OHV?
Pro. B.S. caller outer
Joined: May 2004
Posts: 9,644
From: IL
RE: OHV?
ORIGINAL: 2000Si
It's more in the design of the engine actually. Pushrods are just the usual design in torquey engines.
Low velocity air creates more torque. Pushrods have a horrible top end, usually redling around 5500ish. That puts their torque band from near idle to a few thousand RPMs. Look up the specs on the Viper engines. the SRT10 makes 525 ft lbs somewhere around 1700 rpm.
magiarn: ALL DOHC/SOHC engines are OHV. OHV simply means that the valves are overhead of the engine block. But since SOHC/DOHC are named accordingly, pushrods have been known to be called OHVs since there's only one cam and it sits inside the engine block and not in the head(s) itself/themselves.
ORIGINAL: GreyStang
Why would the existence of pushrods create more torque?
Bottom line an cam-in-block or cam-in-head engine is gonna behave pretty much the same way. But the advantage of cam-in-head is there is less complexity, and less pieces. So they can rev much higher without risk of valve float.
ORIGINAL: 2000Si
good = creates more torque
bad = not as breathable in the top end of the power band.
ORIGINAL: NewMexMustang
Are pushrods good...disadvantages?
Are pushrods good...disadvantages?
bad = not as breathable in the top end of the power band.
Bottom line an cam-in-block or cam-in-head engine is gonna behave pretty much the same way. But the advantage of cam-in-head is there is less complexity, and less pieces. So they can rev much higher without risk of valve float.
Low velocity air creates more torque. Pushrods have a horrible top end, usually redling around 5500ish. That puts their torque band from near idle to a few thousand RPMs. Look up the specs on the Viper engines. the SRT10 makes 525 ft lbs somewhere around 1700 rpm.
magiarn: ALL DOHC/SOHC engines are OHV. OHV simply means that the valves are overhead of the engine block. But since SOHC/DOHC are named accordingly, pushrods have been known to be called OHVs since there's only one cam and it sits inside the engine block and not in the head(s) itself/themselves.
As for the OHV thing, I would say both definitions are correct, mine being a somwhat older one (but then again I am old).
Guest
Posts: n/a
RE: OHV?
I was basing most of what I was talking about on mid 90s OHV engines. The 5.0, and LT1s persay. Of course technology will allow increases in revs and a broader power band. I apologize, I thought my first line was explanatory, and then with my paragraph I generalized older, more popular OHV engines.
6th Gear Member
Joined: Mar 2004
Posts: 5,867
From: VA
RE: OHV?
OHV=cam in the block. one cam for both heads, having pushrods/lifters instead of lifters and followers(which sohc and dohc have)
SOHC/DOHC= one or two cams per head. sohc will have one cam operating both intake and exhaust valves. while dohc has one cam for intake, and one cam for exhaust.
SOHC/DOHC= one or two cams per head. sohc will have one cam operating both intake and exhaust valves. while dohc has one cam for intake, and one cam for exhaust.
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