Advanced timing or more compression for HP

[Pack Mule]

I have a cat based big bore with 13:1 comp and a 3* key. What would work best for more HP at 6000 ft more comp or more timing?

 

[Deano670]

I am assuming that 3 is a 3 degree key correct??? In my opinion id be hittin the heads with a hammer. However is it carbed or efi? What pipes are on it? What kind of clutching is in it??

 

[snotterite]

I have a cat based big bore with 13:1 comp and a 3* key. What would work best for more HP at 6000 ft more comp or more timing?

Cat Based big bore

What is the top end?

 

[Deano670]

In other words as I forgot to type, WHOS BIG BORE IS IT

 

[snotterite]

In other words as I forgot to type, WHOS BIG BORE IS IT

Old guys.................HELP THE..................young Guys.

 

[Deano670]

Well my friend there is something tobe said for years of EXPERIENCE!!! You've probably forgotten more than I'll ever know

 

[snotterite]

One problem with old age......................WTF are we talking about??

 

[Deano670]

Ummm a big--- i mean bore ooooops sorry guys. But seriously dude im sure if you can give us more detail someone can help NO DOUBT

 

[mtndoctor]

I have a cat based big bore with 13:1 comp and a 3* key. What would work best for more HP at 6000 ft more comp or more timing?

so the big bore doesn't work so good eh! try a shop with mtn 6000' experience, testing and building.

 

[Pack Mule]

its an Engine Tech 1160, 13:1, with a 3.5* Key with 42.5mm carbs

 

[Pack Mule]

Jaws Ds, 75 gram weights, 120/330 primary, 49* helix with Cat red White 3rd hole at 6500+ ft Spins 7800 RpM

 

[snotterite]

Your compression is good or close to spec?

 

[Deano670]

Man at 13:1 that baby's just gettin warmed up Hit it with the HAMMER

 

[mtndoctor]

Jaws Ds, 75 gram weights, 120/330 primary, 49* helix with Cat red White 3rd hole at 6500+ ft Spins 7800 RpM

sounds like your on par, try a 160/330-340 pri. with a 52/44 try for 7900-8000
keep compression low for the big piston, who built the motor?
031 belt? squish clearance?

 

[snotterite]

Without seeing the unit I agree with mtndoctor. Increasing comp. that is to spec can actually work against you. The increased comp will require the use of some of the h.p. you intended to be delivered to the drive system.We have seen a slight increase in bottom end and a drop in the top end. This issue is highly contested by many.

 

[Deano670]

And we're off AGAIN

 

[Deano670]

You do know there is a bunch more porting that can happen inside that engine yet, which would nicely compliment more compression. You could stand to see another 14-17 hp

Just my opinion

 

[mtndoctor]

time to slip on the rubber boots.

 

[snotterite]

time to slip on the rubber boots.

And velcro gloves?.................................rubber boots are so multi tasking.

 

[Pack Mule]

Comp is good 130 PSI both sides