differences between 700 nonVES and VES heads

[Jay]

I just bought an '04 700 RMK for the wife and was wondering if I could use aftermarket heads for the '98 700 on the '04? I have sets of Hymark and Union Bay That I would like to use? Anyone? Also I would like to find a set of twin pipes for the '04, did SLP ever make race twins without the humongous can for the 700 VES?

[smwizzz]

I'm gonna say there is no real difference in the ves/non-ves head. Compression ratio is the big key. You can cc the heads with a piece of plexi-glass. Drill a 3/8 hole in the middle and a smaller hole near the outer edge. You need a real accurate measuring device. Use a small amount of grease to seal the plexiglass to the head. I also use a couple c-clamps to hold it in place with duct tape on them so they don't mark anything. Compare... . You can check the bore on the heads with a vernier caliper. Check in a couple different spots. You can also compare (I mean COMPARE) the squish with a vernier using the depth guage. If everything adds up then you got it made. I actually have a stock 700 head that is VES as a spare if you need one. You can always cut the stock head to gain compression. You can cc the engine c/w the head to measure the exact compression ratio. You can actually do this to each cylinder to basically blueprint the engine. Once you know the exact compression ratio you will have a good idea where to go with fuel octane. The more compression the higher the octane. Note: high compression and high octane are no good without timing. One thing leads to another.... and another.... and.....

[785rmk]

I know that the VES and non ves heads aren't interchangable. One difference is the small port for the ves. Also just to solidify my answer. Take a look at the different part numbers from SLP for the 98-05 700. The only common ones were the 98-00. The rest were different. They wouldn't go to all the trouble if they were interchanable.

[smwizzz]

Originally Posted by 785rmk

I know that the VES and non ves heads aren't interchangable. One difference is the small port for the ves. Also just to solidify my answer. Take a look at the different part numbers from SLP for the 98-05 700. The only common ones were the 98-00. The rest were different. They wouldn't go to all the trouble if they were interchanable.

Can't argue, never tried to interchange them. They look different on the exterior. I'm not sure about the bolt pattern, it may be different also. The key for me would be the actual measurements if the bolt pattern is the same. Also something to note is the small ports for ves are actually in the cylinder and not the head. On some of the big bore 2 stroke stuff there was a small bleed port used as a decompression port for starting. I am not sure if Polaris was one of the ones who tried this. As far as part numbers go, every casting has a part number and there is no doubt the ves and non ves are different castings.

[785rmk]

Originally Posted by smwizzz

Can't argue, never tried to interchange them. They look different on the exterior. I'm not sure about the bolt pattern, it may be different also. The key for me would be the actual measurements if the bolt pattern is the same. Also something to note is the small ports for ves are actually in the cylinder and not the head. On some of the big bore 2 stroke stuff there was a small bleed port used as a decompression port for starting. I am not sure if Polaris was one of the ones who tried this. As far as part numbers go, every casting has a part number and there is no doubt the ves and non ves are different castings.

Sorry about that, I reread my post sounded like an azzhat. Thanks for correcting me on the head pressure port. I has been a few years since I have had a VES apart. I know when we had our shop we carried a slew of different heads for the 700, and if they were able to interchange them we wouldn't have had so many of them laying around. Jay if you wanted you could try to bolt it on. Worst thing that could happen is that it wouldn't seal and if it did fit you would just have to worry about putting a hole in the top of the piston.

[Jay]

Thanks for the tips guys, I'm just kicking some thoughts around now for what I'm going to do to it. I'd like to go with the basics, a set of twin pipes, head, reeds, etc. I probably shouldn't admit it but if I screwed it up it wouldn't be the first time I burned down one of "her" sleds.

[smwizzz]

Originally Posted by 785rmk

Sorry about that, I reread my post sounded like an azzhat. Thanks for correcting me on the head pressure port. I has been a few years since I have had a VES apart. I know when we had our shop we carried a slew of different heads for the 700, and if they were able to interchange them we wouldn't have had so many of them laying around. Jay if you wanted you could try to bolt it on. Worst thing that could happen is that it wouldn't seal and if it did fit you would just have to worry about putting a hole in the top of the piston.

No probs.... Been a long time since i messed with non ves myself. The key to the head would be connecting rod center and stroke (I am very sure they are the same in ves and non), and the bolt center diameter of the cyl head bolts. After that, I am sure you will have no probs bolting them on. At that point I would rotate the engine by hand to make sure it moves freely. Once this is established... using a piece of solder bent at 90 degrees, insert it into the combustion chamber over the piston and slowly rotate the engine. The piston will come up and squish the solder. You can then measure the squish thickness. I am not sure the specs, but I am sure if you check the old one before you dissassemble it would be a good comparison. I personally would check actual compression ratio also. Only other question would be depending upon year and which parts you were mixing you could run into an o-ring vs gasket issue. I am sure a gasket would work just fine.

[johnsodo]

i did run a non ves head on a ves 03 800 just had to do some thing about the det senser i removered it form my cdi

[johnsodo]

btw slp did make twins for it it was the same ons for the 800 ves and yes ther are some race twins out ther of it form slp but a 98 head on a 04 over the years thay have change some things on thim h20 by pass det temp out let and on the 700 cover bolt down holes