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Why do the engines need a rebuild every 40 hours?

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Jameel Jam
(@jamolah)
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Joined: 3 years ago
Posts: 6
Topic starter  

Since the Radical uses a Suzuki hayabusa engines, just curious why they need a tear-down/rebuild when in the Radicals, yet they don't need a tear-down/rebuild in the street going motorcycle? 

 

According to research I've done they require a rebuild every 40 hours at a cost of $3000USD for a non-certified shop and $6000USD at certified shop, is that correct?

 


   
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CharleyH
(@charleyhradicalsportscarregistry-com)
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Joined: 6 years ago
Posts: 1822
 

Hi Jameel (@jamolah), Welcome!  There are several reasons why the SR3 engines have more frequent overhaul periods then the similar engine in a Hayabusa motorcycle.  The first reason is that the engines are now pushing much more weight and they are driving two wheels vs. one wheel in a motorcycle.  The second reason is that the way the engine is used.  In a racing application like the Radical the car spends much more time at full throttle then it would in a street bike application.  So in short the engines in the Radicals work a lot harder.

When it comes to engine overhauls it is true that you can have a non certified shop do an overhaul for a fraction of the cost of a certified shop, but I HIGHLY RECOMMEND only using a certified Radical shop to do overhauls.  These engines start life as a Hayabusa engine, but they are modified to work in an automotive environment and the non certified shops do not have the knowledge required or access to the Radical unique parts.  Radical is constantly learning from the thousands of cars being driven and they constantly update parts and processes and this knowledge is only available to the Radical shops.  For examples the K8 (2010 and newer) engines actually use parts from a K7 (2009 and earlier) cam tensioner because they found that the newer style tensioner works great in a motorcycle application but was causing cam chains to break in an automotive application.  Your local motorcycle shop wont know things like this.  I can't tell you the number of times I have heard people tell me that they were going to use a local shop to "save money" and then it ends up costing them much more after the engine blows up.  

Another thing to consider is engine size.  The 1500 engines require overhauls every 40 hours but the 1340's are less stressed and can go 90 to 100 hours between overhauls.  So if you plan to use the car for track days you may want to consider a 1340.  They have less power but they do last a lot longer between overhauls.

Regarding cost, I would say a certified shop will cost you between $6k and 10k depending on how much work needs to be done.  Also you should have the Gear Drive Unit) overhauled when the engine is done and that cost between $2k and 4k.  You can save a bit of money if you remove the engine and GDU and bring it to the dealer but I recommend, when possible, just to bring your car there and let them go over the car to make sure everything is working properly.

Charley


   
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Jameel Jam
(@jamolah)
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Joined: 3 years ago
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@charleyhradicalsportscarregistry-com

Thank you for the quick and informative reply.

Yes I am looking at the 1340 engine. So 90 to 100 hours is a lot more reasonable, this could take 3 to 4 seasons.  

Okay,  so I'm looking at engine and gear drive about every 3 or 4 seasons at a cost of $10,000USD. Which is around $13,000 to $14,000 CDN. hmmm.... okay I'll have to think about that. 

 

I've heard the term GDU in other posts, but what is that? is that the CPU?


   
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CharleyH
(@charleyhradicalsportscarregistry-com)
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@jamolah, GDU = Gear Drive Unit.


   
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Victor Ling
(@azwcat)
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Joined: 4 years ago
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@jamolah, note that the maintenance interval is referenced to engine run time, not track time.  Due to warm up and other factors, your engine run time will be 2-3x your actual on track (engine on-load) time.  Also, the 6-10k rebuild cost is the cost if you deliver the engine to the shop.  If you are not removing/reinstalling the engine yourself, add 2-3k for the labor, plus crating/shipping charges. 

 

 


   
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John Annunziata
(@johnannz)
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Joined: 5 years ago
Posts: 168
 

There seems to be more 1340cc vs 1500cc north of the border.  When I was doing the search for my car the majority of the Radicals I found in Canada were 1340's 


   
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Jameel Jam
(@jamolah)
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Joined: 3 years ago
Posts: 6
Topic starter  
Posted by: @azwcat

@jamolah, note that the maintenance interval is referenced to engine run time, not track time.  Due to warm up and other factors, your engine run time will be 2-3x your actual on track (engine on-load) time.  Also, the 6-10k rebuild cost is the cost if you deliver the engine to the shop.  If you are not removing/reinstalling the engine yourself, add 2-3k for the labor, plus crating/shipping charges. 

 

 

Oh that's a valid point. Thanks for bringing that to my attention,  because I didn't think of that aspect. 


   
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Thomas Miller
(@tommymills)
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Posted by: @azwcat

@jamolah, note that the maintenance interval is referenced to engine run time, not track time.  Due to warm up and other factors, your engine run time will be 2-3x your actual on track (engine on-load) time.  Also, the 6-10k rebuild cost is the cost if you deliver the engine to the shop.  If you are not removing/reinstalling the engine yourself, add 2-3k for the labor, plus crating/shipping charges. 

 

 

I know that what you said about rebuild time based on 'run time' not 'on-load' time as that is stated in the manual. But after reading Charlie's and Radical's rationale for 40-hour rebuild intervals due to increased load from increased weight and more drive wheels, why are we counting idle and warm-up time into that equation?

People in colder climates like Utah and Colorado will have significantly more warm-up time on their engines. Warm-up time is relatively low-stress, especially when compared to wide-open throttle. I also know an oil pre-heater will dramatically reduce warm-up times and I have one on my car for that purpose, but it still seems very aggressive to get somewhere in the 15-20 hours of load time on an engine between rebuilds.


   
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Victor Ling
(@azwcat)
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Joined: 4 years ago
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@tommymills , there’s an older thread around here where I asked pretty much the same question.  I think you can justify other rebuild intervals.  I have heard of folks going 200 hours. The most knowledgeable guys will be the shop at spring mtn due to the numbers of engines they see.  They told me the longer you stretch the interval the more stuff needs to be replaced.  Once you get to 13k of parts and labor you have paid for a new engine.  IIRC, they recommended 80 hrs on the 1340.  The 1500 is less forgiving and they don’t recommend extending beyond the factory recommendation.

BTW, stuff does go wrong with these engines.  I had to replace my engine with only about 55 hrs on it.


   
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Rich Kenworthy
(@rich)
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Joined: 3 years ago
Posts: 38
 

I am the certified builder in Ontario, Canada. I have also been a motorcycle technician for over 30 years with an extensive background building and tuning performance engines, particularly pertaining to car use.

Having said that, I can not stress how important the factory training as well as proprietary part knowledge is for my ability to maintain the product to RPE standards. it should be noted that with time scheduled rebuilds on both 1340 & 1500's, the transmission components are also an integral part of that process.

Many of the tests and procedures performed are not found in any service manual and are the result of unparalleled experience.


   
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