Finally had the bike on the dyno today trying to sort a few issue. Some resolved and some are not. 1 issue is the idle and I have another thread looking for injectors that may help with that, they may not also. It came out OK I guess but it is short of what I am looking for and to be honest it is a bit under whelming to ride. It doesn't seem to lack any where but it doesn't have that " oh shit yer" feeling to it either, at least not to me. It did make higher numbers than the sheet attached (152/138) but we decided to pull some timing out of it which smoothed it out some. My target was 100ftlb by 2000 rpm and 140+ ftlb by 4800 rpm, never had a HP number in mind as I rarely ride the bike over 5 - 5500 rpm and if it made the torque target it would have plenty of HP. Figuered targeting the shifting at 5000 rpm would keep the forward progression going at a descent rate. It didn't fall much short but I felt I was being a little conservative with the target mostly to save a little self embarrassment after over estimating my last engine build capabilities. . Ambitious or deliousional? maybe. In part I got caught between 2 worlds with this motor which didn't help. I started building the motor for a dyna but shifted to a tourer before the motor was complete. Originally I was targeting 11.2:1 CR but with the change of bike I thought lowering it was prudent. Without buying a set of dished pistons I could only get down to 10.8 :1 with out changing the squish which I wasn't prepared to do or alternatively open up the chambers also something I wasn't prepared to do. I think the CP is a bit low for the 640's and a bit high for the 585's which should have got me the torque I was looking for. I can't see much else I can do with the current set up other than have another go at it to move things to the left more. It doesn't appear to fall over short of shutting it off so I think there is rom to improve Any one got any ideas where to from here?
Wish i had some of that torque on mine!
Just an observation, but it sounds like your build ended up the reverse of what you really wanted. In other words, big HP later with less low down torque. Especially if you don't ride much past 5-5500. I'd almost guarantee a Cam change will go a fair way to fix that. Something like a TR 662-2, S&S 625 , wood 9f etc. Might need a tick more compression, maybe .030 head gasket.
Would be a great motor for a Dyna !. Nice one.
Very nice Max. You must have pulled some strings to get a run on the dyno so soon. How about a Supercharger or a Turbo maybe, im sure you would be satisfied with the power then.
there you go perfect example of 124" @ 10.8:1 making 148 ftlb
oh and the answer to this riddle is NOT " Just live with it"
You have answered your own question, comp is too low for 640 cams. 60 deg close, you need 11.2. Then it will go more all thru the range.Currently it will feel soft, but good to ride. As to your idle, weeelll, it should idle nice..... :-) I can sort that.... Cheers.
for the twin cam models there are a lot of different set up's aval esp on cam choice, where people can get a little bit lost in it all , no different to on the clicker's on the late model jap bike suspension's etc to many veriable's , when i spoke to you on the ph about this before the build we did say 11, low something C.Ratio , because we have run a 124 on BP 98 pump gas @ the race track under 12 to 1 C,Ratio no worries on the 640 cam , eg 124 S&S B2 heads with race kit include 12 to 1 S&S piston's rec 640 cam not a 675 they say a 675 would be slower as & e.g. but i think & have mension this before that for a street bike it is not good to have to much torque down low as it can load the big end up a bit esp on a heavry bike & rider combo, on a customer's bike i always lean on the safe side of set-up for worse case con'd's just in case . allow for 2 up on a hot day etc , but if it is a purpose built bike thats a different story, iv'e heard the 58m.m. throttle body is a bit hard to tune , i wouldn't know i don't tune fuel injection only carb's but i do race on them 58's , tuned by the shop i'am to old too learn fuel injection & i will leave it up to the younger fellow's , maybe the numbers you have are not to bad anyway , keep & eye on the engine temp as dyno's can be a bit lean on the fuel for a air cooled street bike set up but on the hole i think it's not too bad give her a couple of thousand klm's to settle in , how much would a roadglide weigh in @ + rider, all the best for the new year