High compression 'shee.

[Misssppelllleddd]

Well I pretty much got my 'shee set up for low end now. I know it lacks the top end revs but I really do like how it runs on the MX track. I can stick on a dirtbikes ass pretty well until they get to the woops and bigger tables and doubles. It can seriously keep up on the turns with the 4-pokes too. Believe it or not, alot of 4-poke MX riders are really impressed with how my 'shee runs with the low end.

 

I am using a Trinity Stage IV head with 19cc domes (210 lbs compression), weiseco 795 pistons, Hotrods +4 stroker, Wildcard Racing aggressive trail and 4mil port (Brandon ported for as much low end as possible), Pro-Circuit Platinum Pipes and 304 silencers, V-Force 3 reed cages, 1/4 in. reed spacers (between reeds and port), Trinity Stage IV 2-in-1 intake with 33mm PWK, K&N filter pod, Dynatek FS CDI (curve 3), and Dynatek coil. I don't use a timing plate and don't have detonation problems. I run with at least 110 octane fuel but I try to get 112 if I can just to be on the safer side. I use Golden Spectro and mix at 40:1.

 

For cooling I have a megaflow impeller, CV4 hoses, a PWR radiator, and use Engine Ice. I have no problems with it overheating either.

 

I am using a Hinson complete 8-plate clutch system. I tried stock at first and seemed to slip here and there but no problems after the Hinson setup.

 

Drag racing really sucks for this build though! lol. Before I did the build and went with high compression I could start out in 2nd gear with a 13/42 sprocket setup. Now I have a 15/42 sprocket setup and can't keep the front end down if I try to start off the line in 1st or 2nd. It just pops up really fast! So I gotta start in 3rd gear. Also the high compression fights off top end rpm's as well.

 

It doesn't take much throttle to get the low end jump so I would suggest a thumb throttle. I did try a twist throttle but whenever I would hit a woop section or had a hard landing on the track I would get a little too much of a snappy response. I'm not saying it's impossible to run with a twist throttle but it would require alot of practice. The thumb throttle works great for me.

 

Pretty much this is my "product review" on a high compression 'shee.

 

I know I should change the reed cages since I won't be using much advantage of the top end gains from the V-Force 3's, so what would be a good reed cage for low end?

Edited February 21, 2010 by Misssppelllleddd

[trail rider]

nice review on that engine setup. have you done any tight woods or trail riding to see how it performs? and about how would you describe the powerband compared to a average piped/stock port engine, like a smoother powerband or more agressive hit just earlier in the rpms? would love to see some videos of the bike in action too.

[Misssppelllleddd]

I don't like to ride tight trails much but from what tight trails I rode at Haspin I was pretty satisfied about how well it did. It can speed out of tight turns pretty quick.

 

The power band has a much harder hit in lower rpm's than stock but gets smooth after that. When I used to have a stock setup I remember it having a pretty strong power band between mid range and high end. It takes some practice to learn how it runs because it is much different than stock.

 

There are a few vids of it in action on Bansheetube when I went on a couple group rides but no vids covering only it's performance. I will try to make one this summer. I have a few pics of it on my profile gallery.

[bigborebanshee]

 

Drag racing really sucks for this build though! lol. Before I did the build and went with high compression I could start out in 2nd gear with a 13/42 sprocket setup. Now I have a 15/42 sprocket setup and can't keep the front end down if I try to start off the line in 1st or 2nd. It just pops up really fast! So I gotta start in 3rd gear. Also the high compression fights off top end rpm's as well.

 

Your just running the wrong pipe.You should be running a Fatty,I ran PC with 190psi and I could never get the tires to break out of the gate,the PC does not make enough on the bottom to strike the tires like the fatty does.You won't have the over rev that you get with the PC..but with all that compression you don't need that rpm anyways.

 

Your other option is to go to a less aggressive tire,maybe one with wider lug spacing.It may help the tire break traction a little easier.