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leighton
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hey guys here a question for you all. which do you think is a better all round engine mac 21 or novarossi21 and why?
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ClayGlover
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man, now that's a loaded question. as far as power and speed, you'll get different people who like either one of them over the other. it's kinda like the blue oval vs. bowtie thing. i like the macs due to the boat-specific friendly features, like rear exhaust (read that as "front" exhaust for the airplane and car guys). they both haul a$$ and i'd say they're probably the most popular race engines right now. that says alot. i've never run a cmb 21 though. they are nice contender too i suspect. 
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TomMoorehouse
Guest
my MAC .21 worked properly right out of the box. My Nova Rossi had to be worked a little to get working right. The MAC has more rpm's for me, and the Nova Rossi has more torque.
My choice would be the MAC 21 because:
1. Its exhaust pattern (front exhaust) is easier for boats
2. Its long lasting (My MAC 21 finished over 200 tanks, and its still going stong. I am about to scrap my NR 21 LS that finished about 100 tanks....)
3. Work right out of the box, while with my NR 21 LS I had to change the carb and the cooling head for it to work
4. Lesser maintenance cost - I don't know about other parts of the world but NR parts, especially their bearings, are crazily expensive over here
The only good point about the NR is that I feel its a bit more powerful than other engines.
FYI I also ran the CMB Valvola on gear box and direct drive, and I found that on direct drive the performance and logevity is to be also the same as a MAC. I also have the CMB 21 LS 2003, but after 20 tanks the balls in the rear bearing broke and it took out the whole combustion chamber. I checked and found the balls of the CMB 21 LS is smaller than NR...Powerwise it seems that the CMB 21 LS is about the same as the MAC and Valvolas.
My 0.002 cent
1. Its exhaust pattern (front exhaust) is easier for boats
2. Its long lasting (My MAC 21 finished over 200 tanks, and its still going stong. I am about to scrap my NR 21 LS that finished about 100 tanks....)
3. Work right out of the box, while with my NR 21 LS I had to change the carb and the cooling head for it to work
4. Lesser maintenance cost - I don't know about other parts of the world but NR parts, especially their bearings, are crazily expensive over here
The only good point about the NR is that I feel its a bit more powerful than other engines.
FYI I also ran the CMB Valvola on gear box and direct drive, and I found that on direct drive the performance and logevity is to be also the same as a MAC. I also have the CMB 21 LS 2003, but after 20 tanks the balls in the rear bearing broke and it took out the whole combustion chamber. I checked and found the balls of the CMB 21 LS is smaller than NR...Powerwise it seems that the CMB 21 LS is about the same as the MAC and Valvolas.
My 0.002 cent
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nitrotoys
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I would say a MAC .21 I have one in a ducer and it just screams.
Never had a NR but have had a CMB.
Macs like to rev, i think a mac out of the box is competive.
and if you dont like the speeds, send it to Andy and he will squeeze more out of it for you. I have about 5-6 gals of 40% through mine and still starts and runs great, has great compression still.
macs i feel dont have the amount of torque as others.
you cant spin the big props with this engine, but you can spin the hell out of a smaller one.
if i was to do again, i would buy another mac in a heart beat
NT
Never had a NR but have had a CMB.
Macs like to rev, i think a mac out of the box is competive.
and if you dont like the speeds, send it to Andy and he will squeeze more out of it for you. I have about 5-6 gals of 40% through mine and still starts and runs great, has great compression still.
macs i feel dont have the amount of torque as others.
you cant spin the big props with this engine, but you can spin the hell out of a smaller one.
if i was to do again, i would buy another mac in a heart beat
NT
This is an interesting question, and of course since I run Novarossi I will be a bit impartial. As far as stock engine goes Mac and Novarossi migh have the same power but when Novarossi is done right (no carb or cooling head change required)
Mac 21 can't come even close. I can only speek for the kind of boats we use in North America, Mac 21 might be actualy better when used with gears, I don't know.
2003 Novarossi is a very, very impressive engine, it will run high 70's to low 80's in well set up heat racing boat. I would prefer if Novarossi was rear exhaust because it would have a bit more power, maybe some day. I had Mac 21, I had a good look at it and sold it without running it because I didn't think it would run better than Novarossi. If someday Mac engine runs better than Novarossi I will be getting one.
Advanced Racing Tech
Frank
Mac 21 can't come even close. I can only speek for the kind of boats we use in North America, Mac 21 might be actualy better when used with gears, I don't know.
2003 Novarossi is a very, very impressive engine, it will run high 70's to low 80's in well set up heat racing boat. I would prefer if Novarossi was rear exhaust because it would have a bit more power, maybe some day. I had Mac 21, I had a good look at it and sold it without running it because I didn't think it would run better than Novarossi. If someday Mac engine runs better than Novarossi I will be getting one.
Advanced Racing Tech
Frank
Frank, May I ask you some question? Is your 2003 Novarossi 21 the R1 WC-M? (The one with rings engraved on the carb throat at the crankcase) I am quite interested in getting one of that to try, but due to its price (Many thanks to the increasing Euro rate) I am quite reluctant to grab it immediately before getting more info about that.... <_< Over here in my place the price of a WC-M is about 30% more than a CMB 21 LS, and about 20% more than the last NR purple head....
If your is the R1 WC-M, could you tell me what's the difference between the WC-M and the last NR purple head? Just by looking at the picture, I see that the crankcase is changed, so is the crank and gone is the water cool backplate. I am more interested in the change of the porting and piston/liner of the R1 WC-M.
Thanks!
If your is the R1 WC-M, could you tell me what's the difference between the WC-M and the last NR purple head? Just by looking at the picture, I see that the crankcase is changed, so is the crank and gone is the water cool backplate. I am more interested in the change of the porting and piston/liner of the R1 WC-M.
Thanks!
Here are some facts and my opinion about Novarossi R1 WC-Mjasoncsc said:
- new crankcase inside and outside,
- porting is different from LS - good,
- crankcase is heavier - bad
- liner is the same except for the subported exhaust (good on cars , not sure if is good on boats, need more testing)
- piston is dome shape with dish
- same crankshaft (for some strange reason this engine did'n recieve crank with heavy metal insets) - big mistake
I wouldn't spend extra money on this engine, LS 03 version is very very good when done right.
Advance Racing Tech
Frank
Joe_Knesek
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Frank, I've ran both motors and believe my MAC is stronger than the Nova Rossi and my Nova Rossi was one you built. If you didn't run the MAC, how can you determine for sure that the Nova Rossi is stronger? Many of the things we do don't turn out as we expected. Without pond time, it's just a guess.
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TomMoorehouse
Guest
Come on Andy..... where are you.... lets hear what you have to say!
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Guest
Guest
Well, like Frank, I'm a bit partial.
I like facts.
2003 IMPBA Internats 21 hydro 1st and 2nd with MAC.
MAC won IMPBA US-1 Hydro in 2001 and 2003.
2003 NAMBA Nats 21 hydro 1st MAC/Vavola
Off the top of my head I don't know all the mono class and sport 21 hydro class details on which engine did exactly what at the 2003 NAMBA/IMPBA nats, but I'm sure if you all look you'll find that MAC's prevailed over N.R.
IMPBA hydro and Mono Oval records are held by MAC.
I think one of Franks/Kently's NR's has the IMPBA hydro SAW record.
In NAMBA the Hydro Oval and SAW record is held by a NR that was set up by me 5 years ago.
We have many very happy MAC 21 owners that used to run NR.
The MAC 21 keeps getting faster and more powerful with each new batch, kinda like computers.
We are currently out of MAC 21's.
The next batch we get will be more powerful than the last.
I always did like NR, but my goal is to leave them behind to suck roostertail.
Also, for those of you who like to race cars. The MAC Buggy engine placed 2nd in the A-main at Maxey's International Nitro Challenge last weekend against a field of predominantly NR and OS engines.
Of 85 total entries 12 engines were MAC and 10 of those placed in the upper 1/3.
The 2nd place MAC engine drivin by Travis Scrambling had 2 gallons of fuel run through it before the start of the grueling 1-Hour long A-main. World class driver Jeremy Kortz won with a OS MAX.
To give you a idea of the beating these engines take, Greg Degani, the current World Champion, was leadind the race but drop out at the 50 min. mark do to engine faliure (not a MAC).
We have turned the MAC Buggy engine up to 40,600 rpm with no faliure. :unsure:
I like facts.
2003 IMPBA Internats 21 hydro 1st and 2nd with MAC.
MAC won IMPBA US-1 Hydro in 2001 and 2003.
2003 NAMBA Nats 21 hydro 1st MAC/Vavola
Off the top of my head I don't know all the mono class and sport 21 hydro class details on which engine did exactly what at the 2003 NAMBA/IMPBA nats, but I'm sure if you all look you'll find that MAC's prevailed over N.R.
IMPBA hydro and Mono Oval records are held by MAC.
I think one of Franks/Kently's NR's has the IMPBA hydro SAW record.
In NAMBA the Hydro Oval and SAW record is held by a NR that was set up by me 5 years ago.
We have many very happy MAC 21 owners that used to run NR.
The MAC 21 keeps getting faster and more powerful with each new batch, kinda like computers.
We are currently out of MAC 21's.
The next batch we get will be more powerful than the last.
I always did like NR, but my goal is to leave them behind to suck roostertail.
Also, for those of you who like to race cars. The MAC Buggy engine placed 2nd in the A-main at Maxey's International Nitro Challenge last weekend against a field of predominantly NR and OS engines.
Of 85 total entries 12 engines were MAC and 10 of those placed in the upper 1/3.
The 2nd place MAC engine drivin by Travis Scrambling had 2 gallons of fuel run through it before the start of the grueling 1-Hour long A-main. World class driver Jeremy Kortz won with a OS MAX.
To give you a idea of the beating these engines take, Greg Degani, the current World Champion, was leadind the race but drop out at the 50 min. mark do to engine faliure (not a MAC).
We have turned the MAC Buggy engine up to 40,600 rpm with no faliure. :unsure:
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Great post Andy, now if you'd just remember to sign in......
Oh..... that was me. I'm gonna stay a newbie forever at this rate.
And yes that's where I've been for the last several days... Buggy racing. Well... I was just Wrenching.
Man, those guys at the World class level can drive. Ten cars for 1-hour (92 laps) and very few crashes. I crash on every other lap with the track all to myself. LOL
Wow..... a 1 hour race... Intense! And never a chance to back off the throttle and cruise like we get to do in boat racing many times.
And yes that's where I've been for the last several days... Buggy racing. Well... I was just Wrenching.
Man, those guys at the World class level can drive. Ten cars for 1-hour (92 laps) and very few crashes. I crash on every other lap with the track all to myself. LOL
Wow..... a 1 hour race... Intense! And never a chance to back off the throttle and cruise like we get to do in boat racing many times.
Preston_Hall
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I had a SGX with a MAC. I was unhappy with the performance and was then told to skirt the P/S and plug the rotor. No speed increase, but it quit loading up. Also, you couldn't idle down very well. Put one of Frank's engines in it and gained some speed and could idle down to a crawl. I have also been very pleased with all the stock NR's I have owned. I have no idea why you would change the cooling head or the carb (except maybe to remove the low end needle). The amount of fuel you run through a motor could be a useless measurement of life span. If you run it rich enough it could last forever. Too lean and it may be done in a couple dozen runs.
One of the most impressive things I have ever seen was one of Frank's newer motors in a stock (unmodified) RR extreme running 78mph. (Joe, you would have seen the same speed if you wouldn't have added the center sponson and had the boat set up to spec)
A fellow club member has been running the CMB. He has it running very well.
I am sure you could get hundreds of testimonials on this subject. Some can make the NR run well, others MAC, CMB, Picco....................
One of the most impressive things I have ever seen was one of Frank's newer motors in a stock (unmodified) RR extreme running 78mph. (Joe, you would have seen the same speed if you wouldn't have added the center sponson and had the boat set up to spec)
A fellow club member has been running the CMB. He has it running very well.
I am sure you could get hundreds of testimonials on this subject. Some can make the NR run well, others MAC, CMB, Picco....................
A slightly different perspective - not specific to performance as such....
I'm a little biased toward the NR's personally but in all fairness I have not owned a MAC21. I do like the drum rotor / no need for 180 degree header tho'! Andy's product support is second to none also.
The thing I really like about the Nova's is that the casting and machining quality is superb. I can't comment on the MAC's, but the CMB's I've had the opportunity to play with have not been comparable in this regard. I guess you get what you pay for tho'.... Nova's sure are expensive little engines B)
Tim.
I'm a little biased toward the NR's personally but in all fairness I have not owned a MAC21. I do like the drum rotor / no need for 180 degree header tho'! Andy's product support is second to none also.
The thing I really like about the Nova's is that the casting and machining quality is superb. I can't comment on the MAC's, but the CMB's I've had the opportunity to play with have not been comparable in this regard. I guess you get what you pay for tho'.... Nova's sure are expensive little engines B)
Tim.
Joe_Knesek
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Preston, it ran 78 when I had it using the short Irwin unmuffled pipe. Once I changed to the parabolic pipe I never regained the speed. I also had Ron VanWagnon change the bearings and that may have been the problem because I understand you found a tick in them. They were only 1 race old but the Boca bearing must not be as good as the stock ones. I sold you the motor exactly the same way I got it from Bill including the water jacket and carb.Preston_Hall said:
The third sponson only helped it launch and wasn't in the water after it was up to speed. When I first built the boat, it would not launch at all. I had KP set it up and it ran well from that point.
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Many poeple run well with the Nova. Many poeple run well with the MAC.
A few poeple have problems with Nova. A few poeple have problems with MAC.
Some like Ford's. Some like Chevy's. I could'nt decide so I have a Ford and a Chevy.
Before MAC, I could'nt decide about boat engines either so I had Nova and Picco.
P.S. If you like crank induction .21 engines like Nova and Picco. We will soon have availible a crank induction MAC 21 inboard at a very competitive price.
This engine is based on the MAC Buggy engine which has run 69 mph in a Jag rigger. The engine was stock and running 60%. We have made crankshaft, crankcase and Piston/liner improvements to this new inboard version, so we expect to see big performance from this new little MAC.
A few poeple have problems with Nova. A few poeple have problems with MAC.
Some like Ford's. Some like Chevy's. I could'nt decide so I have a Ford and a Chevy.
Before MAC, I could'nt decide about boat engines either so I had Nova and Picco.
P.S. If you like crank induction .21 engines like Nova and Picco. We will soon have availible a crank induction MAC 21 inboard at a very competitive price.
This engine is based on the MAC Buggy engine which has run 69 mph in a Jag rigger. The engine was stock and running 60%. We have made crankshaft, crankcase and Piston/liner improvements to this new inboard version, so we expect to see big performance from this new little MAC.
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Andy,
Are there performance advantages to the layout of the MAC 21 as opposed to the car type layout of most other engines? I would have thought that the drum induction built into the ballraced crankshaft of a car type layout would have less drag as opposed to a bushed drum seperate from a ballraced crankshaft as per the MAC 21? :huh:
Thus I guess the question is would you expect the crank induction inboard MAC 21 to outperform a comparably setup conventional MAC 21?
Ian.
Are there performance advantages to the layout of the MAC 21 as opposed to the car type layout of most other engines? I would have thought that the drum induction built into the ballraced crankshaft of a car type layout would have less drag as opposed to a bushed drum seperate from a ballraced crankshaft as per the MAC 21? :huh:
Thus I guess the question is would you expect the crank induction inboard MAC 21 to outperform a comparably setup conventional MAC 21?
Ian.
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TomMoorehouse
Guest
good question nitrocrazed..... what ya think andy.... i might be in the market for a new 21 soon.
