Hello guys,
I'm asking myself what kind of engine is more reliable for track use only. It's obvious which engine will deliver a better
performance/weight/price factor in most cases but that's not what I want to speak about. I'm also fully aware of every other general pros
and cons (bec. vs cec), that's why this shouldn't be debated here.
I read through many forums and noticed that many seven type bec builds had problems with engine failures, most of them used the hayabusa engine in a
westfield. But what is the reason for this? I continued reading and there are basically three theories which are linked to oil starvation but no one
has a concrete answer:
1. Bike engines can't withstand and were not designed for the higher G-Forces during cornering which you can reach with four compared to two
wheels.
2. The hayabusa engine is mounted longitudinal in all seven type builds but was developed for a transverse application.
Therefore the hayabusa engine can cope with high G-Forces with a proper drysump kit and in an transverse application only e.g. Mid-engined locost
(XTR2 or others). The reason for this is that the engine will experience forces which it was designed to cope with, if mounted longitudinal different
forces will influence the engine which it can't cope with as well. (The longitudinal hayabusa V8 mounted in the Radical SR8 has a different
block, so it isn't comparable to a stock engine)
3. The westfield dry sump kit isn't up to the job if used for the track only and it doesn't matter how the engine is mounted or if it is a
bike engine or not.
Basically I want to decide what engine will be cheaper as a long term solution with many, many miles on the track. A 200hp+ NA Duratec engine or a
stok hayabusa engine, let's assume both engines have a proper dry sump kit installed.
Furthermore I read that many guys are overhauling/refreshing their hayabusa engines, although I read on bike forums that many covered 60k miles on a
stock hayabusa engine without an engine overhaul. I assume therefore that the lifespan of a bike engine is beeing significantly reduced in a car
application? What kind of overhaul intervalls can I expect for a hayabusa engine which is beeing used with four wheels on the track only ?
Is there a specific reason linked to reliability why only car engines are beeing used in the Westfield Race Series in UK and NL?
On the other hand hayabusa engines are powering all SR3's, SR4's which are beeing used in the radical cup, wonder how long these engines are
holding up? (But most are stroked, so not really comparable to an untouched stock engine)
This thread was posted also in these forums:
http://boardroom.wscc.co.uk/cgi-bin/ikonboard.cgi?act=ST&f=3&t=89886&st=&&#entry904018
http://www.locostusa.com/forums/viewtopic.php?f=4&t=12367
[Edited on 20/5/11 by reb]
[Edited on 20/5/11 by reb]
[Edited on 20/5/11 by reb]
One answer is that the g-load on a bike pushes the oil to the sump vertically due to the bike being leaned over in the corner.
A car forces the oil to the side and up the side of the oil pan away from the pickup, the reason there a so many baffles in a car engine to try and
hold the oil near the pickup during hard cornering.
quote:
Originally posted by Canada EH!
One answer is that the g-load on a bike pushes the oil to the sump vertically due to the bike being leaned over in the corner.
A car forces the oil to the side and up the side of the oil pan away from the pickup, the reason there a so many baffles in a car engine to try and hold the oil near the pickup during hard cornering.
Andy Bates at AB Performance for this one.
Top Bloke
I have a zx12 in mine and it has never had a problem.
Dry sumped.
Done 4000 km now only on trackdays.
http://www.youtube.com/watch?v=ajGoWEL12fE
Soren S2
quote:
Originally posted by sorens2
I have a zx12 in mine and it has never had a problem.
Dry sumped.
Done 4000 km now only on trackdays.
http://www.youtube.com/watch?v=ajGoWEL12fE
Soren S2
If I had a choice of a dry-sumped Busa or a dry-sumped Duratec and my main concern was reliability and longevity, then I'd be taking the Ford lump... no contest!
quote:
Originally posted by scootz
If I had a choice of a dry-sumped Busa or a dry-sumped Duratec and my main concern was reliability and longevity, then I'd be taking the Ford lump... no contest!
Based on the testimonies that this debate throws up time after time after time after time.
Mine is a paceproducts.co.uk
Like this.
Thanks. Here is a video with the new intake feeding only cold air to the engine.
http://www.youtube.com/watch?v=v4g5EeLDmQY
Soren S2
I understand the need to dry sump a bike engine, But why dry sump a car engine?
A properly baffled wet sump on a car will last ages and the cost will be substantially cheaper.
ATB Dan.
quote:
Originally posted by scutter
I understand the need to dry sump a bike engine, But why dry sump a car engine?
A properly baffled wet sump on a car will last ages and the cost will be substantially cheaper.
ATB Dan.
I did more research and found out that powertec/radicalperformanceengines are granting a 40 hour warranty on their
1300cc hayabusa engines which are developing 230hp (+27% more power compared to a standard engine).
This probably means that the engine should get an overhaul/refresh arround every 40 hours.
The main differences compared to a stock hayabusa engine seem to be:
- Forged high compression pistons
- Forged rods
- Race ported and polished cylinder head
- Reprofiled high-lift camshafts and adjustable sprockets
- Titanium valves and retainers
- Race valve springs
- Dry sump system
If we have these values as a starting point, how many hours do you guys think a standard hayabusa engine could handle on the race track? I imagine
definately more then the radical engines due to standard parts and a lower hp output of the same ccm.
@ sorens2
I assume that you have been arround 30 hours on the race track to reach your stated 4000 km?
@ Jon Ison
Can you estimate how many hours you were effectively racing on the track, seperate values for both engines would be best?
@ all
thanks so far for all replies!
80% of the mileage on my car is on track, this year I have done to date 6 track days and probably 60 road miles tops.
After speaking with duratec engine specialists, bike engine specialists and some drivers who are participating in races with these engines I managed
to gather some information:
Rebuild intervals for race applications:
Duratec 200hp rebuild intervall: 50-60h
Powertec 220hp hayabusa rebuild intervall: 40h
Refreshed standard hayabusa engine: ~30h
Not refurbished standard hayabusa bike engine out of a bike: ~20h (will mostly fail due to a rod going through the block)
Be aware that these numbers will greatly expand if you use these engines in a road going kit car.
Therefore you can't really rule out any of these engine types especially as both of these engines will deliver nearly the same power/weight ratio
in a seven type car.
Struggle to see how you get similar power to weight ratios though...
quote:
Originally posted by scutter
I understand the need to dry sump a bike engine, But why dry sump a car engine?
A properly baffled wet sump on a car will last ages and the cost will be substantially cheaper.
ATB Dan.
With our zx10, we are running on slicks so pulling fair bit of g forces. We have a billet sump, baffle plate and accusump. Similar to what others have
with similar cars which haven't had any oil surge issues.
EDIT: and is a lot cheaper than a dry sump kit!
[Edited on 25/5/11 by eddie99]
Here is an overview which I found in one of Radical's user manuals (SR4).
The total cost except an engine and gear drive rebuild, brake discs, damages to the fuel
tank is 5365,00 GBP if all the stated parts have to be replaced/rebuild after the mentioned amount of "hours".
Radical also says that engines which are not being raced will hold up 90 hours.
However I'm asking myself why the front and rear uprights have to be replaced, a bearing change would do the job?
Furthermore the front and rear wishbones have to be replaced too, although a change of the spherical and rubber bushings would do the job as well?
[Edited on 25/5/11 by reb]