in it. If taking out stock cranks below 900-1000 hp and 7000 rpm there are other problems going on.