Anybody ever use a Romac balancer for a 455 on their nailhead? Or any experience with Romac in general? Looking at an SFI approved one for about $250 and wondering if I should pull the trigger or go with an ATI... Thanks, wes
Since nobody said anything, I just went and did it. Romac part # 0243sa (steel centre with aluminum outer ring) Got it from "boosterboy" on the board for $269.oo plus shipping. Had to machine a little off of the crank end of the balancer to make it the same thickness of the original nailhead piece (no shimming accessories then). Original bolt was too short, new bolt was too long, so threw new bolt in the lathe and machined a little off of it. Fits with zero interference: And timing marks were pretty close. wes
Is it well known that the 455 external crank balancer provides same balance as NH stock balancer? How do you know that your engine is still balanced after this swap? why does EFI require a different balancer - crank position sensor?
I wanted to ask the same question.From what i can see NH balancer isnt symethrical like 455 looks alike.I mean that there is more weight on one side of the NH balancer.I thougnt it was made to add some (counter)weight couse of small counterweights on crankshaft.
455 balancers are quite close to the stock nailhead balance. Close enough to just do the swap without balancing the assy? I don't know, you'd have to ask someone like Tom Telesco. I put this balancer on in conjunction with my new engine rebuild. The part that needs to be machined is the "tube" (I guess you can call it that) that goes over the crank and though the front cover. I don't have any pictures of that process. It just needs to be about 1/4" shorter.. Or you can shim out your accessories. Depending on the EFI system you're using, some require a crank position sensor (CPS). Usually those can be bolted to your balancer. The only reason you'd really be in need of a different balancer for EFI is if you had something like a Buick V6 and wanted to run the stock CPS setup where the reluctor rings are integral with the balancer.
pardon, i'm as dense as a bag of gravel. still don't understand why you are swapping the stock NH balancer for the 455. stock balancer is dead, 455 balancer is cool, or does something to provide ECM input, or...
SFI race rules require an SFI approved balancer. We are using a 455 balancer also with our combination. I believe it was about 5 grams different than the Nailhead balancer we had been using.
Not only that, but I get a helluva lot more sleep at night running a new balancer than I would running a stock or even rebuilt balancer. The steel/aluminum balancers are quite light too.
The harmonic frequencies of the NH and 455 aren't too close, the NH critical orders occur at lower RPM.
this thread shows the 430 frequencies and indicates differences between 66 and 67 cranks. http://www.v8buick.com/showthread.php?t=218560 i don't have a source for the NH harmonic frequencies.
