Quench Height opinions.....
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From: Sierra Vista, AZ
Bret,
Appreciate the formula and figures. Effective quench is exactly what I was looking for, as I posted this. I know .030" is too tight for many, but will see how it works and of course if there are any problems I will be posting back up...too bad its going to take another 2 months before I get home
Appreciate the formula and figures. Effective quench is exactly what I was looking for, as I posted this. I know .030" is too tight for many, but will see how it works and of course if there are any problems I will be posting back up...too bad its going to take another 2 months before I get home
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From: Sierra Vista, AZ
Originally Posted by DavidNJ
It may pay to call the rod manufacturer. They may have a good idea on stretch and expansion.
David,
Actually there is a big difference in terms of force on the small end of the rod when you compare a stock LS1 Mahle piston and pin and a Aftermarket forged piston and pin.
Stock Piston = 434g
Stock Pin = 160g
Aftermarket Piston = 410g-370g
Aftermarket Pin = 118g
Now at 6500rpm you have Peak Piston G's of 2810 @ TDC
So the stock setup of 594g's vs. the 508g's for the aftermarket.... 86g difference. Now that doesn't seem like a lot unless you buy lots of illegal substances but in a motor that's a ton in terms of force trying to stretch the rod.
.086Kg x 2810g's x 9.81 (g constant) = 2370N = 533 lbs of F
I would consider 500+ lbs of force trying to rip the rod out of the block a good amount.
Now up that RPM to 7000 you have a difference of 618 lbs of F
7500 RPM = 711 lbs of F
That 1000rpm increased the extra loads the stock parts have on the rods and rod bolts another 33%
That makes a good argument for the ARP rod bolts IMHO.
Still the stretch on the rods is a constand here since we are still using steel rods. Unless someone wants to do the FEA on it or hang basically a 1 ton pickup (4640 lbs)from a connecting rod and measure the stretch it's hard to say exactly what it is but we are only talking about a few thou. The best thing to do is yank a head and check to see if it's touching.
Bret
Actually there is a big difference in terms of force on the small end of the rod when you compare a stock LS1 Mahle piston and pin and a Aftermarket forged piston and pin.
Stock Piston = 434g
Stock Pin = 160g
Aftermarket Piston = 410g-370g
Aftermarket Pin = 118g
Now at 6500rpm you have Peak Piston G's of 2810 @ TDC
So the stock setup of 594g's vs. the 508g's for the aftermarket.... 86g difference. Now that doesn't seem like a lot unless you buy lots of illegal substances but in a motor that's a ton in terms of force trying to stretch the rod.
.086Kg x 2810g's x 9.81 (g constant) = 2370N = 533 lbs of F
I would consider 500+ lbs of force trying to rip the rod out of the block a good amount.
Now up that RPM to 7000 you have a difference of 618 lbs of F
7500 RPM = 711 lbs of F
That 1000rpm increased the extra loads the stock parts have on the rods and rod bolts another 33%
That makes a good argument for the ARP rod bolts IMHO.
Still the stretch on the rods is a constand here since we are still using steel rods. Unless someone wants to do the FEA on it or hang basically a 1 ton pickup (4640 lbs)from a connecting rod and measure the stretch it's hard to say exactly what it is but we are only talking about a few thou. The best thing to do is yank a head and check to see if it's touching.
Bret
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From: BFE
Also folks,
we are talking numbers and expension rates but a very important factor we shouldn't forget is the shape and design of the quench area.
So different castings like AFR have a double quench area instead of one. Another factor promoting a more efficient burn in the AFRs.
Meaning it will be more advantageous to run tighter quenches on an AFR than a GM casting.
we are talking numbers and expension rates but a very important factor we shouldn't forget is the shape and design of the quench area.
So different castings like AFR have a double quench area instead of one. Another factor promoting a more efficient burn in the AFRs.
Meaning it will be more advantageous to run tighter quenches on an AFR than a GM casting.
Tight quench works in both styles of chambers.The volume of mixture trapped between
the cylinder head and piston does not contribute to combustion therefore reducing its
volume picks up power.Since the area of quench is not in combustion at tdc it also runs cooler in that area .
the cylinder head and piston does not contribute to combustion therefore reducing its
volume picks up power.Since the area of quench is not in combustion at tdc it also runs cooler in that area .
