Looking for some guestimations on a mild 131" and a wild 131" on pump gas. What are some realistic numbers? The engine I'm referencing to does have headwork on chicken heads, huge valves, woods cam, not for sure which ones, v&h competition exhaust. Trying to ballpark what kind of power he has. Thanks, Ryan

 

pretty much impossible to say with out real specs (a lot of motors with big this & big that,with junk heads and mis-matched parts,dont put out much)

 

thanks for the reply...yes, i do understand you would be snowballing ideas out there. I understand what you are saying.

the engine is in a street glide. It runs very hard. The owner used to pilot a 5.90 116mph iron head drag bike back in late 80s. Lets assume he has all his ducks in a row for the 131 he built.....just looking for questimations.

Last year I had a 103 hp sporty that he beat me with the 131" blacktop arm drop race and roll ons. This year Im making more power and I beat him. Was just curious as to how much power is needed to outrun my sporty that weighs 480lbs or 690lb with me on it compared to his heavier street glide.

 

the races and roll ons were close last year but i lost two drags and two roll ons. This year i beat him on the two drags but i couldnt get past him on roll ons. My clutch was letting go at high rpm on 3 to 5th gear. So I am confident I could get him on the roll ons even though we are starting at a low rpm about 3 grand which is a disadvantage for me compared to the tq a well built big twin would have at that rpm.

 

a decent 131 should b doing at least 140,(my 127" is 142 at the wheel)

 

Thanks for the info. Looks like your 127" makes some great power.

 

I was told by an old dog ...1 HP for each CI is rule of thumb....less its running like a dog and more than its running like a scalded dog!!!

Hope this helps

 

thanks, I have been told that also. Im not very savvy with big twin power in big cubic inch engines like a 131". It seems as if the big twins are harder to get beyond the 1 hp per cubic inch than a 4 cam based sporty engine. Although a 131" making 140hp/tq is prob a blast to ride.

 

evo & TC big twins are not a big deal to get HP per CID & more.even our VERY mildest builds do at least a HP per CID

 

Maybe I worded that wrong. I agree getting big twins too or just 1 hp per cube. You just dont see too many in the 1.25 to 1.5 range. Its not that hard anymore to get a xl engine in that range.