Anyone run a Bender 800 Big Bore?

M

MM 700

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Joined
Jul 29, 2005
Messages
129
Age
44
Location
Iowa
Have any complaints? Is it reliable? How was the power increase? Anyother info welcome.

Would like to find a used 800, I think it would be a good motor.
 

I had a 780 big bore and switched to a ported 700.The ported motor felt faster ans was way cheaper than a big bore.
 
We ran a Bender 800 in a 97 SX. Bender dyno'd the motor at 174.5 hp with their tripple pipes. Fully reliable on the trail or lake. Lots of fun too. Never had any issues. Justin Fuller did the work for us. He is still available to do those big bores and can be reached in New York at 716-699-6299.
 
Justin built my ported motor!!! His shop is called full power performance located in Ellicotville ny.He's the one who convinced me into going with the ported motor because i'd get better reliabilty with just a tad less horsepower. He wasnt cheap but he did a great job with mine.
 
below is a copy of the dyno sheet from dynotech. this is typical h.p. for a trail 800 motor. this is my 2nd one. they are very dependable. thousands of miles & no issues. have also had ported 700's. the 800 is much faster. has more h.p. bottom - mid & top.
bluehammer: 174.5 h.p. on a 800?? seen a bunch of them dynoed & they all are high 150's. leaned out around 162.

bob


This 800cc big bore kit has cast pistons, iron sleeves, and very quiet DynoPort triple pipes developed by Tim

Bender and Rich Daly. Stock 33mm carbs are used here.

SXR with Bender 800 big bore and DynoPort pipes (this was 110 HP stock)

EngSpd STPTrq STPPwr BSFC B Fuel B AirTmp BaroP

RPM Clb-ft CHp lb/hph lb/hr degF in/Hg

6900 78.3 102.8 0.757 78.5 40 29.70

7000 79.2 105.5 0.747 79.4 40 29.70

7100 78.9 106.6 0.767 82.4 40 29.70

7200 79.2 108.5 0.773 84.6 40 29.70

7300 81.4 113.2 0.764 87.3 39 29.70

7400 81.6 115.0 0.776 90.1 39 29.70

7500 81.6 116.6 0.766 90.3 38 29.70

7600 83.3 120.6 0.748 91.1 38 29.70

7700 85.7 125.7 0.754 95.7 38 29.70

7800 86.1 127.9 0.736 95.0 39 29.70

7900 87.5 131.6 0.724 96.1 39 29.70

8000 89.7 136.6 0.705 97.2 39 29.70

8100 90.7 139.8 0.706 99.9 37 29.70

8200 93.3 145.7 0.687 101.3 37 29.70

8300 93.3 147.5 0.679 101.3 37 29.70

8400 94.5 151.1 0.672 102.8 36 29.71

8500 94.5 152.9 0.674 104.4 36 29.71

8600 93.7 153.4 0.673 104.3 38 29.71

8700 93.1 154.2 0.668 104.1 38 29.71

8800 92.9 155.7 0.659 103.5 39 29.71
8900 90.5 153.4 0.662 102.4 40 29.71

9000 87.3 149.6 0.691 104.3 39 29.70
 
awesome! im really thinking about trying that big bore out next year. on the bender site it says 25 hp gain with pipes and another 25hp with there big bore. thats 162 peak hp so those dyno numbers are right on.
 
Mine was a maximum performance 780 big bore,wasnt impressed.The bender BB does sound like its built better but i didnt want to spend the extra money on pipes.
 
don't want to hi-jack your thread but has anyone tryed to make there own BB kit? If you did how did it work and was it worth the time and money? I'm looking into doing it my self.

Thanks
 
blueh:
i think your taliking srx... mm is talking sx. below is an article & dyno sheet from dynotech. this is my trail 835 srx. we dynoed it the same day we did the sx800. 45 more h.p. than the sx. justin is correct, as usual, the 780 big bore srx makes about the same h.p. as the ported srx. justin did a race ported 835 srx that was around 215 h.p..

"Now here is Bob’s SRX700 modified by Bender Racing to 835cc (same bore as the SXR800 but the longer stroke of the SRX = 835cc). This one was done by Justin Fuller who was Bender’s tech guy/ port guy before Bender Racing was purchased by DynoPort (Justin purchased Bender’s turbo division now Full Power Performance). Justin told me it takes 20 hours of grinding to get this big bore port timing/ shapes optimized. He also told me that the SXR is restrictive from carbs to cylinders, crankcase is smaller, cylinder castings too narrow to be optimized hence the lower airflow and HP. The SRX is most
ideal to modify, since the cost to modify is almost the same. On this big bore SRX a rack of 38mm Mikuni carbs from a SkiDoo Mach Z triple (same bore spacing) are used in place of the restrictive stock 33’s. This sled as 12.5/1 compression ratio, stock timing ECU, and 2500 miles of trail riding before this test. This sled his been reliable for 2500 miles of Bob’s respectful trail/ lakerunning."

SRX with Bender 835 big bore with DynoPort pipes (this was 140 HP stock)

EngSpd STPTrq STPPwr BSFC B Fuel B AirTmp STPCor BaroP
RPM Clb-ft CHp lb/hph lb/hr degF Factor in/Hg
7000 107.3 143.0 0.783 111.5 46 1.004 29.66
7100 106.5 144.0 0.779 111.9 44 1.002 29.66
7200 106.5 146.0 0.782 114.4 41 0.999 29.66
7300 107.5 149.4 0.777 116.4 40 0.998 29.66
7400 108.6 153.0 0.751 115.2 40 0.998 29.66
7500 111.1 158.6 0.725 115.4 39 0.997 29.66
7600 111.1 160.7 0.726 117.2 39 0.997 29.66
7700 115.2 168.8 0.705 119.4 39 0.997 29.66
7800 114.7 170.3 0.691 118.2 39 0.997 29.66
7900 116.5 175.3 0.664 117.0 38 0.996 29.66
8000 120.1 182.9 0.643 118.3 37 0.995 29.66
8100 119.8 184.7 0.646 120.1 37 0.995 29.66
8200 119.1 185.9 0.644 120.5 37 0.995 29.66
8300 121.1 191.3 0.618 119.0 37 0.995 29.66
8400 121.4 194.1 0.622 121.4 37 0.995 29.66
8500 119.8 193.8 0.627 122.3 37 0.995 29.66
8600 118.1 193.3 0.615 119.7 36 0.994 29.66
8700 115.7 191.7 0.615 118.9 35 0.993 29.66
8800 113.8 190.6 0.619 118.8 36 0.994 29.66
8900 110.3 187.0 0.627 117.9 37 0.995 29.66
9000 106.8 183.1 0.634 116.7 37 0.995 29.66
 
Nice,Justin is the man!! When i was there he was building an Appex.I cant remember if it was supercharged or turbo but he said it would make some monster h.p.
 
Bufalobob,

The 800SX was ported and dyno'd with 38's if memory serves me correctly. My son would remember all of the details of that motor and dyno sheet. But it did pull 174.5 on their dyno. We also had a fully ported 700 redhead that Justin built and dyno'd at 167.5 hp at 10,200 rpms with 42 PSI's. This was backed up at Northeast Ohio Dyno a short while later, but we put silencers on the pipes and still pulled 164.5 on that dyno. Both dyno runs were with Klotz fuel. The 800 was dyno'd with premimum unleaded.
We also had one of Justin's 835's with case porting and dyno'd at Bender at 198.5 with another set of 42 Big Airs on C12 and Benders pro stock pipes. I'm sure that more ponies could have been found on that day, but dyno's, as you are aware, get expensive after a few hours.

Yea, I'd say that Justin is the man when it comes to reliability and horsepower.
 
Bluehammer is talking about my sled, and he is right; it pulled almost 175 hp on Bender''s dyno. Justin himself was even impressed on the power it made. If memory serves me right, we ran a tighter head on it when we were racing it. Somewhere around 150 lbs of compression.. Initially ran the stock 33's on it, but moved up to some 38's.
This was the funnest sled I ever rode. Awesome in the trails and a great sleeper on the lake. I could post on here forever about the bigger cc sleds I've beaten on the lake, especially the Cats.
Spend the money and set it up properly; you won't be disappointed.
 
The stats on my engine from Bender are 167.9 hp. This is the high altitude engine. It is a redhead. The clutching can be tricky. Still trying differant set-ups.
 
Hello Bufalo. Thanks for the insight on the bender secondary spring. It made a huge improvement. I'll be upping the total wt of the primary wt's. Going to add 4.5 more grams total. Making it 132 total. I run this above 10k altitude.
Tom
 
hey MM 700, there is a SRX 983 motor for sale in the classified section if ya wanted to take a look, i seen it there just then.
 
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