;-)

No. .075 is alot to deck from a head to begin with, but it depends on several factors. Your final compression ratio is the single most important aspect when it comes to determining your octane requirements. From my own experience, I would bet my bottom dollar that .075 will not run without detonation (Maybe serious engine damage) on 93 octane pump gas.

My suggestion is for you to purchase a set of aftermarket pipes with jetting and forego the head mods. Modifying your head is something generally done in the later stages of performance mods. Its one of those things you do when you're trying to get every ounce of power out of an engine that already has the basics.

I recommend Toomey pipes. With Toomey pipes you can purchase the additional Hush Kit 2.5 that will retain the quiet sound levels of stock, and still produce (on average) 46.5 peak rear wheel horsepower. The Toomey pipes also have one of the broadest power bands for a top-end pipe in the industry.

You can't go wrong with the Toomey jetting kit, and the whole package is easy to install.

Good Luck Chief,
Slick

 

Now you did hit a big point. The hush kit (or something that soudns like that). 46.5hp and as quiet as stock (spark arrested)? That sounds good.
BUT.
What I didn't mention is that I also have pipes that seem to be home made (I bought the quad with them on, and didn't think about asking what they were). They fit and seem to work real well, it's just that I see the "slices" and welding job...I don't think a big pipes company would do it that way...the test pipes maybe.
I had put on the stock back, but took them away again (to put the whatever pipes) because 2 brackets out of three went f*** off.
So I already have good pipes, and It would be real tough spending 1000$ (canada) for something that's just a bit better than what I have.
BTW if someone knows (or think he knows) what they could be, tell me.
If I only had the stock pipes, I would probaly have got new ones...
So 0.075 is too much. What's the dome size for stock head? With premium pump fuel, up to what compreession can I go? I've seen 10:1. Is that a good thing? 6.5:1 is the original if my remeberings are good.

 

Without actually seeing the pipes they could be anyones. Most pipes made by performance shops that build "thier" own, section cones together to get the desired pipe geometry. It's just a different way of manufacturing pipes, it would be different than say FMF using a die stamped pipe body.

I would seriously recommend contacting one of the performance shops...any of the big names(or MacDizzy), and get your head totally recut. The pocket shape of a Banshee head has some room improvement. If you're going to go to the hassle of taking your head off to have it cut, go the distance and spend just a tad more and get it totally recut.

A hop-up shop will be able to cut your pocket, re-cut the squish and set your compressuon ratio and get you to run on premium pump gas safely, for under $150 USD. .075" is too much to take off you'll machine into the squish band, the squish recess is only .065" if I remember right. I can't stress enough how important it is to do this correctly, or you'll ruin an engine. Detonation is instant and very destructive. If you're lucky....if you're lucky all you'll do is toast a set of pistons, but far worse often and does happen....

Machining the gasket mating surface of a head is a cheap way to gain compression, but you're far better off to have the entire head machined.

 

R42176:--
What squish clearance did this net you??? With a Banshee head, squish recess is .065", you machined .075" off and then recut the squish recess to .010". The Banshee head gasket is only .017" thick, with a .010" squish recess that would net you a .027" squish clearance( w/ zero deck hgt.) TOO CLOSE...definately too close to run on pump gas. Typically the closest you would want to get would be .032" maybe .03".

I'm slightly confused about your statement about getting into the water jacket at .075", are you talking about machining the pocket or the gasket mating surface???

 

OK.
Does anyone know a someone near montreal that could do this the way it should be?
If I have to send my engine to california, that's gonne take real long!!

 

It's been a few years but 0.10" sounds correct for cutting the squish into the head. I can't remember what the final squish clearance comes out to but it is higher than 0.27" because the piston edge does not come to the exact top of the cylinder. I have never had a problem with doing this and it has only raised the compression up to around 165-170 when cutting a max of .075" off the head. Never had a detonation issue even with advancing the timing and running 93 octane.

If you cut too far you break into the water jacket on the gasket surface near where the hose adaptor bolts on the back of the head.

Jeff

 

Just send it in to the USA. Cant you take the head off yourself?? It is simple. Don't send in your entire engine, when you can send in your head that probably weighs only around a pound maybe.

By the way, why did you put a tow hitch on your Banshee?

 

To tow a trailer!

 

We have a 4x8 trailer, and it really sucked to drive 1 mile with the lawnmowing tractor whereas I could have done in a blink with my shee.
I'll put a pic on the website so everyone can admire my piece of art..hehe.
I know it's not tough, but I know it, so I'm careful to what's in the trailer. For example, now the trailer is full of gravel...1 ton. I won't try to move it with my shee...That would be fun to see the shee in the air, attached to the trailer by the butt.
hehe.
Taking the pic and putting on the web as soon as tonight.

 

The problem with sending it to the US is that I don't really trust the mail (canadian for what I know). They're slow (it took for a little box from france to here 4 months...) and man would I get mad if they loose it!!
But, I could overcome my premade opinion.
Who's the best shop?
Or maybe i'll wait to seize or break something to modify it...and get it up to 370.
Still, who do you recommend the most?