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Registered:
May 2002
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Converting a lumpy engine into a true racer?
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Fri, 04 October 2002 23:48
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After reading a bit on the relationship between bore/stroke and torque/revs I was thinking. Would it be worthwhile getting a holden 5 litre or simmilar (ford 5.6 would be nice) and putting a crank that reduced displacement? If you added a smaller crank and longer conrods then you could shorten the stroke and still have an alright capacity? This should make it rev better.
Has there been any reasearch on the topic or is there a reason that I cannot see that makes it not possible/worthwile?
Tim.
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Location:
Narellan
Registered:
September 2002
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Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 00:48
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A long time ago a mate of mine had an obscenely destroked 253. It took forever to get a manifold to fit the valley right and not leak (due to the block being severly decked) and finding the right pushrods and rocker ratio was a bit of a problem. The motor ran big comp and had a huge cam in it as well. On the street below 4500rpm the motor made almost no torque due to the short stroke/big cam combo. On the flip side from 5500-7000 (I saw 7500 on the odd occasion) it was an absolute peach and sounded like no other V8 I've ever heard. The motor would have great in a club car but on the street proved to be almost useless. For a big V8 the gen 3 chev has bugger all torque down low, a destroked one would be shocking, that and big motors don't take too kindly to revved to buggery all the time like a 4AGE.
Anyway thats just an opinion. It depends on how you like to drive. If flat out all the time is how you like to drive, go build yourself a monster rev-hungry beast and have fun.......
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Location:
c'town, NSW
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 08:54
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hey kiwi jake what do u drive? i may have seen it zooming around narellan/cambo..
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Location:
Narellan
Registered:
September 2002
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Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 09:39
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Rob...I now drive a new V6 commodore ute (extractors, exhaust, hi-flo filter & cold air induction and it makes a whole 145hp at the rear wheels)S#*TBOX . Only because my work pays for it though. I did have an AE71 corolla with a 4AGZE in it but sold it when I got my ute. I'm now working on something much more sinister now. It's quite possible you may have have seen my mates old commodore (VB-VH one of those). I've heard of the odd sighting around the traps. If it goes like it used to it would still be very quick by street terms.
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Location:
c'town, NSW
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 12:46
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ahh k kewl
<-- if u see this zoomin round that'll be me.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 13:35
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No offence, but it would probably be wiser, and cheaper to spend your money on something like a 1UZFE. They are lighter, stronger, already have a good bore/stroke ratio for revs, and have a MUCH better head design. Just a thought.
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Location:
New Zealand
Registered:
May 2002
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 Re: Converting a lumpy engine into a true racer?
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Sat, 05 October 2002 21:16
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If you reduce the stroke you will lose capacity, longer rods won't make any difference to the capacity but will improve the reviness of the engine.
Destroking is quite common here in NZ for speedway cars to keep in the right capacity class, with the 265 valiant motors very popular as they have the head flow to support high revs and work well when brought down to 4 litres. These motors are now being replaced by by the Lexus V8 (and other jap import motors), with all sorts of tricky features as they are not allowed to run fuel injection (finally a decent carby V8 to put in an old toyota...).
As JCMF said this is probably a better starting point.
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Location:
Newcastle NSW
Registered:
June 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 02:28
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Take formula 1 engines as an example, they use 3L V10's ans V12's
and rev to 16-17 Grand.  . Although in saying that they have more pistons than most of us will ever have in one car  .
A friend of mine once calculated that by destroking a 1UZFE to a crazy 2L that with the addition of some bulletproof forged gear crammed into it that it would have a theoretical redline of 14 grand! i ha-vent had the chance to check his calculations but they seem to be close.
Now that would sound as sweet as any motor on the planet!
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Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 02:39
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Yeah I knew it wouldn't be better than a 1UZ but I wanted to know if it'd worm. I only wanted longer rods so that the CR was the same with out decking the block too much. A 14K RPM v8 would be a nice street car...
Tim.
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Location:
Sydney, OZ
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 02:51
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Take formula 1 engines as an example, they use 3L V10's ans V12's and rev to 16-17 Grand. .
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they also run needle bearings throughout... You get any engine to rev like crazy, but you also need the right stuff to get them too, reliably
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I supported Toymods
Location:
Berowra-Sydney
Registered:
July 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 05:48
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hmmm convert the celica to back seat drive with a 3L V12 in front hmmmm 
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Location:
Brisbane, Queensland
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 09:36
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thats not such a stupid idea.
I once found on the net a Fiat X1/9 or either a Triumph TR-7
well anyway these guys shoehorned in a jag v12 motor into it.
Talk about insane!!!!
Aparently they wrote the car off and the engine has gone to some other project, I wish I could find the website again.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Converting a lumpy engine into a true racer?
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Sun, 06 October 2002 12:36
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They also use pneumatic valves, no springs. A lot more stable under the sort of revs they endure. Then there is the problem of them having to be rebuilt every race...
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