Club G40 Forum
Club G40 => General Car Chat => Topic started by: randombadger69 on February 27, 2012, 10:58:19 am
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Anyone G-charged a 1043cc before?
..Other than Phils comedy build!
I stripped out a 2G block. Which confirms the bore to be 75.0mm. I measured the rods and they are the same length as the PY rods.
Which makes me think all i need to change is the crank into a PY block to create a 1043cc with low compression?
Ideally i want to build a 1043cc turbo, but as i have all the gubbins to run it with a G-lader, im thinking of testing the water first before i invest in turbo componentry.
Just wondered if anyone else has had a play around with the 1L lumps and boost.
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wouldn't the crank alter the stroke? putting g40 pistons in would lower the compression wouldn't it?
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This is what im hoping. That the py pistons and rods will lower the compression to 8.0:1 with the 2g crank. One way to find out. . .
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What's your aim with this?
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One way to find out. . .
(http://4.bp.blogspot.com/-axaSrmMATO8/TWRzGp17P_I/AAAAAAAAAzo/XIcfsDl4hHI/s1600/Harry-Hill-Fight-AP-WDC5.jpg)
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^ ;D
What's your aim with this?
To build a high revving boosted engine. Im also interested as to what sort of power can be achieved from 1043cc. In the back of my mind im toying (dreaming) about Group H 1150cc category.
1043cc + 2mm overbore?
From what iv gathered stroke provides torque. A lot of Vee race engines seem to have say a bore of 80mm and a stroke of 50mm in comparison. Making the engine geared more towards higher revving power rather than torque.
Seems not many bother with the 1043cc displacement, binning it in exchange for a 1272cc. Which is understandable.
At the eschdorf round of the berg-cup last year, saw this Audi 50 in the 1150cc class. It was flying, sounded N/A.
(http://alkaspace.com/usr/7105/1100_mk1_polo.j.jpg)
Just an experiment really, im hoping i can do it on the cheap. A hone, a set of rings, new shells and maybe a skim of a cyl head (depending on how flat my spare is).
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Laders dont like massively high revving. Quite easy to take the bearings outside of their happy happy tolerances.
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Yes indeed, ideally i will use a turbo. I Just want to get something running with boost to start with before i spend out on a turbo/make a manifold etc.
Turbo will make it easier fitting the engine in my mk1 golf as well. I can use the golf o/s engine mount instead of having to use the polo, G-bracketry.
Out of interest what would you say the highest revs a G-lader can handle without imminent death?
And whats the standard ratio i.e. with the engine idling at 1000 RPM what is the G-lader Revving at in relation with factory pulley?
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1.6 x crank revs... theres some calcs i did regarding the top lader bearings in a post on here somewhere
http://www.polog40.co.uk/forum/index.php/topic,7198.15.html
normal top bearings have a limit of 12,600rpm
the charger spins 1.6x crank speed on a 76mm normal pulley.
therefore at 6500rpm= charger spins at 10,400 rpm
76/65 = 17% smaller (ish)
therefore a 65mm pulley is 12,160rpm
a 60mm pulley is 13,173 rpm
a 58mm pulley is 13,628 rpm
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I thought it was the seals that gave up over a certain RPM. If it's just bearings then a harder wearing/ more expensive variety could be found surely?
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Cheers for that pete. Your wealth of g40 knowledge never fails to impress! What causes bearing failure in this instance? Excessive heat? Insufficient lubrication? The cartridge bearings could certainly be upgraded. Full ceramic being a viable option? Although at £100 a go, could get expensive!
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i think its excessive heat causes the seals to fail and then dirt ingress and or grease loss. This causes further heat and bearing seizure.. and therefore timing belt slips/snaps.
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Bit of a contradiction in wanting to build a high reving enigne at low cost but I can see the apeal.
Matching the laider to the revs is just a question of pulley size; you need to go bigger. Also the standard G40 fuel system, inlet & exhaust setup on a 1 litre will flow plenty enough. In fact if you can just increase the revs by 20 - 30% and match the charger revs accordingly with a remap or aftermarket ECU you should easily make the same power as a G40.Could you stick a G40 head on there too?
Then you need to look at what else is over reving and becoming stressed, Oil & water pump (cavitation?) Distributor. Look for increased wear on all the bearing. Choose your gears cairfully too
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This rev counter might be useful
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I wish i could afford/was clever enough to get it revving that high ^
Bit of a contradiction in wanting to build a high reving enigne at low cost but I can see the apeal.
Matching the laider to the revs is just a question of pulley size; you need to go bigger. Also the standard G40 fuel system, inlet & exhaust setup on a 1 litre will flow plenty enough. In fact if you can just increase the revs by 20 - 30% and match the charger revs accordingly with a remap or aftermarket ECU you should easily make the same power as a G40.Could you stick a G40 head on there too?
Then you need to look at what else is over reving and becoming stressed, Oil & water pump (cavitation?) Distributor. Look for increased wear on all the bearing. Choose your gears cairfully too
I know what your saying regarding cost and revs.
This is a bit of an experiment really.
So far I have in the G40 parts bin:
PY block, pistons and rods.
2G crank
G40 oil pump (anyone know flow rates on this, is it in the haynes?)
G40 head
Choice of camshafts either PY,2G,MH or 3F standard or a 272 Dbilas.
3F inlet manifold
G40 Exhaust manifold and downpipe.
A couple of worn G-laders (will be getting a re-build on one if they're repairable).
G40 fuel pump
GT gearbox - may need revising.
Ignition may well be something that needs alteration in time.
I read that the standard hydro buckets are good for 8.5K revs? I see Bar-tek tuning do buckets for over these revs.
Doubt i'll be pushing past that at this stage.
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The rev counter is on my 25 year old bike. It's a 4 cylinder 250cc twin cam 16 valve making 45bhp at 15000 rpm with the rev limiter set at 18500 rpm. It's about the same power as a 1 litre Polo but only 25% of the torque.
You can't simply increase the revs on an engine to get more power as the volumetric efficiency (i.e. torque) drops off so much at high rpm you end up with less power (torque x revs). For example the reason the boost apparently goes up at high rpm on a G40 is that the engine's ability to consume the air drops off rather than the charger spinning faster. It will make peak power at below maximum boost. (You should see a high boost figure on your 1 litre with standard G40 pulleys as it will be consuming 25% less air than a 1.3 at the same revs.) You can move peak power up the rev range with things like big valve head, suitable cam (3F?), and high flowing manifolds (3F and 4 branch).
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This makes sense! Is peak power on your bike at 15000rpm?
Im not trying to build anything amazing that screams to 10,000 rpm. I just think it will be interesting/funny to see whats achievable with the short stroke.
It's a shame my standard pulley got broken en-route from germany. Will have to try an source something.
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can probably supply a stock v belt pulley, if not then maxrpm have second hand ones for cheapish
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This makes sense! Is peak power on your bike at 15000rpm?
Yes, peak power is at 15000 and then it drops off to the red line. The high revving engine was mainly a marketing gimmick as the power was limited to 45bhp by the Japanese learner laws (still makes the same power as an early 1960's Grand Prix 250 though).
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Anyone G-charged a 1043cc before?
..Other than Phils comedy build!
I stripped out a 2G block. Which confirms the bore to be 75.0mm. I measured the rods and they are the same length as the PY rods.
Which makes me think all i need to change is the crank into a PY block to create a 1043cc with low compression?
Ideally i want to build a 1043cc turbo, but as i have all the gubbins to run it with a G-lader, im thinking of testing the water first before i invest in turbo componentry.
Just wondered if anyone else has had a play around with the 1L lumps and boost.
Spot the mistake :D
Of course everything measured the same as a 1272cc.. it is a 1272cc.
Pulled the wrong lump apart. It was the HZ lump I had sat there I meant to be checking! DOH!
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lol! :D
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Not sure this is going to work as i'd planned. I stripped out an HZ lump and had a butchers.
Compared the PY piston and rod to the HZ piston and rod. The rods seem to measure the same circa 122mm c-c. However the HZ piston is about 10mm taller from centre of gudgeon pin to face of piston than the PY piston.
Which if I did what i'd planned; PY rods and pistons on an HZ crank, then i'd end up with very little compression.
So I may have to use the PY rods on HZ pistons giving me 9.5:1 compression ratio :o
I may have my AAV engine apart and see what the pistons look like in that.
Need to get my hands on a dial gauge.
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And a few headgaskets.... ;)
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And a few headgaskets.... ;)
That wouldn't be a problem, got plenty of these from my 1306cc build.
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interesting stuff!
standard pulley size will get you just shy of 8,000rpm on standard top bearing.
wouldn't mind hearing exhaust notes at 8k... build it :D
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Aah.. don't!
I want to, just we went and found a turbo...
I might have to put a stock 1043cc in with 2 headgaskets. A pattern BGA type copper oil feed seal on the bottom and a genuine type with a rubber oil main seal on top and a shitty old AAV head as it will go bang and i don't want to waste a good G40 head. (A camshaft I can sacrifice if it came to it, but exhaust valves.. ideally not).
Hmm.
Unless someone fancies machining my HZ pistons for peanuts?!
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Depends how much boost you run. Chris' 9.5:1 AAV lump seems to be holding up okay though I think he's around 12psi on a K03 for daily use.
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I'd probably only be using a standard pulley if i went with the 1043cc. What do they produce 0.7 bar isn't it?
Pesumably due to reduced capacity the boost pressure would rise?
Which in turn will increase charge intake temp.
The turbo we have looks quite large, I dont think that it would be a good idea on a 1043cc. Anyone used a KKK K14 turbo on a 1272cc block?
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ive turbod a 1043 by accident, ran it on a renault 5 turbo carb with a t25 turbo, sized the turbo for a 1272 so on a 1043 it didnt pull full boost of 18psi till 3rd gear, it ran a 16.7 1/4 mile. tbh i wouldnt bother wasting your time doing it, just use a 1.3 aav like i inteded to do first time around or a 1.4 abd