Destroked B20VTEC turbo (theoretically)

[Touge Tom]

was thinking the other day has anyone built a B20VTEC, with a P72 head, cam's with 296 intake DUR and 290 exhaust DUR using a B16 crank with B20 rod's?... lets say with 13 comp pistons @ 84.5mm diameter.

i know the rods would be to short for the full 2 liter stroke and compression would be severely affected.

But i was reading some article's on the relation between bore X stroke. and less stroke would enable the motor to rev more freely.

so i thought considering the compression would be now less due to the rod ratio, and would have to use more boost to make more effective-compression. and be a dog of the mark! would this motor be safe to rev beyond the 10,000rpm mark?

considering, theoretically it's a built motor

[beeza]

Damn,big question straight up!

Any takers?

[lil_foy]

Stroke isn't the only thing that limitates a car from reving you realise?

[Touge Tom]

Stroke isn't the only thing that limitates a car from reving you realise?

yes, i understand this. but all thing's aside is this possible? or reliable for a daily driven, not garaged'n'hidden, weekend warrior.

[TODA AU]

was thinking the other day has anyone built a B20VTEC, with a P72 head, cam's with 296 intake DUR and 290 exhaust DUR using a B16 crank with B20 rod's?... lets say with 13 comp pistons @ 84.5mm diameter.

i know the rods would be to short for the full 2 liter stroke and compression would be severely affected.

But i was reading some article's on the relation between bore X stroke. and less stroke would enable the motor to rev more freely.

so i thought considering the compression would be now less due to the rod ratio, and would have to use more boost to make more effective-compression. and be a dog of the mark! would this motor be safe to rev beyond the 10,000rpm mark?

considering, theoretically it's a built motor

Answers are as follows:
B20Vtec Yes... P72 Head Yes... 296/290 cams Yes...
B16 crank & B20 rods, no... Use B16B crank & rods... (B16A rod is too short for block deck height with std installed heigh piston)
Capacity would be 1736cc @ 84.5mm bore...

Less stroke & long rods = top end power with coresponding losses down low.
Less stroke & short rods = Good low end & midrange, but dead up top.

Compression will be lower becasue you have reduced your swept volume.
C/R = Swept volume / Clearance volume
Rod rato has nothing to do with it.

One a near zero deck is achived, the C/R is arrived at as usual. Select a piston with a suitable crown volume.
Using more boost on a low compression slug, just makes the slug feel laggier.

I can build a turbo engine that is safe to rev past 10,000rpm & will last more than 5 years on the road....
Done it before plenty of times... not many others have though.
Tip is as with any engine build that is going to perform as intended & last.
Quality parts are needed together with quality machining, assembly etc...
Best advice.... Think about how much you really want this thing & be honest with yourself casue if you're on a turd skinner's budget it usually ends in tears.
Oh & I wouldn't be using a std B20 block as a start point.

[quangsuke]

Answers are as follows:
B20Vtec Yes... P72 Head Yes... 296/290 cams Yes...
B16 crank & B20 rods, no... Use B16B crank & rods... (B16A rod is too short for block deck height with std installed heigh piston)
Capacity would be 1736cc @ 84.5mm bore...

Less stroke & long rods = top end power with coresponding losses down low.
Less stroke & short rods = Good low end & midrange, but dead up top.

Compression will be lower becasue you have reduced your swept volume.
C/R = Swept volume / Clearance volume
Rod rato has nothing to do with it.

One a near zero deck is achived, the C/R is arrived at as usual. Select a piston with a suitable crown volume.
Using more boost on a low compression slug, just makes the slug feel laggier.

I can build a turbo engine that is safe to rev past 10,000rpm & will last more than 5 years on the road....
Done it before plenty of times... not many others have though.
Tip is as with any engine build that is going to perform as intended & last.
Quality parts are needed together with quality machining, assembly etc...
Best advice.... Think about how much you really want this thing & be honest with yourself casue if you're on a turd skinner's budget it usually ends in tears.
Oh & I wouldn't be using a std B20 block as a start point.

exactly what i was going to say =D

great response.
guess i know what im doing when i win the lottery. (amongst other things too)

[Touge Tom]

Thanks fella's. It was just a thought to get others opinions on how it Would go. I'd rather all motor anyway.

[Touge Tom]

Considering the swep volume, I guess it wouldn't make enough exhaust gas pressure to spool up the compressor for any disired effect. I should have thought of that.

[beeza]

"if you're on a turd skinner's budget it usually ends in tears."

hehehehehe,nice one Adrian!

[mugen_ctr]

ok, hypothetical question, given theres no budget, possible to build up any b-series to rev upto pass 12,000rpm an beyond the moon? or is this simply another mans dream?

[GSi_PSi]

Why dont you just sleeve the b20 and go for gold ?

[MikeyG]

if you got money to play with.. darton sleeve from us.. forge internals tuning is a must tho