deus1978

iTrader: (3)

This is not a "which is faster" thread. This is not a "Tell me that your brand is best because thats what YOU run". I know both mills are great, both have loads of power, and are plenty fast. I have had experience with both of them at our track but no long term exposure.

I want to know specifically which mill "should" (all things being equal) get more gallons through them because of build quality, tougher quality requirements, and materials quality. I have a P5 and I am approaching 8 gallons and I want something that I can get a lot of fuel mileage out of because I can't and don't want to buy new motors all the time (I don't like the price point of the Nova's). The Nova is Italian built and the quality speaks for itself and I don't think many will dispute that (except the recent bearing issue but please don't derail this thread).

The Sirio is Italian built but it's not unheard of to only get 2 or 3 gallons out of the earlier Kanai's and this scares me. Have they spent timing improving the longevity of the mill or just increased the power in the 4th generation? We are familiar with the track record of the V-Spec as well, and it's been less than stellar. It seems like we always see a "new" version of the V-Spec and the claim is that they fixed the legacy problems (Bearings, Carb) and the last few revisions seem to have not fixed the issues (I may be uneducated here, but I still see the same old complaints time and time again). Now that they have the new ceramic bearings, are all the problems actually "fixed"? I still see reviews saying that some people only get a gallon through them before they lose pinch. It's hard to find good information because there are to many people that run this mills lean and try to get the last bit of power out of them, which of course will shorten engine life. There are also those that have no clue how to tune and those that would keep running when the air filter pops off and sucks in dirt and wonder why the mill dies in a few short gallons.

If anyone would educate me on this it would be great. I want longevity which is not the mindset of most racers, they want the fastest/best/biggest hyped/most "blinged" out mill they can buy and go "crap, this only lasted a gallon?" after it dies.

gameholic2

The last Sirio engine i had was the Kanai evo2, it worked fairly well untill the mixture needle started leaking and my rod dissintegrated...
since i have no experience with the later versions i will not comment on them.
O.S on the other hand has become my motor of choice simply because they are so easy to tune and never seem to stall unless the tank is dry, not to mention It makes decent power <----"Understatement"
The problem with OS is that there manufacturing quality standards seem to vary greatly..
I had a speed that ran perfectly for about 4 gallons then it started pissing fuel from the front bearing... i changed it and now it's at 9 gallons and still going strong on the other hand, I got a standard V-spec and i'm at 10 gallons (practice motor) and never had any problems with it.
Bottom line OS is like the lottery you can play every day for 10 years and never win a dime or you can play once and win big lol
For the performance of these engines i think they are worth the Gamble but that's just me.
Hope i helped a bit.

ehartman_49348

iTrader: (27)

Both are great motors and the RB will probably last longer straight out of the box. It is recommended to send the V-Spec in for a pinch at about the 1.5 gallon mark. If you do that, it should last a long time!

NOS2stage

iTrader: (2)

i like RB motor , they seem to last a very long time.

deus1978

iTrader: (3)

Thanks for the replies so far.

gameholic2, I think you may of hit it on the head with the lottery comparison, either you get a good one or you don't, which speaks for the overall quality and validates the "across the spectrum" results I've been reading. Thanks for the feedback, that's what I'm looking for. It seems like you either get a good one or you don't... hopefully the "new" bearings (I "think" they're all supposed to be ceramic now) will alleviate a lot of the issues that plagued previous generations. The 10 gallons on your V-Spec does look promising, which one do you have?

A note on the pinch, it was my understanding that after you pinch a motor, you cause the sleeve to wear quicker because you stress the metal. Traditional thinking (or maybe just my way of thinking) seems to be that after you pinch a motor, you can only expect a few more gallons of life before needing subsequent pinches and after a few pinches, have to replace the "innards" (which is surprisingly costly for an OS product).

I always had the mentality that you shouldn't pinch a mill until you absolutely need it and lose all your compression so you can try to keep the integrity of the sleeve. Is this not really true anymore? Can you get 10+ gallons on a mill if it's taken care if you pinch it at the 1.5 gallon mark? It's interesting that you brought that up and got me thinking. My views on this may be out of date as materials have improved over the years.

ehartman_49348

iTrader: (27)

That's what Rick Brake from RB Mods told me.... Give him a call and he will give you a fair comparision between the two.

pitpop

...as long as the air cleaners are changed often and kept clean, the CL7 will last a LONG time. Even though we run for Sirio, I can still tell you without any doubt, the CL7 will likely out last any engine. It's just the nature of the beast, they're durable.

Integra

iTrader: (8)

Ive personally seen 2 CL7B cranks fail....1 at the con rod bushing and one at the nose of the crank.

brit_bulldog

they are both good but for flat out speed go for the Sirio evo sti

pitpop

Last year, the CL7B came with a super hardened and light weight black coated crank. This crankshaft is designed for all out extreme performance, and the technology is borrowed from on-road. This crank shaft cannot take any abuse. If your chassis flexes, and the clutch bell hits the chassis, you run a serious risk of damaging the engine. There are ways to assure there won't be any problems. You need to make sure all the clearances are good. Use a dremel on your chassis plate to clear the clutch bell, as well as make sure the gear mesh has some backlash. If the mesh is tight, you might put lateral load on the crank shaft.

The new ceramic bearing equiped CL7B (black crank case) has a standard hardened steel crank, which is much stronger than the old version. All the new off-road engines have this tougher crank shaft that can withstand some serious abuse. Off road is pretty rough on the engines and I like the new crank.