Cylinder sleeves
- Thread starter tinker
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
Decreased stroke allows for a better rod to stroke ratio.
The better the rod to stroke ratio exerts less force on the crank, rods and skirts of the pistons. It also allows the engine to breath better. This makes more power. The rod to stroke ratio is extremely important when it comes to high revs. The higher the number the better. Most F1 engines would be in the region of 2.3 to 1.
The destroking would most like allow you to use Honda journaled rods, these make more power due to lower friction and lower mass forces which will increase engine life.
If you look a an F1 engine or even a Cart engine, they have big bores and short strokes, have you done a peak piston speed calculation, the speed of the pistons in your motor will be so much higher than in a short stroke high rod to stroke engine. The G forces will be huge in the engine you are planning on building.
Also a smaller bore will have trouble breathing not just because of the low rod to stroke ratio but the smaller bore that will shroud the valves. As to the bore being more stable, not nessecarily so, there is ways to stabilize and infact because the piston is decending less you could probably fill the lower water jacket area with block cement. The less the piston travel will also mean less flexing in the block's walls.
If your engine builder has suggested building such an engine, kick him in the arse and then sack him, he is an idiot. If you dreamed up this idea, you have got out of this just in the nick of time and this post has saved you big bucks. Go to a reputable engine builder and pay him, with your level of knowledge on this design issue you are doomed to failure. I would advise you to read Smokey Yunicks power secrets, he gives good straight forward advise on these areas.
Good luck
Greg
Cheers Greg
Yep. Race rules. Once the engine goes FI then a 1.7 equalisation applies. Hence to race in the 6 Litre class the capacity needs to be around 3.5L. I could have gone with a 3.5L V6 or S6 but the V* would be more reliable (9000 RPM, 20psi, 11:1, methanol).
- Messages
- 5,631
- Location
- Sydney, Australia
I'd leave the bore as is and de-stroke the engine.
Probably easier and more reliable plus it will give a very oversquare engine that will use the head to it's full benefit.
Probably easier and more reliable plus it will give a very oversquare engine that will use the head to it's full benefit.
Brad Bedell
New Member
- Messages
- 88
- Location
- Dallas TX
I agree with this one. Destroke it and spin it until even the humming birds get confused. I've found more RPM/wider RPM band is almost always more useful on the track.Zuffen said:
There are a number of reasons that I would prefer to decrease the bore.
1. De-stroking would require a billit crank which will not be as strong as the original forged unit.
2. De-stroking will provide less low down torque and require longer rods to achieve 11:1 comp.
3. Having a decreased bore will provide thicker cylinder walls which will provide less opportunity for wall flex due to piston side wall forces at high piston pistons.
This engine is being built for FI running at about 20psi, 9000rpm, methanol and 850 - 900hp. So crank strength is really important.
1. De-stroking would require a billit crank which will not be as strong as the original forged unit.
2. De-stroking will provide less low down torque and require longer rods to achieve 11:1 comp.
3. Having a decreased bore will provide thicker cylinder walls which will provide less opportunity for wall flex due to piston side wall forces at high piston pistons.
This engine is being built for FI running at about 20psi, 9000rpm, methanol and 850 - 900hp. So crank strength is really important.
Brad Bedell
New Member
- Messages
- 88
- Location
- Dallas TX
Good points, we all have our reasons. 
Look at the Darton sleeves web site. If I'm not mistaken, they have CAD files on all their sleeves in the catalog.
http://www.darton-international.com/mainpage.htm
-B
Look at the Darton sleeves web site. If I'm not mistaken, they have CAD files on all their sleeves in the catalog.
http://www.darton-international.com/mainpage.htm
-B
928s
New Member
- Messages
- 46
- Location
- Sydney Australia
I'm sorry but you are wrong on all the points you make. As for the crank not being as strong, that is incorrect, a machined billet will always be stronger than a cheap high production forging, what type of forging is it anyway? There is two main types, also you are not taking into consideration the increased overlap of the journals, one of the main weak points of any crank.
Decreased stroke allows for a better rod to stroke ratio.
The better the rod to stroke ratio exerts less force on the crank, rods and skirts of the pistons. It also allows the engine to breath better. This makes more power. The rod to stroke ratio is extremely important when it comes to high revs. The higher the number the better. Most F1 engines would be in the region of 2.3 to 1.
The destroking would most like allow you to use Honda journaled rods, these make more power due to lower friction and lower mass forces which will increase engine life.
If you look a an F1 engine or even a Cart engine, they have big bores and short strokes, have you done a peak piston speed calculation, the speed of the pistons in your motor will be so much higher than in a short stroke high rod to stroke engine. The G forces will be huge in the engine you are planning on building.
Also a smaller bore will have trouble breathing not just because of the low rod to stroke ratio but the smaller bore that will shroud the valves. As to the bore being more stable, not nessecarily so, there is ways to stabilize and infact because the piston is decending less you could probably fill the lower water jacket area with block cement. The less the piston travel will also mean less flexing in the block's walls.
If your engine builder has suggested building such an engine, kick him in the arse and then sack him, he is an idiot. If you dreamed up this idea, you have got out of this just in the nick of time and this post has saved you big bucks. Go to a reputable engine builder and pay him, with your level of knowledge on this design issue you are doomed to failure. I would advise you to read Smokey Yunicks power secrets, he gives good straight forward advise on these areas.
Good luck
Greg
rarson
New Member
- Messages
- 217
- Location
- Manchester, CT
You could offset grind the cam down to a Honda 48mm rod journal (common nascar rod journal dimension), giving you 8mm less stroke. If I did my math correctly, that'll give you about 3.6L. I'd do this and then get a smaller sleeve. LA Sleeve probably has a shelf set that you could use for this. If not, they can make a set for a reasonable price (probably significantly less than Darton).
Attachments
928s
New Member
- Messages
- 46
- Location
- Sydney Australia
I haven't bothered to do the math, seems the initiater of the thread not that fussed either, but you could weld the journal so that you could offset grind it exactly how much stroke you required, after welding you would then need to straighten the crank and hard chrome the journals.
Cheers Greg
I've been off the air for a while. My latest plan, following advice from others, is to keep the bore std. and reduce the stroke to 72mm. As was pointed out earlier this will reduce both the piston speed (ave. 25 to 21.8m/s, peak 40.7 to 35.3 m/s) and accelleration by about 14% over the std. stroke. I have resisted changing the stroke because it means using a billet but there appears to be no option. Hence, if I am going to use a billet, does anyone know what a suitable grade of steel would be to handle the power required (900HP @ 9100RPM) and who might be able to build such a unit?
For the turbos I am planning to use Garrett GT37 x 2, each producing about 50lb/min at a pressure ratio of 2.75 with 1650cc/min methanol injectors.
For the turbos I am planning to use Garrett GT37 x 2, each producing about 50lb/min at a pressure ratio of 2.75 with 1650cc/min methanol injectors.
C
cowboy bebop
Guest
Lextreme II
Just call me "Lex"
- Messages
- 12,033
- Location
- City of Halos
Please contact one of our members "aeropc" for information on billet crank. There are many guys in the US and Australia can build a billet crank. From what aeropc stated is about $2000 USD.
turboteener
New Member
- Messages
- 119
- Location
- Huntsville, Al
A billet crank will not be stronger than a forging. A billet crank will not have the properly aligned grain structure that a forging has. This is one of the reasons a forged crank is stronger, but in a limited production run a billet crank will probably be cheaper.
When you shorten the stroke and run a longer rod your piston speed well drop. This is good. You will also increase the dwell time at TDC, but there are some drawbacks. The pistons speed and acceleration will decrease as will the negative pressure drop in the cylinder. This can help out if a head is not blessed with properly sized ports. Decreasing the rod ratio will help make huge ports work in a low RPM application. You will have to be care about how your port the motor. Smokey likes to talk about using the longest rod possible. I don't tend to follow that. Every engine is different and its piston speed requirements will be different. When you change the internal geometry you can affect many other factors than just piston speed.
Since you are boosting the engine why bother turning the engine to 9K. One of the benefits of boost is you can make more power down low and you don't have to torture the engine with high RPM. It will be cheaper in the end if you keep the revs down and look to broaden your torque curve.
When you shorten the stroke and run a longer rod your piston speed well drop. This is good. You will also increase the dwell time at TDC, but there are some drawbacks. The pistons speed and acceleration will decrease as will the negative pressure drop in the cylinder. This can help out if a head is not blessed with properly sized ports. Decreasing the rod ratio will help make huge ports work in a low RPM application. You will have to be care about how your port the motor. Smokey likes to talk about using the longest rod possible. I don't tend to follow that. Every engine is different and its piston speed requirements will be different. When you change the internal geometry you can affect many other factors than just piston speed.
Since you are boosting the engine why bother turning the engine to 9K. One of the benefits of boost is you can make more power down low and you don't have to torture the engine with high RPM. It will be cheaper in the end if you keep the revs down and look to broaden your torque curve.
- Messages
- 5,631
- Location
- Sydney, Australia
Turboteener,
Never a truer word spoken.
You supercharge engines for low down grunt not 9,000rpm engine speeds.
If you want to rev a supercharged engine to 9,000rpm the bottom end boost will suffer as you can't spin the charger fast enough down low without running out of charger revs up high.
Look at an Eaton. 12,000rpm is it. On a 1.8 drive 6,500 engine rpm is 11,700 charger rpm. You can run the charger at 12,000rpm when the engine is at 9,000 but the drive ratio drops to 1.33 which will mean it won't produce any boost until about 3,000 engine rpm.
AA Fuel Dragsters are an exception.
Never a truer word spoken.
You supercharge engines for low down grunt not 9,000rpm engine speeds.
If you want to rev a supercharged engine to 9,000rpm the bottom end boost will suffer as you can't spin the charger fast enough down low without running out of charger revs up high.
Look at an Eaton. 12,000rpm is it. On a 1.8 drive 6,500 engine rpm is 11,700 charger rpm. You can run the charger at 12,000rpm when the engine is at 9,000 but the drive ratio drops to 1.33 which will mean it won't produce any boost until about 3,000 engine rpm.
AA Fuel Dragsters are an exception.
Brad Bedell
New Member
- Messages
- 88
- Location
- Dallas TX
One can get 14,000 to 20,000 RPM out of a whipplecharger. Their 5.0l displacement supercharger can spin 16,000rpm. With VVT-I, one could really custom taylor a torque curve that looks more like a table than a curve.
All good stuff. For this application I am planning to use a twin turbo setup so blowers are out and blower RPM becomes a non-issue. The reason for the high engine RPM is to reduce the boost required for this application. At 9000 rpm I need a boost pressure of about 24psi. If I reduce the RPM to 7000 then the boost will increase to 34psi however the discharge temp will increase to over 400F and this will require a lot of cooling.
As with everything, its all a bit of a compromise.
As with everything, its all a bit of a compromise.
- Messages
- 5,631
- Location
- Sydney, Australia
Tinker,
At 9,000rpm the 1UZ is way past its capability with stock internals.
You will need rods, pistons, ARP studs and more to make it hold together.
Are you prepared to spend $1,200 (pistons) $2,800 (rods) and (400.00) studs plus over $1,000 for gaskets? Don't forget bearings, machining, balancing and assembly and we've only started. You're loking at a $15,000+ engine here.
Of course if you shop hard and get int GP's you will cut the above cost to less than half.
At 9,000rpm the 1UZ is way past its capability with stock internals.
You will need rods, pistons, ARP studs and more to make it hold together.
Are you prepared to spend $1,200 (pistons) $2,800 (rods) and (400.00) studs plus over $1,000 for gaskets? Don't forget bearings, machining, balancing and assembly and we've only started. You're loking at a $15,000+ engine here.
Of course if you shop hard and get int GP's you will cut the above cost to less than half.
