reving to 8k safely
Taken my stock bottom end, stock valve spring car to 8500 rpm lots of times to keep the 37r in it's optimal RPM range during races. I would recommend, but the engine can handle it.
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Head studs protect againt stretching which is caused from running higher in cylinder pressures caused by increased boost or compression....
Rod Bolts wouldnt be a bad idea..
Scorke
Rod Bolts wouldnt be a bad idea..
Scorke
Last edited by scorke; May 17, 2007 at 10:41 AM.
from what i heared from a friend you can get the stock block to rev to 10k with a 2.0 build but 1. is that safe even if you do build it up and 2. what do you need to do to do that?
How do head studs protect against the damage caused by revving high?
Do you know what head studs do? Do your pistons hit the head?
Head studs protect againt stretching which is caused from running higher in cylinder pressures caused by increased boost or compression....
Scorke
Do you know what head studs do? Do your pistons hit the head?
Head studs protect againt stretching which is caused from running higher in cylinder pressures caused by increased boost or compression....
Scorke
Originally Posted by evodan2004
Don't u think adding arp rod bolts would add some insureance when reving to 8k on stock block???
RPMs kill engines.....
https://www.evolutionm.net/forums/sh...9&postcount=17
The rod ratio of the stock 4G63 is not condusive to high revs. I'm sure some people have pushed the limits of the stock bottom end and valvetrain....but i don't recommend pushing it too far over stock.
On the stock turbo, i run 7800rpm on the stock bottom end and stock valvetrain. Once i install my HKS 280 cams, i will NOT raise my revlimiter at all over 7700-7800 rpm on the stock valvetrain due to aggresive ramp rates, which will only exacerbate valve float issues. Although, the stock bottom end should be able to handle the piston acceleration @ 7800rpm.
CJ
Originally Posted by iTune
The biggest enemy to your rods/rod bolts is engines revs. The higher you rev the more stresses multiply.
For instance, this is a Honda K20A(for example only):
Piston acceleration at TDC for K20A @ 8400 rpm = 4300 G's
Piston acceleration at TDC for K20A @ 9500 rpm = 5600 G's
As you can see, the acceleration of the piston multiplies a lot as revs increase. Of course, this particular engine has a 86mm bore and a 86mm stroke, it's a square engine. It also has a rod ratio that supports high revs from the factory. This is not a 4G63, as the 4G63 is a much different engine. But it illustrates my point very well.
This is not even taking into account the valvetrain and what it's physical limits are in regards to valve float. I'm not too sure what the max RPM is of the stock valvetrain on the 4G63 is. But, if you plan on running high RPM's, upgraded valve springs/retainers are a must, no matter what you do with the bottom end.
I would recommend staying within 500rpm of stock fuel cutoff. This is a good area to stay in with the stock valvetrain and stock bottom end.
For instance, this is a Honda K20A(for example only):
Piston acceleration at TDC for K20A @ 8400 rpm = 4300 G's
Piston acceleration at TDC for K20A @ 9500 rpm = 5600 G's
As you can see, the acceleration of the piston multiplies a lot as revs increase. Of course, this particular engine has a 86mm bore and a 86mm stroke, it's a square engine. It also has a rod ratio that supports high revs from the factory. This is not a 4G63, as the 4G63 is a much different engine. But it illustrates my point very well.
This is not even taking into account the valvetrain and what it's physical limits are in regards to valve float. I'm not too sure what the max RPM is of the stock valvetrain on the 4G63 is. But, if you plan on running high RPM's, upgraded valve springs/retainers are a must, no matter what you do with the bottom end.
I would recommend staying within 500rpm of stock fuel cutoff. This is a good area to stay in with the stock valvetrain and stock bottom end.
The rod ratio of the stock 4G63 is not condusive to high revs. I'm sure some people have pushed the limits of the stock bottom end and valvetrain....but i don't recommend pushing it too far over stock.
On the stock turbo, i run 7800rpm on the stock bottom end and stock valvetrain. Once i install my HKS 280 cams, i will NOT raise my revlimiter at all over 7700-7800 rpm on the stock valvetrain due to aggresive ramp rates, which will only exacerbate valve float issues. Although, the stock bottom end should be able to handle the piston acceleration @ 7800rpm.
CJ
CJ