New race engine - looking for hop-up tricks

[rotax454]

If going motor crazy on V990 with oval flange exhaust ports use the Akro EVO6 exhaust. One 1060-1102cc motors this can be worth up to ten bhp overthe stock headers!

Need some help understanding this. Are there different exhaust port configurations in the rotax motors ? Why is the Akro EV06 system so good? What about the Arrow collector and their canisters?

[rotax454]

[QUOTE=Micah / AF1 Racing;3017711]I too use steel liners for all 1102cc motors. They are MUCH stronger than the aluminum would be once 5mm oversize pistons are installed. 1102cc is tested both track and street. The only downside seen so far is that the stock starter motor and battery are marginal once you start compressing that much air in each cylinder to 12.??:1. So far all of the steel liner 1060cc and 1102cc motors I have built have made more power than coated alloy bores AND actually run a little cooler. QUOTE]

"Coated" you mean Nikasil? Wow, hard to understand given all of the benifits of that coating. Less friction = more power. Your thoughts on this?

[Murf99]

Are these steel, or ductile iron cylinders, available for purchase anywhere?

Are there concerns with the piston tipping at the bottom of stroke, on the 1102 kit?

By increasing the displacement from 1060 to 1102, I'm looking at roughly a 1060/1102 = 1.04 = grossly 4% increase in power? Are there other effects than simply a percent increase of displacement that I'm missing? I'm simply trying to understand all facets of the work and cost, in order that I can ride the peak of the cost / bennefit curve...

Forgive my stupid questions, but I like those...

[Gabro]

Akro EVO6 exhaust. One 1060-1102cc motors this can be worth up to ten bhp overthe stock headers!

i'm working on a nw project, making 52mm instead of 48mm primary flame tubes for evo6

[Micah / AF1 Racing]

The EVO 6 is just the best performing pipe I have ever tested on an Aprilia twin. I have tested lots too, years of dyno tuning on Aprilia motorcycles. It is "da bomb. At least on a naturally aspirated V990.

The displacemtn thing is by no means a direct link to the gain in power. The stock heads are not high velocity, basically the ports are oversized. The stock cams when Properly timed, have good lift and duration numbers. Going from 998 cc to 1102-1127 c is 10-11% gain in displacement BUT, with a much stronger vacuum signal through the stock ports, with the camshaft timed properly, the dynamic compression is way up too, well that 10% change in motor total displacement turns intro 30-40% gains in power on a relatively safe scale. Custom dyno tuning, cylinder to cylinder, mapping is required to see proper results. My personal heads are off the an INDY car shop for porting then to Bastrop Texas for final seat cutting and reshaping and a .5mm deck. I just want to see how similar my results are to a true professional's results. I am ready to be humbled.

The newest design of 1102cc pistons are going in my LA Sleeve built (on a torque plate, they measure perfect) cylinders. Compression on the dynamic side should be a very real 13:1 if not a little higher. This is my E85 experimental motor. I am trying to embrace corn fuel at some level. The realistic gain over straight gasoline is 10% roughly. I would like to see 150 bhp on my oh so conservative dyno! This would be in the 170-18"+ range on a dyno jet with street gearing ratios and my BST wheels on any inertia type dyno.

Rods and valves and undecided as yet. I would like $750 Ferrera valves and $750 Carillo rods too. Shooting for .002" clearance on all rotating bearings and a bit more than that on piston to bore. Shower injection is good for 4-5 bhp usually across a broad range. Money is an issue however. 2004 stock RSVR rods and stock valves may have to work due to budgetary matters. They are very strong but heavier than I desire. The newest 102mm pistons are only 20 grams heavier than the stoc 97mm slugs.

My personal goal for the naturally aspirated version of me personal "Punisher" motor is 180+ mph at the Texas Mile land speed race. For 200 mph nitrous or boost is required. No twin I can imagine would do that naturally aspirated.

[deefred]

If the transition from midrange to topend power is too abrupt you don´t dare to go WOT until the bike is almost fully upright and you will loose time.

[rotax454]

The EVO 6 is just the best performing pipe I have ever tested on an Aprilia twin. I have tested lots too, years of dyno tuning on Aprilia motorcycles. It is "da bomb. At least on a naturally aspirated V990.

.

Being a newby, please excuse my lack of knowledge. Is this the EVO 6 system that you are referring too? Just didn't understand the EVO 6 reference.
http://www.af1racing.com/store/Scrip...idproduct=1626

[Micah / AF1 Racing]

This is the pipe I am speaking of, this version is no longer built so the used market is where you find one. There is a newer version with catalyzers in the mid pipes but I have not tested it. I suspect with the cats gutted it would be the same gains since it uses the same collector and headers with that oh-so-perfect Akro taper to all sections.

[derbybrit1]

There was virtually no difference in weight between the Ferrea stainless valves I used and the stock valves. And they were $450 retail.

If you really want to push the limits of normally aspirated, you need to to use the type of fuel that Bonneville record holders use. Is that nitromethane? Dave can get you some hydrazine.

Here is some Bonneville record infor for what I can identify as twins:

	650CC								Frame (Chassis) Classification
S-F	B. Johnson	Triumph	Aug-62	230.269		Streamliner Fuel
									P	Production
	1000CC
APS-PBF	Wilson-Wade-Mabry	Triumph	Aug-96	213.245		Special Construction Partial Streamlining Pushrod Supercharged Fuel			M	Modified
									MPS	Modified Partial Streamlining
	1650CC
APS-PBF	Minonno D&D Exhaust	H/D	4-Aug	225.819		Special Construction Partial Streamlining Pushrod Supercharged Fuel			A	Special Construction
APS-PF	NRHS VTwin Performance	Buell	7-Sep	202.602		Special Construction Pushrod Fuel			APS	Special Construction Partial Streamlining
MPS-PF	NRHS V-Twin Performance	Buell	4-Oct	205.642		Modified Partial Streamlining Pushrod Fuel
									S	Streamliner
	2000CC								SC	Sidecar
A-F	J. Angerer	Triumph	Aug-73	201.432		Special Construction Fuel			SCS	Sidecar Streamliner
APS-PBF	Jon Minono	Triumph	Aug-91	221.518		Special Construction Partial Streamlining Pushrod Supercharged Fuel
APS-PF	Dan Kinsey	H/D	Aug-90	214.565		Special Construction Pushrod Fuel
S-F	C. Rayborn	H/D	Aug-70	265.492		Streamliner Fuel
S-PG	California Fritz	H/D	3-Oct	215.113		Streamliner Pushrod Gasoline			Engine Classification
	3000CC								P	Production
APS-BF	J. Minono	Triumph	Aug-92	214.663		Special Construction Partial Streamlining Supercharged Fuel			PP	Production Pushrod
APS-F	D. Campos	H/D	Aug-74	231.597		Special Construction Partial Streamlining Fuel			PV	Production Vintage
APS-G	D. Campos	H/D	Aug-74	208.45		Special Construction Partial Streamlining Gasoline			PB	Production Supercharged
APS-PBF	Mabry Racing	Triumph	1-Aug	238.74		Special Construction Partial Streamlining Pushrod Supercharged Fuel
APS-PBG	Bullett	S & S	11-Sep	201.226		Special Construction Partial Streamlining Pushrod Supercharged Gasoline			PG	Pushrod: Gasoline
S-PF	D. Campos	H/D	Aug-90	322.149		Streamliner Pushrod Fuel			PF	Pushrod: Fuel
S-PG	D. Campos	H/D	Aug-90	208.415		Streamliner Pushrod Gasoline			PBG	Pushrod, Supercharged: Gasoline
									PBF	Pushrod, Supercharged: Fuel
UNLIMITED
APS-PG	Spyke Bob Moreland	H/D	6-Aug	203.687		Special Construction Partial Streamlining Pushrod Gasoline			VG	Vintage: Gasoline
									VF	Vintage: Fuel
									VBG	Vintage, Supercharged: Gasoline
									VBF	Vintage, Supercharged: Fuel
									AG	Modified: Gasoline
									AF	Modified: Fuel
									BG	Supercharged: Gasoline
									BF	Supercharged: Fuel
									UG	Unlimited: Gasoline
									UF	Unlimited: Fuel
									D, DB	Diesel
									W	Steam, Turbine, Electric

[Micah / AF1 Racing]

I know Nitro-methanol would get me plenty of power, but for simplicity sake I like E85 for right now, combined with nitrous later 200mph should be possible. I will peachy thrilled if it breaks 185mph and perfectly happy with anything over 180mph in the Mile for Naturally aspirated! Well built N/A is one step closer to full out turbocharged...so....

[GreaseSnake]

. The only downside seen so far is that the stock starter motor and battery are marginal once you start compressing that much air in each cylinder to 12.??:1. .... coated alloy bores AND actually run a little cooler.
!

I can hear the starter going a bit slower but with a starter solenoid that's a bit more stable at lower voltage it's quite ok. Running approx.13:1 static on the 1127.

I too have the same experience, they run run cooler.

[JAndrewG]

Bit of a thread jack, but how is that 1127 holding up for you GreaseSnake? How many km's at this point?

[FASTER !]

Aftermarket camshafts ...

1) Favaretti
2) Kaemna
3) Kent Cams

Interesting cam lobe centres on the Kent cams guys , 110 inlet and 110 exhaust. Is there anyone out there running these cams and what sort of gains can you report on ?

[derbybrit1]

From the Master of the Mountain hisself:

http://www.apriliaforum.com/forums/s...ams+less+power

[FASTER !]

I have that post by Clarkie in my info file on the RSV ; Interesting reading for sure. The stock billet/cast cams seem to be a very good compromise between output and aggressive grind , without taking out the reliability factor. Derby , what would you say to something like Kent Cams and a 1060 kit with some porting on the exhaust side ? I think Gab mentioned somewhere there's about 10 hp in porting the stock 2 valve heads properly in the exhaust port area. I am looking at a 1060 kit at the end of the year to match my 57's and if I can gain something by running a better cam it may be a good thing ?

I need to consolidate my plans for the Factory I use on Trackdays , If I can gain 10-15 wheel hp for around 2000 dollars I will be a happy puppy !!!