hotairgypsy
forum member
- Joined
- Oct 30, 2007
- Posts
- 490
- Reaction score
- 1
do you think it could handle 700 on a regular basis? I have several posts stating it can handle up there in range.
How much HP can the stock crankshaft handle
- Thread starter hotairgypsy
- Start date
US-1
Banned
hotairgypsy
forum member
- Joined
- Oct 30, 2007
- Posts
- 490
- Reaction score
- 1
Here's the bottom line, kids: THE STOCK CRANK WILL LIVE FINE UP TO 7000 RPM!!!!!
Actually, the stock crank is lighter than the forged Cobra crank so it will rpm quicker too. The problem with the cast crank is the lack of counterweights in the center of the crankshaft. This leads to flexing of the shaft at higher rpms. HIGHER RPM.....you know.....OVER 7000 or so. The crank will take 7200 rpm blasts on occassion but not sustained high rpm usage. Eventually, the flexing will lead to stress fractures. I have only seen TWO broken cast cranks in the last ten years or so. I broke one of them at 7700 rpm....and it was destroked.
For what you are wanting to do the cast crank is fine as long as it is properly prepped and balanced. I would go with a decent set of H or I beam rods and a set of flat tops (or as close to flat as you can get; -5cc is about it I believe). For convenience and costs sake you could easily find a set of used Manley rods from a Terminator engine along with a cast crank and Probe Engineering pistons. Teksid blocks can be found for not too much money also. Stock valves should be ok for limited nitrous use but I would definitely invest in a good set of valvesprings and retainers for the times when you crack open the solenoids.
You should be able to do a low cost shortblock for less than $1500 if you shop around.
Actually, the stock crank is lighter than the forged Cobra crank so it will rpm quicker too. The problem with the cast crank is the lack of counterweights in the center of the crankshaft. This leads to flexing of the shaft at higher rpms. HIGHER RPM.....you know.....OVER 7000 or so. The crank will take 7200 rpm blasts on occassion but not sustained high rpm usage. Eventually, the flexing will lead to stress fractures. I have only seen TWO broken cast cranks in the last ten years or so. I broke one of them at 7700 rpm....and it was destroked.
For what you are wanting to do the cast crank is fine as long as it is properly prepped and balanced. I would go with a decent set of H or I beam rods and a set of flat tops (or as close to flat as you can get; -5cc is about it I believe). For convenience and costs sake you could easily find a set of used Manley rods from a Terminator engine along with a cast crank and Probe Engineering pistons. Teksid blocks can be found for not too much money also. Stock valves should be ok for limited nitrous use but I would definitely invest in a good set of valvesprings and retainers for the times when you crack open the solenoids.
You should be able to do a low cost shortblock for less than $1500 if you shop around.
hotairgypsy
forum member
- Joined
- Oct 30, 2007
- Posts
- 490
- Reaction score
- 1
there is your post. so then the stock crank can do 700HP as long as it is not reved up over the 7k range?
I know Whipplechicks car runs mid 10s on a stock cast crank, and is at 600 rwhp---and, I haven't heard of any stock crankshaft failures, as its the stock rods that go first. I do believe that a couple have broken on procharger cars because of the immense load placed on the snout of the crankshaft---but I don't know for sure.
GERMANSHEPERD
forum member
I think Id be more scared of the stock rods vs the crank.
GERMANSHEPERD
forum member
we couldve made that pic post #2 and thats all that needs to be said!
why ? they're strong as hell lmao
i'll get some pics of my crank and the rest today too lmao yea if it were me id just pick up a old cobra crank you can get them for dirt cheap
So the safe & economic way for a FI would have to buy a kit like this one http://www.livernoismotorsports.com/product.phtml?p=1002 open the engine, put it in, close and have fun without concern ?
yep either that or a full shortblock but as long as your motor is in good shape that and a few other nick nacs is all you need
Thx.
My engine is only 14kmiles. and i'm NA. So it must be in a good shape. Still debating what will be my build. (the FI is choosen, the rest...).
Could you define other nick nacs ?
why ? they're strong as hell lmao
This one is my favorite. When I first took apart my stock motor back in 2006, I was shocked at what I saw, and took this picture.
And the term "toothbrush rod" was born. Might as well be "toothpick rod"
This one is my favorite. When I first took apart my stock motor back in 2006, I was shocked at what I saw, and took this picture.
And the term "toothbrush rod" was born. Might as well be "toothpick rod"
lol yea really i know they build them this way to cut costs down but damn man atleast add a little meat to them
adams wifes car had like like 600 hp on the stock crank with forged rods. i havent seen one broke
Similar threads
Support us!
Support Us - Become A Supporting Member Today!
Click Here For Details
Sponsor Links
