Cheaters in motor racing in NZ

**Smorg** · 10th April 2006, 16:27

Originally Posted by scumdog

It's a shame they don't tow large boats with GTI-Rs........

Different strokes for different folks.

I wonder why NZ Police don't use Jappas for front line work very often??

I know the Australian Police use the occasional WRX for frontline work although they mostly have Holdens, Fords or Land Crusiers

**Lou Girardin** · 10th April 2006, 16:48

Originally Posted by CaN

That's it folks, the official word from the Harley Davidson retailer.

But what do I RIDE?

**The Stranger:Me** · 10th April 2006, 17:45

What's that got to do with ripping off poor bikers with old technology crap?

**Buster** · 10th April 2006, 18:01

Originally Posted by scumdog

I wonder why NZ Police don't use Jappas for front line work very often??

Because larger capicity engines get more out of LPG.

**cowpoos** · 10th April 2006, 20:22

push rod engines are more of a bad habbit by a few car manifactures than an effcient use of air and petrol....

the high horsepower drag engines used in the states based on production pushrod motors is because the rules dictate it...no other reason...other wise they would all be running high horse power euro 6's 8's and 12's [and jap 4's and 6's with huge turbo's make massive HP]..with over head cam shafts...

pushrod engines have more moving parts to lift and return a valve than OHC engines...there are tolerences from the cam...bottom of the push rod...top of the push rod btween the rocker and the rod...and the rocker and the valve...they may only be a few thou's of a inch but add them all together and you have alot of inaccuracy in your timing yer?
the very direct articulation of valve control in a ohc engine gives alot more accuracy in the valve timing...being very precise means the can run them open and closed alot closer to ideal...also the effect of this presicion in ohc engines means they can run far higher RPM with control of the valves and timing...enabling the engine to move more air in a givin time frame...there fore producing higher power...

this restriction in high rpm reliability and function serverly limits pushrod engines producing efficient horse power...that is why they make them big...the larger capacities enable more air to flow...but with less rpm able to be used they can not ever compete with a higher reving ohc engine on equal footing.... in real world terms....
also the smaller displacment higher reving engines hadv less moving interia...there fore require less HP to increase engine RPM at any givin point in the rev range...

really.....people like them still....so they are made....not because they are good....not at all....the future is going to be interesting with more stringent emission laws....its gunna be hard for these pushrod engines to be efficient enough to meet up and coming emission laws....and I notice ford hav already produced a OHC v8 for production...

**Quasievil** · 10th April 2006, 20:35

FORDS SUCK!!!!!!

HOLDENS RULE!!!!!

Thats all I got to say................. can I have a drive now CAN ???

**Motu** · 10th April 2006, 22:05

It's not about rpm,that's just a by product...there are plenty of high revving pushrod motors.In any modern engine (from the late 70s on) it's about emissions,an ohc set up is needed to give fast valve opening and closing speeds,they need to slam that valve wide open and then shut it as fast as possible,that sort of stuff stresses a pushrod motor a fair bit.

**cowpoos** · 10th April 2006, 23:05

Originally Posted by Motu

set up is needed to give fast valve opening and closing speeds,they need to slam that valve wide open and then shut it as fast as possible,that sort of stuff stresses a pushrod motor a fair bit.

plenty is not a word I would use for the amount of high reving pushrod engines out there...buggar all is a better discription...

how do you mean RPM is a by product? where are you coming from with that?

**Motu** · 10th April 2006, 23:33

Well let's just say that there are a lot of ohc motors that rev lower than many pushrod motors as another way to look at it.OHC does not automaticly mean high revs....nor does desmo,the desmo Dukes didn't rev much higher than the non desmo - but they had better valve control.Higher revs come from better valve control....a well designed pushrod engine (Mercedes Indy V8) can have better valve control than a poorly designed ohc engine.

**scumdog** · 11th April 2006, 00:19

Originally Posted by cowpoos

....and I notice ford hav already produced a OHC v8 for production...

Yep, the 427 (7 litres) SOHC Ford V8 came out about 1965 I believe, was not that readily available though.

Biggest problem was its 10 mile long timing chain set-up, I wonder how it would go with belts instead of chains?

**Ixion** · 11th April 2006, 01:18

Pushrod valve gear is easy good to 8000 rpm+. OHC doesn't really have much advantage in revs over a high cam pushrod. Especially with large valves, where OHC loses the multiplier effect of the rockers .And OHV with a simple gear cam drive avoids the timing variability inevitable with a long cam chain (or belt)

But sidevalves are better.

And best of all is NO valves. Real engines don't need all these valves and camshafts and whatnot. Just complicate things.

(By the way, have I mentioned gaiters lately ?)

**cowpoos** · 11th April 2006, 10:47

Originally Posted by Ixion

Pushrod valve gear is easy good to 8000 rpm+. OHC doesn't really have much advantage in revs over a high cam pushrod. Especially with large valves

oh gwad....... go hug a pushrod....go on....sheeessssh!

**limbimtimwim** · 11th April 2006, 16:28

Originally Posted by CaN

I tried to include a Ford too for comparison but none were in the top 100 or so entries.

It's an old list. And Aston Martin are owned by Ford. I think an old Cosworth Escort or a new Hi Po Focus would do quite well.

Not that I am a Ford fan really.

Anyway, I am OT.

**The Stranger:Me** · 11th April 2006, 17:07

Originally Posted by limbimtimwim

It's an old list. And Aston Martin are owned by Ford. I think an old Cosworth Escort or a new Hi Po Focus would do quite well.

Not that I am a Ford fan really.

Anyway, I am OT.

Well depends on your definition of old really.
Some here cling to what happened when the Ausie cars got dorked by the turbos, probably 15yrs ago (I am sure someone will correct me), by contrast some of the entries in the full list are from 2004.