Novarossi 421B
08-14-2008, 10:42 PM
#1
Novarossi 421B
Anyone ever run this engine before? It's the Novarossi 421B with the turbo head button but has the 25.4mm rear bearing instead of the 25.8mm bearing. Please feel free to comment and thanks in advance.
08-15-2008, 01:34 AM
#2
Tech Apprentice
Yes, It screams!! I have the epoxy filled crank one though. This motor seemed real sensitive, constantly changing throughout the day. Made a ton of power though.
08-15-2008, 12:21 PM
#4
The 421 B is simply stunning !! When tuned correctly it is an unreal powerhouse , best pipe I have found for it is the Mielke 2011 pipe/header combo . The Turbo version is a touch more sensative and to be safe, run a hot plug with a slightly rich setting . AND KEEP A GOOD FILTER ON IT!!! If this engine loses it's compression it is the dog of the centry !! I am still running mine and it has WAY over 23 gallons on it with only a front bearing replacement and a pinch, just replaced the crank and rod at the 23 gallon mark but have done nothing else! (didn't really need to change the crank either, but it was a modded one and wasn't as good on fuel, stock one is better on fuel, with same performance!!)
08-15-2008, 01:34 PM
#5
I'm concerned about the longevity of the rear bearing due to the fact that it is 25.4mm instead of 25.8mm and 26mm that other Novarossi engines have.
08-15-2008, 03:01 PM
#6
all the original P5s and 421s had the 14x25.4x6 bearings and had great reliability, how ever, i have seen more issues with the 25.8 in the current NRs, if you can get a 421 in great shape or even new from someone, grab it
and yes the 821 is the pissed off brother of the 421, it is a great mill.
08-15-2008, 03:37 PM
#7
The smaller bearing is far better ! Way more durrable ! I have over 23 gallons on mine !
08-15-2008, 04:02 PM
#8
The 421B came in 25.4 and I believe there may have been a 25.8 version. If it has a 6 bolt head, its 25.4, and a 4 bolt head would have 25.8, same case as P5X. I just saw a stack of these engines at a LHS last night. They had Ron Paris Racing labels on the box. I think they were modded versions, but not sure.
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