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General Category >> Rubber Side Down! >> DR650 motor transplant?
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Message started by Armen on 01/31/18 at 18:22:02

Title: DR650 motor transplant?
Post by Armen on 01/31/18 at 18:22:02

So, has anyone done it? Aside from the header pipe on the wrong side, what other grief is there? Motor mounts are no big deal. I'm assuming the black box from the DR ignition must be used.
With all the effort it takes to make a Savage motor work well, seems it might be less grief to start with a DR. Used ones on Ebay for not tons of $.
thanks,
-Armen

Title: Re: DR650 motor transplant?
Post by batman on 01/31/18 at 19:51:49

Armen, The biggest problem in fitting it in Savage frame may be that the cylinder leans forward on DR ,there might not be enough room for it or the exhaust .Converting to a double down tube frame at the front of the motor might allow it . But after looking at the DR ,it has so much going for it, I'd be inclined to try making it look more like a Savage.

Title: Re: DR650 motor transplant?
Post by zipidachimp on 02/01/18 at 00:05:46

Where I live, 1/2 hour south of the mountains, a street bike with a dr650 engine would have me spending all of my waking hours on the road.
My ideal bike, but I would have to build it. I'm handy, but not that handy! 8-)
Maybe we could talk SandmanRed into building us frames!
or this!
http://www.bikeexif.com/suzuki-dr650-custom

Title: Re: DR650 motor transplant?
Post by LANCER on 02/01/18 at 02:38:48

Looks like a fun project.

Title: Re: DR650 motor transplant?
Post by Armen on 02/01/18 at 03:17:56

I've got too much time and energy tied up in the Savage to switch to a complete DR, but I was wondering about a motor swap. At this point, I'll take the head to my porting guy and make the best of what I have.
Sort of arbitrary goals of 300 lbs and 35 HP.
Maybe a DR based one when I retire ::)

Title: Re: DR650 motor transplant?
Post by Dave on 02/01/18 at 05:48:07

Armen:

I think 35HP is pretty easy to accomplish with a Savage engine....maybe even 40 HP. The Wiseco piston, Stage 3 cam, and a little port work makes an engine that runs really well and is noticeably more peppy than the stock engine.....and your lightened flywheel helps get another 1/2 second off the 0-60 time. The stock carb works OK with the engine mods and I ran that carb for a year on my modified engine - the Mikuni round slide is a bit more responsive and may provide a bit more HP.

I am well satisfied with how my modified engine works, and I don't have any need for a bigger/badder engine in my bike. I like riding on roads with lots of curves, and I seldom use more than 1/2 throttle on any ride (unless Oldfeller is pushing on my backside). The simple mods still provide an engine that starts easily, gets good mpg, and other than using premium fuel it acts just like a stock engine and can cruise smoothly all day if needed. The extra power allows for taller gearing that allows a lower rpm at highway speeds, and the motor temps drop with the lower rpm the taller gearing provides.

I have about 10,000 miles on my modified motor, and it makes me smile every time I go riding! :)

Title: Re: DR650 motor transplant?
Post by savagebob on 02/01/18 at 16:33:37

out of interest has anyone actually put their modified savages onto a dyno? Are there any confirmed dyno read outs around?

Title: Re: DR650 motor transplant?
Post by Armen on 02/01/18 at 17:31:53

Thanks Dave.
This go round, the bike will have a stage 3 bump stick, Ryca muffler, Mikuni RS40 flat slide carb, and not much else in the motor department. Next go-round, it gets the high compression 697cc kit, ported head, and twiddled combustion chamber. 40 HP would be nice. With only 300 lbs (or less), it should be a hoot.

Title: Re: DR650 motor transplant?
Post by savagebob on 02/01/18 at 19:39:55

Is 50hp even close to being realistic with these motors natural aspirated? Just wondering.

Title: Re: DR650 motor transplant?
Post by Dave on 02/02/18 at 03:54:57

6D7F687F797B7C717C1E0 wrote:

Is 50hp even close to being realistic with these motors natural aspirated? Just wondering.

I think 50HP is a bit optimistic unless you try something really radical. The modified engines get a boost in torque and some HP - I believe the problem is the cylinder head has such poor flow that it is hard to keep the power up as the rpm's build.

I think that oldindian got his 97mm engine dynoed......I need to go try and find his thread.

Title: Re: DR650 motor transplant?
Post by kojones on 02/02/18 at 04:49:20

726077606664636E63010 wrote:

Is 50hp even close to being realistic with these motors natural aspirated? Just wondering.

46 hp on the rear wheel is realistic. http://suzukisavage.com/cgi-bin/YaBB.pl?num=1431205825/13

Title: Re: DR650 motor transplant?
Post by Dave on 02/02/18 at 06:55:24

I think that dyno run is pretty revealing about the strengths and weaknesses of the Savage motor. The low rpm torque builds really quickly and makes for good low rpm acceleration - the maximum torque occurs at 3,500 rpm and it drops slowly until around 5,700 rpm where it drops quickly. I believe this is a result of the poor flow in the head - and a reduction in efficiency in filling/emptying the cylinder as the rpm climbs.

Title: Re: DR650 motor transplant?
Post by Armen on 02/02/18 at 07:22:05

And that is what I want. A motor with good low end. Not to buzz the crap out of it to get going. A bike that goes 20-80 MPH well.
I guess I should get going on the project...