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Woz tinkerer
Joined: 05 Oct 2001 Posts: 126
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Posted: Fri Oct 05, 2001 10:18 pm Post subject: g161->1.8+ |
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i was wondering how much you could sensibly bore out a g161 - so that its still able to be thrashed about abit without having to worry about changing the block over the next weekend
the reason im asking this is because, why dont people just get g161's (which come basically 'free' when you buy a bomb to strip) and get them bored out, rather than using up $$$ that could be later on put towards a turbo or something.
Is there a main advantage to having a larger stroke than a wider bore? How does this work?
The main point im getting at is that if you plan on spending heaps on performance, your going to use that performance, and especially with a turbo setup you'd probably be worried about blowing the bottom end if you plan on playing with the boost, and if its only a g161 block with a larger bore its much easier to replace than a decent condition g180 or g200. |
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4BIDIN newbie
Joined: 05 Oct 2001 Posts: 6
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Posted: Sat Oct 06, 2001 1:05 am Post subject: Re: g161->1.8+ |
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cubic inchs makes hp you cant beat that.
The extra cc makes for a lot more torqure at less rpm so you dont have to rev them as hard small cced engines have to be reved hard to make the same power.
As for stroking a longer rod and shorter piston means less power needed to move the piston the same distance so this means your engine is making more hp because less power is needed to drive it . |
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TXcoupe petrol head
Joined: 05 Oct 2001 Posts: 1675
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Posted: Sat Oct 06, 2001 1:22 am Post subject: Re: g161->1.8+ |
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yeah if you want more inches stroke it |
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MatMan tinkerer
Joined: 04 Oct 2001 Posts: 280
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Posted: Sat Oct 06, 2001 2:38 pm Post subject: Re: g161->1.8+ |
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An undersquare engine ( larger stroke than the bore ) will have more torque and lower RPM than an oversquare engine ( larger bore than the stroke) which will have more RPM but less torque. To prove this just look at motorbikes IE Harley VS Firestorm. A harley is undersquare and lucky to rev to 5000 while a Firestorm can rev out to 11 or 12 grand - don't quote me on exact RPM here |
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Benjamin backyard mechanic
Joined: 05 Oct 2001 Posts: 525
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Posted: Sat Oct 06, 2001 10:18 pm Post subject: Re: g161->1.8+ |
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I agree with the torque factor, but I like to be able to use the revs a little, and having now driven both warm g180 and g161, I prefer the revability of the smaller engine.
Finding these things in abundance for cheap or free is a bonus. I inquired about a g180 recently, figures pointing in the $500+ direction. Too pricey.
Makes me wonder though about the guy in here (won't name names) who was on his fourth g161 after blowups.
Food for thought though
Benjamin |
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Ben Wight backyard mechanic
Joined: 04 Oct 2001 Posts: 946
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Posted: Sun Oct 07, 2001 6:46 pm Post subject: Re: g161->1.8+ |
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You also have to realise though, that if you are at the point of detonation where you are breaking pistons, you rarely damage the actual bore of the block, just the pistons. Therfore, pistons for a G161 or for a G200 are roughly the same.
So why not buy a G200? Well to get 2 litres from a G161, you have to use a 2 or 1800 crank anyway, and then bore it out to accept 2 litre or oversize 1800 pistons. I cant remember the exact combo, but it becomes expensive to buy all of the individual bits. Afterall, who is going to sell an 1800 crank, without the block? For the same price, you could probably get both.
As far as I remember, you can only bore the 1600 out to around 17XXcc's with the standard crank and 1.5mm oversize 1800 pistons. This wont make as much torque as an 1800 or 2 litre. So if you are building a performance engine, why settle for less. |
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darla rice boy
Joined: 11 Oct 2001 Posts: 23
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Posted: Thu Oct 11, 2001 4:36 pm Post subject: Re: g161->1.8+ |
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If Fish wants more inches, I stroke it |
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