|
||||||||||
|
||||||||||
27 Jun 2003, 03:19 (Ref:644296) | #1 | ||
Racer
Join Date: Mar 2003
Posts: 422
|
Pushrod Engines
Why do people blast GeneralMotors for using pushrod engines?I mean Bently uses pushrod engines for its main cars and you know how expensive they are and rollsroyce was using them too untill BMW bought them
|
||
|
27 Jun 2003, 04:44 (Ref:644314) | #2 | ||
Veteran
Join Date: Jan 2003
Posts: 4,536
|
no idea- they relate pushrod for being too old tech.
mind you 1924 bugatti had Overheadcam motors so pushrods and OHC are equally old in tech. Different strokes for different folks I guess. I love em and now with good EFI systems and managment even better.I Bet NASCAR has alot to do with the pushrod is old Idea. But the old bit is reallly the Carburettors i would argue and people refer to the motors as Pushrod when the real vintage piece is that 750cfm carb sitting on the plenum. |
||
__________________
SuperTrucks rule- end of story. Listen to my ramblings! Follow my twitter @davidAET I am shameless ... |
27 Jun 2003, 08:49 (Ref:644490) | #3 | ||
Veteran
Join Date: Aug 1999
Posts: 2,482
|
Rolls-Royce went back to using the old pushrod engines as the BMW engines didn't have enough grunt.
|
||
__________________
"Not the pronoun but a player with the unlikely name of Who is on first." |
27 Jun 2003, 10:13 (Ref:644566) | #4 | ||
Racer
Join Date: Aug 2002
Posts: 199
|
Nothing wrong with pushrods as long as the engine does the job. All this multi valve stuff is just to keep the marketing men happy - who needs a 16 valve Nissan Micra, for God's sake?
|
||
__________________
A smell of petroleum prevails throughout. |
27 Jun 2003, 11:40 (Ref:644631) | #5 | ||
Veteran
Join Date: Oct 2000
Posts: 3,366
|
Real men have....
Hang on my blown four litre has variable valve timing, sequential EFI and four valve double overhead cams... But the bike has belt driven desmo valves, now that's horn! |
||
__________________
I am grateful that I am not as judgemental as all those censorious, self-righteous people around me. |
27 Jun 2003, 19:37 (Ref:645044) | #6 | ||
Veteran
Join Date: Sep 2002
Posts: 2,193
|
Just try to do some DIY work on these modern computerised wonders...
|
||
__________________
Think, then act. Don't act, then think. -Jamie Hyneman |
27 Jun 2003, 20:55 (Ref:645093) | #7 | ||
Veteran
Join Date: Nov 2002
Posts: 693
|
Yeah, the pushrod engine is not as reliable as the OHC engine because it has more parts. Parts that are somewhat unessecary. Granted the geardriven cam is more reliable than the belt of chain driven OHC, but the fact a pushrod engine has more parts leaves more to go wrong. As a result they keep the revs down and it doesn't make as much top end power.
|
||
__________________
When asked facetiously if he knew he’d ruined a good story line by beating Patrick, Wheldon responded bluntly, “Don’t care one bit.” |
28 Jun 2003, 00:04 (Ref:645181) | #8 | ||
Racer
Join Date: Dec 2002
Posts: 338
|
A pushrod motor won't rev hard!?!?!?!?!
I know of plenty of pushrod motors that will pull over 8000rpm, some in excess of 10000rpm. Even my dodgy old Corolla will pull 8000+rpm with only a cam change. I think the actual engine design (bore/stroke ratio etc) has more to do with revability and power than whether it has pushrods or OHCs |
||
__________________
Think drifting is tough. Try it on gravel, in the dark, amonst trees............... |
28 Jun 2003, 00:21 (Ref:645191) | #9 | ||
Veteran
Join Date: Feb 2002
Posts: 4,936
|
Not as reliable, evo? You've never had a Mopar slant six, have you?
|
||
__________________
"Put a ****ing wheel on there! Let me go out again!" -Gilles Villeneuve, Zandvoort, 1979 |
28 Jun 2003, 10:00 (Ref:645344) | #10 | ||
Veteran
Join Date: Oct 2000
Posts: 3,366
|
A 225 slant six! The stuff of legends - then they went and stuffed it up with the hemis.
|
||
__________________
I am grateful that I am not as judgemental as all those censorious, self-righteous people around me. |
29 Jun 2003, 16:41 (Ref:646212) | #11 | ||
Rookie
Join Date: May 2003
Posts: 64
|
Actually multi-valve, multi-cam engines only make ABSOLUTE sense in small compact vehicles. If you put a larger displacement engine in you need larger gears, thus a larger gearbox, differential and halfshafts. If you MUST keep the weight down to ~2500 lbs like in a Celica GT-S, Honda ITR or CTR, Peugeot GTi, Renault Clio Sport a small displacement, relatively high-revving engine is de rigeur if you wish to have a high power-to-weight ratio AND keep the overall mass of the vehicle down. In a larger vehicle one can run a 7.0L normally aspirated V8 and have all the torque [power] one could use [or not, as the case may be]. I love variable valve timing and cam phasing. I adore small cars. If I had my couple of hundred million dollar trust fund and tens of million EURO income per year I'd opt for large displacement, multi-valve, cam-phased engine. Obviously.
|
||
__________________
"This is the law: The purpose of fighting is to win. There is no possible victory in defense. The sword is more important than the shield and skill is more important than either. The final weapon is the brain. All else is supplemental." ~ John Steinbeck |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Pushrod Mounted Damper Suspension...from CSR or DSR | RacingManiac | Sportscar & GT Racing | 2 | 4 Oct 2003 02:39 |
Pushrod 3 valve head | gttouring | Sportscar & GT Racing | 16 | 21 Sep 2003 20:32 |
Engines | Edmonton | ChampCar World Series | 45 | 23 Apr 2003 15:46 |
IC Engines | JGM | Road Car Forum | 4 | 21 Apr 2003 17:37 |
Pushrod/pullrod | cos | Formula One | 3 | 2 Feb 2002 00:02 |