More dyno #'s Ported vs oem 100 vs 92 and ignition advance

[chadihman]

I spent some time with the dyno tonight. My brothers ported 460 with 210 psi comp had an advantage of only .3 hp over the dual port oem 460 but the ported saw had more torque at lower rpms.

The next test was 100 vs 92 octane in the ported 460 blowing 210 psi with stock ignition timing. This shocked me as I thought for sure the 100 would have done well but the 100 only showed .03 hp gain.

The next test was with a 6 deg ignition advance 100 vs 92 octane. The 92 won that one by .18 hp.

The most power made was running 92 octane with a 6 deg ignition advance. The igniton advance gave a nice .47 hp gain.

I'm tired and ready for bed now. I'm tired of running the dyno:msp_ohmy: I can taste two stroke exhaust.:msp_razz:

 

[blsnelling]

Awesome stuff. I love the cold hard facts! I'd love to see my 440/460 hybrid on that dyno. As they say, the proof's in the pudding! I might go home with my tail between my legs

 

[Magnumitis]

I spent some time with the dyno tonight. My brothers ported 460 with 210 psi comp had an advantage of only .3 hp over the dual port oem 460 but the ported saw had more torque at lower rpms.

The next test was 100 vs 92 octane in the ported 460 blowing 210 psi with stock ignition timing. This shocked me as I thought for sure the 100 would have done well but the 100 only showed .03 hp gain.

The next test was with a 6 deg ignition advance 100 vs 92 octane. The 92 won that one by .18 hp.

The most power made was running 92 octane with a 6 deg ignition advance. The igniton advance gave a nice .47 hp gain.

I'm tired and ready for bed now. I'm tired of running the dyno:msp_ohmy: I can taste two stroke exhaust.:msp_razz:

Get some fresh air and a cold drink. Thank you for your hard work and sharing it here

 

[struggle]

I for one do find this interesting for sure.

I'm found 91 octane available near me as I'm going back to that over A/V fuel as it is just a little bit less of a hassle to get.

I did like the extra stability for storage though on the A/V fuel as that was my primary concern with being able to store longer term.

 

[tree monkey]

i tested fuel some years ago, lower octane=more power

as long as your testing fuel, try oil ratio 50/1 40/1 32/1 20/1 16/1

you will find that the more oil =more power

 

[old-cat]

as long as your testing fuel, try oil ratio 50/1 40/1 32/1 20/1 16/1

you will find that the more oil =more power

This is really strange to me. That's not saying much though, with my little pea brain! Do you know why? More oil = less friction? It seems like more oil should be less btu.

 

[chadihman]

Back a while ago I posted #'s of oem muffler vs dual port and I was amazed at the power gain of .7 hp with a dual port. Everything works together to make more power but the biggest gain came from the dual port muffler. The next impressive gain came from an ignition advance. I'm thinking the porting power came more from higher compression and not the port work.

I can't wait to test some 064 pop up pistons in a oem 460 jug. Maybe we can make really nice gains with just installing a pop up, dual port muffler and an ignition advance. I was really impressed with Brad's stage one results in the 261. Before I get grilled I'd like to say there is a place for porting and some saws need it more than others.

Seems like a good port job takes the saw to flatter hp curve. It gives the saw max hp from a broader range in rpms. A stock saw has its max hp around 9000 rpms a ported saw may have it at 10.000 or higher and may hold that hp all the way down to 8000 or lower rpms. Wow it's like rocket science:msp_confused: and there's tons more to test

 

[old-cat]

I'm not really qualified for this remark, BUT, I have also come to that conclusion, that compression is the real factor and porting is a skill like black magic! I seriously doubt pop up pistons are good, they probably interfere with the flame?

 

[chadihman]

I'm not really qualified for this remark, BUT, I have also come to that conclusion, that compression is the real factor and porting is a skill like black magic! I seriously doubt pop up pistons are good, they probably interfere with the flame?

I have to find the truth.

 

[wyk]

I'm not really qualified for this remark, BUT, I have also come to that conclusion, that compression is the real factor and porting is a skill like black magic! I seriously doubt pop up pistons are good, they probably interfere with the flame?

I have seen some racing 250 and 500 gt two stroke pistons with designs that weren't remotely flat.

 

[cory@owen]

i tested fuel some years ago, lower octane=more power

as long as your testing fuel, try oil ratio 50/1 40/1 32/1 20/1 16/1

you will find that the more oil =more power

Is that because its a leaner mixture? Or does that apply even if the carb is adjusted to correct the off mixture?

 

[blsnelling]

My guess is that you will find that the difference between a popup and a flat top, when compression is the same, will be negligible. I'm very anxious to see those results though.

As far as the 046 goes, they respond VERY well to porting. I don't run as high of compression as you are, but I don't think that's your issue. What are your port timings? If you don't want to discuss that in this thread, i understand. PM me if you want.

 

[blsnelling]

This is really strange to me. That's not saying much though, with my little pea brain! Do you know why? More oil = less friction? It seems like more oil should be less btu.

Is that because its a leaner mixture? Or does that apply even if the carb is adjusted to correct the off mixture?

It's because of better ring seal.

 

[yakcatr]

Have you tested aspen fuel?
Or a oxygenated race fuel?

 

[chadihman]

Have you tested aspen fuel?
Or a oxygenated race fuel?

No I haven't

 

[Yukon Stihl]

:crazy1:

I have to find the truth.

:msp_wink:The truth is out there :msp_rolleyes:

 

[Adirondackstihl]

Have you tested aspen fuel?
Or a oxygenated race fuel?

My best friend raced MX professionally. Factory suspensions and motors. Went to the nationals 5 times....etc...etc..
Anyway, he used to run an oxygenated fuel in his CR's. It was called FASS GASS. I cant for the life of me find any info on the stuff anymore.
This was about 12yrs ago though.

Mixed with Castor 927.....mmmm....man did that shat smell yummy!!!

 

[chadihman]

:crazy1:

:msp_wink:The truth is out there :msp_rolleyes:

Where where where!!!!!!

 

[barneyrb]

My best friend raced MX professionally. Factory suspensions and motors. Went to the nationals 5 times....etc...etc..
Anyway, he used to run an oxygenated fuel in his CR's. It was called FASS GASS. I cant for the life of me find any info on the stuff anymore.
This was about 12yrs ago though.

Mixed with Castor 927.....mmmm....man did that shat smell yummy!!!

I run 927 during summer months but it will separate when cold.

 

[chadihman]

As far as the 046 goes, they respond VERY well to porting. I don't run as high of compression as you are, but I don't think that's your issue. What are your port timings? If you don't want to discuss that in this thread, i understand. PM me if you want.

Ex set at 98 deg or 164 duration Intake set at 100 deg or 160 duration Transfers set at 116 deg or 128 duration. Blow down 18 squish .026

This saw runs a good bit better than my 461.