who's seen one run ? Is it worth the trouble... hp#s Hows it compare to a well running 900. Lets here it boyz whats the skinny? Hello anyone????
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970? bb 900 cat
- Thread starter DMS
- Start date
who's seen one run ? Is it worth the trouble... hp#s Hows it compare to a well running 900. Lets here it boyz whats the skinny? Hello anyone????
H
high time
Well-known member
Are you talking about the bore to fit the 1000 pistons in the 862. Yes, that's a great set up. I love mine. It's better than any engine I've ever had or any of my buddies of any brand, stock or mod..
Why??????? Because it's an easy start, huge power, and it scares my buddies.
It does need adapter plate for the new style recoil and a shim under the cylinders.
Owen
Why??????? Because it's an easy start, huge power, and it scares my buddies.
It does need adapter plate for the new style recoil and a shim under the cylinders.
Owen
Thanx Hightime that is the combo I am refering to,my 900 runs very well just thinkin about an upgrade. CAn I purchase a shim or just build one on the mill. any comparison youll give me would be greatly appreciated. thanx Don
H
high time
Well-known member
We made our shim. I don't have the thickness in my notes. I'll try to find it. It isn't much because you'll need two gaskets with it. It looks like less than a 1/16 of an inch. There is a guy out West that makes the whole kit. Including the adapter for the new recoil. I highly recomend that. It's made the stupid old recoil rope problems go away and you can actually pull the engine over with high comp. heads. Oh yeah, that's you biggest problem, the heads. I bought billet 925 heads and had my son recut them to the new bore. I'm not sure, but it might require dome and squish band work also.
I did a post on the mod section, who else running is running the 973 coversion on their 862 ? If you search for that you'll find that Cat dealer who's doing the kit. He responded.
Owen
I did a post on the mod section, who else running is running the 973 coversion on their 862 ? If you search for that you'll find that Cat dealer who's doing the kit. He responded.
Owen
We've got one running, made it ourselves. We had the shim cut from .050 sheet, with two SLP base gaskets at .020 each, that gives it the right height. The stock base gaskets from Cat are .015, so if you use them you might need a thicker shim. We cut speedwerx domes for a 900 and it seems to work great. It is a huge improvement over a stock 900, and will smoke at least one '07 M1000.
It works so well we are probably going to do it to all three 900s we're running.
The adapter for the larger recoil isn't strictly necessary, but it sure does help on the cold mornings.
It works so well we are probably going to do it to all three 900s we're running.
The adapter for the larger recoil isn't strictly necessary, but it sure does help on the cold mornings.
Thanx alot Hightime and Idcatman3 it looks like I am probably going to do the kit.and again thanx for the info....Don
High time if you would let me know what your notes say thanx again...Don
H
high time
Well-known member
.060 sounds right, if you use Cat's gaskets. Oh yeah, we had to regrind the exhaust valves to match the larger bore too. They're not working. That's giving me fits right now. It could be that the travel of the valves are less and the servo goes to default. Although I seem to be having a voltage problem too, maybe they're related.
Owen
Owen
IS the travel really less? If you grind off the ends so that the valves are shorter to fit the new bore then the travel of the valve doesnt change. Just he lenght of the valve it is moving, right?
H
high time
Well-known member
I can see you point, But
That's a hard one to visualize. Maybe it could be stated this way; You must grind off enough valve to match the new bore, so as that is pulled into the wide open position, it is now recieding deeper into the valve cavity. It would not help anymore than if it was flush with the top of the exhaust port. Therefore the travel could be shorter.
I can't edit the you point on the topic line [your point]
Owen
That's a hard one to visualize. Maybe it could be stated this way; You must grind off enough valve to match the new bore, so as that is pulled into the wide open position, it is now recieding deeper into the valve cavity. It would not help anymore than if it was flush with the top of the exhaust port. Therefore the travel could be shorter.
I can't edit the you point on the topic line [your point]
Owen
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I wouldn't want to remove the valves completely. They are designed in for a reason, they make the engine more efficient at lower RPM so you get better low speed operation, as well as fuel economy. I know lots of people get rid of them, so this is more personal preference. If you do block them open, do you have to plug something into the ecu to trick it? Or do you just unplug the servo?
H
high time
Well-known member
They will do some good but not as much as in the 862
Here's the deal as we increase the bore we are moving closer to the valve cavity. Because it is angled it is impossible to trim the valve to match the bore and still get the port hieght reduction at the same amout as before. At some point the valves become useless. They do still help on the 972 however. A little better fuel economy a little better low end response, but if I can't figure out why mine arn't working they will stay blocked open. I used a small block of wood with a cut in both sides to hold the cables in the long position, then then taped it up.
Owen
Here's the deal as we increase the bore we are moving closer to the valve cavity. Because it is angled it is impossible to trim the valve to match the bore and still get the port hieght reduction at the same amout as before. At some point the valves become useless. They do still help on the 972 however. A little better fuel economy a little better low end response, but if I can't figure out why mine arn't working they will stay blocked open. I used a small block of wood with a cut in both sides to hold the cables in the long position, then then taped it up.
Owen
If you put a schims betwen the cylinder and valveplate, just thick inuff so the middle of the radius on the valve is flush with the cylinderbore, and then just grind the tips on the valve so it fits the cylinder radius. Just a thought.
excuse my spelling
excuse my spelling
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0
00buck
Well-known member
If it's efi you need a by pass chip or it goes in to limp mode.
So you don't need to do anything on a carb? Just the efi models? Thanks.
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