SOHC or DOCH?
06-09-2003
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SOHC stands for single over head cam
it means the engine has only one cam rod to open/close the exhaust and intake valves
DOHC means dual overhead cam
which is basically one cam for intake and one came for exhaust. dohc are usually more adjustable due to the ability to able to tune the intake and exhaust timing the way you want seperately. unlike sohc, which must adjust intake and exhaust timing at the same time
it means the engine has only one cam rod to open/close the exhaust and intake valves
DOHC means dual overhead cam
which is basically one cam for intake and one came for exhaust. dohc are usually more adjustable due to the ability to able to tune the intake and exhaust timing the way you want seperately. unlike sohc, which must adjust intake and exhaust timing at the same time
06-09-2003
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Rep Power: 0 dohc is not necessarily better. sohc engines can spool up faster because there is less valve train to move unlike a dual overhead cam. potential is higher with dohc because of what was said above... ability to tune the intake and exhaust cam separately....
Last edited by ChEe12iO; 06-09-2003 at 08:26 PM.
06-10-2003
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I'm not totally sure but I highly doubt it, plus if you could it would cost so much money it would be cheaper to swap in a DOHC (K20)
06-10-2003
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Rep Power: 0 Originally posted by ChEe12iO
dohc is not necessarily better. sohc engines can spool up faster because there is less valve train to move unlike a dual overhead cam
dohc is not necessarily better. sohc engines can spool up faster because there is less valve train to move unlike a dual overhead cam
Realy? I thought the spool up would be the same if not slower due increased rotional mass of the single cam. The fact the work being done is beign halfed by dohc also should make it faster? Swaping in a different ex. cam for turbo on a dohc with tuning would over came any differances. I don't know.... all do know is my sohc gets better milage then my dohc engine.
Last edited by OMega; 06-10-2003 at 12:49 PM.
06-10-2003
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There are some that believe the SOHC can spin to a faster RPM, however, that's a battle that's still being fought.
As for rebuilding a SOHC to be a DOHC, you'd have to swap the head. IF the DOHC head will fit the SOHC block.
As for rebuilding a SOHC to be a DOHC, you'd have to swap the head. IF the DOHC head will fit the SOHC block.
06-10-2003
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Rep Power: 0 Originally posted by OMega
Realy? I thought the spool up would be the same if not slower due increased rotional mass of the single cam. The fact the work being done is beign halfed by dohc also should make it faster? Swaping in a different ex. cam for turbo on a dohc with tuning would over came any differances. I don't know.... all do know is my sohc gets better milage then my dohc engine.
Realy? I thought the spool up would be the same if not slower due increased rotional mass of the single cam. The fact the work being done is beign halfed by dohc also should make it faster? Swaping in a different ex. cam for turbo on a dohc with tuning would over came any differances. I don't know.... all do know is my sohc gets better milage then my dohc engine.
06-10-2003
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Rep Power: 376 Originally posted by Nuts
you can't fit a DOHC head on an SOHC block.
you can't fit a DOHC head on an SOHC block.
06-10-2003
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Rep Power: 356 Originally posted by CivicRookie
What? Anyone understand this?
What? Anyone understand this?
I think he has his logic a little backwards. How can 1 cam be heavier then 2?
06-10-2003
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Rep Power: 0 the 1st 2 points!
OMega's trying to say the total inertia of a SOHC system would be more than a DOHC system, meaning the engine RPM will increase at a slower rate. (don't think so)
The 2nd point about the work being 1/2 (1 CAM operates intake & the other exhaust) doesn't make any sense, as far as the rate of increasing engine RPM
i don't understand the 3rd point & what the turbo has to do w/ the topic.
Generally SOHC motors have their CAMs tuned for efficiency, rather than power, which is why a SOHC gets better mileage than a DOHC (DOHC motors are tuned for power). If you tuned a DOHC motor for fuel efficiency, it would probably be more efficient...
OMega's trying to say the total inertia of a SOHC system would be more than a DOHC system, meaning the engine RPM will increase at a slower rate. (don't think so)
The 2nd point about the work being 1/2 (1 CAM operates intake & the other exhaust) doesn't make any sense, as far as the rate of increasing engine RPM
i don't understand the 3rd point & what the turbo has to do w/ the topic.
Generally SOHC motors have their CAMs tuned for efficiency, rather than power, which is why a SOHC gets better mileage than a DOHC (DOHC motors are tuned for power). If you tuned a DOHC motor for fuel efficiency, it would probably be more efficient...
06-10-2003
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Rep Power: 0 Mass for mass the sohc is going to be heavyer because of all the lobes. I don't think you could get away with making a lighter cam becuse of all the stress being place on the sohc.
I'm looking at cams as a pully system... could be the wrong way to go about it. From what I rember on b-series cam gears are smaller then the sohc's. Well if the ratio works out right less energy is being used to rotate the cams. Like I said this could be the wrong way to look at it.
The turbo parts was for ChEe12iO "spooling up". Now as I look at it I think he was talking about how fast the rpm increase.
I'm looking at cams as a pully system... could be the wrong way to go about it. From what I rember on b-series cam gears are smaller then the sohc's. Well if the ratio works out right less energy is being used to rotate the cams. Like I said this could be the wrong way to look at it.
The turbo parts was for ChEe12iO "spooling up". Now as I look at it I think he was talking about how fast the rpm increase.
06-11-2003
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Rep Power: 0 Stock for stock, a DOHC will own a SOHC. Even if you tuned both of them (and this is for the argument on whether or not the SOHC can get RPM's up faster), the DOHC would still be better in the long run.
At least I think that's right..
At least I think that's right..
06-11-2003
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Rep Power: 356 Originally posted by chocobo15_2000
does black99vtec have a dohc head on a sohc block?
does black99vtec have a dohc head on a sohc block?
No one knows for sure, not even him.
06-12-2003
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Rep Power: 0 what ever happened to black99vtec, havent heard from him in a while, or is he still finishing up the swap of that sr20det into his vic
06-14-2003
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Rep Power: 0 Originally posted by 01WingsWestCivic
what ever happened to black99vtec, havent heard from him in a while, or is he still finishing up the swap of that sr20det into his vic
what ever happened to black99vtec, havent heard from him in a while, or is he still finishing up the swap of that sr20det into his vic
06-15-2003
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Originally posted by MugenRacerX
SOHC or DOCH? (from the title)
is that sohc or Dueshe? i think you should do the later.
jk
dohc will be better for tuning
SOHC or DOCH? (from the title)
is that sohc or Dueshe? i think you should do the later.
jk
dohc will be better for tuning
I'd say keep the SOHC until you make some good money then put in a K20A or K20A2.
I know that if I had one in my engine bay, then I wouldn't be able to eat properly.
The D17A2 will definetely serve you well for gas mileage.
06-15-2003
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Rep Power: 0 A single cam will have more mass than one of the cams from a DOHC engine. But it will have less than the two smaller cams together. So total cam mass is less in a SOHC engine. That would be anadvantage to SOHC but it may not be a performance advantage...
Is the K20a2 DOHC how about the engine in the NSX or s2000? These cars are geared towards high performance. If SOHC was better for performance common sense would dictate that those engines would utilize that design.
Is the K20a2 DOHC how about the engine in the NSX or s2000? These cars are geared towards high performance. If SOHC was better for performance common sense would dictate that those engines would utilize that design.
Last edited by MatrixShark; 06-15-2003 at 09:58 AM.
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