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How much NOS will a cast crank take

Posted By: scottb

How much NOS will a cast crank take - 12/17/09 01:45 AM

A friend wants to put NOS on his car with a stock 360 cast crank and stock rods ross pistons what would be a safe amount .I told him lets build a good steel crank and h beam rods motor together frist then put the NOS to it
Posted By: emarine01

Re: How much NOS will a cast crank take - 12/17/09 01:55 AM

We sprayed the piss outa a pretty much stock 360 with 125 shot, only thing was ring gap set up for the shot and arp rod bolts and reduced timing when spraying,beware.... its fun
Posted By: blk00rt

Re: How much NOS will a cast crank take - 12/17/09 01:55 AM

I have always heard that a stock engine could take a 150 hp shot of nitrous. I ran my magnum motor at this level for 3 years before I build my 408.
Posted By: cheapstreetdustr

Re: How much NOS will a cast crank take - 12/17/09 02:26 AM

been sprayin a stock 360 bottom end since o4
.63 and .78 jets depending on track.. on a big shot plate.
seems to be taking it...?
dont know what that computes to ?
it is polished rods and lightend rotating assy.
with K.B. hypers..
fwiw..
cheapst.

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Posted By: n20mstr

Re: How much NOS will a cast crank take - 12/17/09 03:02 AM

i had a stock 360 bottom end with forged repl pistons, Stock crank stock rods etc, In my car it ran 13.00 on motor and 10.90 with nitrous, It had two plates stacked for a two stage, both jetted at 175each so yea that was 350hp on a stock crank stock rod motor. Keep it out of detonation youll be surprised at what lives..Id keep it to 175 though and you should be ok. A 360 cast crank is pretty beefy
Posted By: bigtimeauto

Re: How much NOS will a cast crank take - 12/17/09 03:06 AM

Quote:

Keep it out of detonation youll be surprised at what lives..Id keep it to 175 though and you should be ok. A 360 cast crank is pretty beefy



Detonation is your biggest enemy
Posted By: mshred

Re: How much NOS will a cast crank take - 12/17/09 01:58 PM

when you all say stock bottom end, are the ring gaps and rings themselves stock as well?
Posted By: scottb

Re: How much NOS will a cast crank take - 12/17/09 03:25 PM

As far as i know the rings are not cut for NOS
Posted By: dart_73_br

Re: How much NOS will a cast crank take - 12/17/09 06:40 PM

Quote:

both jetted at 175each so yea that was 350hp on a stock crank stock rod motor.



Posted By: Sub95

Re: How much NOS will a cast crank take - 12/17/09 07:36 PM

Quote:

been sprayin a stock 360 bottom end since o4
.63 and .78 jets depending on track.. on a big shot plate.
seems to be taking it...?
dont know what that computes to ?
it is polished rods and lightend rotating assy.
with K.B. hypers..
fwiw..
cheapst.




.068 around 200hp .078 around 275hp


most stock engines can take a 150 shot with no problems, as long as you take timing out and run good fuel, might have to put a colder plug in. just keep reading the plugs.
Posted By: D-50

Re: How much NOS will a cast crank take - 12/18/09 12:37 AM

blk00rt did your magnum motor have hyperutectic pistons when you were spraying N.O.S. on it.If it did,were the rings gapped bigger for it.I have a 360/380hp crate motor and I was wanting to try spraying it without regapping the rings.Maybe 100 or 125.I only run 1/8 mile.

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Posted By: blk00rt

Re: How much NOS will a cast crank take - 12/18/09 12:54 AM

the 360 magnum was a completly stock lower end. It had hyper pistons and rings were never touched. I ran it for 2-3 years on the stock bottom block until I decided to change to the 408.
Posted By: hemiiroc

Re: How much NOS will a cast crank take - 12/18/09 01:01 AM



.068 around 200hp .078 around 275hp


most stock engines can take a 150 shot with no problems, as long as you take timing out and run good fuel, might have to put a colder plug in. just keep reading the plugs.



I always thought .082 was about 200
Posted By: D-50

Re: How much NOS will a cast crank take - 12/18/09 01:10 AM

Quote:

the 360 magnum was a completly stock lower end. It had hyper pistons and rings were never touched. I ran it for 2-3 years on the stock bottom block until I decided to change to the 408.



Thanks for the info.Did you say you sprayed 150 on it?

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Posted By: Adobedude

Re: How much NOS will a cast crank take - 12/18/09 01:18 AM

There's a number of guys on the Dakota R/T Forums spraying 150 on stock bottom ends, and have been for years...
Posted By: blk00rt

Re: How much NOS will a cast crank take - 12/18/09 01:59 AM

"Thanks for the info.Did you say you sprayed 150 on it?"
yes, I do have a timing retard unit and I pull 1-2 degrees out but I dont really have to, I do it just to be safe.
Posted By: Sue

Re: How much NOS will a cast crank take - 12/18/09 02:00 AM

Thats no different than How many licks to the center of a Tootsie Roll Pop.

It will take just enough to brake it
Posted By: emarine01

Re: How much NOS will a cast crank take - 12/18/09 02:07 AM

I think you will find that the crank shaft is not the weak link, Its every thing that sits behind it
Posted By: 8secDart

Re: How much NOS will a cast crank take - 12/18/09 02:28 AM

Got a stock bottom end 400,I mean stock.I have hit this motor with 250 forever.Keep the timing out and all will be good.Lenny
Posted By: mshred

Re: How much NOS will a cast crank take - 12/18/09 05:32 AM

what's the max you can spray without regapping the rings?
Posted By: 8secDart

Re: How much NOS will a cast crank take - 12/18/09 06:43 PM

The rings are the last thing to lose sleep over.If you have Moly rings you will blow the moly off the rings long before the ring gap is an issue.If you keep the motor happy the sky is the limit.
Posted By: Monte_Smith

Re: How much NOS will a cast crank take - 12/18/09 10:29 PM

This is a question that has no answer, other than, "when the crank breaks, THAT was the limit" for that crank. Same as how much power, can my stock block, 8.75 rear, or whatever take. There is no set number Many on here have had good luck, as read in these posts, I can produce just as many however, that broke a cast crank on a 100hp shot. I guess the bottom line here is this, you want to spray your stock, cast crank motor, go ahead, just don't be surprised when it breaks the crank or shatters a cast piston, because it DOES happen all the time.

Monte
Posted By: B3422W5

Re: How much NOS will a cast crank take - 12/18/09 11:07 PM

Quote:

This is a question that has no answer, other than, "when the crank breaks, THAT was the limit" for that crank. Same as how much power, can my stock block, 8.75 rear, or whatever take. There is no set number Many on here have had good luck, as read in these posts, I can produce just as many however, that broke a cast crank on a 100hp shot. I guess the bottom line here is this, you want to spray your stock, cast crank motor, go ahead, just don't be surprised when it breaks the crank or shatters a cast piston, because it DOES happen all the time.

Monte





Monte, B3 here...

Its my little brothers car that is being
discussed.


Its a Hensley built shortblock with all stock components except it does have Ross forged pistons, and the shortblock is screwed together nicely, externally balanced.

What type/brand kit would you recommend for a 125-150 shot the likes of which he is going to purchase??

Btw, he doesnt often get the car out, i think last year he MIGHT have put 15 laps on it at most( 3 outings).. a lot of racing with it to him might be 5 or 6 outings all year.

It has a holley blue pump, is about 10-1 compression, has a 108 lsa cam in at 104,( kinda biggish at 258@50) a single plane intake and a 750 holley on it, small tube open headers( 1 5/8). He generally has timing around 34-36 degrees, 904 and 8 inch convertor.


Any advice he will appreciate. The car currently typically runs 11.40's and 50's.

I think he hopes to run 10.70's with it and i think that is realistic, but i am no nitrous expert, or even know hardly anything much about the stuff other that it can make you laugh
Posted By: VIPERDUST

Re: How much NOS will a cast crank take - 12/19/09 04:03 AM

Tell Rick he can't go and outrun me. We won't stand for that.lol What's been goin on Don?
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