engine size and rpm

simon96 · rice boy Joined: 21 Oct 2001 Posts: 46

i have posted a while ago a question on 1.6 vs 1.8 vs 2.0 g-series. this sparked some furios debate over which went better, the common concensus being that the smaller engine rev harder. why?

Adam · Site Admin Joined: 04 Oct 2001 Posts: 682

The 1.8 and the two litre have the same stroke don't they? meaning they should rev the same...

Gats · newbie Joined: 08 Oct 2001 Posts: 7

The G161 should rev harder than both the G180 and the G200 as it has a shorter stroke. The G161's stroke is 75 mm, while the strokes of the G180 and G200 are 82 mm.

Cheers

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

I always thought that the 1800 had a shorter stroke than a 2 litre, but a couple of people have posted that they both have an 82mm stroke.

Due to the 1600's shorter stroke, it will inherantly its max power at higher in the rev range. Regardless of where it makes it, a 1600 compared to a larger stroke engine of relative tune will always come second due to it simply pumping less air.

Thus, if you plan to do mods, save up and do the mods to the biggest engine you can find. This engine will go the hardest.

Ben Wight

FrAsErTaG · tinkerer Joined: 04 Oct 2001 Posts: 166

I to was lead to believe the G180 had a shorter stroke then the G200..
go figure
hehe

9EMI · rice boy Joined: 19 Oct 2001 Posts: 16

g180 and g200 crankshafts are the same stroke, the g200 has more oil galleries i believe though

Tooleeda · tinkerer Joined: 04 Oct 2001 Posts: 93

Crank only has 2 Galleries per rod, but they are bigger.
Ive heard the G200 block is actually taller than the G180 (when I was enquiring about a G180 timing chain for the 2litre with shaved head) but this is only heresay. It would mean the crank is slightly different though.

Fastgem · tinkerer Joined: 04 Oct 2001 Posts: 166

Apparently the g200 block is 7mm taller than the g161. The only thing that confuses me a little is that some people have said they have used a g200 crank and rods in a g161 so as far as theory goes unless you modify the pistons then they will be sitting 7mm positive to the deck which is a substantial amount to say the least. I have a bare g200 block that I could measure but unfortunately I don’t have anything to measure it accurately with.

9EMI · rice boy Joined: 19 Oct 2001 Posts: 16

hey, yeah thanks for the correction, meant to say more substantial oil galleries. have heard that the two litre crank is more desirable, apart from larger diameter galleries, people have remarked that they are stronger (without reason), however this doesnt really seem to be an issue as there are many 1800 crankshafts in extremely quick geminis, so seems to be more like unreliable heresay. unfortunately, havent had enough experience with testing these components to their extreme, so cannot prove/disprove, but doubt one would outperform the other drastically.

quick (unaccurate) measurement of a bare g180 block comes in at around 215mm.

BADGEM · tinkerer Joined: 05 Nov 2001 Posts: 195

I dunno about that I got a 1600cc and it revs to the shit house on the freeway U can hear the bitch just rev at 100 km's but it's got heaps of kick, i drive in 4th at 40 km's
and get 185 (off the clock) in the same gear.
up hills the 1600cc is shit.
but straight line not bad for a an old engine.
I knock off a few cars and get those rear wheels pumping out smokeeeeeeeeeee

BADGEM · tinkerer Joined: 05 Nov 2001 Posts: 195

I dunno about that I got a 1600cc and it revs to the shit house on the freeway U can hear the bitch just rev at 100 km's but it's got heaps of kick, i drive in 4th at 40 km's
and get 185 (off the clock) in the same gear.
up hills the 1600cc is shit.
but straight line not bad for a an old engine.
I knock off a few cars and get those rear wheels pumping out smokeeeeeeeeeee
I got a hold of a tacho spit fire about 6 months ago and slapped it on
on the free way it would rev at 4 grand
NO shit, I set the shift light to come on at 9,000 rpm
and the light came on.
My mates where there to see it
9 grand out of 1600cc

Tooleeda · tinkerer Joined: 04 Oct 2001 Posts: 93

Outright strength of a crank is really insignificant. Anything will be good if its balanced properly. If youre rebuilding, it is really worth spending a couple of hundred to balance the crank and flywheel. Even a balanced G200 crank will quite happily rev to 6500 and beyond.

Woz · tinkerer Joined: 05 Oct 2001 Posts: 126

ive heard from a few sources that the g200 has lubrication problems - ie. rods through cylender walls is far more common in a g200 than a g180 - if this is the case, it may be an indication that the people that have fast g180's have done their homework...

Turbo TG · newbie Joined: 30 Oct 2001 Posts: 7

Yeah? well i mine reved out 15,000 rpm and still had heaps more to go and so i dragged victor bray and won. Then i glued on some cardboard wings and flew to new zealand and back, all on less than a tank. And you can ask my mum if you dont believe me because she helped me make the wings!

matey_mate · tinkerer Joined: 23 Oct 2001 Posts: 165

mine hit the redline at 80 grand and i put paper on the sides and flew to fucken hawaii