Thoughts and experiences with 800 mono-block conversions

800 mono

i allso like to know about the 800 mono i just priced 600r pistons $257 + $80 for each ring= $834, 800 mono for about $1300 if i can use my carbs and pipe. some good old advice might save this poor boy thanks :yo:

800 MONO

Firts post for me on here... So I will say that the 800 mono, or 800r setup as some like to call it is not always the best performer. I spend a lot of time on the HCS forums and there are a number of guys struggling to get these 800r motors to perform as well as they though they would. I think the most important variable when doing these conversions is that you cannot cut corners and expect it to run well. The most basic 800r conversions basically involve boring the cases to accept the 800 mono cylinders, plugging the injection ports and putting on a OEM head. Unfortunately these motors will rarely outrun a stock 600r motor that is clutched and jetted properly. The key components to making the 800r run well is basically time, money, and labor(or just more money) is that the upper case needs to be fully port matched with the cylinder, a aftermarket head is needed(preferably a PAR 13.6-1, if not more at elevation), 40mm carbs, a pipe that is made specifically for the motor and chassis(dynoport, or custom), updated pistons such as Wiseco or RK drop ins, possibly even the "fix kit" etc... etc... Basicly you cant cut corners... I haven't looked around here very much, but on HCS there are a bunch of threads that basically start with "my 800r doesn't beat my buddies 600r" and then they go on to say how they have a cut stock 800cfi pipe, mismatched y-pipe, OEM pistons and head, etc.. Hope this helps!

The 800 cylinders on the 600r bottom is a good set up. I tried to run a stock head and it sucked, I went to a 13.6 to 1 head and it ran better. It would stay right with a good running stock 2010 800 dragon. I went to a 14.4 to 1 head and now it will pull away from any pro (0-60mph) but after 60 its dead even.
I have a stock 800 cfi pipe cut to fit and stock carbs. im not sure way but it like to turn rpm 8,500-8,700 is its sweet spot.

the big block 800 make more power but are heavy and the fit and finish is not as nice. IMO

AND I RUN SPI PISTONS........and love them

Just getting done with my buddies. Hope to run it in a week or so. We will run and tune it against my well setup fully ported 660ho 144" iqr. His is setup in a 05 chassis, stock front end 136" ice age rails on stock rear with 141" track. Motor is fully case ported and matched, Indy Dan cylinder and piston kit (best top end option IMO), par 13.6:1 head, 42mm mikuni rack, balanced and cut primary from Indy Dan, cat secondary. Gonna start with 21-45 gearing, 10-64 weights with dark blue/white Polaris spring. See how it runs. Jetting is 520n mains, stock r needles in middle position, 50 pilot, .9 paj. Dynoport full exhaust. He's got a lot invested into this setup. It's more than just boring the case for cylinders and putting a pipe in. Lots of money needs to be invested to make them run on top. For the money you invest, might want to look elsewhere, sell the 600r motor and drop in something cheaper to build and maintain and easier to setup like a 660/685/727 or 800 bb.

Running an 800r and it rips! race department 600 pipes with modified stingers for the 8, bored race carbs and a modified cdi with original cfi 800 head. faster than the triple piped race gas xcr mountain mod that i rode in the past!

Its does require the spendy gas though and it would be nice to run a single pipe for the sake of always having fuel, so if anybody is looking for a great set of pipes and matching cdi with stingers along with tuning baselines lmk!