Put the 530 engine in over the week, and took a rip around the block (a few times) - definately more midrange torque. Only revved it to 7500rpm and seat of the pants pulls hard! Off to the dyno shop next week for break-in and carb set up. Ill post differences in power curve from 450.
It definitely seems to give the bike a lot more grunt than 31cc should. I think it must have a bit more compression and less drag from 2 rings. The biggest difference is the ability to loft the front with your wrist. Top end isn't much different but that increased midrange is what makes the bike so much more fun.
Lofting the front end in racing looks good, but actually slows you down. With this 530, over the TC450 powerplant I'm hoping to get a better launch from the start line which will place me better. The increased torque should help with corner exits. And the 6th gear should help with maintaining a higher top speed (the TC 450 engine's gearbox is too closely spaced for 1/4 mile straights - hence the poor starts with tall final gearing). I'm off to the dyno today to set the carb up. I'm sure the final numbers will look impressive. Keep you posted...
Agreed… I would think the 530 kit makes no sense for racing unless you are going into the head as well. For riding on the street where you aren’t always @7-10k rpm is where the 530 kit is in its element. And lofting the front wheel at ease is just fun… and we ride for fun. I am going to take my bike to the 1/8th mile dragstrip tonight (test and tune) for a real world dyno. I ran 8.4/8.3 seconds consistently with the 501cc, so if I can break into the high 7’s that will really be something. But via butt dyno the bike is does not have anything more on top with the big bore, so I won’t be surprised if my time isn’t any better since any gain will be offset by the fact that I will just be more wheelie prone. But the bike is with 530 kit is MUCH stronger in midrange, which is useful for street and trail riding…. Racing you would probably need to throw another $2k at the top end, but the greater torque will help you use the taller gearing.
Well, youre close to being correct; Dyno'd today, and very different from the 450. (numbers dont do it justice) First off, at 4000 rpm, it puts out 29ft/lbs torque, at 5000 rpm its at 35ft/lbs, carrying all that torque to a peak of 42ft/lbs to around 7800 rpm, at which point it slowly declines. Peak power is at 7800. The 450 peaked out at 36ft/lbs at 8500, starting at 6200 rpm (torque delivery). The head is the same, ported and decked. Horsepower increase is 15% over the 450. It seems the behavior of the engine has changed, but wont know that till track time (this weekend). The 450 required to be revved out, and power delivery hits hard at high rpm with plenty of over-rev. This 530 pulls like a raped-ape from 4500rpm. My dyno (Factory Pro) guy was very impressed with the torque curve (or lack thereof; more like a flat-line!). With that 6 speed tranny, im hoping it'll pull me along nicely. I was told this motor will be a lesson in throttle control. Keep ya posted...
Dahyum! 42ft-lbs? Well the rpm at peak torque is surprising, but I believe the number. I guess I am thinking it has a torque peak lower than that because it seems to rip from 5k to 8k rpm so hard. I didn't get to the dragstrip tonight because of thunderstorms, but maybe next week I will get some comparative times before/after.
Update / review; Well it didn't change the riding characteristic of the bike very much. It enhances it! I've found that the bike comes on the power much earlier and pulls all the way to 9500+ rpm. I'm sure I gained some more mph down the straight, but now a Aprilla 550 doenst walk away from me. I could even keep in the draft of SV 650's. Definatley a worthwhile project if you need to rebuild a 510!
Does the cylinder get sufficient fuel mixture with standard injection and the standard cylinder head? Because the husky special parts catalogue says it should only be fitted with the 2,5k cylinder head designed for it...
If you are carb’ed you will have to rejet, and if you have EFI you will have to alter your injection maps; to add more fuel. I used a PCV and it added a significant amount of fuel to maintain same AFR. Surely with the upgraded RR head/cams/valves you could get more up top, but I can’t see how it holds much back anywhere else.
@ wilmar13 : thanks, but I find it curious that in your case the AFR was affected by only increasing cylinder volume... One would think you needed to add more fuel because you could let more air in into the cylinder. But without other cams or valves that cant be the case? How much does a standard 510 piston kit cost? I guess the big bore kit is worth the extra cost?
I'm sure that FINDING the RR head and cams aren't easy! I will have to agree that more top end can be achieved by better flow. That's a whole lot more $$. My 530 pulls cleanly well past 9500. Just no reason to rev it any further.
