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Thread: sr18vet - sr16 or sr20 crank based?

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Posts: 1-10 of 35
2010-11-30 08:11:43
#1
sr18vet - sr16 or sr20 crank based?
To make the long story short - the thechnical requirements of drag championship in Russia have changed. I want to get into a "weaker" class.
The rule is : Calculated displacement = engine displacement * 1.6 if turbo or 1,4 if a rotary engine.
That is why the 2.0 * 1.6 = 3.2 , and my class limit is a 3.0 liters. So I will have to race against rb26 and 2jz because they are in the higher class.

So I have decided to build a 1.8t engine. (3 000cc/1.6=1875cc)

There are two options :

sr20 crank and the bore is 83.3 mm
sr16 crank and the bore is 93.8 mm

93mm bore is too much for the sr20 block and there are no such pistons. the max are 90mm. so the max will be 1747 ( wich is 7% less than the max displacement of the class)

what engine will be better for the drag? the "torquy" one or the "revy" ?
where can I get sr20vet 83mm bore pistons? who can make them?
2010-11-30 11:08:34
#2
A high ultra high reving big bore 1.8L motor will do the trick. The smaller crank 1.8L motor will rev to 10,000-11,000 RPMs under boost safly.

92mm bore with 68.9mm SR16VE crank = 1.832L

If you must be right at 1.8L build the engine below

91mm bore with 68.9mm SR15VE crank = 1.792L
2010-11-30 13:20:11
#3
the target displacement is 1875cc. so the 92 bore will be good.
will the block hold the 92mm? where to order 92mm pistons?

I already have sr20det cp pistons 86.5. I planned to try them into a sr16vet.
The theoretical compression ratio will be around 8.2 will they fit? do I have to make valve notches?
2010-11-30 13:21:43
#4
why do I have to use ultra high rew engine? why not just make the turbo 9k sr20 crank engine?
2010-11-30 13:47:48
#5
Originally Posted by Denismo
will the block hold the 92mm?
With sleeves it can be done.

Originally Posted by Denismo
where to order 92mm pistons?
Mazworx I believe. You'll also need their head gasket.

Originally Posted by Denismo
why do I have to use ultra high rew engine? why not just make the turbo 9k sr20 crank engine?
Because you will make way more power with the short stroke, big bore combination. To get to that power however, you'll need to rev it pretty high.
2010-11-30 17:32:53
#6
Originally Posted by BenFenner
With sleeves it can be done.

Mazworx I believe. You'll also need their head gasket.

Because you will make way more power with the short stroke, big bore combination. To get to that power however, you'll need to rev it pretty high.


but the torque wins. the sr20 crank will give the earlier boost and torque?

I feel that there is a lot of power and torque in the 10-11k engine, but the valvetrain, the water pump and the ignition will have to be upgraded as well.
Maybe I will not have enough funds to supply such setup in this season. My sr20det-vet is almost finished.

If the sr20ve block will fit the rnn14 tranny and the chassis, I will try to begin to assemble the sr18vet on the spare s20ve shortblock.
2010-11-30 17:40:30
#7
you can not build a SR18VE with a 86mm crank the bore would be to small to fit the VE valves. The VE intake valves would hit the top of the block and the exhaust valves would hit the inside of the cylinder walls.
2010-11-30 19:29:40
#8
Originally Posted by Denismo
but the torque wins.
Since when?

Originally Posted by Denismo
the sr20 crank will give the earlier boost and torque?
Yes.

But again, who gives a flying fuck about torque? You're trying to win drag races? You need power.

Originally Posted by Denismo
I feel that there is a lot of power and torque in the 10-11k engine, but the valvetrain, the water pump and the ignition will have to be upgraded as well.
Maybe I will not have enough funds to supply such setup in this season.
You do have a point about the cost of going with high revs.
2010-11-30 19:44:42
#9
Why not.build a sr18de. Vey cheap. We got one actually sitting at the shop.

Stratton.
2010-12-01 14:40:44
#10
Originally Posted by Andreas
you can not build a SR18VE with a 86mm crank the bore would be to small to fit the VE valves. The VE intake valves would hit the top of the block and the exhaust valves would hit the inside of the cylinder walls.


the de/ve valves differ so much? in the sr18de engine they dont hit.
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