SRX/Viper engines

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livewire_101proof

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wondering if anyone knows if the chamber sizes are any diffrent between 600 and 700 SRX heads - if i can use 600 heads on my 700.

also an idea ive had, while im rebuilding. its a 2000 srx 700 and thought of trying some viper cylinders for the porting they have over an srx. and have heard that part of the cooling problems of vipers are due to the onepiece head design so i thought i could use my srx heads, probably could use the o ring seal like srx or maybee just go to a regular gasket like the vipers use. Im thinking it will work but figured someone here will probably know. wonder if there any powervalve diffrences i would run into also? not sure, but since i already have a cracked cylinder, a bolt broke off in a head, and could aquire the viper parts that it would not be a whole lot more expensive for me to do. maybe its too much trouble and would be better off getting the one stock cylinder and head and paying to get a porting job done.

also if this is done the way I am thinking, it would be a little closer to the idea that so many have had about using viper cdi boxes for the timing advance. i already have done away with the 2000 cdi and harness so the plugs would be the same i think. thanks ahead of time for any input or opinions.
 
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600 srx heads will fit your 700 cylinders, but the chambers are going to need some machining to work properly. the diameter of the squish band, will need to machined for the larger 69mm bore of the 700 cylinder. the cc size of the 600 head is going to be smaller, yielding high comp ratio. maybe need 50/50 mix of race gas a 93 pump?? also, viper cylinders will fit your srx case and bolt up, but the exhaust manifold setup is different. you would need to modify your manifolds, to make them bolt up/work, and then your length of exhaust changes, which is going to change otherthings as well. also, there is powervalve changes too...vipers are different from 700 srx valves and 600 srx valves are different too. just get a new stock cylinder and head and have the 700 srx cylinders ported.

also, you said you changed out the wiring harness?? what harness you got in there now? are you planning on running a viper box on that srx for trails or what?
 
got a cdi and wiring off a 01 cause i wanted the dual controls for the hand/thumb warmers. have heard the timing is too much for trail riding so probably would not try it but thought of using a viper box if i were to go drag racing, not sure how much if any it would help but i can rob the box of my wifes viper to try it and see if it does anything before buying one.

i probably will just get a stocker and put it back together, but just out of curiosity, if i were to use the viper cylinders, do ya think that if you were to use a thicker base gasket like the power up kits use, then the 600 heads might put the compression about where you would want it? enough to be able to use high test pump gas, dont have a problem with spending the extra 2 dollars diffrence between a tank of regular or high test. would want to be able to ride it to a station and fill up instead of finding race fuel all the time though.

will get stock to put together for now cause im thinkin of sellin it, cause i have one more sled than i can ride at one time, but on the other hand, i love the ol srx, it has almost become a hobby to play with than anything else, so if i dont think anyone is gonna want to buy it then i will probably end up trying something like this, if i get bored and need a new project in the garage.
 
thicker base gasket would reduce the comp, but that will up the port timing. not to mention, the 600 srx heads will need machining work to work on a 700 cylinder, no matter what the application is, or how thick of base gasket you use. at minimum, you need to have the max dia of the squish band machined to the 69mm bore dia of the 700 srx cylinder. but, now you do that and the squish band width becomes too wide and will yield too high of msv, causing deto.
 
Do any of you guys ever try a viper crank in a srx? does it fit? i was reading on a site that the viper crank was built better and lighter then the srx crank. Any one ever try?
 
viper crank is lighter but has the same stroke and fits in the 01-02 srx cases, i beleive by approx 1.5 pounds. It will rev/spin up faster but you would probily loose a lot of torque which would be more noticable with the triple pipes.

I am currently running an 01 srx motor with viper cylinders in my 02 viper single piped. With this combo it does not rev as fast as the viper crank but I find it pulls harder mid range. It is 136" and against a 2005 700 venture(viper motor) of the line consistantly the veture is 2 sled legths ahead until about 60km/h then the viper pulls ahead by about 6 sled lengths and they top out at about the same speed.
 
O.k. seems to make sence. So other words, putting the viper crank, wouldnt be any good to a srx. i am running a 2001 srx, motor seems to be out of a different srx, but not sure what year. Im guessing the same year. does the heads on a viper with the tripple pipes of a srx and the stock srx crank, would that make any diffrence ?
 
eric.s.t said:
O.k. seems to make sence. So other words, putting the viper crank, wouldnt be any good to a srx. i am running a 2001 srx, motor seems to be out of a different srx, but not sure what year. Im guessing the same year. does the heads on a viper with the tripple pipes of a srx and the stock srx crank, would that make any diffrence ?
Click to expand...

are you asking about bolting srx heads and pipes onto viper cylinders, w/srx bottom end?
 
yeah, srx heads on the viper cylinders, cylinders on the bottom end or the srx So bascly srx motor with viper cylinders and power vavles obviously
 
eric.s.t said:
Do any of you guys ever try a viper crank in a srx? does it fit? i was reading on a site that the viper crank was built better and lighter then the srx crank. Any one ever try?
Click to expand...

I am running a Viper crank in my 2002 SRX..I actually assembled a completely different engine using SRX cases, ported SRX cylinders ect. and set my original SRX engine, completely assembled with carbs, recoil + all, on the shelf.
I wanted to try the Viper crank for possible benefits due to its lighter weight + smaller pork chop counter weights for more crank case volume and turbulance. I have not noticed any negative power effects using the lighter crank but it really does feel different, likes to rev very quickly in the 6000 - 8000 rpm range, the sled pulls very well on top end and still holds its own in drag races against much larger sleds.
If I have noticed any negative effect it would be in fuel mileage but that could be a result of other changes I have made.

Bob
 
eric.s.t said:
yeah, srx heads on the viper cylinders, cylinders on the bottom end or the srx So bascly srx motor with viper cylinders and power vavles obviously
Click to expand...

you can put srx heads on viper cylinders and have all that on a srx bottom end, in a srx chassis, but you will need to make new manifold flanges, so the srx pipes/manifolds bolt up, as the bolt pattern is different. also, the viper exhaust port exit is oval and the srx is a circle.
 
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